avformat/matroskadec: Fix sample_aspect_ratio for stereo matroska content
[ffmpeg.git] / libavformat / matroskadec.c
index 560ded5..f05ddd6 100644 (file)
 
 #include "config.h"
 
+#include <inttypes.h>
 #include <stdio.h>
-#if CONFIG_BZLIB
-#include <bzlib.h>
-#endif
-#if CONFIG_ZLIB
-#include <zlib.h>
-#endif
 
 #include "libavutil/avstring.h"
 #include "libavutil/base64.h"
 #include "libavutil/intfloat.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/lzo.h"
+#include "libavutil/mathematics.h"
+#include "libavutil/opt.h"
+#include "libavutil/time_internal.h"
 
 #include "libavcodec/bytestream.h"
+#include "libavcodec/flac.h"
 #include "libavcodec/mpeg4audio.h"
 
 #include "avformat.h"
 #include "internal.h"
 #include "isom.h"
 #include "matroska.h"
+#include "oggdec.h"
 /* For ff_codec_get_id(). */
 #include "riff.h"
 #include "rmsipr.h"
 
+#if CONFIG_BZLIB
+#include <bzlib.h>
+#endif
+#if CONFIG_ZLIB
+#include <zlib.h>
+#endif
+
 typedef enum {
     EBML_NONE,
     EBML_UINT,
@@ -65,6 +72,7 @@ typedef enum {
     EBML_UTF8,
     EBML_BIN,
     EBML_NEST,
+    EBML_LEVEL1,
     EBML_PASS,
     EBML_STOP,
     EBML_SINT,
@@ -84,18 +92,18 @@ typedef const struct EbmlSyntax {
     } def;
 } EbmlSyntax;
 
-typedef struct {
+typedef struct EbmlList {
     int nb_elem;
     void *elem;
 } EbmlList;
 
-typedef struct {
+typedef struct EbmlBin {
     int      size;
     uint8_t *data;
     int64_t  pos;
 } EbmlBin;
 
-typedef struct {
+typedef struct Ebml {
     uint64_t version;
     uint64_t max_size;
     uint64_t id_length;
@@ -103,24 +111,24 @@ typedef struct {
     uint64_t doctype_version;
 } Ebml;
 
-typedef struct {
+typedef struct MatroskaTrackCompression {
     uint64_t algo;
     EbmlBin  settings;
 } MatroskaTrackCompression;
 
-typedef struct {
+typedef struct MatroskaTrackEncryption {
     uint64_t algo;
     EbmlBin  key_id;
 } MatroskaTrackEncryption;
 
-typedef struct {
+typedef struct MatroskaTrackEncoding {
     uint64_t scope;
     uint64_t type;
     MatroskaTrackCompression compression;
     MatroskaTrackEncryption encryption;
 } MatroskaTrackEncoding;
 
-typedef struct {
+typedef struct MatroskaTrackVideo {
     double   frame_rate;
     uint64_t display_width;
     uint64_t display_height;
@@ -131,7 +139,7 @@ typedef struct {
     uint64_t alpha_mode;
 } MatroskaTrackVideo;
 
-typedef struct {
+typedef struct MatroskaTrackAudio {
     double   samplerate;
     double   out_samplerate;
     uint64_t bitdepth;
@@ -148,16 +156,16 @@ typedef struct {
     uint8_t *buf;
 } MatroskaTrackAudio;
 
-typedef struct {
+typedef struct MatroskaTrackPlane {
     uint64_t uid;
     uint64_t type;
 } MatroskaTrackPlane;
 
-typedef struct {
+typedef struct MatroskaTrackOperation {
     EbmlList combine_planes;
 } MatroskaTrackOperation;
 
-typedef struct {
+typedef struct MatroskaTrack {
     uint64_t num;
     uint64_t uid;
     uint64_t type;
@@ -169,12 +177,12 @@ typedef struct {
     uint64_t default_duration;
     uint64_t flag_default;
     uint64_t flag_forced;
-    uint64_t codec_delay;
     uint64_t seek_preroll;
     MatroskaTrackVideo video;
     MatroskaTrackAudio audio;
     MatroskaTrackOperation operation;
     EbmlList encodings;
+    uint64_t codec_delay;
 
     AVStream *stream;
     int64_t end_timecode;
@@ -182,16 +190,16 @@ typedef struct {
     uint64_t max_block_additional_id;
 } MatroskaTrack;
 
-typedef struct {
+typedef struct MatroskaAttachment {
     uint64_t uid;
     char *filename;
     char *mime;
     EbmlBin bin;
 
     AVStream *stream;
-} MatroskaAttachement;
+} MatroskaAttachment;
 
-typedef struct {
+typedef struct MatroskaChapter {
     uint64_t start;
     uint64_t end;
     uint64_t uid;
@@ -200,17 +208,17 @@ typedef struct {
     AVChapter *chapter;
 } MatroskaChapter;
 
-typedef struct {
+typedef struct MatroskaIndexPos {
     uint64_t track;
     uint64_t pos;
 } MatroskaIndexPos;
 
-typedef struct {
+typedef struct MatroskaIndex {
     uint64_t time;
     EbmlList pos;
 } MatroskaIndex;
 
-typedef struct {
+typedef struct MatroskaTag {
     char *name;
     char *string;
     char *lang;
@@ -218,7 +226,7 @@ typedef struct {
     EbmlList sub;
 } MatroskaTag;
 
-typedef struct {
+typedef struct MatroskaTagTarget {
     char    *type;
     uint64_t typevalue;
     uint64_t trackuid;
@@ -226,27 +234,34 @@ typedef struct {
     uint64_t attachuid;
 } MatroskaTagTarget;
 
-typedef struct {
+typedef struct MatroskaTags {
     MatroskaTagTarget target;
     EbmlList tag;
 } MatroskaTags;
 
-typedef struct {
+typedef struct MatroskaSeekhead {
     uint64_t id;
     uint64_t pos;
 } MatroskaSeekhead;
 
-typedef struct {
+typedef struct MatroskaLevel {
     uint64_t start;
     uint64_t length;
 } MatroskaLevel;
 
-typedef struct {
+typedef struct MatroskaCluster {
     uint64_t timecode;
     EbmlList blocks;
 } MatroskaCluster;
 
-typedef struct {
+typedef struct MatroskaLevel1Element {
+    uint64_t id;
+    uint64_t pos;
+    int parsed;
+} MatroskaLevel1Element;
+
+typedef struct MatroskaDemuxContext {
+    const AVClass *class;
     AVFormatContext *ctx;
 
     /* EBML stuff */
@@ -284,15 +299,22 @@ typedef struct {
     /* File has a CUES element, but we defer parsing until it is needed. */
     int cues_parsing_deferred;
 
+    /* Level1 elements and whether they were read yet */
+    MatroskaLevel1Element level1_elems[64];
+    int num_level1_elems;
+
     int current_cluster_num_blocks;
     int64_t current_cluster_pos;
     MatroskaCluster current_cluster;
 
     /* File has SSA subtitles which prevent incremental cluster parsing. */
     int contains_ssa;
+
+    /* WebM DASH Manifest live flag/ */
+    int is_live;
 } MatroskaDemuxContext;
 
-typedef struct {
+typedef struct MatroskaBlock {
     uint64_t duration;
     int64_t  reference;
     uint64_t non_simple;
@@ -302,7 +324,7 @@ typedef struct {
     int64_t discard_padding;
 } MatroskaBlock;
 
-static EbmlSyntax ebml_header[] = {
+static const EbmlSyntax ebml_header[] = {
     { EBML_ID_EBMLREADVERSION,    EBML_UINT, 0, offsetof(Ebml, version),         { .u = EBML_VERSION } },
     { EBML_ID_EBMLMAXSIZELENGTH,  EBML_UINT, 0, offsetof(Ebml, max_size),        { .u = 8 } },
     { EBML_ID_EBMLMAXIDLENGTH,    EBML_UINT, 0, offsetof(Ebml, id_length),       { .u = 4 } },
@@ -313,12 +335,12 @@ static EbmlSyntax ebml_header[] = {
     { 0 }
 };
 
-static EbmlSyntax ebml_syntax[] = {
+static const EbmlSyntax ebml_syntax[] = {
     { EBML_ID_HEADER, EBML_NEST, 0, 0, { .n = ebml_header } },
     { 0 }
 };
 
-static EbmlSyntax matroska_info[] = {
+static const EbmlSyntax matroska_info[] = {
     { MATROSKA_ID_TIMECODESCALE, EBML_UINT,  0, offsetof(MatroskaDemuxContext, time_scale), { .u = 1000000 } },
     { MATROSKA_ID_DURATION,      EBML_FLOAT, 0, offsetof(MatroskaDemuxContext, duration) },
     { MATROSKA_ID_TITLE,         EBML_UTF8,  0, offsetof(MatroskaDemuxContext, title) },
@@ -329,14 +351,13 @@ static EbmlSyntax matroska_info[] = {
     { 0 }
 };
 
-static EbmlSyntax matroska_track_video[] = {
+static const EbmlSyntax matroska_track_video[] = {
     { MATROSKA_ID_VIDEOFRAMERATE,      EBML_FLOAT, 0, offsetof(MatroskaTrackVideo, frame_rate) },
     { MATROSKA_ID_VIDEODISPLAYWIDTH,   EBML_UINT,  0, offsetof(MatroskaTrackVideo, display_width), { .u=-1 } },
     { MATROSKA_ID_VIDEODISPLAYHEIGHT,  EBML_UINT,  0, offsetof(MatroskaTrackVideo, display_height), { .u=-1 } },
     { MATROSKA_ID_VIDEOPIXELWIDTH,     EBML_UINT,  0, offsetof(MatroskaTrackVideo, pixel_width) },
     { MATROSKA_ID_VIDEOPIXELHEIGHT,    EBML_UINT,  0, offsetof(MatroskaTrackVideo, pixel_height) },
     { MATROSKA_ID_VIDEOCOLORSPACE,     EBML_BIN,   0, offsetof(MatroskaTrackVideo, color_space) },
-    { MATROSKA_ID_VIDEOSTEREOMODE,     EBML_UINT,  0, offsetof(MatroskaTrackVideo, stereo_mode) },
     { MATROSKA_ID_VIDEOALPHAMODE,      EBML_UINT,  0, offsetof(MatroskaTrackVideo, alpha_mode) },
     { MATROSKA_ID_VIDEOPIXELCROPB,     EBML_NONE },
     { MATROSKA_ID_VIDEOPIXELCROPT,     EBML_NONE },
@@ -344,11 +365,12 @@ static EbmlSyntax matroska_track_video[] = {
     { MATROSKA_ID_VIDEOPIXELCROPR,     EBML_NONE },
     { MATROSKA_ID_VIDEODISPLAYUNIT,    EBML_NONE },
     { MATROSKA_ID_VIDEOFLAGINTERLACED, EBML_NONE },
+    { MATROSKA_ID_VIDEOSTEREOMODE,     EBML_UINT,  0, offsetof(MatroskaTrackVideo, stereo_mode), { .u = MATROSKA_VIDEO_STEREOMODE_TYPE_NB } },
     { MATROSKA_ID_VIDEOASPECTRATIO,    EBML_NONE },
     { 0 }
 };
 
-static EbmlSyntax matroska_track_audio[] = {
+static const EbmlSyntax matroska_track_audio[] = {
     { MATROSKA_ID_AUDIOSAMPLINGFREQ,    EBML_FLOAT, 0, offsetof(MatroskaTrackAudio, samplerate), { .f = 8000.0 } },
     { MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, EBML_FLOAT, 0, offsetof(MatroskaTrackAudio, out_samplerate) },
     { MATROSKA_ID_AUDIOBITDEPTH,        EBML_UINT,  0, offsetof(MatroskaTrackAudio, bitdepth) },
@@ -356,13 +378,13 @@ static EbmlSyntax matroska_track_audio[] = {
     { 0 }
 };
 
-static EbmlSyntax matroska_track_encoding_compression[] = {
+static const EbmlSyntax matroska_track_encoding_compression[] = {
     { MATROSKA_ID_ENCODINGCOMPALGO,     EBML_UINT, 0, offsetof(MatroskaTrackCompression, algo), { .u = 0 } },
     { MATROSKA_ID_ENCODINGCOMPSETTINGS, EBML_BIN,  0, offsetof(MatroskaTrackCompression, settings) },
     { 0 }
 };
 
-static EbmlSyntax matroska_track_encoding_encryption[] = {
+static const EbmlSyntax matroska_track_encoding_encryption[] = {
     { MATROSKA_ID_ENCODINGENCALGO,        EBML_UINT, 0, offsetof(MatroskaTrackEncryption,algo), {.u = 0} },
     { MATROSKA_ID_ENCODINGENCKEYID,       EBML_BIN, 0, offsetof(MatroskaTrackEncryption,key_id) },
     { MATROSKA_ID_ENCODINGENCAESSETTINGS, EBML_NONE },
@@ -372,7 +394,7 @@ static EbmlSyntax matroska_track_encoding_encryption[] = {
     { MATROSKA_ID_ENCODINGSIGNATURE,      EBML_NONE },
     { 0 }
 };
-static EbmlSyntax matroska_track_encoding[] = {
+static const EbmlSyntax matroska_track_encoding[] = {
     { MATROSKA_ID_ENCODINGSCOPE,       EBML_UINT, 0, offsetof(MatroskaTrackEncoding, scope),       { .u = 1 } },
     { MATROSKA_ID_ENCODINGTYPE,        EBML_UINT, 0, offsetof(MatroskaTrackEncoding, type),        { .u = 0 } },
     { MATROSKA_ID_ENCODINGCOMPRESSION, EBML_NEST, 0, offsetof(MatroskaTrackEncoding, compression), { .n = matroska_track_encoding_compression } },
@@ -381,34 +403,35 @@ static EbmlSyntax matroska_track_encoding[] = {
     { 0 }
 };
 
