rtpenc: Always do the default initialization regardless of codecs
[ffmpeg.git] / libavformat / nutenc.c
index 00f76e5..b7b0c9c 100644 (file)
  * nut muxer
  * Copyright (c) 2004-2007 Michael Niedermayer
  *
- * This file is part of FFmpeg.
+ * This file is part of Libav.
  *
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include <stdint.h>
+
+#include "libavutil/intreadwrite.h"
+#include "libavutil/mathematics.h"
+#include "libavutil/tree.h"
+#include "libavutil/dict.h"
+#include "libavutil/time.h"
+#include "libavutil/opt.h"
+#include "libavcodec/mpegaudiodata.h"
 #include "nut.h"
-#include "tree.h"
+#include "internal.h"
+#include "avio_internal.h"
+#include "riff.h"
+
+static int find_expected_header(AVCodecContext *c, int size, int key_frame,
+                                uint8_t out[64])
+{
+    int sample_rate = c->sample_rate;
+
+    if (size > 4096)
+        return 0;
+
+    AV_WB24(out, 1);
+
+    if (c->codec_id == AV_CODEC_ID_MPEG4) {
+        if (key_frame) {
+            return 3;
+        } else {
+            out[3] = 0xB6;
+            return 4;
+        }
+    } else if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO ||
+               c->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
+        return 3;
+    } else if (c->codec_id == AV_CODEC_ID_H264) {
+        return 3;
+    } else if (c->codec_id == AV_CODEC_ID_MP3 ||
+               c->codec_id == AV_CODEC_ID_MP2) {
+        int lsf, mpeg25, sample_rate_index, bitrate_index, frame_size;
+        int layer           = c->codec_id == AV_CODEC_ID_MP3 ? 3 : 2;
+        unsigned int header = 0xFFF00000;
+
+        lsf           = sample_rate < (24000 + 32000) / 2;
+        mpeg25        = sample_rate < (12000 + 16000) / 2;
+        sample_rate <<= lsf + mpeg25;
+        if (sample_rate < (32000 + 44100) / 2)
+            sample_rate_index = 2;
+        else if (sample_rate < (44100 + 48000) / 2)
+            sample_rate_index = 0;
+        else
+            sample_rate_index = 1;
+
+        sample_rate = avpriv_mpa_freq_tab[sample_rate_index] >> (lsf + mpeg25);
+
+        for (bitrate_index = 2; bitrate_index < 30; bitrate_index++) {
+            frame_size =
+                avpriv_mpa_bitrate_tab[lsf][layer - 1][bitrate_index >> 1];
+            frame_size = (frame_size * 144000) / (sample_rate << lsf) +
+                (bitrate_index & 1);
+
+            if (frame_size == size)
+                break;
+        }
+
+        header |= (!lsf) << 19;
+        header |= (4 - layer) << 17;
+        header |= 1 << 16; //no crc
+        AV_WB32(out, header);
+        if (size <= 0)
+            return 2;  //we guess there is no crc, if there is one the user clearly does not care about overhead
+        if (bitrate_index == 30)
+            return -1;  //something is wrong ...
+
+        header |= (bitrate_index >> 1) << 12;
+        header |= sample_rate_index << 10;
+        header |= (bitrate_index & 1) << 9;
+
+        return 2; //FIXME actually put the needed ones in build_elision_headers()
+        //return 3; //we guess that the private bit is not set
+//FIXME the above assumptions should be checked, if these turn out false too often something should be done
+    }
+    return 0;
+}
+
+static int find_header_idx(AVFormatContext *s, AVCodecContext *c, int size,
+                           int frame_type)
+{
+    NUTContext *nut = s->priv_data;
+    uint8_t out[64];
+    int i;
+    int len = find_expected_header(c, size, frame_type, out);
+
+    for (i = 1; i < nut->header_count; i++) {
+        if (len == nut->header_len[i] && !memcmp(out, nut->header[i], len)) {
+            return i;
+        }
+    }
+
+    return 0;
+}
 
-static void build_frame_code(AVFormatContext *s){
+static void build_elision_headers(AVFormatContext *s)
+{
+    NUTContext *nut = s->priv_data;
+    int i;
+    //FIXME this is lame
+    //FIXME write a 2pass mode to find the maximal headers
+    static const uint8_t headers[][5] = {
+        { 3, 0x00, 0x00, 0x01 },
+        { 4, 0x00, 0x00, 0x01, 0xB6},
+        { 2, 0xFF, 0xFA }, //mp3+crc
+        { 2, 0xFF, 0xFB }, //mp3
+        { 2, 0xFF, 0xFC }, //mp2+crc
+        { 2, 0xFF, 0xFD }, //mp2
+    };
+
+    nut->header_count = 7;
+    for (i = 1; i < nut->header_count; i++) {
+        nut->header_len[i] = headers[i - 1][0];
+        nut->header[i]     = &headers[i - 1][1];
+    }
+}
+
+static void build_frame_code(AVFormatContext *s)
+{
     NUTContext *nut = s->priv_data;
     int key_frame, index, pred, stream_id;
-    int start=1;
-    int end= 254;
-    int keyframe_0_esc= s->nb_streams > 2;
+    int start = 1;
+    int end   = 254;
+    int keyframe_0_esc = s->nb_streams > 2;
     int pred_table[10];
     FrameCode *ft;
 
-    ft= &nut->frame_code[start];
-    ft->flags= FLAG_CODED;
-    ft->size_mul=1;
-    ft->pts_delta=1;
+    ft            = &nut->frame_code[start];
+    ft->flags     = FLAG_CODED;
+    ft->size_mul  = 1;
+    ft->pts_delta = 1;
     start++;
 
-    if(keyframe_0_esc){
+    if (keyframe_0_esc) {
         /* keyframe = 0 escape */
-        FrameCode *ft= &nut->frame_code[start];
-        ft->flags= FLAG_STREAM_ID | FLAG_SIZE_MSB | FLAG_CODED_PTS;
-        ft->size_mul=1;
+        FrameCode *ft = &nut->frame_code[start];
+        ft->flags    = FLAG_STREAM_ID | FLAG_SIZE_MSB | FLAG_CODED_PTS;
+        ft->size_mul = 1;
         start++;
     }
 
-    for(stream_id= 0; stream_id<s->nb_streams; stream_id++){
-        int start2= start + (end-start)*stream_id / s->nb_streams;
-        int end2  = start + (end-start)*(stream_id+1) / s->nb_streams;
+    for (stream_id = 0; stream_id < s->nb_streams; stream_id++) {
+        int start2 = start + (end - start) * stream_id       / s->nb_streams;
+        int end2   = start + (end - start) * (stream_id + 1) / s->nb_streams;
         AVCodecContext *codec = s->streams[stream_id]->codec;
-        int is_audio= codec->codec_type == CODEC_TYPE_AUDIO;
-        int intra_only= /*codec->intra_only || */is_audio;
+        const AVCodecDescriptor *desc = avcodec_descriptor_get(codec->codec_id);
+        int is_audio          = codec->codec_type == AVMEDIA_TYPE_AUDIO;
+        int intra_only        = /*codec->intra_only || */ is_audio;
         int pred_count;
 
