vmd: Split audio and video decoder
authorNidhi Makhijani <nidhimj22@gmail.com>
Mon, 7 Jul 2014 04:11:04 +0000 (09:41 +0530)
committerDiego Biurrun <diego@biurrun.de>
Mon, 7 Jul 2014 14:45:00 +0000 (07:45 -0700)
Signed-off-by: Diego Biurrun <diego@biurrun.de>
libavcodec/Makefile
libavcodec/vmdaudio.c [new file with mode: 0644]
libavcodec/vmdav.c [deleted file]
libavcodec/vmdvideo.c [new file with mode: 0644]

index d3d531e..fcd35cd 100644 (file)
@@ -390,8 +390,8 @@ OBJS-$(CONFIG_VBLE_DECODER)            += vble.o
 OBJS-$(CONFIG_VC1_DECODER)             += vc1dec.o vc1.o vc1data.o vc1dsp.o \
                                           msmpeg4dec.o msmpeg4.o msmpeg4data.o
 OBJS-$(CONFIG_VCR1_DECODER)            += vcr1.o
 OBJS-$(CONFIG_VC1_DECODER)             += vc1dec.o vc1.o vc1data.o vc1dsp.o \
                                           msmpeg4dec.o msmpeg4.o msmpeg4data.o
 OBJS-$(CONFIG_VCR1_DECODER)            += vcr1.o
-OBJS-$(CONFIG_VMDAUDIO_DECODER)        += vmdav.o
-OBJS-$(CONFIG_VMDVIDEO_DECODER)        += vmdav.o
+OBJS-$(CONFIG_VMDAUDIO_DECODER)        += vmdaudio.o
+OBJS-$(CONFIG_VMDVIDEO_DECODER)        += vmdvideo.o
 OBJS-$(CONFIG_VMNC_DECODER)            += vmnc.o
 OBJS-$(CONFIG_VORBIS_DECODER)          += vorbisdec.o vorbisdsp.o vorbis.o \
                                           vorbis_data.o xiph.o
 OBJS-$(CONFIG_VMNC_DECODER)            += vmnc.o
 OBJS-$(CONFIG_VORBIS_DECODER)          += vorbisdec.o vorbisdsp.o vorbis.o \
                                           vorbis_data.o xiph.o
diff --git a/libavcodec/vmdaudio.c b/libavcodec/vmdaudio.c
new file mode 100644 (file)
index 0000000..66c5865
--- /dev/null
@@ -0,0 +1,233 @@
+/*
+ * Sierra VMD audio decoder
+ *
+ * This file is part of Libav.
+ *
+ * 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.
+ *
+ * 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * Sierra VMD audio decoder
+ * by Vladimir "VAG" Gneushev (vagsoft at mail.ru)
+ * for more information on the Sierra VMD format, visit:
+ *   http://www.pcisys.net/~melanson/codecs/
+ *
+ * The audio decoder, expects each encoded data
+ * chunk to be prepended with the appropriate 16-byte frame information
+ * record from the VMD file. It does not require the 0x330-byte VMD file
+ * header, but it does need the audio setup parameters passed in through
+ * normal libavcodec API means.