-static EbmlSyntax matroska_track_encodings[] = {
+static const EbmlSyntax matroska_track_encodings[] = {
     { MATROSKA_ID_TRACKCONTENTENCODING, EBML_NEST, sizeof(MatroskaTrackEncoding), offsetof(MatroskaTrack, encodings), { .n = matroska_track_encoding } },
     { 0 }
 };
 
-static EbmlSyntax matroska_track_plane[] = {
+static const EbmlSyntax matroska_track_plane[] = {
     { MATROSKA_ID_TRACKPLANEUID,  EBML_UINT, 0, offsetof(MatroskaTrackPlane,uid) },
     { MATROSKA_ID_TRACKPLANETYPE, EBML_UINT, 0, offsetof(MatroskaTrackPlane,type) },
     { 0 }
 };
 
-static EbmlSyntax matroska_track_combine_planes[] = {
+static const EbmlSyntax matroska_track_combine_planes[] = {
     { MATROSKA_ID_TRACKPLANE, EBML_NEST, sizeof(MatroskaTrackPlane), offsetof(MatroskaTrackOperation,combine_planes), {.n = matroska_track_plane} },
     { 0 }
 };
 
-static EbmlSyntax matroska_track_operation[] = {
+static const EbmlSyntax matroska_track_operation[] = {
     { MATROSKA_ID_TRACKCOMBINEPLANES, EBML_NEST, 0, 0, {.n = matroska_track_combine_planes} },
     { 0 }
 };
 
-static EbmlSyntax matroska_track[] = {
+static const EbmlSyntax matroska_track[] = {
     { MATROSKA_ID_TRACKNUMBER,           EBML_UINT,  0, offsetof(MatroskaTrack, num) },
     { MATROSKA_ID_TRACKNAME,             EBML_UTF8,  0, offsetof(MatroskaTrack, name) },
     { MATROSKA_ID_TRACKUID,              EBML_UINT,  0, offsetof(MatroskaTrack, uid) },
     { MATROSKA_ID_TRACKTYPE,             EBML_UINT,  0, offsetof(MatroskaTrack, type) },
     { MATROSKA_ID_CODECID,               EBML_STR,   0, offsetof(MatroskaTrack, codec_id) },
     { MATROSKA_ID_CODECPRIVATE,          EBML_BIN,   0, offsetof(MatroskaTrack, codec_priv) },
+    { MATROSKA_ID_CODECDELAY,            EBML_UINT,  0, offsetof(MatroskaTrack, codec_delay) },
     { MATROSKA_ID_TRACKLANGUAGE,         EBML_UTF8,  0, offsetof(MatroskaTrack, language),     { .s = "eng" } },
     { MATROSKA_ID_TRACKDEFAULTDURATION,  EBML_UINT,  0, offsetof(MatroskaTrack, default_duration) },
     { MATROSKA_ID_TRACKTIMECODESCALE,    EBML_FLOAT, 0, offsetof(MatroskaTrack, time_scale),   { .f = 1.0 } },
@@ -419,7 +442,6 @@ static EbmlSyntax matroska_track[] = {
     { MATROSKA_ID_TRACKOPERATION,        EBML_NEST,  0, offsetof(MatroskaTrack, operation),    { .n = matroska_track_operation } },
     { MATROSKA_ID_TRACKCONTENTENCODINGS, EBML_NEST,  0, 0,                                     { .n = matroska_track_encodings } },
     { MATROSKA_ID_TRACKMAXBLKADDID,      EBML_UINT,  0, offsetof(MatroskaTrack, max_block_additional_id) },
-    { MATROSKA_ID_CODECDELAY,            EBML_UINT,  0, offsetof(MatroskaTrack, codec_delay) },
     { MATROSKA_ID_SEEKPREROLL,           EBML_UINT,  0, offsetof(MatroskaTrack, seek_preroll) },
     { MATROSKA_ID_TRACKFLAGENABLED,      EBML_NONE },
     { MATROSKA_ID_TRACKFLAGLACING,       EBML_NONE },
@@ -432,32 +454,33 @@ static EbmlSyntax matroska_track[] = {
     { 0 }
 };
 
-static EbmlSyntax matroska_tracks[] = {
+static const EbmlSyntax matroska_tracks[] = {
     { MATROSKA_ID_TRACKENTRY, EBML_NEST, sizeof(MatroskaTrack), offsetof(MatroskaDemuxContext, tracks), { .n = matroska_track } },
     { 0 }
 };
 
-static EbmlSyntax matroska_attachment[] = {
-    { MATROSKA_ID_FILEUID,      EBML_UINT, 0, offsetof(MatroskaAttachement, uid) },
-    { MATROSKA_ID_FILENAME,     EBML_UTF8, 0, offsetof(MatroskaAttachement, filename) },
-    { MATROSKA_ID_FILEMIMETYPE, EBML_STR,  0, offsetof(MatroskaAttachement, mime) },
-    { MATROSKA_ID_FILEDATA,     EBML_BIN,  0, offsetof(MatroskaAttachement, bin) },
+static const EbmlSyntax matroska_attachment[] = {
+    { MATROSKA_ID_FILEUID,      EBML_UINT, 0, offsetof(MatroskaAttachment, uid) },
+    { MATROSKA_ID_FILENAME,     EBML_UTF8, 0, offsetof(MatroskaAttachment, filename) },
+    { MATROSKA_ID_FILEMIMETYPE, EBML_STR,  0, offsetof(MatroskaAttachment, mime) },
+    { MATROSKA_ID_FILEDATA,     EBML_BIN,  0, offsetof(MatroskaAttachment, bin) },
     { MATROSKA_ID_FILEDESC,     EBML_NONE },
     { 0 }
 };
 
-static EbmlSyntax matroska_attachments[] = {
-    { MATROSKA_ID_ATTACHEDFILE, EBML_NEST, sizeof(MatroskaAttachement), offsetof(MatroskaDemuxContext, attachments), { .n = matroska_attachment } },
+static const EbmlSyntax matroska_attachments[] = {
+    { MATROSKA_ID_ATTACHEDFILE, EBML_NEST, sizeof(MatroskaAttachment), offsetof(MatroskaDemuxContext, attachments), { .n = matroska_attachment } },
     { 0 }
 };
 
-static EbmlSyntax matroska_chapter_display[] = {
-    { MATROSKA_ID_CHAPSTRING, EBML_UTF8, 0, offsetof(MatroskaChapter, title) },
-    { MATROSKA_ID_CHAPLANG,   EBML_NONE },
+static const EbmlSyntax matroska_chapter_display[] = {
+    { MATROSKA_ID_CHAPSTRING,  EBML_UTF8, 0, offsetof(MatroskaChapter, title) },
+    { MATROSKA_ID_CHAPLANG,    EBML_NONE },
+    { MATROSKA_ID_CHAPCOUNTRY, EBML_NONE },
     { 0 }
 };
 
-static EbmlSyntax matroska_chapter_entry[] = {
+static const EbmlSyntax matroska_chapter_entry[] = {
     { MATROSKA_ID_CHAPTERTIMESTART,   EBML_UINT, 0, offsetof(MatroskaChapter, start), { .u = AV_NOPTS_VALUE } },
     { MATROSKA_ID_CHAPTERTIMEEND,     EBML_UINT, 0, offsetof(MatroskaChapter, end),   { .u = AV_NOPTS_VALUE } },
     { MATROSKA_ID_CHAPTERUID,         EBML_UINT, 0, offsetof(MatroskaChapter, uid) },
@@ -469,7 +492,7 @@ static EbmlSyntax matroska_chapter_entry[] = {
     { 0 }
 };
 
-static EbmlSyntax matroska_chapter[] = {
+static const EbmlSyntax matroska_chapter[] = {
     { MATROSKA_ID_CHAPTERATOM,        EBML_NEST, sizeof(MatroskaChapter), offsetof(MatroskaDemuxContext, chapters), { .n = matroska_chapter_entry } },
     { MATROSKA_ID_EDITIONUID,         EBML_NONE },
     { MATROSKA_ID_EDITIONFLAGHIDDEN,  EBML_NONE },
@@ -478,12 +501,12 @@ static EbmlSyntax matroska_chapter[] = {
     { 0 }
 };
 
-static EbmlSyntax matroska_chapters[] = {
+static const EbmlSyntax matroska_chapters[] = {
     { MATROSKA_ID_EDITIONENTRY, EBML_NEST, 0, 0, { .n = matroska_chapter } },
     { 0 }
 };
 
-static EbmlSyntax matroska_index_pos[] = {
+static const EbmlSyntax matroska_index_pos[] = {
     { MATROSKA_ID_CUETRACK,           EBML_UINT, 0, offsetof(MatroskaIndexPos, track) },
     { MATROSKA_ID_CUECLUSTERPOSITION, EBML_UINT, 0, offsetof(MatroskaIndexPos, pos) },
     { MATROSKA_ID_CUERELATIVEPOSITION,EBML_NONE },
@@ -492,18 +515,18 @@ static EbmlSyntax matroska_index_pos[] = {
     { 0 }
 };
 
-static EbmlSyntax matroska_index_entry[] = {
+static const EbmlSyntax matroska_index_entry[] = {
     { MATROSKA_ID_CUETIME,          EBML_UINT, 0,                        offsetof(MatroskaIndex, time) },
     { MATROSKA_ID_CUETRACKPOSITION, EBML_NEST, sizeof(MatroskaIndexPos), offsetof(MatroskaIndex, pos), { .n = matroska_index_pos } },
     { 0 }
 };
 
-static EbmlSyntax matroska_index[] = {
+static const EbmlSyntax matroska_index[] = {
     { MATROSKA_ID_POINTENTRY, EBML_NEST, sizeof(MatroskaIndex), offsetof(MatroskaDemuxContext, index), { .n = matroska_index_entry } },
     { 0 }
 };
 
-static EbmlSyntax matroska_simpletag[] = {
+static const EbmlSyntax matroska_simpletag[] = {
     { MATROSKA_ID_TAGNAME,        EBML_UTF8, 0,                   offsetof(MatroskaTag, name) },
     { MATROSKA_ID_TAGSTRING,      EBML_UTF8, 0,                   offsetof(MatroskaTag, string) },
     { MATROSKA_ID_TAGLANG,        EBML_STR,  0,                   offsetof(MatroskaTag, lang), { .s = "und" } },
@@ -513,7 +536,7 @@ static EbmlSyntax matroska_simpletag[] = {
     { 0 }
 };
 
-static EbmlSyntax matroska_tagtargets[] = {
+static const EbmlSyntax matroska_tagtargets[] = {
     { MATROSKA_ID_TAGTARGETS_TYPE,       EBML_STR,  0, offsetof(MatroskaTagTarget, type) },
     { MATROSKA_ID_TAGTARGETS_TYPEVALUE,  EBML_UINT, 0, offsetof(MatroskaTagTarget, typevalue), { .u = 50 } },
     { MATROSKA_ID_TAGTARGETS_TRACKUID,   EBML_UINT, 0, offsetof(MatroskaTagTarget, trackuid) },
@@ -522,57 +545,57 @@ static EbmlSyntax matroska_tagtargets[] = {
     { 0 }
 };
 
-static EbmlSyntax matroska_tag[] = {
+static const EbmlSyntax matroska_tag[] = {
     { MATROSKA_ID_SIMPLETAG,  EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTags, tag),    { .n = matroska_simpletag } },
     { MATROSKA_ID_TAGTARGETS, EBML_NEST, 0,                   offsetof(MatroskaTags, target), { .n = matroska_tagtargets } },
     { 0 }
 };
 
-static EbmlSyntax matroska_tags[] = {
+static const EbmlSyntax matroska_tags[] = {
     { MATROSKA_ID_TAG, EBML_NEST, sizeof(MatroskaTags), offsetof(MatroskaDemuxContext, tags), { .n = matroska_tag } },
     { 0 }
 };
 
-static EbmlSyntax matroska_seekhead_entry[] = {
+static const EbmlSyntax matroska_seekhead_entry[] = {
     { MATROSKA_ID_SEEKID,       EBML_UINT, 0, offsetof(MatroskaSeekhead, id) },
     { MATROSKA_ID_SEEKPOSITION, EBML_UINT, 0, offsetof(MatroskaSeekhead, pos), { .u = -1 } },
     { 0 }
 };
 
-static EbmlSyntax matroska_seekhead[] = {
+static const EbmlSyntax matroska_seekhead[] = {
     { MATROSKA_ID_SEEKENTRY, EBML_NEST, sizeof(MatroskaSeekhead), offsetof(MatroskaDemuxContext, seekhead), { .n = matroska_seekhead_entry } },
     { 0 }
 };
 