-        for(key_frame=0; key_frame<2; key_frame++){
-            if(intra_only && keyframe_0_esc && key_frame==0)
-                continue;
-
-            {
-                FrameCode *ft= &nut->frame_code[start2];
-                ft->flags= FLAG_KEY*key_frame;
-                ft->flags|= FLAG_SIZE_MSB | FLAG_CODED_PTS;
-                ft->stream_id= stream_id;
-                ft->size_mul=1;
+        for (key_frame = 0; key_frame < 2; key_frame++) {
+            if (!intra_only || !keyframe_0_esc || key_frame != 0) {
+                FrameCode *ft = &nut->frame_code[start2];
+                ft->flags     = FLAG_KEY * key_frame;
+                ft->flags    |= FLAG_SIZE_MSB | FLAG_CODED_PTS;
+                ft->stream_id = stream_id;
+                ft->size_mul  = 1;
+                if (is_audio)
+                    ft->header_idx = find_header_idx(s, codec, -1, key_frame);
                 start2++;
             }
         }
 
-        key_frame= intra_only;
-#if 1
-        if(is_audio){
-            int frame_bytes= codec->frame_size*(int64_t)codec->bit_rate / (8*codec->sample_rate);
+        key_frame = intra_only;
+        if (is_audio) {
+            int frame_bytes = codec->frame_size * (int64_t)codec->bit_rate /
+                              (8 * codec->sample_rate);
             int pts;
-            for(pts=0; pts<2; pts++){
-                for(pred=0; pred<2; pred++){
-                    FrameCode *ft= &nut->frame_code[start2];
-                    ft->flags= FLAG_KEY*key_frame;
-                    ft->stream_id= stream_id;
-                    ft->size_mul=frame_bytes + 2;
-                    ft->size_lsb=frame_bytes + pred;
-                    ft->pts_delta=pts;
+            for (pts = 0; pts < 2; pts++)
+                for (pred = 0; pred < 2; pred++) {
+                    FrameCode *ft = &nut->frame_code[start2];
+                    ft->flags      = FLAG_KEY * key_frame;
+                    ft->stream_id  = stream_id;
+                    ft->size_mul   = frame_bytes + 2;
+                    ft->size_lsb   = frame_bytes + pred;
+                    ft->pts_delta  = pts;
+                    ft->header_idx = find_header_idx(s, codec, frame_bytes + pred, key_frame);
                     start2++;
                 }
-            }
-        }else{
-            FrameCode *ft= &nut->frame_code[start2];
-            ft->flags= FLAG_KEY | FLAG_SIZE_MSB;
-            ft->stream_id= stream_id;
-            ft->size_mul=1;
-            ft->pts_delta=1;
+        } else {
+            FrameCode *ft = &nut->frame_code[start2];
+            ft->flags     = FLAG_KEY | FLAG_SIZE_MSB;
+            ft->stream_id = stream_id;
+            ft->size_mul  = 1;
+            ft->pts_delta = 1;
             start2++;
         }
-#endif
 
-        if(codec->has_b_frames){
-            pred_count=5;
-            pred_table[0]=-2;
-            pred_table[1]=-1;
-            pred_table[2]=1;
-            pred_table[3]=3;
-            pred_table[4]=4;
-        }else if(codec->codec_id == CODEC_ID_VORBIS){
-            pred_count=3;
-            pred_table[0]=2;
-            pred_table[1]=9;
-            pred_table[2]=16;
-        }else{
-            pred_count=1;
-            pred_table[0]=1;
+        if (desc && desc->props & AV_CODEC_PROP_REORDER) {
+            pred_count    = 5;
+            pred_table[0] = -2;
+            pred_table[1] = -1;
+            pred_table[2] = 1;
+            pred_table[3] = 3;
+            pred_table[4] = 4;
+        } else if (codec->codec_id == AV_CODEC_ID_VORBIS) {
+            pred_count    = 3;
+            pred_table[0] = 2;
+            pred_table[1] = 9;
+            pred_table[2] = 16;
+        } else {
+            pred_count    = 1;
+            pred_table[0] = 1;
         }
 
-        for(pred=0; pred<pred_count; pred++){
-            int start3= start2 + (end2-start2)*pred / pred_count;
-            int end3  = start2 + (end2-start2)*(pred+1) / pred_count;
+        for (pred = 0; pred < pred_count; pred++) {
+            int start3 = start2 + (end2 - start2) * pred / pred_count;
+            int end3   = start2 + (end2 - start2) * (pred + 1) / pred_count;
 
-            for(index=start3; index<end3; index++){
-                FrameCode *ft= &nut->frame_code[index];
-                ft->flags= FLAG_KEY*key_frame;
-                ft->flags|= FLAG_SIZE_MSB;
-                ft->stream_id= stream_id;
+            for (index = start3; index < end3; index++) {
+                FrameCode *ft = &nut->frame_code[index];
+                ft->flags     = FLAG_KEY * key_frame;
+                ft->flags    |= FLAG_SIZE_MSB;
+                ft->stream_id = stream_id;
 //FIXME use single byte size and pred from last
-                ft->size_mul= end3-start3;
-                ft->size_lsb= index - start3;
-                ft->pts_delta= pred_table[pred];
+                ft->size_mul  = end3 - start3;
+                ft->size_lsb  = index - start3;
+                ft->pts_delta = pred_table[pred];
+                if (is_audio)
+                    ft->header_idx = find_header_idx(s, codec, -1, key_frame);
             }
         }
     }
-    memmove(&nut->frame_code['N'+1], &nut->frame_code['N'], sizeof(FrameCode)*(255-'N'));
-    nut->frame_code[  0].flags=
-    nut->frame_code[255].flags=
-    nut->frame_code['N'].flags= FLAG_INVALID;
-}
-
-/**
- * Gets the length in bytes which is needed to store val as v.
- */
-static int get_length(uint64_t val){
-    int i=1;
-
-    while(val>>=7)
-        i++;
-
-    return i;
+    memmove(&nut->frame_code['N' + 1], &nut->frame_code['N'],
+            sizeof(FrameCode) * (255 - 'N'));
+    nut->frame_code[0].flags       =
+        nut->frame_code[255].flags =
+        nut->frame_code['N'].flags = FLAG_INVALID;
 }
 
-static void put_v(ByteIOContext *bc, uint64_t val){
-    int i= get_length(val);
-
-    while(--i>0)
-        put_byte(bc, 128 | (val>>(7*i)));
-
-    put_byte(bc, val&127);
-}
-
-static void put_t(NUTContext *nut, StreamContext *nus, ByteIOContext *bc, uint64_t val){
+static void put_tt(NUTContext *nut, AVRational *time_base, AVIOContext *bc,
+                   uint64_t val)
+{
     val *= nut->time_base_count;
-    val += nus->time_base - nut->time_base;
-    put_v(bc, val);
+    val += time_base - nut->time_base;
+    ff_put_v(bc, val);
 }
-
 /**
- * stores a string as vb.
+ * Store a string as vb.
  */
-static void put_str(ByteIOContext *bc, const char *string){
-    int len= strlen(string);
+static void put_str(AVIOContext *bc, const char *string)
+{
+    int len = strlen(string);
 
-    put_v(bc, len);
-    put_buffer(bc, string, len);
+    ff_put_v(bc, len);
+    avio_write(bc, string, len);
 }
 
-static void put_s(ByteIOContext *bc, int64_t val){
-    put_v(bc, 2*FFABS(val) - (val>0));
+static void put_s(AVIOContext *bc, int64_t val)
+{
+    ff_put_v(bc, 2 * FFABS(val) - (val > 0));
 }
 