+ */
+
+#include <string.h>
+
+#include "libavutil/channel_layout.h"
+#include "libavutil/common.h"
+#include "libavutil/intreadwrite.h"
+
+#include "avcodec.h"
+#include "internal.h"
+
+#define BLOCK_TYPE_AUDIO    1
+#define BLOCK_TYPE_INITIAL  2
+#define BLOCK_TYPE_SILENCE  3
+
+typedef struct VmdAudioContext {
+    int out_bps;
+    int chunk_size;
+} VmdAudioContext;
+
+static const uint16_t vmdaudio_table[128] = {
+    0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
+    0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
+    0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
+    0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230,
+    0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280,
+    0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0,
+    0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320,
+    0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370,
+    0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0,
+    0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480,
+    0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700,
+    0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00,
+    0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000
+};
+
+static av_cold int vmdaudio_decode_init(AVCodecContext *avctx)
+{
+    VmdAudioContext *s = avctx->priv_data;
+
+    if (avctx->channels < 1 || avctx->channels > 2) {
+        av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
+        return AVERROR(EINVAL);
+    }
+    if (avctx->block_align < 1) {
+        av_log(avctx, AV_LOG_ERROR, "invalid block align\n");
+        return AVERROR(EINVAL);
+    }
+
+    avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO :
+                                                   AV_CH_LAYOUT_STEREO;
+
+    if (avctx->bits_per_coded_sample == 16)
+        avctx->sample_fmt = AV_SAMPLE_FMT_S16;
+    else
+        avctx->sample_fmt = AV_SAMPLE_FMT_U8;
+    s->out_bps = av_get_bytes_per_sample(avctx->sample_fmt);
+
+    s->chunk_size = avctx->block_align + avctx->channels * (s->out_bps == 2);
+
+    av_log(avctx, AV_LOG_DEBUG, "%d channels, %d bits/sample, "
+           "block align = %d, sample rate = %d\n",
+           avctx->channels, avctx->bits_per_coded_sample, avctx->block_align,
+           avctx->sample_rate);
+
+    return 0;
+}
+
+static void decode_audio_s16(int16_t *out, const uint8_t *buf, int buf_size,
+                             int channels)
+{
+    int ch;
+    const uint8_t *buf_end = buf + buf_size;
+    int predictor[2];
+    int st = channels - 1;
+
+    /* decode initial raw sample */
+    for (ch = 0; ch < channels; ch++) {
+        predictor[ch] = (int16_t)AV_RL16(buf);
+        buf += 2;
+        *out++ = predictor[ch];
+    }
+
+    /* decode DPCM samples */
+    ch = 0;
+    while (buf < buf_end) {
+        uint8_t b = *buf++;
+        if (b & 0x80)
+            predictor[ch] -= vmdaudio_table[b & 0x7F];
+        else
+            predictor[ch] += vmdaudio_table[b];
+        predictor[ch] = av_clip_int16(predictor[ch]);
+        *out++ = predictor[ch];
+        ch ^= st;
+    }
+}
+
+static int vmdaudio_decode_frame(AVCodecContext *avctx, void *data,
+                                 int *got_frame_ptr, AVPacket *avpkt)
+{
+    AVFrame *frame     = data;
+    const uint8_t *buf = avpkt->data;
+    const uint8_t *buf_end;
+    int buf_size = avpkt->size;
+    VmdAudioContext *s = avctx->priv_data;
+    int block_type, silent_chunks, audio_chunks;
+    int ret;
+    uint8_t *output_samples_u8;
+    int16_t *output_samples_s16;
+
+    if (buf_size < 16) {
+        av_log(avctx, AV_LOG_WARNING, "skipping small junk packet\n");
+        *got_frame_ptr = 0;
+        return buf_size;
+    }
+
+    block_type = buf[6];
+    if (block_type < BLOCK_TYPE_AUDIO || block_type > BLOCK_TYPE_SILENCE) {
+        av_log(avctx, AV_LOG_ERROR, "unknown block type: %d\n", block_type);
+        return AVERROR(EINVAL);
+    }
+    buf      += 16;