-static EbmlSyntax matroska_segment[] = {
-    { MATROSKA_ID_INFO,        EBML_NEST, 0, 0, { .n = matroska_info } },
-    { MATROSKA_ID_TRACKS,      EBML_NEST, 0, 0, { .n = matroska_tracks } },
-    { MATROSKA_ID_ATTACHMENTS, EBML_NEST, 0, 0, { .n = matroska_attachments } },
-    { MATROSKA_ID_CHAPTERS,    EBML_NEST, 0, 0, { .n = matroska_chapters } },
-    { MATROSKA_ID_CUES,        EBML_NEST, 0, 0, { .n = matroska_index } },
-    { MATROSKA_ID_TAGS,        EBML_NEST, 0, 0, { .n = matroska_tags } },
-    { MATROSKA_ID_SEEKHEAD,    EBML_NEST, 0, 0, { .n = matroska_seekhead } },
+static const EbmlSyntax matroska_segment[] = {
+    { MATROSKA_ID_INFO,        EBML_LEVEL1, 0, 0, { .n = matroska_info } },
+    { MATROSKA_ID_TRACKS,      EBML_LEVEL1, 0, 0, { .n = matroska_tracks } },
+    { MATROSKA_ID_ATTACHMENTS, EBML_LEVEL1, 0, 0, { .n = matroska_attachments } },
+    { MATROSKA_ID_CHAPTERS,    EBML_LEVEL1, 0, 0, { .n = matroska_chapters } },
+    { MATROSKA_ID_CUES,        EBML_LEVEL1, 0, 0, { .n = matroska_index } },
+    { MATROSKA_ID_TAGS,        EBML_LEVEL1, 0, 0, { .n = matroska_tags } },
+    { MATROSKA_ID_SEEKHEAD,    EBML_LEVEL1, 0, 0, { .n = matroska_seekhead } },
     { MATROSKA_ID_CLUSTER,     EBML_STOP },
     { 0 }
 };
 
-static EbmlSyntax matroska_segments[] = {
+static const EbmlSyntax matroska_segments[] = {
     { MATROSKA_ID_SEGMENT, EBML_NEST, 0, 0, { .n = matroska_segment } },
     { 0 }
 };
 
-static EbmlSyntax matroska_blockmore[] = {
+static const EbmlSyntax matroska_blockmore[] = {
     { MATROSKA_ID_BLOCKADDID,      EBML_UINT, 0, offsetof(MatroskaBlock,additional_id) },
     { MATROSKA_ID_BLOCKADDITIONAL, EBML_BIN,  0, offsetof(MatroskaBlock,additional) },
     { 0 }
 };
 
-static EbmlSyntax matroska_blockadditions[] = {
+static const EbmlSyntax matroska_blockadditions[] = {
     { MATROSKA_ID_BLOCKMORE, EBML_NEST, 0, 0, {.n = matroska_blockmore} },
     { 0 }
 };
 
-static EbmlSyntax matroska_blockgroup[] = {
+static const EbmlSyntax matroska_blockgroup[] = {
     { MATROSKA_ID_BLOCK,          EBML_BIN,  0, offsetof(MatroskaBlock, bin) },
     { MATROSKA_ID_BLOCKADDITIONS, EBML_NEST, 0, 0, { .n = matroska_blockadditions} },
     { MATROSKA_ID_SIMPLEBLOCK,    EBML_BIN,  0, offsetof(MatroskaBlock, bin) },
@@ -584,7 +607,7 @@ static EbmlSyntax matroska_blockgroup[] = {
     { 0 }
 };
 
-static EbmlSyntax matroska_cluster[] = {
+static const EbmlSyntax matroska_cluster[] = {
     { MATROSKA_ID_CLUSTERTIMECODE, EBML_UINT, 0,                     offsetof(MatroskaCluster, timecode) },
     { MATROSKA_ID_BLOCKGROUP,      EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster, blocks), { .n = matroska_blockgroup } },
     { MATROSKA_ID_SIMPLEBLOCK,     EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster, blocks), { .n = matroska_blockgroup } },
@@ -593,7 +616,7 @@ static EbmlSyntax matroska_cluster[] = {
     { 0 }
 };
 
-static EbmlSyntax matroska_clusters[] = {
+static const EbmlSyntax matroska_clusters[] = {
     { MATROSKA_ID_CLUSTER,  EBML_NEST, 0, 0, { .n = matroska_cluster } },
     { MATROSKA_ID_INFO,     EBML_NONE },
     { MATROSKA_ID_CUES,     EBML_NONE },
@@ -602,7 +625,7 @@ static EbmlSyntax matroska_clusters[] = {
     { 0 }
 };
 
-static EbmlSyntax matroska_cluster_incremental_parsing[] = {
+static const EbmlSyntax matroska_cluster_incremental_parsing[] = {
     { MATROSKA_ID_CLUSTERTIMECODE, EBML_UINT, 0,                     offsetof(MatroskaCluster, timecode) },
     { MATROSKA_ID_BLOCKGROUP,      EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster, blocks), { .n = matroska_blockgroup } },
     { MATROSKA_ID_SIMPLEBLOCK,     EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster, blocks), { .n = matroska_blockgroup } },
@@ -616,7 +639,7 @@ static EbmlSyntax matroska_cluster_incremental_parsing[] = {
     { 0 }
 };
 
-static EbmlSyntax matroska_cluster_incremental[] = {
+static const EbmlSyntax matroska_cluster_incremental[] = {
     { MATROSKA_ID_CLUSTERTIMECODE, EBML_UINT, 0, offsetof(MatroskaCluster, timecode) },
     { MATROSKA_ID_BLOCKGROUP,      EBML_STOP },
     { MATROSKA_ID_SIMPLEBLOCK,     EBML_STOP },
@@ -625,7 +648,7 @@ static EbmlSyntax matroska_cluster_incremental[] = {
     { 0 }
 };
 
-static EbmlSyntax matroska_clusters_incremental[] = {
+static const EbmlSyntax matroska_clusters_incremental[] = {
     { MATROSKA_ID_CLUSTER,  EBML_NEST, 0, 0, { .n = matroska_cluster_incremental } },
     { MATROSKA_ID_INFO,     EBML_NONE },
     { MATROSKA_ID_CUES,     EBML_NONE },
@@ -650,7 +673,7 @@ static int matroska_resync(MatroskaDemuxContext *matroska, int64_t last_pos)
     id = avio_rb32(pb);
 
     // try to find a toplevel element
-    while (!url_feof(pb)) {
+    while (!avio_feof(pb)) {
         if (id == MATROSKA_ID_INFO     || id == MATROSKA_ID_TRACKS      ||
             id == MATROSKA_ID_CUES     || id == MATROSKA_ID_TAGS        ||
             id == MATROSKA_ID_SEEKHEAD || id == MATROSKA_ID_ATTACHMENTS ||
@@ -681,7 +704,7 @@ static int ebml_level_end(MatroskaDemuxContext *matroska)
             return 1;
         }
     }
-    return 0;
+    return (matroska->is_live && matroska->ctx->pb->eof_reached) ? 1 : 0;
 }
 
 /*
@@ -703,7 +726,7 @@ static int ebml_read_num(MatroskaDemuxContext *matroska, AVIOContext *pb,
      * use it safely here to catch EOS. */
     if (!(total = avio_r8(pb))) {
         /* we might encounter EOS here */
-        if (!url_feof(pb)) {
+        if (!avio_feof(pb)) {
             int64_t pos = avio_tell(pb);
             av_log(matroska->ctx, AV_LOG_ERROR,
                    "Read error at pos. %"PRIu64" (0x%"PRIx64")\n",
@@ -784,7 +807,7 @@ static int ebml_read_sint(AVIOContext *pb, int size, int64_t *num)
 
         /* big-endian ordering; build up number */
         while (n++ < size)
-            *num = (*num << 8) | avio_r8(pb);
+            *num = ((uint64_t)*num << 8) | avio_r8(pb);
     }
 
     return 0;
@@ -921,9 +944,7 @@ static int ebml_parse_id(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
         matroska->levels[matroska->num_levels - 1].length == 0xffffffffffffff)
         return 0;  // we reached the end of an unknown size cluster
     if (!syntax[i].id && id != EBML_ID_VOID && id != EBML_ID_CRC32) {
-        av_log(matroska->ctx, AV_LOG_INFO, "Unknown entry 0x%X\n", id);
-        if (matroska->ctx->error_recognition & AV_EF_EXPLODE)
-            return AVERROR_INVALIDDATA;
+        av_log(matroska->ctx, AV_LOG_DEBUG, "Unknown entry 0x%"PRIX32"\n", id);
     }
     return ebml_parse_elem(matroska, &syntax[i], data);
 }
@@ -934,8 +955,11 @@ static int ebml_parse(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
     if (!matroska->current_id) {
         uint64_t id;
         int res = ebml_read_num(matroska, matroska->ctx->pb, 4, &id);
-        if (res < 0)
-            return res;
+        if (res < 0) {
+            // in live mode, finish parsing if EOF is reached.
+            return (matroska->is_live && matroska->ctx->pb->eof_reached &&
+                    res == AVERROR_EOF) ? 1 : res;
+        }
         matroska->current_id = id | 1 << 7 * res;
     }
     return ebml_parse_id(matroska, syntax, matroska->current_id, data);
@@ -972,6 +996,54 @@ static int ebml_parse_nest(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
     return res;
 }
 
+static int is_ebml_id_valid(uint32_t id)
+{
+    // Due to endian nonsense in Matroska, the highest byte with any bits set
+    // will contain the leading length bit. This bit in turn identifies the
+    // total byte length of the element by its position within the byte.
+    unsigned int bits = av_log2(id);
+    return id && (bits + 7) / 8 ==  (8 - bits % 8);
+}
+
+/*
+ * Allocate and return the entry for the level1 element with the given ID. If
+ * an entry already exists, return the existing entry.
+ */
+static MatroskaLevel1Element *matroska_find_level1_elem(MatroskaDemuxContext *matroska,
+                                                        uint32_t id)
+{
+    int i;
+    MatroskaLevel1Element *elem;
+
+    if (!is_ebml_id_valid(id))
+        return NULL;
+
+    // Some files link to all clusters; useless.
+    if (id == MATROSKA_ID_CLUSTER)
+        return NULL;
+
+    // There can be multiple seekheads.
+    if (id != MATROSKA_ID_SEEKHEAD) {
+        for (i = 0; i < matroska->num_level1_elems; i++) {
+            if (matroska->level1_elems[i].id == id)
+                return &matroska->level1_elems[i];
+        }
+    }
+
+    // Only a completely broken file would have more elements.
+    // It also provides a low-effort way to escape from circular seekheads
+    // (every iteration will add a level1 entry).
+    if (matroska->num_level1_elems >= FF_ARRAY_ELEMS(matroska->level1_elems)) {
+        av_log(matroska->ctx, AV_LOG_ERROR, "Too many level1 elements or circular seekheads.\n");
+        return NULL;
+    }
+
+    elem = &matroska->level1_elems[matroska->num_level1_elems++];
+    *elem = (MatroskaLevel1Element){.id = id};
+
+    return elem;
+}
+
 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
                            EbmlSyntax *syntax, void *data)
 {
@@ -990,6 +1062,7 @@ static int ebml_parse_elem(MatroskaDemuxContext *matroska,
     uint64_t length;
     int res;
     void *newelem;
+    MatroskaLevel1Element *level1_elem;
 