 #ifdef TRACE
-static inline void put_v_trace(ByteIOContext *bc, uint64_t v, char *file, char *func, int line){
-    av_log(NULL, AV_LOG_DEBUG, "put_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
+static inline void ff_put_v_trace(AVIOContext *bc, uint64_t v, const char *file,
+                                  const char *func, int line)
+{
+    av_log(NULL, AV_LOG_DEBUG, "ff_put_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
 
-    put_v(bc, v);
+    ff_put_v(bc, v);
 }
 
-static inline void put_s_trace(ByteIOContext *bc, int64_t v, char *file, char *func, int line){
+static inline void put_s_trace(AVIOContext *bc, int64_t v, const char *file,
+                               const char *func, int line)
+{
     av_log(NULL, AV_LOG_DEBUG, "put_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
 
     put_s(bc, v);
 }
-#define put_v(bc, v)  put_v_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+#define ff_put_v(bc, v)  ff_put_v_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 #define put_s(bc, v)  put_s_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 #endif
 
 //FIXME remove calculate_checksum
-static void put_packet(NUTContext *nut, ByteIOContext *bc, ByteIOContext *dyn_bc, int calculate_checksum, uint64_t startcode){
-    uint8_t *dyn_buf=NULL;
-    int dyn_size= url_close_dyn_buf(dyn_bc, &dyn_buf);
-    int forw_ptr= dyn_size + 4*calculate_checksum;
-
-    if(forw_ptr > 4096)
-        init_checksum(bc, av_crc04C11DB7_update, 0);
-    put_be64(bc, startcode);
-    put_v(bc, forw_ptr);
-    if(forw_ptr > 4096)
-        put_le32(bc, get_checksum(bc));
-
-    if(calculate_checksum)
-        init_checksum(bc, av_crc04C11DB7_update, 0);
-    put_buffer(bc, dyn_buf, dyn_size);
-    if(calculate_checksum)
-        put_le32(bc, get_checksum(bc));
+static void put_packet(NUTContext *nut, AVIOContext *bc, AVIOContext *dyn_bc,
+                       int calculate_checksum, uint64_t startcode)
+{
+    uint8_t *dyn_buf = NULL;
+    int dyn_size     = avio_close_dyn_buf(dyn_bc, &dyn_buf);
+    int forw_ptr     = dyn_size + 4 * calculate_checksum;
+
+    if (forw_ptr > 4096)
+        ffio_init_checksum(bc, ff_crc04C11DB7_update, 0);
+    avio_wb64(bc, startcode);
+    ff_put_v(bc, forw_ptr);
+    if (forw_ptr > 4096)
+        avio_wl32(bc, ffio_get_checksum(bc));
+
+    if (calculate_checksum)
+        ffio_init_checksum(bc, ff_crc04C11DB7_update, 0);
+    avio_write(bc, dyn_buf, dyn_size);
+    if (calculate_checksum)
+        avio_wl32(bc, ffio_get_checksum(bc));
 
     av_free(dyn_buf);
 }
 
-static void write_mainheader(NUTContext *nut, ByteIOContext *bc){
-    int i, j, tmp_pts, tmp_flags, tmp_stream, tmp_mul, tmp_size, tmp_fields;
+static void write_mainheader(NUTContext *nut, AVIOContext *bc)
+{
+    int i, j, tmp_pts, tmp_flags, tmp_stream, tmp_mul, tmp_size, tmp_fields,
+        tmp_head_idx;
+    int64_t tmp_match;
 
-    put_v(bc, 3); /* version */
-    put_v(bc, nut->avf->nb_streams);
-    put_v(bc, MAX_DISTANCE);
-    put_v(bc, nut->time_base_count);
+    ff_put_v(bc, nut->version);
+    ff_put_v(bc, nut->avf->nb_streams);
+    ff_put_v(bc, nut->max_distance);
+    ff_put_v(bc, nut->time_base_count);
 
-    for(i=0; i<nut->time_base_count; i++){
-        put_v(bc, nut->time_base[i].num);
-        put_v(bc, nut->time_base[i].den);
+    for (i = 0; i < nut->time_base_count; i++) {
+        ff_put_v(bc, nut->time_base[i].num);
+        ff_put_v(bc, nut->time_base[i].den);
     }
 
-    tmp_pts=0;
-    tmp_mul=1;
-    tmp_stream=0;
-    for(i=0; i<256;){
-        tmp_fields=0;
-        tmp_size=0;
+    tmp_pts      = 0;
+    tmp_mul      = 1;
+    tmp_stream   = 0;
+    tmp_match    = 1 - (1LL << 62);
+    tmp_head_idx = 0;
+    for (i = 0; i < 256; ) {
+        tmp_fields = 0;
+        tmp_size   = 0;
 //        tmp_res=0;
-        if(tmp_pts    != nut->frame_code[i].pts_delta) tmp_fields=1;
-        if(tmp_mul    != nut->frame_code[i].size_mul ) tmp_fields=2;
-        if(tmp_stream != nut->frame_code[i].stream_id) tmp_fields=3;
-        if(tmp_size   != nut->frame_code[i].size_lsb ) tmp_fields=4;
+        if (tmp_pts != nut->frame_code[i].pts_delta)
+            tmp_fields = 1;
+        if (tmp_mul != nut->frame_code[i].size_mul)
+            tmp_fields = 2;
+        if (tmp_stream != nut->frame_code[i].stream_id)
+            tmp_fields = 3;
+        if (tmp_size != nut->frame_code[i].size_lsb)
+            tmp_fields = 4;
 //        if(tmp_res    != nut->frame_code[i].res            ) tmp_fields=5;
-
-        tmp_pts   = nut->frame_code[i].pts_delta;
-        tmp_flags = nut->frame_code[i].flags;
-        tmp_stream= nut->frame_code[i].stream_id;
-        tmp_mul   = nut->frame_code[i].size_mul;
-        tmp_size  = nut->frame_code[i].size_lsb;
+        if (tmp_head_idx != nut->frame_code[i].header_idx)
+            tmp_fields = 8;
+
+        tmp_pts    = nut->frame_code[i].pts_delta;
+        tmp_flags  = nut->frame_code[i].flags;
+        tmp_stream = nut->frame_code[i].stream_id;
+        tmp_mul    = nut->frame_code[i].size_mul;
+        tmp_size   = nut->frame_code[i].size_lsb;
 //        tmp_res   = nut->frame_code[i].res;
+        tmp_head_idx = nut->frame_code[i].header_idx;
 