+    buf_size -= 16;
+
+    /* get number of silent chunks */
+    silent_chunks = 0;
+    if (block_type == BLOCK_TYPE_INITIAL) {
+        uint32_t flags;
+        if (buf_size < 4) {
+            av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
+            return AVERROR(EINVAL);
+        }
+        flags         = AV_RB32(buf);
+        silent_chunks = av_popcount(flags);
+        buf      += 4;
+        buf_size -= 4;
+    } else if (block_type == BLOCK_TYPE_SILENCE) {
+        silent_chunks = 1;
+        buf_size = 0; // should already be zero but set it just to be sure
+    }
+
+    /* ensure output buffer is large enough */
+    audio_chunks = buf_size / s->chunk_size;
+
+    /* drop incomplete chunks */
+    buf_size     = audio_chunks * s->chunk_size;
+
+    /* get output buffer */
+    frame->nb_samples = ((silent_chunks + audio_chunks) * avctx->block_align) /
+                        avctx->channels;
+    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return ret;
+    }
+    output_samples_u8  =            frame->data[0];
+    output_samples_s16 = (int16_t *)frame->data[0];
+
+    /* decode silent chunks */
+    if (silent_chunks > 0) {
+        int silent_size = FFMIN(avctx->block_align * silent_chunks,
+                                frame->nb_samples * avctx->channels);
+        if (s->out_bps == 2) {
+            memset(output_samples_s16, 0x00, silent_size * 2);
+            output_samples_s16 += silent_size;
+        } else {
+            memset(output_samples_u8,  0x80, silent_size);
+            output_samples_u8 += silent_size;
+        }
+    }
+
+    /* decode audio chunks */
+    if (audio_chunks > 0) {
+        buf_end = buf + (buf_size & ~(avctx->channels > 1));
+        while (buf + s->chunk_size <= buf_end) {
+            if (s->out_bps == 2) {
+                decode_audio_s16(output_samples_s16, buf, s->chunk_size,
+                                 avctx->channels);
+                output_samples_s16 += avctx->block_align;
+            } else {
+                memcpy(output_samples_u8, buf, s->chunk_size);
+                output_samples_u8  += avctx->block_align;
+            }
+            buf += s->chunk_size;
+        }
+    }
+
+    *got_frame_ptr = 1;
+
+    return avpkt->size;
+}
+
+AVCodec ff_vmdaudio_decoder = {
+    .name           = "vmdaudio",
+    .long_name      = NULL_IF_CONFIG_SMALL("Sierra VMD audio"),
+    .type           = AVMEDIA_TYPE_AUDIO,
+    .id             = AV_CODEC_ID_VMDAUDIO,
+    .priv_data_size = sizeof(VmdAudioContext),
+    .init           = vmdaudio_decode_init,
+    .decode         = vmdaudio_decode_frame,
+    .capabilities   = CODEC_CAP_DR1,
+};
diff --git a/libavcodec/vmdav.c b/libavcodec/vmdav.c
deleted file mode 100644 (file)
index a1e39c0..0000000
+++ /dev/null
@@ -1,681 +0,0 @@
-/*
- * Sierra VMD Audio & Video Decoders
- * Copyright (C) 2004 the ffmpeg project
- *
- * This file is part of Libav.
- *
- * 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.
- *
- * 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 Libav; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-/**
- * @file
- * Sierra VMD audio & video decoders
- * by Vladimir "VAG" Gneushev (vagsoft at mail.ru)
- * for more information on the Sierra VMD format, visit:
- *   http://www.pcisys.net/~melanson/codecs/
- *
- * The video decoder outputs PAL8 colorspace data. The decoder expects
- * a 0x330-byte VMD file header to be transmitted via extradata during
- * codec initialization. Each encoded frame that is sent to this decoder
- * is expected to be prepended with the appropriate 16-byte frame
- * information record from the VMD file.
- *
- * The audio decoder, like the video decoder, expects each encoded data
- * chunk to be prepended with the appropriate 16-byte frame information
- * record from the VMD file. It does not require the 0x330-byte VMD file
- * header, but it does need the audio setup parameters passed in through
- * normal libavcodec API means.