     data = (char *) data + syntax->data_offset;
     if (syntax->list_elem_size) {
@@ -1032,11 +1105,20 @@ static int ebml_parse_elem(MatroskaDemuxContext *matroska,
     case EBML_BIN:
         res = ebml_read_binary(pb, length, data);
         break;
+    case EBML_LEVEL1:
     case EBML_NEST:
         if ((res = ebml_read_master(matroska, length)) < 0)
             return res;
         if (id == MATROSKA_ID_SEGMENT)
             matroska->segment_start = avio_tell(matroska->ctx->pb);
+        if (id == MATROSKA_ID_CUES)
+            matroska->cues_parsing_deferred = 0;
+        if (syntax->type == EBML_LEVEL1 &&
+            (level1_elem = matroska_find_level1_elem(matroska, syntax->id))) {
+            if (level1_elem->parsed)
+                av_log(matroska->ctx, AV_LOG_ERROR, "Duplicate element\n");
+            level1_elem->parsed = 1;
+        }
         return ebml_parse_nest(matroska, syntax->def.n, data);
     case EBML_PASS:
         return ebml_parse_id(matroska, syntax->def.n, id, data);
@@ -1067,6 +1149,7 @@ static void ebml_free(EbmlSyntax *syntax, void *data)
         case EBML_BIN:
             av_freep(&((EbmlBin *) data_off)->data);
             break;
+        case EBML_LEVEL1:
         case EBML_NEST:
             if (syntax[i].list_elem_size) {
                 EbmlList *list = data_off;
@@ -1074,7 +1157,7 @@ static void ebml_free(EbmlSyntax *syntax, void *data)
                 for (j = 0; j < list->nb_elem;
                      j++, ptr += syntax[i].list_elem_size)
                     ebml_free(syntax[i].def.n, ptr);
-                av_free(list->elem);
+                av_freep(&list->elem);
             } else
                 ebml_free(syntax[i].def.n, data_off);
         default:
@@ -1116,7 +1199,7 @@ static int matroska_probe(AVProbeData *p)
      * availability of that array of characters inside the header.
      * Not fully fool-proof, but good enough. */
     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++) {
-        int probelen = strlen(matroska_doctypes[i]);
+        size_t probelen = strlen(matroska_doctypes[i]);
         if (total < probelen)
             continue;
         for (n = 4 + size; n <= 4 + size + total - probelen; n++)
@@ -1212,15 +1295,13 @@ static int matroska_decode_buffer(uint8_t **buf, int *buf_size,
             newpktdata = av_realloc(pkt_data, pkt_size);
             if (!newpktdata) {
                 inflateEnd(&zstream);
+                result = AVERROR(ENOMEM);
                 goto failed;
             }
             pkt_data          = newpktdata;
             zstream.avail_out = pkt_size - zstream.total_out;
             zstream.next_out  = pkt_data + zstream.total_out;
-            if (pkt_data) {
-                result = inflate(&zstream, Z_NO_FLUSH);
-            } else
-                result = Z_MEM_ERROR;
+            result = inflate(&zstream, Z_NO_FLUSH);
         } while (result == Z_OK && pkt_size < 10000000);
         pkt_size = zstream.total_out;
         inflateEnd(&zstream);
@@ -1247,15 +1328,13 @@ static int matroska_decode_buffer(uint8_t **buf, int *buf_size,
             newpktdata = av_realloc(pkt_data, pkt_size);
             if (!newpktdata) {
                 BZ2_bzDecompressEnd(&bzstream);
+                result = AVERROR(ENOMEM);
                 goto failed;
             }
             pkt_data           = newpktdata;
             bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
             bzstream.next_out  = pkt_data + bzstream.total_out_lo32;
-            if (pkt_data) {
-                result = BZ2_bzDecompress(&bzstream);
-            } else
-                result = BZ_MEM_ERROR;
+            result = BZ2_bzDecompress(&bzstream);
         } while (result == BZ_OK && pkt_size < 10000000);
         pkt_size = bzstream.total_out_lo32;
         BZ2_bzDecompressEnd(&bzstream);
@@ -1282,65 +1361,6 @@ failed:
     return result;
 }
 
-#if FF_API_ASS_SSA
-static void matroska_fix_ass_packet(MatroskaDemuxContext *matroska,
-                                    AVPacket *pkt, uint64_t display_duration)
-{
-    AVBufferRef *line;
-    char *layer, *ptr = pkt->data, *end = ptr + pkt->size;
-
-    for (; *ptr != ',' && ptr < end - 1; ptr++)
-        ;
-    if (*ptr == ',')
-        ptr++;
-    layer = ptr;
-    for (; *ptr != ',' && ptr < end - 1; ptr++)
-        ;
-    if (*ptr == ',') {
-        int64_t end_pts = pkt->pts + display_duration;
-        int sc = matroska->time_scale * pkt->pts / 10000000;
-        int ec = matroska->time_scale * end_pts  / 10000000;
-        int sh, sm, ss, eh, em, es, len;
-        sh     = sc / 360000;
-        sc    -= 360000 * sh;
-        sm     = sc / 6000;
-        sc    -= 6000 * sm;
-        ss     = sc / 100;
-        sc    -= 100 * ss;
-        eh     = ec / 360000;
-        ec    -= 360000 * eh;
-        em     = ec / 6000;
-        ec    -= 6000 * em;
-        es     = ec / 100;
-        ec    -= 100 * es;
-        *ptr++ = '\0';
-        len    = 50 + end - ptr + FF_INPUT_BUFFER_PADDING_SIZE;
-        if (!(line = av_buffer_alloc(len)))
-            return;
-        snprintf(line->data, len,
-                 "Dialogue: %s,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s\r\n",
-                 layer, sh, sm, ss, sc, eh, em, es, ec, ptr);
-        av_buffer_unref(&pkt->buf);
-        pkt->buf  = line;
-        pkt->data = line->data;
-        pkt->size = strlen(line->data);
-    }
-}
-
-static int matroska_merge_packets(AVPacket *out, AVPacket *in)
-{
-    int ret = av_grow_packet(out, in->size);
-    if (ret < 0)
-        return ret;
-
-    memcpy(out->data + out->size - in->size, in->data, in->size);
-
-    av_free_packet(in);
-    av_free(in);
-    return 0;
-}
-#endif
-
 static void matroska_convert_tag(AVFormatContext *s, EbmlList *list,
                                  AVDictionary **metadata, char *prefix)
 {
@@ -1384,7 +1404,7 @@ static void matroska_convert_tags(AVFormatContext *s)
 
     for (i = 0; i < matroska->tags.nb_elem; i++) {
         if (tags[i].target.attachuid) {
-            MatroskaAttachement *attachment = matroska->attachments.elem;
+            MatroskaAttachment *attachment = matroska->attachments.elem;
             for (j = 0; j < matroska->attachments.nb_elem; j++)
                 if (attachment[j].uid == tags[i].target.attachuid &&
                     attachment[j].stream)
@@ -1411,24 +1431,17 @@ static void matroska_convert_tags(AVFormatContext *s)
 }
 
 static int matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska,
-                                         int idx)
+                                         uint64_t pos)
 {
-    EbmlList *seekhead_list = &matroska->seekhead;
     uint32_t level_up       = matroska->level_up;
     uint32_t saved_id       = matroska->current_id;
-    MatroskaSeekhead *seekhead = seekhead_list->elem;
     int64_t before_pos = avio_tell(matroska->ctx->pb);
     MatroskaLevel level;
     int64_t offset;
     int ret = 0;
 
-    if (idx >= seekhead_list->nb_elem            ||
-        seekhead[idx].id == MATROSKA_ID_SEEKHEAD ||
-        seekhead[idx].id == MATROSKA_ID_CLUSTER)
-        return 0;
-
     /* seek */
-    offset = seekhead[idx].pos + matroska->segment_start;
+    offset = pos + matroska->segment_start;
     if (avio_seek(matroska->ctx->pb, offset, SEEK_SET) == offset) {
         /* We don't want to lose our seekhead level, so we add
          * a dummy. This is a crude hack. */
@@ -1465,30 +1478,34 @@ static int matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska,
 static void matroska_execute_seekhead(MatroskaDemuxContext *matroska)
 {
     EbmlList *seekhead_list = &matroska->seekhead;
-    int64_t before_pos = avio_tell(matroska->ctx->pb);
     int i;
 
     // we should not do any seeking in the streaming case
-    if (!matroska->ctx->pb->seekable ||
-        (matroska->ctx->flags & AVFMT_FLAG_IGNIDX))
+    if (!matroska->ctx->pb->seekable)
         return;
 
     for (i = 0; i < seekhead_list->nb_elem; i++) {
-        MatroskaSeekhead *seekhead = seekhead_list->elem;
-        if (seekhead[i].pos <= before_pos)
+        MatroskaSeekhead *seekheads = seekhead_list->elem;
+        uint32_t id  = seekheads[i].id;
+        uint64_t pos = seekheads[i].pos;
+
+        MatroskaLevel1Element *elem = matroska_find_level1_elem(matroska, id);
+        if (!elem || elem->parsed)
             continue;
 
+        elem->pos = pos;
+
         // defer cues parsing until we actually need cue data.
-        if (seekhead[i].id == MATROSKA_ID_CUES) {
-            matroska->cues_parsing_deferred = 1;
+        if (id == MATROSKA_ID_CUES)
             continue;
-        }
 
-        if (matroska_parse_seekhead_entry(matroska, i) < 0) {
+        if (matroska_parse_seekhead_entry(matroska, pos) < 0) {
             // mark index as broken
             matroska->cues_parsing_deferred = -1;
             break;
         }
+
+        elem->parsed = 1;
     }
 }
 
@@ -1496,15 +1513,19 @@ static void matroska_add_index_entries(MatroskaDemuxContext *matroska)
 {
     EbmlList *index_list;
     MatroskaIndex *index;
-    int index_scale = 1;
+    uint64_t index_scale = 1;
     int i, j;
 
+    if (matroska->ctx->flags & AVFMT_FLAG_IGNIDX)
+        return;
+
     index_list = &matroska->index;
     index      = index_list->elem;
-    if (index_list->nb_elem &&
-        index[0].time > 1E14 / matroska->time_scale) {
-        av_log(matroska->ctx, AV_LOG_WARNING, "Working around broken index.\n");
-        index_scale = matroska->time_scale;
+    if (index_list->nb_elem < 2)
+        return;
+    if (index[1].time > 1E14 / matroska->time_scale) {
+        av_log(matroska->ctx, AV_LOG_WARNING, "Dropping apparently-broken index.\n");
+        return;
     }
     for (i = 0; i < index_list->nb_elem; i++) {
         EbmlList *pos_list    = &index[i].pos;
@@ -1522,17 +1543,21 @@ static void matroska_add_index_entries(MatroskaDemuxContext *matroska)
 }
 
 static void matroska_parse_cues(MatroskaDemuxContext *matroska) {
-    EbmlList *seekhead_list = &matroska->seekhead;
-    MatroskaSeekhead *seekhead = seekhead_list->elem;
     int i;
 
-    for (i = 0; i < seekhead_list->nb_elem; i++)
-        if (seekhead[i].id == MATROSKA_ID_CUES)
+    if (matroska->ctx->flags & AVFMT_FLAG_IGNIDX)
+        return;
+
+    for (i = 0; i < matroska->num_level1_elems; i++) {
+        MatroskaLevel1Element *elem = &matroska->level1_elems[i];
+        if (elem->id == MATROSKA_ID_CUES && !elem->parsed) {
+            if (matroska_parse_seekhead_entry(matroska, elem->pos) < 0)
+                matroska->cues_parsing_deferred = -1;
+            elem->parsed = 1;
             break;
-    av_assert1(i <= seekhead_list->nb_elem);
+        }
+    }
 
-    if (matroska_parse_seekhead_entry(matroska, i) < 0)
-       matroska->cues_parsing_deferred = -1;
     matroska_add_index_entries(matroska);
 }
 
@@ -1562,84 +1587,99 @@ static void matroska_metadata_creation_time(AVDictionary **metadata, int64_t dat
     char buffer[32];
     /* Convert to seconds and adjust by number of seconds between 2001-01-01 and Epoch */
     time_t creation_time = date_utc / 1000000000 + 978307200;
-    struct tm *ptm = gmtime(&creation_time);
+    struct tm tmpbuf, *ptm = gmtime_r(&creation_time, &tmpbuf);
     if (!ptm) return;
-    strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", ptm);
-    av_dict_set(metadata, "creation_time", buffer, 0);
+    if (strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", ptm))
+        av_dict_set(metadata, "creation_time", buffer, 0);
 }
 
-static int matroska_read_header(AVFormatContext *s)
+static int matroska_parse_flac(AVFormatContext *s,
+                               MatroskaTrack *track,
+                               int *offset)
 {
-    MatroskaDemuxContext *matroska = s->priv_data;
-    EbmlList *attachements_list = &matroska->attachments;
-    EbmlList *chapters_list     = &matroska->chapters;
-    MatroskaAttachement *attachements;
-    MatroskaChapter *chapters;
-    MatroskaTrack *tracks;
-    uint64_t max_start = 0;
-    int64_t pos;
-    Ebml ebml = { 0 };
-    AVStream *st;
-    int i, j, k, res;
+    AVStream *st = track->stream;
+    uint8_t *p = track->codec_priv.data;
+    int size   = track->codec_priv.size;
 