-        for(j=0; i<256; j++,i++){
-            if(i == 'N'){
+        for (j = 0; i < 256; j++, i++) {
+            if (i == 'N') {
                 j--;
                 continue;
             }
-            if(nut->frame_code[i].pts_delta != tmp_pts   ) break;
-            if(nut->frame_code[i].flags     != tmp_flags ) break;
-            if(nut->frame_code[i].stream_id != tmp_stream) break;
-            if(nut->frame_code[i].size_mul  != tmp_mul   ) break;
-            if(nut->frame_code[i].size_lsb  != tmp_size+j) break;
-//            if(nut->frame_code[i].res       != tmp_res   ) break;
+            if (nut->frame_code[i].pts_delta  != tmp_pts      ||
+                nut->frame_code[i].flags      != tmp_flags    ||
+                nut->frame_code[i].stream_id  != tmp_stream   ||
+                nut->frame_code[i].size_mul   != tmp_mul      ||
+                nut->frame_code[i].size_lsb   != tmp_size + j ||
+//              nut->frame_code[i].res        != tmp_res      ||
+                nut->frame_code[i].header_idx != tmp_head_idx)
+                break;
         }
-        if(j != tmp_mul - tmp_size) tmp_fields=6;
-
-        put_v(bc, tmp_flags);
-        put_v(bc, tmp_fields);
-        if(tmp_fields>0) put_s(bc, tmp_pts);
-        if(tmp_fields>1) put_v(bc, tmp_mul);
-        if(tmp_fields>2) put_v(bc, tmp_stream);
-        if(tmp_fields>3) put_v(bc, tmp_size);
-        if(tmp_fields>4) put_v(bc, 0 /*tmp_res*/);
-        if(tmp_fields>5) put_v(bc, j);
+        if (j != tmp_mul - tmp_size)
+            tmp_fields = 6;
+
+        ff_put_v(bc, tmp_flags);
+        ff_put_v(bc, tmp_fields);
+        if (tmp_fields > 0)
+            put_s(bc, tmp_pts);
+        if (tmp_fields > 1)
+            ff_put_v(bc, tmp_mul);
+        if (tmp_fields > 2)
+            ff_put_v(bc, tmp_stream);
+        if (tmp_fields > 3)
+            ff_put_v(bc, tmp_size);
+        if (tmp_fields > 4)
+            ff_put_v(bc, 0 /*tmp_res*/);
+        if (tmp_fields > 5)
+            ff_put_v(bc, j);
+        if (tmp_fields > 6)
+            ff_put_v(bc, tmp_match);
+        if (tmp_fields > 7)
+            ff_put_v(bc, tmp_head_idx);
     }
+    ff_put_v(bc, nut->header_count - 1);
+    for (i = 1; i < nut->header_count; i++) {
+        ff_put_v(bc, nut->header_len[i]);
+        avio_write(bc, nut->header[i], nut->header_len[i]);
+    }
+    // flags had been effectively introduced in version 4
+    if (nut->version > NUT_STABLE_VERSION)
+        ff_put_v(bc, nut->flags);
 }
 
-static int write_streamheader(NUTContext *nut, ByteIOContext *bc, AVCodecContext *codec, int i){
-    put_v(bc, i);
-    switch(codec->codec_type){
-    case CODEC_TYPE_VIDEO: put_v(bc, 0); break;
-    case CODEC_TYPE_AUDIO: put_v(bc, 1); break;
-//    case CODEC_TYPE_TEXT : put_v(bc, 2); break;
-    default              : put_v(bc, 3); break;
+static int write_streamheader(AVFormatContext *avctx, AVIOContext *bc,
+                              AVStream *st, int i)
+{
+    NUTContext *nut       = avctx->priv_data;
+    AVCodecContext *codec = st->codec;
+    const AVCodecDescriptor *desc = avcodec_descriptor_get(codec->codec_id);
+    unsigned codec_tag    = av_codec_get_tag(ff_nut_codec_tags, codec->codec_id);
+
+    ff_put_v(bc, i);
+    switch (codec->codec_type) {
+    case AVMEDIA_TYPE_VIDEO:
+        ff_put_v(bc, 0);
+        break;
+    case AVMEDIA_TYPE_AUDIO:
+        ff_put_v(bc, 1);
+        break;
+    case AVMEDIA_TYPE_SUBTITLE:
+        ff_put_v(bc, 2);
+        break;
+    default:
+        ff_put_v(bc, 3);
+        break;
+    }
+    ff_put_v(bc, 4);
+
+    if (!codec_tag || codec->codec_id == AV_CODEC_ID_RAWVIDEO)
+        codec_tag = codec->codec_tag;
+
+    if (codec_tag) {
+        avio_wl32(bc, codec_tag);
+    } else {
+        av_log(avctx, AV_LOG_ERROR, "No codec tag defined for stream %d\n", i);
+        return AVERROR(EINVAL);
     }
-    put_v(bc, 4);
-    if (codec->codec_tag){
-        put_le32(bc, codec->codec_tag);
-    }else
-        return -1;
-
-    put_v(bc, nut->stream[i].time_base - nut->time_base);
-    put_v(bc, nut->stream[i].msb_pts_shift);
-    put_v(bc, nut->stream[i].max_pts_distance);
-    put_v(bc, codec->has_b_frames);
-    put_byte(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */
-
-    put_v(bc, codec->extradata_size);
-    put_buffer(bc, codec->extradata, codec->extradata_size);
-
-    switch(codec->codec_type){
-    case CODEC_TYPE_AUDIO:
-        put_v(bc, codec->sample_rate);
-        put_v(bc, 1);
-        put_v(bc, codec->channels);
+
+    ff_put_v(bc, nut->stream[i].time_base - nut->time_base);
+    ff_put_v(bc, nut->stream[i].msb_pts_shift);
+    ff_put_v(bc, nut->stream[i].max_pts_distance);
+    ff_put_v(bc, (desc && desc->props & AV_CODEC_PROP_REORDER) ? 16 : 0);
+    avio_w8(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */
+
+    ff_put_v(bc, codec->extradata_size);
+    avio_write(bc, codec->extradata, codec->extradata_size);
+
+    switch (codec->codec_type) {
+    case AVMEDIA_TYPE_AUDIO:
+        ff_put_v(bc, codec->sample_rate);
+        ff_put_v(bc, 1);
+        ff_put_v(bc, codec->channels);
         break;
-    case CODEC_TYPE_VIDEO:
-        put_v(bc, codec->width);
-        put_v(bc, codec->height);
-
-        if(codec->sample_aspect_ratio.num<=0 || codec->sample_aspect_ratio.den<=0){
-            put_v(bc, 0);
-            put_v(bc, 0);
-        }else{
-            put_v(bc, codec->sample_aspect_ratio.num);
-            put_v(bc, codec->sample_aspect_ratio.den);
+    case AVMEDIA_TYPE_VIDEO:
+        ff_put_v(bc, codec->width);
+        ff_put_v(bc, codec->height);
+
+        if (st->sample_aspect_ratio.num <= 0 ||
+            st->sample_aspect_ratio.den <= 0) {
+            ff_put_v(bc, 0);
+            ff_put_v(bc, 0);
+        } else {
+            ff_put_v(bc, st->sample_aspect_ratio.num);
+            ff_put_v(bc, st->sample_aspect_ratio.den);
         }
-        put_v(bc, 0); /* csp type -- unknown */
+        ff_put_v(bc, 0); /* csp type -- unknown */
         break;
     default:
         break;
@@ -317,242 +483,462 @@ static int write_streamheader(NUTContext *nut, ByteIOContext *bc, AVCodecContext
     return 0;
 }
 
-static int add_info(ByteIOContext *bc, char *type, char *value){
+static int add_info(AVIOContext *bc, const char *type, const char *value)
+{
     put_str(bc, type);
     put_s(bc, -1);
     put_str(bc, value);
     return 1;
 }
 