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include "libavutil/channel_layout.h"
-#include "libavutil/common.h"
-#include "libavutil/intreadwrite.h"
-#include "avcodec.h"
-#include "internal.h"
-#include "bytestream.h"
-
-#define VMD_HEADER_SIZE 0x330
-#define PALETTE_COUNT 256
-
-/*
- * Video Decoder
- */
-
-typedef struct VmdVideoContext {
-
-    AVCodecContext *avctx;
-    AVFrame *prev_frame;
-
-    const unsigned char *buf;
-    int size;
-
-    unsigned char palette[PALETTE_COUNT * 4];
-    unsigned char *unpack_buffer;
-    int unpack_buffer_size;
-
-    int x_off, y_off;
-} VmdVideoContext;
-
-#define QUEUE_SIZE 0x1000
-#define QUEUE_MASK 0x0FFF
-
-static void lz_unpack(const unsigned char *src, int src_len,
-                      unsigned char *dest, int dest_len)
-{
-    unsigned char *d;
-    unsigned char *d_end;
-    unsigned char queue[QUEUE_SIZE];
-    unsigned int qpos;
-    unsigned int dataleft;
-    unsigned int chainofs;
-    unsigned int chainlen;
-    unsigned int speclen;
-    unsigned char tag;
-    unsigned int i, j;
-    GetByteContext gb;
-
-    bytestream2_init(&gb, src, src_len);
-    d = dest;
-    d_end = d + dest_len;
-    dataleft = bytestream2_get_le32(&gb);
-    memset(queue, 0x20, QUEUE_SIZE);
-    if (bytestream2_get_bytes_left(&gb) < 4)
-        return;
-    if (bytestream2_peek_le32(&gb) == 0x56781234) {
-        bytestream2_get_le32(&gb);
-        qpos = 0x111;
-        speclen = 0xF + 3;
-    } else {
-        qpos = 0xFEE;
-        speclen = 100;  /* no speclen */
-    }
-
-    while (dataleft > 0 && bytestream2_get_bytes_left(&gb) > 0) {
-        tag = bytestream2_get_byteu(&gb);
-        if ((tag == 0xFF) && (dataleft > 8)) {
-            if (d + 8 > d_end || bytestream2_get_bytes_left(&gb) < 8)
-                return;
-            for (i = 0; i < 8; i++) {
-                queue[qpos++] = *d++ = bytestream2_get_byteu(&gb);
-                qpos &= QUEUE_MASK;
-            }
-            dataleft -= 8;
-        } else {
-            for (i = 0; i < 8; i++) {
-                if (dataleft == 0)
-                    break;
-                if (tag & 0x01) {
-                    if (d + 1 > d_end || bytestream2_get_bytes_left(&gb) < 1)
-                        return;
-                    queue[qpos++] = *d++ = bytestream2_get_byte(&gb);
-                    qpos &= QUEUE_MASK;
-                    dataleft--;
-                } else {
-                    chainofs = bytestream2_get_byte(&gb);
-                    chainofs |= ((bytestream2_peek_byte(&gb) & 0xF0) << 4);
-                    chainlen = (bytestream2_get_byte(&gb) & 0x0F) + 3;
-                    if (chainlen == speclen) {
-                        chainlen = bytestream2_get_byte(&gb) + 0xF + 3;
-                    }
-                    if (d + chainlen > d_end)
-                        return;
-                    for (j = 0; j < chainlen; j++) {
-                        *d = queue[chainofs++ & QUEUE_MASK];
-                        queue[qpos++] = *d++;
-                        qpos &= QUEUE_MASK;
-                    }
-                    dataleft -= chainlen;
-                }
-                tag >>= 1;
-            }
-        }
-    }
-}
-
-static int rle_unpack(const unsigned char *src, unsigned char *dest,
-    int src_count, int src_size, int dest_len)
-{
-    unsigned char *pd;
-    int i, l, used = 0;
-    unsigned char *dest_end = dest + dest_len;
-    GetByteContext gb;
-    uint16_t run_val;
-
-    bytestream2_init(&gb, src, src_size);
-    pd = dest;
-    if (src_count & 1) {
-        if (bytestream2_get_bytes_left(&gb) < 1)
-            return 0;
-        *pd++ = bytestream2_get_byteu(&gb);
-        used++;