-    matroska->ctx = s;
-
-    /* First read the EBML header. */
-    if (ebml_parse(matroska, ebml_syntax, &ebml) ||
-        ebml.version         > EBML_VERSION      ||
-        ebml.max_size        > sizeof(uint64_t)  ||
-        ebml.id_length       > sizeof(uint32_t)  ||
-        ebml.doctype_version > 3                 ||
-        !ebml.doctype) {
-        av_log(matroska->ctx, AV_LOG_ERROR,
-               "EBML header using unsupported features\n"
-               "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
-               ebml.version, ebml.doctype, ebml.doctype_version);
-        ebml_free(ebml_syntax, &ebml);
-        return AVERROR_PATCHWELCOME;
-    } else if (ebml.doctype_version == 3) {
-        av_log(matroska->ctx, AV_LOG_WARNING,
-               "EBML header using unsupported features\n"
-               "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
-               ebml.version, ebml.doctype, ebml.doctype_version);
+    if (size < 8 + FLAC_STREAMINFO_SIZE || p[4] & 0x7f) {
+        av_log(s, AV_LOG_WARNING, "Invalid FLAC private data\n");
+        track->codec_priv.size = 0;
+        return 0;
     }
-    for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++)
-        if (!strcmp(ebml.doctype, matroska_doctypes[i]))
-            break;
-    if (i >= FF_ARRAY_ELEMS(matroska_doctypes)) {
-        av_log(s, AV_LOG_WARNING, "Unknown EBML doctype '%s'\n", ebml.doctype);
-        if (matroska->ctx->error_recognition & AV_EF_EXPLODE) {
-            ebml_free(ebml_syntax, &ebml);
-            return AVERROR_INVALIDDATA;
+    *offset = 8;
+    track->codec_priv.size = 8 + FLAC_STREAMINFO_SIZE;
+
+    p    += track->codec_priv.size;
+    size -= track->codec_priv.size;
+
+    /* parse the remaining metadata blocks if present */
+    while (size >= 4) {
+        int block_last, block_type, block_size;
+
+        flac_parse_block_header(p, &block_last, &block_type, &block_size);
+
+        p    += 4;
+        size -= 4;
+        if (block_size > size)
+            return 0;
+
+        /* check for the channel mask */
+        if (block_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
+            AVDictionary *dict = NULL;
+            AVDictionaryEntry *chmask;
+
+            ff_vorbis_comment(s, &dict, p, block_size, 0);
+            chmask = av_dict_get(dict, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
+            if (chmask) {
+                uint64_t mask = strtol(chmask->value, NULL, 0);
+                if (!mask || mask & ~0x3ffffULL) {
+                    av_log(s, AV_LOG_WARNING,
+                           "Invalid value of WAVEFORMATEXTENSIBLE_CHANNEL_MASK\n");
+                } else
+                    st->codec->channel_layout = mask;
+            }
+            av_dict_free(&dict);
         }
-    }
-    ebml_free(ebml_syntax, &ebml);
 
-    /* The next thing is a segment. */
-    pos = avio_tell(matroska->ctx->pb);
-    res = ebml_parse(matroska, matroska_segments, matroska);
-    // try resyncing until we find a EBML_STOP type element.
-    while (res != 1) {
-        res = matroska_resync(matroska, pos);
-        if (res < 0)
-            return res;
-        pos = avio_tell(matroska->ctx->pb);
-        res = ebml_parse(matroska, matroska_segment, matroska);
+        p    += block_size;
+        size -= block_size;
     }
-    matroska_execute_seekhead(matroska);
 
-    if (!matroska->time_scale)
-        matroska->time_scale = 1000000;
-    if (matroska->duration)
-        matroska->ctx->duration = matroska->duration * matroska->time_scale *
-                                  1000 / AV_TIME_BASE;
-    av_dict_set(&s->metadata, "title", matroska->title, 0);
-    av_dict_set(&s->metadata, "encoder", matroska->muxingapp, 0);
+    return 0;
+}
 
-    if (matroska->date_utc.size == 8)
-        matroska_metadata_creation_time(&s->metadata, AV_RB64(matroska->date_utc.data));
+static void mkv_stereo_mode_display_mul(int stereo_mode, int *h_width, int *h_height)
+{
+    switch (stereo_mode) {
+        case MATROSKA_VIDEO_STEREOMODE_TYPE_MONO:
+        case MATROSKA_VIDEO_STEREOMODE_TYPE_CHECKERBOARD_RL:
+        case MATROSKA_VIDEO_STEREOMODE_TYPE_CHECKERBOARD_LR:
+        case MATROSKA_VIDEO_STEREOMODE_TYPE_BOTH_EYES_BLOCK_RL:
+        case MATROSKA_VIDEO_STEREOMODE_TYPE_BOTH_EYES_BLOCK_LR:
+            break;
+        case MATROSKA_VIDEO_STEREOMODE_TYPE_RIGHT_LEFT:
+        case MATROSKA_VIDEO_STEREOMODE_TYPE_LEFT_RIGHT:
+        case MATROSKA_VIDEO_STEREOMODE_TYPE_COL_INTERLEAVED_RL:
+        case MATROSKA_VIDEO_STEREOMODE_TYPE_COL_INTERLEAVED_LR:
+            *h_width = 2;
+            break;
+        case MATROSKA_VIDEO_STEREOMODE_TYPE_BOTTOM_TOP:
+        case MATROSKA_VIDEO_STEREOMODE_TYPE_TOP_BOTTOM:
+        case MATROSKA_VIDEO_STEREOMODE_TYPE_ROW_INTERLEAVED_RL:
+        case MATROSKA_VIDEO_STEREOMODE_TYPE_ROW_INTERLEAVED_LR:
+            *h_height = 2;
+            break;
+    }
+}
+
+static int matroska_parse_tracks(AVFormatContext *s)
+{
+    MatroskaDemuxContext *matroska = s->priv_data;
+    MatroskaTrack *tracks = matroska->tracks.elem;
+    AVStream *st;
+    int i, j, ret;
+    int k;
 
-    tracks = matroska->tracks.elem;
     for (i = 0; i < matroska->tracks.nb_elem; i++) {
         MatroskaTrack *track = &tracks[i];
         enum AVCodecID codec_id = AV_CODEC_ID_NONE;
@@ -1663,9 +1703,17 @@ static int matroska_read_header(AVFormatContext *s)
                    track->type);
             continue;
         }
-        if (track->codec_id == NULL)
+        if (!track->codec_id)
             continue;
 
+        if (track->audio.samplerate < 0 || track->audio.samplerate > INT_MAX ||
+            isnan(track->audio.samplerate)) {
+            av_log(matroska->ctx, AV_LOG_WARNING,
+                   "Invalid sample rate %f, defaulting to 8000 instead.\n",
+                   track->audio.samplerate);
+            track->audio.samplerate = 8000;
+        }
+
         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
             if (!track->default_duration && track->video.frame_rate > 0)
                 track->default_duration = 1000000000 / track->video.frame_rate;
@@ -1740,7 +1788,7 @@ static int matroska_read_header(AVFormatContext *s)
         }
 
         st = track->stream = avformat_new_stream(s, NULL);
-        if (st == NULL) {
+        if (!st) {
             av_free(key_id_base64);
             return AVERROR(ENOMEM);
         }
@@ -1753,28 +1801,31 @@ static int matroska_read_header(AVFormatContext *s)
 
         if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC") &&
              track->codec_priv.size >= 40               &&
-            track->codec_priv.data != NULL) {
+            track->codec_priv.data) {
             track->ms_compat    = 1;
             bit_depth           = AV_RL16(track->codec_priv.data + 14);
             fourcc              = AV_RL32(track->codec_priv.data + 16);
             codec_id            = ff_codec_get_id(ff_codec_bmp_tags,
                                                   fourcc);
+            if (!codec_id)
+                codec_id        = ff_codec_get_id(ff_codec_movvideo_tags,
+                                                  fourcc);
             extradata_offset    = 40;
         } else if (!strcmp(track->codec_id, "A_MS/ACM") &&
                    track->codec_priv.size >= 14         &&
-                   track->codec_priv.data != NULL) {
+                   track->codec_priv.data) {
             int ret;
             ffio_init_context(&b, track->codec_priv.data,
                               track->codec_priv.size,
                               0, NULL, NULL, NULL, NULL);
-            ret = ff_get_wav_header(&b, st->codec, track->codec_priv.size);
+            ret = ff_get_wav_header(s, &b, st->codec, track->codec_priv.size, 0);
             if (ret < 0)
                 return ret;
             codec_id         = st->codec->codec_id;
             extradata_offset = FFMIN(track->codec_priv.size, 18);
         } else if (!strcmp(track->codec_id, "A_QUICKTIME")
                    && (track->codec_priv.size >= 86)
-                   && (track->codec_priv.data != NULL)) {
+                   && (track->codec_priv.data)) {
             fourcc = AV_RL32(track->codec_priv.data + 4);
             codec_id = ff_codec_get_id(ff_codec_movaudio_tags, fourcc);
             if (ff_codec_get_id(ff_codec_movaudio_tags, AV_RL32(track->codec_priv.data))) {
@@ -1783,7 +1834,7 @@ static int matroska_read_header(AVFormatContext *s)
             }
         } else if (!strcmp(track->codec_id, "V_QUICKTIME") &&
                    (track->codec_priv.size >= 21)          &&
-                   (track->codec_priv.data != NULL)) {
+                   (track->codec_priv.data)) {
             fourcc   = AV_RL32(track->codec_priv.data + 4);
             codec_id = ff_codec_get_id(ff_codec_movvideo_tags, fourcc);
             if (ff_codec_get_id(ff_codec_movvideo_tags, AV_RL32(track->codec_priv.data))) {
@@ -1792,6 +1843,12 @@ static int matroska_read_header(AVFormatContext *s)
             }
             if (codec_id == AV_CODEC_ID_NONE && AV_RL32(track->codec_priv.data+4) == AV_RL32("SMI "))
                 codec_id = AV_CODEC_ID_SVQ3;
+            if (codec_id == AV_CODEC_ID_NONE) {
+                char buf[32];
+                av_get_codec_tag_string(buf, sizeof(buf), fourcc);
+                av_log(matroska->ctx, AV_LOG_ERROR,
+                       "mov FourCC not found %s.\n", buf);
+            }
         } else if (codec_id == AV_CODEC_ID_PCM_S16BE) {
             switch (track->audio.bitdepth) {
             case  8:
@@ -1822,8 +1879,8 @@ static int matroska_read_header(AVFormatContext *s)
         } else if (codec_id == AV_CODEC_ID_AAC && !track->codec_priv.size) {
             int profile = matroska_aac_profile(track->codec_id);
             int sri     = matroska_aac_sri(track->audio.samplerate);
-            extradata   = av_mallocz(5 + FF_INPUT_BUFFER_PADDING_SIZE);
-            if (extradata == NULL)
+            extradata   = av_mallocz(5 + AV_INPUT_BUFFER_PADDING_SIZE);
+            if (!extradata)
                 return AVERROR(ENOMEM);
             extradata[0] = (profile << 3) | ((sri & 0x0E) >> 1);
             extradata[1] = ((sri & 0x01) << 7) | (track->audio.channels << 3);
@@ -1835,14 +1892,14 @@ static int matroska_read_header(AVFormatContext *s)
                 extradata_size = 5;
             } else
                 extradata_size = 2;
-        } else if (codec_id == AV_CODEC_ID_ALAC && track->codec_priv.size && track->codec_priv.size < INT_MAX - 12 - FF_INPUT_BUFFER_PADDING_SIZE) {
+        } else if (codec_id == AV_CODEC_ID_ALAC && track->codec_priv.size && track->codec_priv.size < INT_MAX - 12 - AV_INPUT_BUFFER_PADDING_SIZE) {
             /* Only ALAC's magic cookie is stored in Matroska's track headers.
              * Create the "atom size", "tag", and "tag version" fields the
              * decoder expects manually. */
             extradata_size = 12 + track->codec_priv.size;
             extradata      = av_mallocz(extradata_size +
-                                        FF_INPUT_BUFFER_PADDING_SIZE);
-            if (extradata == NULL)
+                                        AV_INPUT_BUFFER_PADDING_SIZE);
+            if (!extradata)
                 return AVERROR(ENOMEM);
             AV_WB32(extradata, extradata_size);
             memcpy(&extradata[4], "alac", 4);
@@ -1851,13 +1908,25 @@ static int matroska_read_header(AVFormatContext *s)
                    track->codec_priv.size);
         } else if (codec_id == AV_CODEC_ID_TTA) {
             extradata_size = 30;
-            extradata      = av_mallocz(extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
-            if (extradata == NULL)
+            extradata      = av_mallocz(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
+            if (!extradata)
                 return AVERROR(ENOMEM);
             ffio_init_context(&b, extradata, extradata_size, 1,
                               NULL, NULL, NULL, NULL);
             avio_write(&b, "TTA1", 4);
             avio_wl16(&b, 1);
+            if (track->audio.channels > UINT16_MAX ||
+                track->audio.bitdepth > UINT16_MAX) {
+                av_log(matroska->ctx, AV_LOG_WARNING,
+                       "Too large audio channel number %"PRIu64
+                       " or bitdepth %"PRIu64". Skipping track.\n",
+                       track->audio.channels, track->audio.bitdepth);
+                av_freep(&extradata);
+                if (matroska->ctx->error_recognition & AV_EF_EXPLODE)
+                    return AVERROR_INVALIDDATA;
+                else
+                    continue;
+            }
             avio_wl16(&b, track->audio.channels);
             avio_wl16(&b, track->audio.bitdepth);
             if (track->audio.out_samplerate < 0 || track->audio.out_samplerate > INT_MAX)
@@ -1913,6 +1982,12 @@ static int matroska_read_header(AVFormatContext *s)
                 st->codec->block_align = track->audio.sub_packet_size;
                 extradata_offset       = 78;
             }
+        } else if (codec_id == AV_CODEC_ID_FLAC && track->codec_priv.size) {
+            ret = matroska_parse_flac(s, track, &extradata_offset);
+            if (ret < 0)
+                return ret;
+        } else if (codec_id == AV_CODEC_ID_PRORES && track->codec_priv.size == 4) {
+            fourcc = AV_RL32(track->codec_priv.data);
         }
         track->codec_priv.size -= extradata_offset;
 
@@ -1925,6 +2000,11 @@ static int matroska_read_header(AVFormatContext *s)
         avpriv_set_pts_info(st, 64, matroska->time_scale * track->time_scale,
                             1000 * 1000 * 1000);    /* 64 bit pts in ns */
 