-static void write_globalinfo(NUTContext *nut, ByteIOContext *bc){
+static int write_globalinfo(NUTContext *nut, AVIOContext *bc)
+{
+    AVFormatContext *s   = nut->avf;
+    AVDictionaryEntry *t = NULL;
+    AVIOContext *dyn_bc;
+    uint8_t *dyn_buf = NULL;
+    int count        = 0, dyn_size;
+    int ret          = avio_open_dyn_buf(&dyn_bc);
+    if (ret < 0)
+        return ret;
+
+    while ((t = av_dict_get(s->metadata, "", t, AV_DICT_IGNORE_SUFFIX)))
+        count += add_info(dyn_bc, t->key, t->value);
+
+    ff_put_v(bc, 0); //stream_if_plus1
+    ff_put_v(bc, 0); //chapter_id
+    ff_put_v(bc, 0); //timestamp_start
+    ff_put_v(bc, 0); //length
+
+    ff_put_v(bc, count);
+
+    dyn_size = avio_close_dyn_buf(dyn_bc, &dyn_buf);
+    avio_write(bc, dyn_buf, dyn_size);
+    av_free(dyn_buf);
+    return 0;
+}
+
+static int write_streaminfo(NUTContext *nut, AVIOContext *bc, int stream_id){
     AVFormatContext *s= nut->avf;
-    ByteIOContext dyn_bc;
+    AVStream* st = s->streams[stream_id];
+    AVIOContext *dyn_bc;
     uint8_t *dyn_buf=NULL;
-    int count=0, dyn_size;
-
-    url_open_dyn_buf(&dyn_bc);
+    int count=0, dyn_size, i;
+    int ret = avio_open_dyn_buf(&dyn_bc);
+    if(ret < 0)
+        return ret;
+
+    for (i=0; ff_nut_dispositions[i].flag; ++i) {
+        if (st->disposition & ff_nut_dispositions[i].flag)
+            count += add_info(dyn_bc, "Disposition", ff_nut_dispositions[i].str);
+    }
+    dyn_size = avio_close_dyn_buf(dyn_bc, &dyn_buf);
 
-    if(s->title    [0]) count+= add_info(&dyn_bc, "Title"    , s->title);
-    if(s->author   [0]) count+= add_info(&dyn_bc, "Author"   , s->author);
-    if(s->copyright[0]) count+= add_info(&dyn_bc, "Copyright", s->copyright);
-    if(!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT))
-                        count+= add_info(&dyn_bc, "Encoder"  , LIBAVFORMAT_IDENT);
+    if (count) {
+        ff_put_v(bc, stream_id + 1); //stream_id_plus1
+        ff_put_v(bc, 0); //chapter_id
+        ff_put_v(bc, 0); //timestamp_start
+        ff_put_v(bc, 0); //length
 
-    put_v(bc, 0); //stream_if_plus1
-    put_v(bc, 0); //chapter_id
-    put_v(bc, 0); //timestamp_start
-    put_v(bc, 0); //length
+        ff_put_v(bc, count);
 
-    put_v(bc, count);
+        avio_write(bc, dyn_buf, dyn_size);
+    }
 
-    dyn_size= url_close_dyn_buf(&dyn_bc, &dyn_buf);
-    put_buffer(bc, dyn_buf, dyn_size);
     av_free(dyn_buf);
+    return count;
 }
 
-static void write_headers(NUTContext *nut, ByteIOContext *bc){
-    ByteIOContext dyn_bc;
-    int i;
+static int write_chapter(NUTContext *nut, AVIOContext *bc, int id)
+{
+    AVIOContext *dyn_bc;
+    uint8_t *dyn_buf     = NULL;
+    AVDictionaryEntry *t = NULL;
+    AVChapter *ch        = nut->avf->chapters[id];
+    int ret, dyn_size, count = 0;
+
+    ret = avio_open_dyn_buf(&dyn_bc);
+    if (ret < 0)
+        return ret;
+
+    ff_put_v(bc, 0);                                        // stream_id_plus1
+    put_s(bc, id + 1);                                      // chapter_id
+    put_tt(nut, nut->chapter[id].time_base, bc, ch->start); // chapter_start
+    ff_put_v(bc, ch->end - ch->start);                      // chapter_len
+
+    while ((t = av_dict_get(ch->metadata, "", t, AV_DICT_IGNORE_SUFFIX)))
+        count += add_info(dyn_bc, t->key, t->value);
 
-    url_open_dyn_buf(&dyn_bc);
-    write_mainheader(nut, &dyn_bc);
-    put_packet(nut, bc, &dyn_bc, 1, MAIN_STARTCODE);
+    ff_put_v(bc, count);
+
+    dyn_size = avio_close_dyn_buf(dyn_bc, &dyn_buf);
+    avio_write(bc, dyn_buf, dyn_size);
+    av_freep(&dyn_buf);
+    return 0;
+}
 
-    for (i=0; i < nut->avf->nb_streams; i++){
-        AVCodecContext *codec = nut->avf->streams[i]->codec;
+static int write_headers(AVFormatContext *avctx, AVIOContext *bc)
+{
+    NUTContext *nut = avctx->priv_data;
+    AVIOContext *dyn_bc;
+    int i, ret;
+
+    ff_metadata_conv_ctx(avctx, ff_nut_metadata_conv, NULL);
+
+    ret = avio_open_dyn_buf(&dyn_bc);
+    if (ret < 0)
+        return ret;
+    write_mainheader(nut, dyn_bc);
+    put_packet(nut, bc, dyn_bc, 1, MAIN_STARTCODE);
+
+    for (i = 0; i < nut->avf->nb_streams; i++) {
+        ret = avio_open_dyn_buf(&dyn_bc);
+        if (ret < 0)
+            return ret;
+        ret = write_streamheader(avctx, dyn_bc, nut->avf->streams[i], i);
+        if (ret < 0)
+            return ret;
+        put_packet(nut, bc, dyn_bc, 1, STREAM_STARTCODE);
+    }
 
-        url_open_dyn_buf(&dyn_bc);
-        write_streamheader(nut, &dyn_bc, codec, i);
-        put_packet(nut, bc, &dyn_bc, 1, STREAM_STARTCODE);
+    ret = avio_open_dyn_buf(&dyn_bc);
+    if (ret < 0)
+        return ret;
+    write_globalinfo(nut, dyn_bc);
+    put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
+
+    for (i = 0; i < nut->avf->nb_streams; i++) {
+        ret = avio_open_dyn_buf(&dyn_bc);
+        if (ret < 0)
+            return ret;
+        ret = write_streaminfo(nut, dyn_bc, i);
+        if (ret < 0)
+            return ret;
+        if (ret > 0)
+            put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
+        else
+            ffio_free_dyn_buf(&dyn_bc);
     }
 
-    url_open_dyn_buf(&dyn_bc);
-    write_globalinfo(nut, &dyn_bc);
-    put_packet(nut, bc, &dyn_bc, 1, INFO_STARTCODE);
+    for (i = 0; i < nut->avf->nb_chapters; i++) {
+        ret = avio_open_dyn_buf(&dyn_bc);
+        if (ret < 0)
+            return ret;
+        ret = write_chapter(nut, dyn_bc, i);
+        if (ret < 0) {
+            ffio_free_dyn_buf(&dyn_bc);
+            return ret;
+        }
+        put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
+    }
 
-    nut->last_syncpoint_pos= INT_MIN;
+    nut->last_syncpoint_pos = INT_MIN;
     nut->header_count++;
+    return 0;
 }
 