-    }
-
-    do {
-        if (bytestream2_get_bytes_left(&gb) < 1)
-            break;
-        l = bytestream2_get_byteu(&gb);
-        if (l & 0x80) {
-            l = (l & 0x7F) * 2;
-            if (pd + l > dest_end || bytestream2_get_bytes_left(&gb) < l)
-                return bytestream2_tell(&gb);
-            bytestream2_get_buffer(&gb, pd, l);
-            pd += l;
-        } else {
-            if (pd + l > dest_end || bytestream2_get_bytes_left(&gb) < 2)
-                return bytestream2_tell(&gb);
-            run_val = bytestream2_get_ne16(&gb);
-            for (i = 0; i < l; i++) {
-                AV_WN16(pd, run_val);
-                pd += 2;
-            }
-            l *= 2;
-        }
-        used += l;
-    } while (used < src_count);
-
-    return bytestream2_tell(&gb);
-}
-
-static int vmd_decode(VmdVideoContext *s, AVFrame *frame)
-{
-    int i;
-    unsigned int *palette32;
-    unsigned char r, g, b;
-
-    GetByteContext gb;
-
-    unsigned char meth;
-    unsigned char *dp;   /* pointer to current frame */
-    unsigned char *pp;   /* pointer to previous frame */
-    unsigned char len;
-    int ofs;
-
-    int frame_x, frame_y;
-    int frame_width, frame_height;
-
-    frame_x = AV_RL16(&s->buf[6]);
-    frame_y = AV_RL16(&s->buf[8]);
-    frame_width = AV_RL16(&s->buf[10]) - frame_x + 1;
-    frame_height = AV_RL16(&s->buf[12]) - frame_y + 1;
-    if (frame_x < 0 || frame_width < 0 ||
-        frame_x >= s->avctx->width ||
-        frame_width > s->avctx->width ||
-        frame_x + frame_width > s->avctx->width) {
-        av_log(s->avctx, AV_LOG_ERROR,
-               "Invalid horizontal range %d-%d\n",
-               frame_x, frame_width);
-        return AVERROR_INVALIDDATA;
-    }
-    if (frame_y < 0 || frame_height < 0 ||
-        frame_y >= s->avctx->height ||
-        frame_height > s->avctx->height ||
-        frame_y + frame_height > s->avctx->height) {
-        av_log(s->avctx, AV_LOG_ERROR,
-               "Invalid vertical range %d-%d\n",
-               frame_x, frame_width);
-        return AVERROR_INVALIDDATA;
-    }
-
-    if ((frame_width == s->avctx->width && frame_height == s->avctx->height) &&
-        (frame_x || frame_y)) {
-
-        s->x_off = frame_x;
-        s->y_off = frame_y;
-    }
-    frame_x -= s->x_off;
-    frame_y -= s->y_off;
-
-    /* if only a certain region will be updated, copy the entire previous
-     * frame before the decode */
-    if (s->prev_frame->data[0] &&
-        (frame_x || frame_y || (frame_width != s->avctx->width) ||
-        (frame_height != s->avctx->height))) {
-
-        memcpy(frame->data[0], s->prev_frame->data[0],
-            s->avctx->height * frame->linesize[0]);
-    }
-
-    /* check if there is a new palette */
-    bytestream2_init(&gb, s->buf + 16, s->size - 16);
-    if (s->buf[15] & 0x02) {
-        bytestream2_skip(&gb, 2);
-        palette32 = (unsigned int *)s->palette;
-        if (bytestream2_get_bytes_left(&gb) >= PALETTE_COUNT * 3) {
-            for (i = 0; i < PALETTE_COUNT; i++) {
-                r = bytestream2_get_byteu(&gb) * 4;
-                g = bytestream2_get_byteu(&gb) * 4;
-                b = bytestream2_get_byteu(&gb) * 4;
-                palette32[i] = (r << 16) | (g << 8) | (b);
-            }
-        } else {
-            av_log(s->avctx, AV_LOG_ERROR, "Incomplete palette\n");
-            return AVERROR_INVALIDDATA;
-        }
-        s->size -= PALETTE_COUNT * 3 + 2;
-    }
-
-    if (!s->size)
-        return 0;
-
-    /* originally UnpackFrame in VAG's code */
-    if (bytestream2_get_bytes_left(&gb) < 1)
-        return AVERROR_INVALIDDATA;
-    meth = bytestream2_get_byteu(&gb);