+        /* convert the delay from ns to the track timebase */
+        track->codec_delay = av_rescale_q(track->codec_delay,
+                                          (AVRational){ 1, 1000000000 },
+                                          st->time_base);
+
         st->codec->codec_id = codec_id;
 
         if (strcmp(track->language, "und"))
@@ -1951,6 +2031,8 @@ static int matroska_read_header(AVFormatContext *s)
 
         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
             MatroskaTrackPlane *planes = track->operation.combine_planes.elem;
+            int display_width_mul = 1;
+            int display_height_mul = 1;
 
             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
             st->codec->codec_tag  = fourcc;
@@ -1958,10 +2040,14 @@ static int matroska_read_header(AVFormatContext *s)
                 st->codec->bits_per_coded_sample = bit_depth;
             st->codec->width      = track->video.pixel_width;
             st->codec->height     = track->video.pixel_height;
+
+            if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB)
+                mkv_stereo_mode_display_mul(track->video.stereo_mode, &display_width_mul, &display_height_mul);
+
             av_reduce(&st->sample_aspect_ratio.num,
                       &st->sample_aspect_ratio.den,
-                      st->codec->height * track->video.display_width,
-                      st->codec->width  * track->video.display_height,
+                      st->codec->height * track->video.display_width * display_width_mul,
+                      st->codec->width  * track->video.display_height * display_height_mul,
                       255);
             if (st->codec->codec_id != AV_CODEC_ID_HEVC)
                 st->need_parsing = AVSTREAM_PARSE_HEADERS;
@@ -1970,13 +2056,14 @@ static int matroska_read_header(AVFormatContext *s)
                 av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
                           1000000000, track->default_duration, 30000);
 #if FF_API_R_FRAME_RATE
-                if (st->avg_frame_rate.num < st->avg_frame_rate.den * 1000L)
+                if (   st->avg_frame_rate.num < st->avg_frame_rate.den * 1000LL
+                    && st->avg_frame_rate.num > st->avg_frame_rate.den * 5LL)
                     st->r_frame_rate = st->avg_frame_rate;
 #endif
             }
 
             /* export stereo mode flag as metadata tag */
-            if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREO_MODE_COUNT)
+            if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB)
                 av_dict_set(&st->metadata, "stereo_mode", ff_matroska_video_stereo_mode[track->video.stereo_mode], 0);
 
             /* export alpha mode flag as metadata tag  */
@@ -1991,23 +2078,32 @@ static int matroska_read_header(AVFormatContext *s)
                 snprintf(buf, sizeof(buf), "%s_%d",
                          ff_matroska_video_stereo_plane[planes[j].type], i);
                 for (k=0; k < matroska->tracks.nb_elem; k++)
-                    if (planes[j].uid == tracks[k].uid) {
-                        av_dict_set(&s->streams[k]->metadata,
+                    if (planes[j].uid == tracks[k].uid && tracks[k].stream) {
+                        av_dict_set(&tracks[k].stream->metadata,
                                     "stereo_mode", buf, 0);
                         break;
                     }
             }
+            // add stream level stereo3d side data if it is a supported format
+            if (track->video.stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB &&
+                track->video.stereo_mode != 10 && track->video.stereo_mode != 12) {
+                int ret = ff_mkv_stereo3d_conv(st, track->video.stereo_mode);
+                if (ret < 0)
+                    return ret;
+            }
         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
             st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
             st->codec->sample_rate = track->audio.out_samplerate;
             st->codec->channels    = track->audio.channels;
             if (!st->codec->bits_per_coded_sample)
                 st->codec->bits_per_coded_sample = track->audio.bitdepth;
-            if (st->codec->codec_id != AV_CODEC_ID_AAC)
+            if (st->codec->codec_id == AV_CODEC_ID_MP3)
+                st->need_parsing = AVSTREAM_PARSE_FULL;
+            else if (st->codec->codec_id != AV_CODEC_ID_AAC)
                 st->need_parsing = AVSTREAM_PARSE_HEADERS;
             if (track->codec_delay > 0) {
                 st->codec->delay = av_rescale_q(track->codec_delay,
-                                                (AVRational){1, 1000000000},
+                                                st->time_base,
                                                 (AVRational){1, st->codec->sample_rate});
             }
             if (track->seek_preroll > 0) {
@@ -2028,42 +2124,139 @@ static int matroska_read_header(AVFormatContext *s)
             }
         } else if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE) {
             st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
-#if FF_API_ASS_SSA
-            if (st->codec->codec_id == AV_CODEC_ID_SSA ||
-                st->codec->codec_id == AV_CODEC_ID_ASS)
-#else
             if (st->codec->codec_id == AV_CODEC_ID_ASS)
-#endif
                 matroska->contains_ssa = 1;
         }
     }
 
-    attachements = attachements_list->elem;
-    for (j = 0; j < attachements_list->nb_elem; j++) {
-        if (!(attachements[j].filename && attachements[j].mime &&
-              attachements[j].bin.data && attachements[j].bin.size > 0)) {
+    return 0;
+}
+
+static int matroska_read_header(AVFormatContext *s)
+{
+    MatroskaDemuxContext *matroska = s->priv_data;
+    EbmlList *attachments_list = &matroska->attachments;
+    EbmlList *chapters_list    = &matroska->chapters;
+    MatroskaAttachment *attachments;
+    MatroskaChapter *chapters;
+    uint64_t max_start = 0;
+    int64_t pos;
+    Ebml ebml = { 0 };
+    int i, j, res;
+
+    matroska->ctx = s;
+    matroska->cues_parsing_deferred = 1;
+
+    /* First read the EBML header. */
+    if (ebml_parse(matroska, ebml_syntax, &ebml) || !ebml.doctype) {
+        av_log(matroska->ctx, AV_LOG_ERROR, "EBML header parsing failed\n");
+        ebml_free(ebml_syntax, &ebml);
+        return AVERROR_INVALIDDATA;
+    }
+    if (ebml.version         > EBML_VERSION      ||
+        ebml.max_size        > sizeof(uint64_t)  ||
+        ebml.id_length       > sizeof(uint32_t)  ||
+        ebml.doctype_version > 3) {
+        av_log(matroska->ctx, AV_LOG_ERROR,
+               "EBML header using unsupported features\n"
+               "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
+               ebml.version, ebml.doctype, ebml.doctype_version);
+        ebml_free(ebml_syntax, &ebml);
+        return AVERROR_PATCHWELCOME;
+    } else if (ebml.doctype_version == 3) {
+        av_log(matroska->ctx, AV_LOG_WARNING,
+               "EBML header using unsupported features\n"
+               "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
+               ebml.version, ebml.doctype, ebml.doctype_version);
+    }
+    for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++)
+        if (!strcmp(ebml.doctype, matroska_doctypes[i]))
+            break;
+    if (i >= FF_ARRAY_ELEMS(matroska_doctypes)) {
+        av_log(s, AV_LOG_WARNING, "Unknown EBML doctype '%s'\n", ebml.doctype);
+        if (matroska->ctx->error_recognition & AV_EF_EXPLODE) {
+            ebml_free(ebml_syntax, &ebml);
+            return AVERROR_INVALIDDATA;
+        }
+    }
+    ebml_free(ebml_syntax, &ebml);
+
+    /* The next thing is a segment. */
+    pos = avio_tell(matroska->ctx->pb);
+    res = ebml_parse(matroska, matroska_segments, matroska);
+    // try resyncing until we find a EBML_STOP type element.
+    while (res != 1) {
+        res = matroska_resync(matroska, pos);
+        if (res < 0)
+            return res;
+        pos = avio_tell(matroska->ctx->pb);
+        res = ebml_parse(matroska, matroska_segment, matroska);
+    }
+    matroska_execute_seekhead(matroska);
+
+    if (!matroska->time_scale)
+        matroska->time_scale = 1000000;
+    if (matroska->duration)
+        matroska->ctx->duration = matroska->duration * matroska->time_scale *
+                                  1000 / AV_TIME_BASE;
+    av_dict_set(&s->metadata, "title", matroska->title, 0);
+    av_dict_set(&s->metadata, "encoder", matroska->muxingapp, 0);
+
+    if (matroska->date_utc.size == 8)
+        matroska_metadata_creation_time(&s->metadata, AV_RB64(matroska->date_utc.data));
+
+    res = matroska_parse_tracks(s);
+    if (res < 0)
+        return res;
+
+    attachments = attachments_list->elem;
+    for (j = 0; j < attachments_list->nb_elem; j++) {
+        if (!(attachments[j].filename && attachments[j].mime &&
+              attachments[j].bin.data && attachments[j].bin.size > 0)) {
             av_log(matroska->ctx, AV_LOG_ERROR, "incomplete attachment\n");
         } else {
             AVStream *st = avformat_new_stream(s, NULL);
-            if (st == NULL)
+            if (!st)
                 break;
-            av_dict_set(&st->metadata, "filename", attachements[j].filename, 0);
-            av_dict_set(&st->metadata, "mimetype", attachements[j].mime, 0);
+            av_dict_set(&st->metadata, "filename", attachments[j].filename, 0);
+            av_dict_set(&st->metadata, "mimetype", attachments[j].mime, 0);
             st->codec->codec_id   = AV_CODEC_ID_NONE;
-            st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
-            if (ff_alloc_extradata(st->codec, attachements[j].bin.size))
-                break;
-            memcpy(st->codec->extradata, attachements[j].bin.data,
-                   attachements[j].bin.size);
 
-            for (i = 0; ff_mkv_mime_tags[i].id != AV_CODEC_ID_NONE; i++) {
-                if (!strncmp(ff_mkv_mime_tags[i].str, attachements[j].mime,
-                             strlen(ff_mkv_mime_tags[i].str))) {
-                    st->codec->codec_id = ff_mkv_mime_tags[i].id;
+            for (i = 0; ff_mkv_image_mime_tags[i].id != AV_CODEC_ID_NONE; i++) {
+                if (!strncmp(ff_mkv_image_mime_tags[i].str, attachments[j].mime,
+                             strlen(ff_mkv_image_mime_tags[i].str))) {
+                    st->codec->codec_id = ff_mkv_image_mime_tags[i].id;
                     break;
                 }
             }
-            attachements[j].stream = st;
+
+            attachments[j].stream = st;
+
+            if (st->codec->codec_id != AV_CODEC_ID_NONE) {
+                st->disposition      |= AV_DISPOSITION_ATTACHED_PIC;
+                st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
+
+                av_init_packet(&st->attached_pic);
+                if ((res = av_new_packet(&st->attached_pic, attachments[j].bin.size)) < 0)
+                    return res;
+                memcpy(st->attached_pic.data, attachments[j].bin.data, attachments[j].bin.size);
+                st->attached_pic.stream_index = st->index;
+                st->attached_pic.flags       |= AV_PKT_FLAG_KEY;
+            } else {
+                st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
+                if (ff_alloc_extradata(st->codec, attachments[j].bin.size))
+                    break;
+                memcpy(st->codec->extradata, attachments[j].bin.data,
+                       attachments[j].bin.size);
+
+                for (i = 0; ff_mkv_mime_tags[i].id != AV_CODEC_ID_NONE; i++) {
+                    if (!strncmp(ff_mkv_mime_tags[i].str, attachments[j].mime,
+                                strlen(ff_mkv_mime_tags[i].str))) {
+                        st->codec->codec_id = ff_mkv_mime_tags[i].id;
+                        break;
+                    }
+                }
+            }
         }
     }
 
@@ -2076,8 +2269,10 @@ static int matroska_read_header(AVFormatContext *s)
                                    (AVRational) { 1, 1000000000 },
                                    chapters[i].start, chapters[i].end,
                                    chapters[i].title);
-            av_dict_set(&chapters[i].chapter->metadata,
-                        "title", chapters[i].title, 0);
+            if (chapters[i].chapter) {
+                av_dict_set(&chapters[i].chapter->metadata,
+                            "title", chapters[i].title, 0);
+            }
             max_start = chapters[i].start;
         }
 