-static int write_header(AVFormatContext *s){
+static int nut_write_header(AVFormatContext *s)
+{
     NUTContext *nut = s->priv_data;
-    ByteIOContext *bc = &s->pb;
-    int i, j;
-
-    nut->avf= s;
+    AVIOContext *bc = s->pb;
+    int i, j, ret;
+
+    nut->avf = s;
+
+    nut->version = NUT_STABLE_VERSION + !!nut->flags;
+    if (nut->flags && s->strict_std_compliance > FF_COMPLIANCE_EXPERIMENTAL) {
+        av_log(s, AV_LOG_ERROR,
+               "The additional syncpoint modes require version %d, "
+               "that is currently not finalized, "
+               "please set -f_strict experimental in order to enable it.\n",
+               nut->version);
+        return AVERROR_EXPERIMENTAL;
+    }
 
-    nut->stream   = av_mallocz(sizeof(StreamContext)*s->nb_streams);
-    nut->time_base= av_mallocz(sizeof(AVRational   )*s->nb_streams);
+    nut->stream = av_mallocz(sizeof(StreamContext) * s->nb_streams);
+    if (s->nb_chapters)
+        nut->chapter = av_mallocz(sizeof(ChapterContext) * s->nb_chapters);
+    nut->time_base = av_mallocz(sizeof(AVRational) * (s->nb_streams +
+                                                      s->nb_chapters));
+    if (!nut->stream || (s->nb_chapters && !nut->chapter) || !nut->time_base) {
+        av_freep(&nut->stream);
+        av_freep(&nut->chapter);
+        av_freep(&nut->time_base);
+        return AVERROR(ENOMEM);
+    }
 
-    for(i=0; i<s->nb_streams; i++){
-        AVStream *st= s->streams[i];
+    for (i = 0; i < s->nb_streams; i++) {
+        AVStream *st = s->streams[i];
         int ssize;
         AVRational time_base;
-        ff_parse_specific_params(st->codec, &time_base.den, &ssize, &time_base.num);
+        ff_parse_specific_params(st, &time_base.den, &ssize,
+                                 &time_base.num);
 
-        av_set_pts_info(st, 64, time_base.num, time_base.den);
+        avpriv_set_pts_info(st, 64, time_base.num, time_base.den);
 
-        for(j=0; j<nut->time_base_count; j++){
-            if(!memcmp(&time_base, &nut->time_base[j], sizeof(AVRational))){
+        for (j = 0; j < nut->time_base_count; j++)
+            if (!memcmp(&time_base, &nut->time_base[j], sizeof(AVRational))) {
                 break;
             }
-        }
-        nut->time_base[j]= time_base;
-        nut->stream[i].time_base= &nut->time_base[j];
-        if(j==nut->time_base_count)
+        nut->time_base[j]        = time_base;
+        nut->stream[i].time_base = &nut->time_base[j];
+        if (j == nut->time_base_count)
             nut->time_base_count++;
 
-        if(av_q2d(time_base) >= 0.001)
+        if (INT64_C(1000) * time_base.num >= time_base.den)
             nut->stream[i].msb_pts_shift = 7;
         else
             nut->stream[i].msb_pts_shift = 14;
-        nut->stream[i].max_pts_distance= FFMAX(1/av_q2d(time_base), 1);
+        nut->stream[i].max_pts_distance =
+            FFMAX(time_base.den, time_base.num) / time_base.num;
     }
 
+    for (i = 0; i < s->nb_chapters; i++) {
+        AVChapter *ch = s->chapters[i];
+
+        for (j = 0; j < nut->time_base_count; j++)
+            if (!memcmp(&ch->time_base, &nut->time_base[j], sizeof(AVRational)))
+                break;
+
+        nut->time_base[j]         = ch->time_base;
+        nut->chapter[i].time_base = &nut->time_base[j];
+        if (j == nut->time_base_count)
+            nut->time_base_count++;
+    }
+
+    nut->max_distance = MAX_DISTANCE;
+    build_elision_headers(s);
     build_frame_code(s);
     assert(nut->frame_code['N'].flags == FLAG_INVALID);
 
-    put_buffer(bc, ID_STRING, strlen(ID_STRING));
-    put_byte(bc, 0);
+    avio_write(bc, ID_STRING, strlen(ID_STRING));
+    avio_w8(bc, 0);
 
-    write_headers(nut, bc);
+    if ((ret = write_headers(s, bc)) < 0)
+        return ret;
 
-    put_flush_packet(bc);
+    avio_flush(bc);
 
     //FIXME index
 
     return 0;
 }
 
-static int get_needed_flags(NUTContext *nut, StreamContext *nus, FrameCode *fc, AVPacket *pkt){
-    int flags= 0;
-
-    if(pkt->flags & PKT_FLAG_KEY                ) flags |= FLAG_KEY;
-    if(pkt->stream_index != fc->stream_id       ) flags |= FLAG_STREAM_ID;
-    if(pkt->size / fc->size_mul                 ) flags |= FLAG_SIZE_MSB;
-    if(pkt->pts - nus->last_pts != fc->pts_delta) flags |= FLAG_CODED_PTS;
-    if(pkt->size > 2*nut->max_distance          ) flags |= FLAG_CHECKSUM;
-    if(FFABS(pkt->pts - nus->last_pts)
-                         > nus->max_pts_distance) flags |= FLAG_CHECKSUM;
+static int get_needed_flags(NUTContext *nut, StreamContext *nus, FrameCode *fc,
+                            AVPacket *pkt)
+{
+    int flags = 0;
+
+    if (pkt->flags & AV_PKT_FLAG_KEY)
+        flags |= FLAG_KEY;
+    if (pkt->stream_index != fc->stream_id)
+        flags |= FLAG_STREAM_ID;
+    if (pkt->size / fc->size_mul)
+        flags |= FLAG_SIZE_MSB;
+    if (pkt->pts - nus->last_pts != fc->pts_delta)
+        flags |= FLAG_CODED_PTS;
+    if (pkt->size > 2 * nut->max_distance)
+        flags |= FLAG_CHECKSUM;
+    if (FFABS(pkt->pts - nus->last_pts) > nus->max_pts_distance)
+        flags |= FLAG_CHECKSUM;
+    if (pkt->size < nut->header_len[fc->header_idx] ||
+        (pkt->size > 4096 && fc->header_idx)        ||
+        memcmp(pkt->data, nut->header[fc->header_idx],
+               nut->header_len[fc->header_idx]))
+        flags |= FLAG_HEADER_IDX;
 
     return flags | (fc->flags & FLAG_CODED);
 }
 
-static int write_packet(AVFormatContext *s, AVPacket *pkt){
-    NUTContext *nut = s->priv_data;
-    StreamContext *nus= &nut->stream[pkt->stream_index];
-    ByteIOContext *bc = &s->pb, dyn_bc;
+static int find_best_header_idx(NUTContext *nut, AVPacket *pkt)
+{
+    int i;
+    int best_i   = 0;
+    int best_len = 0;
+
+    if (pkt->size > 4096)
+        return 0;
+
+    for (i = 1; i < nut->header_count; i++)
+        if (pkt->size >= nut->header_len[i]
+            && nut->header_len[i] > best_len
+            && !memcmp(pkt->data, nut->header[i], nut->header_len[i])) {
+            best_i   = i;
+            best_len = nut->header_len[i];
+        }
+    return best_i;
+}
+
+static int nut_write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    NUTContext *nut    = s->priv_data;
+    StreamContext *nus = &nut->stream[pkt->stream_index];
+    AVIOContext *bc    = s->pb, *dyn_bc;
     FrameCode *fc;
     int64_t coded_pts;
-    int best_length, frame_code, flags, needed_flags, i;
-    int key_frame = !!(pkt->flags & PKT_FLAG_KEY);
-    int store_sp=0;
+    int best_length, frame_code, flags, needed_flags, i, header_idx,
+        best_header_idx;
+    int key_frame = !!(pkt->flags & AV_PKT_FLAG_KEY);
+    int store_sp  = 0;
+    int ret;
+
+    if (pkt->pts < 0) {
+        av_log(s, AV_LOG_ERROR,
+               "Negative pts not supported stream %d, pts %"PRId64"\n",
+               pkt->stream_index, pkt->pts);
+        return AVERROR_INVALIDDATA;
+    }
 
-    if(1LL<<(20+3*nut->header_count) <= url_ftell(bc))
-        write_headers(nut, bc);
+    if (1LL << (20 + 3 * nut->header_count) <= avio_tell(bc))
+        write_headers(s, bc);
 
-    if(key_frame && !!(nus->last_flags & FLAG_KEY))
-        store_sp= 1;
+    if (key_frame && !(nus->last_flags & FLAG_KEY))
+        store_sp = 1;
 
-    if(pkt->size + 30/*FIXME check*/ + url_ftell(bc) >= nut->last_syncpoint_pos + nut->max_distance)
-        store_sp= 1;
+    if (pkt->size + 30 /*FIXME check*/ + avio_tell(bc) >=
+        nut->last_syncpoint_pos + nut->max_distance)
+        store_sp = 1;
 
-//FIXME ensure store_sp is 1 for the first thing
+//FIXME: Ensure store_sp is 1 in the first place.
 
-    if(store_sp){
-        syncpoint_t *sp, dummy= {.pos= INT64_MAX};
+    if (store_sp &&
+        (!(nut->flags & NUT_PIPE) || nut->last_syncpoint_pos == INT_MIN)) {
+        Syncpoint *sp, dummy = { .pos = INT64_MAX };
 
         ff_nut_reset_ts(nut, *nus->time_base, pkt->dts);
-        for(i=0; i<s->nb_streams; i++){
-            AVStream *st= s->streams[i];
-            int index= av_index_search_timestamp(st, pkt->dts, AVSEEK_FLAG_BACKWARD);
-            if(index<0) dummy.pos=0;
-            else        dummy.pos= FFMIN(dummy.pos, st->index_entries[index].pos);
+        for (i = 0; i < s->nb_streams; i++) {
+            AVStream *st   = s->streams[i];
+            int64_t dts_tb = av_rescale_rnd(pkt->dts,
+                nus->time_base->num * (int64_t)nut->stream[i].time_base->den,
+                nus->time_base->den * (int64_t)nut->stream[i].time_base->num,
+                AV_ROUND_DOWN);
+            int index = av_index_search_timestamp(st, dts_tb,
+                                                  AVSEEK_FLAG_BACKWARD);
+            if (index >= 0)
+                dummy.pos = FFMIN(dummy.pos, st->index_entries[index].pos);
         }
-        sp= av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, NULL);
-
-        nut->last_syncpoint_pos= url_ftell(bc);
-        url_open_dyn_buf(&dyn_bc);
-        put_t(nut, nus, &dyn_bc, pkt->dts);
-        put_v(&dyn_bc, sp ? (nut->last_syncpoint_pos - sp->pos)>>4 : 0);
-        put_packet(nut, bc, &dyn_bc, 1, SYNCPOINT_STARTCODE);
+        if (dummy.pos == INT64_MAX)
+            dummy.pos = 0;
+        sp = av_tree_find(nut->syncpoints, &dummy, (void *)ff_nut_sp_pos_cmp,
+                          NULL);
+
+        nut->last_syncpoint_pos = avio_tell(bc);
+        ret                     = avio_open_dyn_buf(&dyn_bc);
+        if (ret < 0)
+            return ret;
+        put_tt(nut, nus->time_base, dyn_bc, pkt->dts);
+        ff_put_v(dyn_bc, sp ? (nut->last_syncpoint_pos - sp->pos) >> 4 : 0);
+
+        if (nut->flags & NUT_BROADCAST) {
+            put_tt(nut, nus->time_base, dyn_bc,
+                   av_rescale_q(av_gettime(), AV_TIME_BASE_Q, *nus->time_base));
+        }
+        put_packet(nut, bc, dyn_bc, 1, SYNCPOINT_STARTCODE);
 
-        ff_nut_add_sp(nut, nut->last_syncpoint_pos, 0/*unused*/, pkt->dts);
+        if ((ret = ff_nut_add_sp(nut, nut->last_syncpoint_pos, 0 /*unused*/, pkt->dts)) < 0)
+            return ret;
     }
     assert(nus->last_pts != AV_NOPTS_VALUE);
 
-    coded_pts = pkt->pts & ((1<<nus->msb_pts_shift)-1);
-    if(ff_lsb2full(nus, coded_pts) != pkt->pts)
-        coded_pts= pkt->pts + (1<<nus->msb_pts_shift);
+    coded_pts = pkt->pts & ((1 << nus->msb_pts_shift) - 1);
+    if (ff_lsb2full(nus, coded_pts) != pkt->pts)
+        coded_pts = pkt->pts + (1 << nus->msb_pts_shift);
+
+    best_header_idx = find_best_header_idx(nut, pkt);
 
-    best_length=INT_MAX;
-    frame_code= -1;
-    for(i=0; i<256; i++){
-        int length= 0;
-        FrameCode *fc= &nut->frame_code[i];
-        int flags= fc->flags;
+    best_length = INT_MAX;
+    frame_code  = -1;
+    for (i = 0; i < 256; i++) {
+        int length    = 0;
+        FrameCode *fc = &nut->frame_code[i];
+        int flags     = fc->flags;
 
-        if(flags & FLAG_INVALID)
+        if (flags & FLAG_INVALID)
             continue;
-        needed_flags= get_needed_flags(nut, nus, fc, pkt);
+        needed_flags = get_needed_flags(nut, nus, fc, pkt);
 
-        if(flags & FLAG_CODED){
+        if (flags & FLAG_CODED) {
             length++;
-            flags |=  needed_flags;
+            flags = needed_flags;
         }
 
-        if((flags & needed_flags) != needed_flags)
+        if ((flags & needed_flags) != needed_flags)
             continue;
 
-        if((flags ^ needed_flags) & FLAG_KEY)
+        if ((flags ^ needed_flags) & FLAG_KEY)
             continue;
 
-        if(flags & FLAG_STREAM_ID)
-            length+= get_length(pkt->stream_index);
+        if (flags & FLAG_STREAM_ID)
+            length += ff_get_v_length(pkt->stream_index);
 
-        if(pkt->size % fc->size_mul != fc->size_lsb)
+        if (pkt->size % fc->size_mul != fc->size_lsb)
             continue;
-        if(flags & FLAG_SIZE_MSB)
-            length += get_length(pkt->size / fc->size_mul);
+        if (flags & FLAG_SIZE_MSB)
+            length += ff_get_v_length(pkt->size / fc->size_mul);
 