@@ -2097,7 +2292,7 @@ static int matroska_deliver_packet(MatroskaDemuxContext *matroska,
 {
     if (matroska->num_packets > 0) {
         memcpy(pkt, matroska->packets[0], sizeof(AVPacket));
-        av_free(matroska->packets[0]);
+        av_freep(&matroska->packets[0]);
         if (matroska->num_packets > 1) {
             void *newpackets;
             memmove(&matroska->packets[0], &matroska->packets[1],
@@ -2127,8 +2322,8 @@ static void matroska_clear_queue(MatroskaDemuxContext *matroska)
     if (matroska->packets) {
         int n;
         for (n = 0; n < matroska->num_packets; n++) {
-            av_free_packet(matroska->packets[n]);
-            av_free(matroska->packets[n]);
+            av_packet_unref(matroska->packets[n]);
+            av_freep(&matroska->packets[n]);
         }
         av_freep(&matroska->packets);
         matroska->num_packets = 0;
@@ -2297,10 +2492,15 @@ static int matroska_parse_rm_audio(MatroskaDemuxContext *matroska,
     }
 
     while (track->audio.pkt_cnt) {
-        AVPacket *pkt = NULL;
-        if (!(pkt = av_mallocz(sizeof(AVPacket))) || av_new_packet(pkt, a) < 0) {
-            av_free(pkt);
+        int ret;
+        AVPacket *pkt = av_mallocz(sizeof(AVPacket));
+        if (!pkt)
             return AVERROR(ENOMEM);
+
+        ret = av_new_packet(pkt, a);
+        if (ret < 0) {
+            av_free(pkt);
+            return ret;
         }
         memcpy(pkt->data,
                track->audio.buf + a * (h * w / a - track->audio.pkt_cnt--),
@@ -2462,6 +2662,8 @@ static int matroska_parse_webvtt(MatroskaDemuxContext *matroska,
         return AVERROR_INVALIDDATA;
 
     pkt = av_mallocz(sizeof(*pkt));
+    if (!pkt)
+        return AVERROR(ENOMEM);
     err = av_new_packet(pkt, text_len);
     if (err < 0) {
         av_free(pkt);
@@ -2474,7 +2676,7 @@ static int matroska_parse_webvtt(MatroskaDemuxContext *matroska,
         buf = av_packet_new_side_data(pkt,
                                       AV_PKT_DATA_WEBVTT_IDENTIFIER,
                                       id_len);
-        if (buf == NULL) {
+        if (!buf) {
             av_free(pkt);
             return AVERROR(ENOMEM);
         }
@@ -2485,7 +2687,7 @@ static int matroska_parse_webvtt(MatroskaDemuxContext *matroska,
         buf = av_packet_new_side_data(pkt,
                                       AV_PKT_DATA_WEBVTT_SETTINGS,
                                       settings_len);
-        if (buf == NULL) {
+        if (!buf) {
             av_free(pkt);
             return AVERROR(ENOMEM);
         }
@@ -2542,10 +2744,16 @@ static int matroska_parse_frame(MatroskaDemuxContext *matroska,
         pkt_data = wv_data;
     }
 
-    if (st->codec->codec_id == AV_CODEC_ID_PRORES)
+    if (st->codec->codec_id == AV_CODEC_ID_PRORES &&
+        AV_RB32(&data[4]) != MKBETAG('i', 'c', 'p', 'f'))
         offset = 8;
 
     pkt = av_mallocz(sizeof(AVPacket));
+    if (!pkt) {
+        if (pkt_data != data)
+            av_freep(&pkt_data);
+        return AVERROR(ENOMEM);
+    }
     /* XXX: prevent data copy... */
     if (av_new_packet(pkt, pkt_size + offset) < 0) {
         av_free(pkt);
@@ -2553,7 +2761,7 @@ static int matroska_parse_frame(MatroskaDemuxContext *matroska,
         goto fail;
     }
 
-    if (st->codec->codec_id == AV_CODEC_ID_PRORES) {
+    if (st->codec->codec_id == AV_CODEC_ID_PRORES && offset == 8) {
         uint8_t *buf = pkt->data;
         bytestream_put_be32(&buf, pkt_size);
         bytestream_put_be32(&buf, MKBETAG('i', 'c', 'p', 'f'));
@@ -2571,8 +2779,8 @@ static int matroska_parse_frame(MatroskaDemuxContext *matroska,
         uint8_t *side_data = av_packet_new_side_data(pkt,
                                                      AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,
                                                      additional_size + 8);
-        if (side_data == NULL) {
-            av_free_packet(pkt);
+        if (!side_data) {
+            av_packet_unref(pkt);
             av_free(pkt);
             return AVERROR(ENOMEM);
         }
@@ -2584,8 +2792,8 @@ static int matroska_parse_frame(MatroskaDemuxContext *matroska,
         uint8_t *side_data = av_packet_new_side_data(pkt,
                                                      AV_PKT_DATA_SKIP_SAMPLES,
                                                      10);
-        if (side_data == NULL) {
-            av_free_packet(pkt);
+        if (!side_data) {
+            av_packet_unref(pkt);
             av_free(pkt);
             return AVERROR(ENOMEM);
         }
@@ -2600,48 +2808,18 @@ static int matroska_parse_frame(MatroskaDemuxContext *matroska,
     else
         pkt->pts = timecode;
     pkt->pos = pos;
+    pkt->duration = lace_duration;
+
+#if FF_API_CONVERGENCE_DURATION
+FF_DISABLE_DEPRECATION_WARNINGS
     if (st->codec->codec_id == AV_CODEC_ID_SUBRIP) {
-        /*
-         * For backward compatibility.
-         * Historically, we have put subtitle duration
-         * in convergence_duration, on the off chance
-         * that the time_scale is less than 1us, which
-         * could result in a 32bit overflow on the
-         * normal duration field.
-         */
         pkt->convergence_duration = lace_duration;
     }
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
 
-    if (track->type != MATROSKA_TRACK_TYPE_SUBTITLE ||
-        lace_duration <= INT_MAX) {
-        /*
-         * For non subtitle tracks, just store the duration
-         * as normal.
-         *
-         * If it's a subtitle track and duration value does
-         * not overflow a uint32, then also store it normally.
-         */
-        pkt->duration = lace_duration;
-    }
-
-#if FF_API_ASS_SSA
-    if (st->codec->codec_id == AV_CODEC_ID_SSA)
-        matroska_fix_ass_packet(matroska, pkt, lace_duration);
-
-    if (matroska->prev_pkt                                 &&
-        timecode                         != AV_NOPTS_VALUE &&
-        matroska->prev_pkt->pts          == timecode       &&
-        matroska->prev_pkt->stream_index == st->index      &&
-        st->codec->codec_id == AV_CODEC_ID_SSA)
-        matroska_merge_packets(matroska->prev_pkt, pkt);
-    else {
-        dynarray_add(&matroska->packets, &matroska->num_packets, pkt);
-        matroska->prev_pkt = pkt;
-    }
-#else
     dynarray_add(&matroska->packets, &matroska->num_packets, pkt);
     matroska->prev_pkt = pkt;
-#endif
 
     return 0;
 
@@ -2695,7 +2873,7 @@ static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,
 
     if (cluster_time != (uint64_t) -1 &&
         (block_time >= 0 || cluster_time >= -block_time)) {
-        timecode = cluster_time + block_time;
+        timecode = cluster_time + block_time - track->codec_delay;
         if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE &&
             timecode < track->end_timecode)
             is_keyframe = 0;  /* overlapping subtitles are not key frame */
@@ -2891,7 +3069,7 @@ static int matroska_read_seek(AVFormatContext *s, int stream_index,
                               int64_t timestamp, int flags)
 {
     MatroskaDemuxContext *matroska = s->priv_data;
-    MatroskaTrack *tracks = matroska->tracks.elem;
+    MatroskaTrack *tracks = NULL;
     AVStream *st = s->streams[stream_index];
     int i, index, index_sub, index_min;
 
@@ -2905,11 +3083,11 @@ static int matroska_read_seek(AVFormatContext *s, int stream_index,
         goto err;
     timestamp = FFMAX(timestamp, st->index_entries[0].timestamp);
 
-    if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
+    if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0 || index == st->nb_index_entries - 1) {
         avio_seek(s->pb, st->index_entries[st->nb_index_entries - 1].pos,
                   SEEK_SET);
         matroska->current_id = 0;
-        while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
+        while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0 || index == st->nb_index_entries - 1) {
             matroska_clear_queue(matroska);
             if (matroska_parse_cluster(matroska) < 0)
                 break;
@@ -2921,18 +3099,20 @@ static int matroska_read_seek(AVFormatContext *s, int stream_index,
         goto err;
 
     index_min = index;
+    tracks = matroska->tracks.elem;
     for (i = 0; i < matroska->tracks.nb_elem; i++) {
         tracks[i].audio.pkt_cnt        = 0;
         tracks[i].audio.sub_packet_cnt = 0;
         tracks[i].audio.buf_timecode   = AV_NOPTS_VALUE;
         tracks[i].end_timecode         = 0;
         if (tracks[i].type == MATROSKA_TRACK_TYPE_SUBTITLE &&
+            tracks[i].stream &&
             tracks[i].stream->discard != AVDISCARD_ALL) {
             index_sub = av_index_search_timestamp(
                 tracks[i].stream, st->index_entries[index].timestamp,
                 AVSEEK_FLAG_BACKWARD);
             while (index_sub >= 0 &&
-                  index_min >= 0 &&
+                  index_min > 0 &&
                   tracks[i].stream->index_entries[index_sub].pos < st->index_entries[index_min].pos &&
                   st->index_entries[index].timestamp - tracks[i].stream->index_entries[index_sub].timestamp < 30000000000 / matroska->time_scale)
                 index_min--;
@@ -2975,20 +3155,395 @@ static int matroska_read_close(AVFormatContext *s)
 
     for (n = 0; n < matroska->tracks.nb_elem; n++)
         if (tracks[n].type == MATROSKA_TRACK_TYPE_AUDIO)
-            av_free(tracks[n].audio.buf);
+            av_freep(&tracks[n].audio.buf);
     ebml_free(matroska_cluster, &matroska->current_cluster);
     ebml_free(matroska_segment, matroska);
 