-        if(flags & FLAG_CHECKSUM)
-            length+=4;
+        if (flags & FLAG_CHECKSUM)
+            length += 4;
 
-        if(flags & FLAG_CODED_PTS)
-            length += get_length(coded_pts);
+        if (flags & FLAG_CODED_PTS)
+            length += ff_get_v_length(coded_pts);
 
-        length*=4;
-        length+= !(flags & FLAG_CODED_PTS);
-        length+= !(flags & FLAG_CHECKSUM);
+        if ((flags & FLAG_CODED)
+            && nut->header_len[best_header_idx] >
+            nut->header_len[fc->header_idx] + 1) {
+            flags |= FLAG_HEADER_IDX;
+        }
 
-        if(length < best_length){
-            best_length= length;
-            frame_code=i;
+        if (flags & FLAG_HEADER_IDX) {
+            length += 1 - nut->header_len[best_header_idx];
+        } else {
+            length -= nut->header_len[fc->header_idx];
+        }
+
+        length *= 4;
+        length += !(flags & FLAG_CODED_PTS);
+        length += !(flags & FLAG_CHECKSUM);
+
+        if (length < best_length) {
+            best_length = length;
+            frame_code  = i;
         }
     }
-    assert(frame_code != -1);
-    fc= &nut->frame_code[frame_code];
-    flags= fc->flags;
-    needed_flags= get_needed_flags(nut, nus, fc, pkt);
-
-    init_checksum(bc, av_crc04C11DB7_update, 0);
-    put_byte(bc, frame_code);
-    if(flags & FLAG_CODED){
-        put_v(bc, (flags^needed_flags) & ~(FLAG_CODED));
-        flags = needed_flags;
-    }
-    if(flags & FLAG_STREAM_ID)  put_v(bc, pkt->stream_index);
-    if(flags & FLAG_CODED_PTS)  put_v(bc, coded_pts);
-    if(flags & FLAG_SIZE_MSB)   put_v(bc, pkt->size / fc->size_mul);
 
-    if(flags & FLAG_CHECKSUM)   put_le32(bc, get_checksum(bc));
-    else                        get_checksum(bc);
+    if (frame_code < 0)
+        return AVERROR_BUG;
 
-    put_buffer(bc, pkt->data, pkt->size);
-    nus->last_flags= flags;
+    fc           = &nut->frame_code[frame_code];
+    flags        = fc->flags;
+    needed_flags = get_needed_flags(nut, nus, fc, pkt);
+    header_idx   = fc->header_idx;
+
+    ffio_init_checksum(bc, ff_crc04C11DB7_update, 0);
+    avio_w8(bc, frame_code);
+    if (flags & FLAG_CODED) {
+        ff_put_v(bc, (flags ^ needed_flags) & ~(FLAG_CODED));
+        flags = needed_flags;
+    }
+    if (flags & FLAG_STREAM_ID)
+        ff_put_v(bc, pkt->stream_index);
+    if (flags & FLAG_CODED_PTS)
+        ff_put_v(bc, coded_pts);
+    if (flags & FLAG_SIZE_MSB)
+        ff_put_v(bc, pkt->size / fc->size_mul);
+    if (flags & FLAG_HEADER_IDX)
+        ff_put_v(bc, header_idx = best_header_idx);
+
+    if (flags & FLAG_CHECKSUM)
+        avio_wl32(bc, ffio_get_checksum(bc));
+    else
+        ffio_get_checksum(bc);
+
+    avio_write(bc, pkt->data + nut->header_len[header_idx],
+               pkt->size - nut->header_len[header_idx]);
+    nus->last_flags = flags;
+    nus->last_pts   = pkt->pts;
 
     //FIXME just store one per syncpoint
-    if(flags & FLAG_KEY)
+    if (flags & FLAG_KEY && !(nut->flags & NUT_PIPE))
         av_add_index_entry(
             s->streams[pkt->stream_index],
             nut->last_syncpoint_pos,
@@ -564,34 +950,52 @@ static int write_packet(AVFormatContext *s, AVPacket *pkt){
     return 0;
 }
 
-static int write_trailer(AVFormatContext *s){
-    NUTContext *nut= s->priv_data;
-    ByteIOContext *bc= &s->pb;
+static int nut_write_trailer(AVFormatContext *s)
+{
+    NUTContext *nut = s->priv_data;
+    AVIOContext *bc = s->pb;
 
-    while(nut->header_count<3)
-        write_headers(nut, bc);
-    put_flush_packet(bc);
+    while (nut->header_count < 3)
+        write_headers(s, bc);
+
+    ff_nut_free_sp(nut);
+    av_freep(&nut->stream);
+    av_freep(&nut->chapter);
+    av_freep(&nut->time_base);
 
     return 0;
 }
 
-AVOutputFormat nut_muxer = {
-    "nut",
-    "nut format",
-    "video/x-nut",
-    "nut",
-    sizeof(NUTContext),
-#ifdef CONFIG_LIBVORBIS
-    CODEC_ID_VORBIS,
-#elif defined(CONFIG_LIBMP3LAME)
-    CODEC_ID_MP3,
-#else
-    CODEC_ID_MP2, /* AC3 needs liba52 decoder */
-#endif
-    CODEC_ID_MPEG4,
-    write_header,
-    write_packet,
-    write_trailer,
-    .flags = AVFMT_GLOBALHEADER,
-    .codec_tag= (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},
+#define OFFSET(x) offsetof(NUTContext, x)
+#define E AV_OPT_FLAG_ENCODING_PARAM
+static const AVOption options[] = {
+    { "syncpoints",  "NUT syncpoint behaviour",                         OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0},             INT_MIN, INT_MAX, E, "syncpoints" },
+    { "default",     "",                                                0,             AV_OPT_TYPE_CONST, {.i64 = 0},             INT_MIN, INT_MAX, E, "syncpoints" },
+    { "none",        "Disable syncpoints, low overhead and unseekable", 0,             AV_OPT_TYPE_CONST, {.i64 = NUT_PIPE},      INT_MIN, INT_MAX, E, "syncpoints" },
+    { "timestamped", "Extend syncpoints with a wallclock timestamp",    0,             AV_OPT_TYPE_CONST, {.i64 = NUT_BROADCAST}, INT_MIN, INT_MAX, E, "syncpoints" },
+    { NULL },
+};
+
+static const AVClass class = {
+    .class_name = "nutenc",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+AVOutputFormat ff_nut_muxer = {
+    .name           = "nut",
+    .long_name      = NULL_IF_CONFIG_SMALL("NUT"),
+    .mime_type      = "video/x-nut",
+    .extensions     = "nut",
+    .priv_data_size = sizeof(NUTContext),
+    .audio_codec    = CONFIG_LIBVORBIS ? AV_CODEC_ID_VORBIS :
+                      CONFIG_LIBMP3LAME ? AV_CODEC_ID_MP3 : AV_CODEC_ID_MP2,
+    .video_codec    = AV_CODEC_ID_MPEG4,
+    .write_header   = nut_write_header,
+    .write_packet   = nut_write_packet,
+    .write_trailer  = nut_write_trailer,
+    .flags          = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
+    .codec_tag      = ff_nut_codec_tags,
+    .priv_class     = &class,
 };