     return 0;
 }
 
+typedef struct {
+    int64_t start_time_ns;
+    int64_t end_time_ns;
+    int64_t start_offset;
+    int64_t end_offset;
+} CueDesc;
+
+/* This function searches all the Cues and returns the CueDesc corresponding the
+ * the timestamp ts. Returned CueDesc will be such that start_time_ns <= ts <
+ * end_time_ns. All 4 fields will be set to -1 if ts >= file's duration.
+ */
+static CueDesc get_cue_desc(AVFormatContext *s, int64_t ts, int64_t cues_start) {
+    MatroskaDemuxContext *matroska = s->priv_data;
+    CueDesc cue_desc;
+    int i;
+    int nb_index_entries = s->streams[0]->nb_index_entries;
+    AVIndexEntry *index_entries = s->streams[0]->index_entries;
+    if (ts >= matroska->duration * matroska->time_scale) return (CueDesc) {-1, -1, -1, -1};
+    for (i = 1; i < nb_index_entries; i++) {
+        if (index_entries[i - 1].timestamp * matroska->time_scale <= ts &&
+            index_entries[i].timestamp * matroska->time_scale > ts) {
+            break;
+        }
+    }
+    --i;
+    cue_desc.start_time_ns = index_entries[i].timestamp * matroska->time_scale;
+    cue_desc.start_offset = index_entries[i].pos - matroska->segment_start;
+    if (i != nb_index_entries - 1) {
+        cue_desc.end_time_ns = index_entries[i + 1].timestamp * matroska->time_scale;
+        cue_desc.end_offset = index_entries[i + 1].pos - matroska->segment_start;
+    } else {
+        cue_desc.end_time_ns = matroska->duration * matroska->time_scale;
+        // FIXME: this needs special handling for files where Cues appear
+        // before Clusters. the current logic assumes Cues appear after
+        // Clusters.
+        cue_desc.end_offset = cues_start - matroska->segment_start;
+    }
+    return cue_desc;
+}
+
+static int webm_clusters_start_with_keyframe(AVFormatContext *s)
+{
+    MatroskaDemuxContext *matroska = s->priv_data;
+    int64_t cluster_pos, before_pos;
+    int index, rv = 1;
+    if (s->streams[0]->nb_index_entries <= 0) return 0;
+    // seek to the first cluster using cues.
+    index = av_index_search_timestamp(s->streams[0], 0, 0);
+    if (index < 0)  return 0;
+    cluster_pos = s->streams[0]->index_entries[index].pos;
+    before_pos = avio_tell(s->pb);
+    while (1) {
+        int64_t cluster_id = 0, cluster_length = 0;
+        AVPacket *pkt;
+        avio_seek(s->pb, cluster_pos, SEEK_SET);
+        // read cluster id and length
+        ebml_read_num(matroska, matroska->ctx->pb, 4, &cluster_id);
+        ebml_read_length(matroska, matroska->ctx->pb, &cluster_length);
+        if (cluster_id != 0xF43B675) { // done with all clusters
+            break;
+        }
+        avio_seek(s->pb, cluster_pos, SEEK_SET);
+        matroska->current_id = 0;
+        matroska_clear_queue(matroska);
+        if (matroska_parse_cluster(matroska) < 0 ||
+            matroska->num_packets <= 0) {
+            break;
+        }
+        pkt = matroska->packets[0];
+        cluster_pos += cluster_length + 12; // 12 is the offset of the cluster id and length.
+        if (!(pkt->flags & AV_PKT_FLAG_KEY)) {
+            rv = 0;
+            break;
+        }
+    }
+    avio_seek(s->pb, before_pos, SEEK_SET);
+    return rv;
+}
+
+static int buffer_size_after_time_downloaded(int64_t time_ns, double search_sec, int64_t bps,
+                                             double min_buffer, double* buffer,
+                                             double* sec_to_download, AVFormatContext *s,
+                                             int64_t cues_start)
+{
+    double nano_seconds_per_second = 1000000000.0;
+    double time_sec = time_ns / nano_seconds_per_second;
+    int rv = 0;
+    int64_t time_to_search_ns = (int64_t)(search_sec * nano_seconds_per_second);
+    int64_t end_time_ns = time_ns + time_to_search_ns;
+    double sec_downloaded = 0.0;
+    CueDesc desc_curr = get_cue_desc(s, time_ns, cues_start);
+    if (desc_curr.start_time_ns == -1)
+      return -1;
+    *sec_to_download = 0.0;
+
+    // Check for non cue start time.
+    if (time_ns > desc_curr.start_time_ns) {
+      int64_t cue_nano = desc_curr.end_time_ns - time_ns;
+      double percent = (double)(cue_nano) / (desc_curr.end_time_ns - desc_curr.start_time_ns);
+      double cueBytes = (desc_curr.end_offset - desc_curr.start_offset) * percent;
+      double timeToDownload = (cueBytes * 8.0) / bps;
+
+      sec_downloaded += (cue_nano / nano_seconds_per_second) - timeToDownload;
+      *sec_to_download += timeToDownload;
+
+      // Check if the search ends within the first cue.
+      if (desc_curr.end_time_ns >= end_time_ns) {
+          double desc_end_time_sec = desc_curr.end_time_ns / nano_seconds_per_second;
+          double percent_to_sub = search_sec / (desc_end_time_sec - time_sec);
+          sec_downloaded = percent_to_sub * sec_downloaded;
+          *sec_to_download = percent_to_sub * *sec_to_download;
+      }
+
+      if ((sec_downloaded + *buffer) <= min_buffer) {
+          return 1;
+      }
+
+      // Get the next Cue.
+      desc_curr = get_cue_desc(s, desc_curr.end_time_ns, cues_start);
+    }
+
+    while (desc_curr.start_time_ns != -1) {
+        int64_t desc_bytes = desc_curr.end_offset - desc_curr.start_offset;
+        int64_t desc_ns = desc_curr.end_time_ns - desc_curr.start_time_ns;
+        double desc_sec = desc_ns / nano_seconds_per_second;
+        double bits = (desc_bytes * 8.0);
+        double time_to_download = bits / bps;
+
+        sec_downloaded += desc_sec - time_to_download;
+        *sec_to_download += time_to_download;
+
+        if (desc_curr.end_time_ns >= end_time_ns) {
+            double desc_end_time_sec = desc_curr.end_time_ns / nano_seconds_per_second;
+            double percent_to_sub = search_sec / (desc_end_time_sec - time_sec);
+            sec_downloaded = percent_to_sub * sec_downloaded;
+            *sec_to_download = percent_to_sub * *sec_to_download;
+
+            if ((sec_downloaded + *buffer) <= min_buffer)
+                rv = 1;
+            break;
+        }
+
+        if ((sec_downloaded + *buffer) <= min_buffer) {
+            rv = 1;
+            break;
+        }
+
+        desc_curr = get_cue_desc(s, desc_curr.end_time_ns, cues_start);
+    }
+    *buffer = *buffer + sec_downloaded;
+    return rv;
+}
+
+/* This function computes the bandwidth of the WebM file with the help of
+ * buffer_size_after_time_downloaded() function. Both of these functions are
+ * adapted from WebM Tools project and are adapted to work with FFmpeg's
+ * Matroska parsing mechanism.
+ *
+ * Returns the bandwidth of the file on success; -1 on error.
+ * */
+static int64_t webm_dash_manifest_compute_bandwidth(AVFormatContext *s, int64_t cues_start)
+{
+    MatroskaDemuxContext *matroska = s->priv_data;
+    AVStream *st = s->streams[0];
+    double bandwidth = 0.0;
+    int i;
+
+    for (i = 0; i < st->nb_index_entries; i++) {
+        int64_t prebuffer_ns = 1000000000;
+        int64_t time_ns = st->index_entries[i].timestamp * matroska->time_scale;
+        double nano_seconds_per_second = 1000000000.0;
+        int64_t prebuffered_ns = time_ns + prebuffer_ns;
+        double prebuffer_bytes = 0.0;
+        int64_t temp_prebuffer_ns = prebuffer_ns;
+        int64_t pre_bytes, pre_ns;
+        double pre_sec, prebuffer, bits_per_second;
+        CueDesc desc_beg = get_cue_desc(s, time_ns, cues_start);
+
+        // Start with the first Cue.
+        CueDesc desc_end = desc_beg;
+
+        // Figure out how much data we have downloaded for the prebuffer. This will
+        // be used later to adjust the bits per sample to try.
+        while (desc_end.start_time_ns != -1 && desc_end.end_time_ns < prebuffered_ns) {
+            // Prebuffered the entire Cue.
+            prebuffer_bytes += desc_end.end_offset - desc_end.start_offset;
+            temp_prebuffer_ns -= desc_end.end_time_ns - desc_end.start_time_ns;
+            desc_end = get_cue_desc(s, desc_end.end_time_ns, cues_start);
+        }
+        if (desc_end.start_time_ns == -1) {
+            // The prebuffer is larger than the duration.
+            if (matroska->duration * matroska->time_scale >= prebuffered_ns)
+              return -1;
+            bits_per_second = 0.0;
+        } else {
+            // The prebuffer ends in the last Cue. Estimate how much data was
+            // prebuffered.
+            pre_bytes = desc_end.end_offset - desc_end.start_offset;
+            pre_ns = desc_end.end_time_ns - desc_end.start_time_ns;
+            pre_sec = pre_ns / nano_seconds_per_second;
+            prebuffer_bytes +=
+                pre_bytes * ((temp_prebuffer_ns / nano_seconds_per_second) / pre_sec);
+
+            prebuffer = prebuffer_ns / nano_seconds_per_second;
+
+            // Set this to 0.0 in case our prebuffer buffers the entire video.
+            bits_per_second = 0.0;
+            do {
+                int64_t desc_bytes = desc_end.end_offset - desc_beg.start_offset;
+                int64_t desc_ns = desc_end.end_time_ns - desc_beg.start_time_ns;
+                double desc_sec = desc_ns / nano_seconds_per_second;
+                double calc_bits_per_second = (desc_bytes * 8) / desc_sec;
+
+                // Drop the bps by the percentage of bytes buffered.
+                double percent = (desc_bytes - prebuffer_bytes) / desc_bytes;
+                double mod_bits_per_second = calc_bits_per_second * percent;
+
+                if (prebuffer < desc_sec) {
+                    double search_sec =
+                        (double)(matroska->duration * matroska->time_scale) / nano_seconds_per_second;
+
+                    // Add 1 so the bits per second should be a little bit greater than file
+                    // datarate.
+                    int64_t bps = (int64_t)(mod_bits_per_second) + 1;
+                    const double min_buffer = 0.0;
+                    double buffer = prebuffer;
+                    double sec_to_download = 0.0;
+
+                    int rv = buffer_size_after_time_downloaded(prebuffered_ns, search_sec, bps,
+                                                               min_buffer, &buffer, &sec_to_download,
+                                                               s, cues_start);
+                    if (rv < 0) {
+                        return -1;
+                    } else if (rv == 0) {
+                        bits_per_second = (double)(bps);
+                        break;
+                    }
+                }
+
+                desc_end = get_cue_desc(s, desc_end.end_time_ns, cues_start);
+            } while (desc_end.start_time_ns != -1);
+        }
+        if (bandwidth < bits_per_second) bandwidth = bits_per_second;
+    }
+    return (int64_t)bandwidth;
+}
+
+static int webm_dash_manifest_cues(AVFormatContext *s)
+{
+    MatroskaDemuxContext *matroska = s->priv_data;
+    EbmlList *seekhead_list = &matroska->seekhead;
+    MatroskaSeekhead *seekhead = seekhead_list->elem;
+    char *buf;
+    int64_t cues_start = -1, cues_end = -1, before_pos, bandwidth;
+    int i;
+
+    // determine cues start and end positions
+    for (i = 0; i < seekhead_list->nb_elem; i++)
+        if (seekhead[i].id == MATROSKA_ID_CUES)
+            break;
+
+    if (i >= seekhead_list->nb_elem) return -1;
+
+    before_pos = avio_tell(matroska->ctx->pb);
+    cues_start = seekhead[i].pos + matroska->segment_start;
+    if (avio_seek(matroska->ctx->pb, cues_start, SEEK_SET) == cues_start) {
+        // cues_end is computed as cues_start + cues_length + length of the
+        // Cues element ID + EBML length of the Cues element. cues_end is
+        // inclusive and the above sum is reduced by 1.
+        uint64_t cues_length = 0, cues_id = 0, bytes_read = 0;
+        bytes_read += ebml_read_num(matroska, matroska->ctx->pb, 4, &cues_id);
+        bytes_read += ebml_read_length(matroska, matroska->ctx->pb, &cues_length);
+        cues_end = cues_start + cues_length + bytes_read - 1;
+    }
+    avio_seek(matroska->ctx->pb, before_pos, SEEK_SET);
+    if (cues_start == -1 || cues_end == -1) return -1;
+
+    // parse the cues
+    matroska_parse_cues(matroska);
+
+    // cues start
+    av_dict_set_int(&s->streams[0]->metadata, CUES_START, cues_start, 0);
+
+    // cues end
+    av_dict_set_int(&s->streams[0]->metadata, CUES_END, cues_end, 0);
+
+    // bandwidth
+    bandwidth = webm_dash_manifest_compute_bandwidth(s, cues_start);
+    if (bandwidth < 0) return -1;
+    av_dict_set_int(&s->streams[0]->metadata, BANDWIDTH, bandwidth, 0);
+
+    // check if all clusters start with key frames
+    av_dict_set_int(&s->streams[0]->metadata, CLUSTER_KEYFRAME, webm_clusters_start_with_keyframe(s), 0);
+
+    // store cue point timestamps as a comma separated list for checking subsegment alignment in
+    // the muxer. assumes that each timestamp cannot be more than 20 characters long.
+    buf = av_malloc_array(s->streams[0]->nb_index_entries, 20 * sizeof(char));
+    if (!buf) return -1;
+    strcpy(buf, "");
+    for (i = 0; i < s->streams[0]->nb_index_entries; i++) {
+        snprintf(buf, (i + 1) * 20 * sizeof(char),
+                 "%s%" PRId64, buf, s->streams[0]->index_entries[i].timestamp);
+        if (i != s->streams[0]->nb_index_entries - 1)
+            strncat(buf, ",", sizeof(char));
+    }
+    av_dict_set(&s->streams[0]->metadata, CUE_TIMESTAMPS, buf, 0);
+    av_free(buf);
+
+    return 0;
+}
+
+static int webm_dash_manifest_read_header(AVFormatContext *s)
+{
+    char *buf;
+    int ret = matroska_read_header(s);
+    MatroskaTrack *tracks;
+    MatroskaDemuxContext *matroska = s->priv_data;
+    if (ret) {
+        av_log(s, AV_LOG_ERROR, "Failed to read file headers\n");
+        return -1;
+    }
+
+    if (!matroska->is_live) {
+        buf = av_asprintf("%g", matroska->duration);
+        if (!buf) return AVERROR(ENOMEM);
+        av_dict_set(&s->streams[0]->metadata, DURATION, buf, 0);
+        av_free(buf);
+
+        // initialization range
+        // 5 is the offset of Cluster ID.
+        av_dict_set_int(&s->streams[0]->metadata, INITIALIZATION_RANGE, avio_tell(s->pb) - 5, 0);
+    }
+
+    // basename of the file
+    buf = strrchr(s->filename, '/');
+    av_dict_set(&s->streams[0]->metadata, FILENAME, buf ? ++buf : s->filename, 0);
+
+    // track number
+    tracks = matroska->tracks.elem;
+    av_dict_set_int(&s->streams[0]->metadata, TRACK_NUMBER, tracks[0].num, 0);
+
+    // parse the cues and populate Cue related fields
+    return matroska->is_live ? 0 : webm_dash_manifest_cues(s);
+}
+
+static int webm_dash_manifest_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    return AVERROR_EOF;
+}
+
+#define OFFSET(x) offsetof(MatroskaDemuxContext, x)
+static const AVOption options[] = {
+    { "live", "flag indicating that the input is a live file that only has the headers.", OFFSET(is_live), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, AV_OPT_FLAG_DECODING_PARAM },
+    { NULL },
+};
+
+static const AVClass webm_dash_class = {
+    .class_name = "WebM DASH Manifest demuxer",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
 AVInputFormat ff_matroska_demuxer = {
     .name           = "matroska,webm",
     .long_name      = NULL_IF_CONFIG_SMALL("Matroska / WebM"),
+    .extensions     = "mkv,mk3d,mka,mks",
     .priv_data_size = sizeof(MatroskaDemuxContext),
     .read_probe     = matroska_probe,
     .read_header    = matroska_read_header,
     .read_packet    = matroska_read_packet,
     .read_close     = matroska_read_close,
     .read_seek      = matroska_read_seek,
+    .mime_type      = "audio/webm,audio/x-matroska,video/webm,video/x-matroska"
+};
+
+AVInputFormat ff_webm_dash_manifest_demuxer = {
+    .name           = "webm_dash_manifest",
+    .long_name      = NULL_IF_CONFIG_SMALL("WebM DASH Manifest"),
+    .priv_data_size = sizeof(MatroskaDemuxContext),
+    .read_header    = webm_dash_manifest_read_header,
+    .read_packet    = webm_dash_manifest_read_packet,
+    .read_close     = matroska_read_close,
+    .priv_class     = &webm_dash_class,
 };