-    if (meth & 0x80) {
-        if (!s->unpack_buffer_size) {
-            av_log(s->avctx, AV_LOG_ERROR,
-                   "Trying to unpack LZ-compressed frame with no LZ buffer\n");
-            return AVERROR_INVALIDDATA;
-        }
-        lz_unpack(gb.buffer, bytestream2_get_bytes_left(&gb),
-                  s->unpack_buffer, s->unpack_buffer_size);
-        meth &= 0x7F;
-        bytestream2_init(&gb, s->unpack_buffer, s->unpack_buffer_size);
-    }
-
-    dp = &frame->data[0][frame_y * frame->linesize[0] + frame_x];
-    pp = &s->prev_frame->data[0][frame_y * s->prev_frame->linesize[0] + frame_x];
-    switch (meth) {
-    case 1:
-        for (i = 0; i < frame_height; i++) {
-            ofs = 0;
-            do {
-                len = bytestream2_get_byte(&gb);
-                if (len & 0x80) {
-                    len = (len & 0x7F) + 1;
-                    if (ofs + len > frame_width ||
-                        bytestream2_get_bytes_left(&gb) < len)
-                        return AVERROR_INVALIDDATA;
-                    bytestream2_get_buffer(&gb, &dp[ofs], len);
-                    ofs += len;
-                } else {
-                    /* interframe pixel copy */
-                    if (ofs + len + 1 > frame_width || !s->prev_frame->data[0])
-                        return AVERROR_INVALIDDATA;
-                    memcpy(&dp[ofs], &pp[ofs], len + 1);
-                    ofs += len + 1;
-                }
-            } while (ofs < frame_width);
-            if (ofs > frame_width) {
-                av_log(s->avctx, AV_LOG_ERROR,
-                       "VMD video: offset > width (%d > %d)\n",
-                       ofs, frame_width);
-                return AVERROR_INVALIDDATA;
-            }
-            dp += frame->linesize[0];
-            pp += s->prev_frame->linesize[0];
-        }
-        break;
-
-    case 2:
-        for (i = 0; i < frame_height; i++) {
-            bytestream2_get_buffer(&gb, dp, frame_width);
-            dp += frame->linesize[0];
-            pp += s->prev_frame->linesize[0];
-        }
-        break;
-
-    case 3:
-        for (i = 0; i < frame_height; i++) {
-            ofs = 0;
-            do {
-                len = bytestream2_get_byte(&gb);
-                if (len & 0x80) {
-                    len = (len & 0x7F) + 1;
-                    if (bytestream2_peek_byte(&gb) == 0xFF) {
-                        int slen = len;
-                        bytestream2_get_byte(&gb);
-                        len = rle_unpack(gb.buffer, &dp[ofs],
-                                         len, bytestream2_get_bytes_left(&gb),
-                                         frame_width - ofs);
-                        ofs += slen;
-                        bytestream2_skip(&gb, len);
-                    } else {
-                        bytestream2_get_buffer(&gb, &dp[ofs], len);
-                        ofs += len;
-                    }
-                } else {
-                    /* interframe pixel copy */
-                    if (ofs + len + 1 > frame_width || !s->prev_frame->data[0])
-                        return AVERROR_INVALIDDATA;
-                    memcpy(&dp[ofs], &pp[ofs], len + 1);
-                    ofs += len + 1;
-                }
-            } while (ofs < frame_width);
-            if (ofs > frame_width) {
-                av_log(s->avctx, AV_LOG_ERROR,
-                       "VMD video: offset > width (%d > %d)\n",
-                       ofs, frame_width);
-                return AVERROR_INVALIDDATA;
-            }
-            dp += frame->linesize[0];
-            pp += s->prev_frame->linesize[0];
-        }
-        break;
-    }
-    return 0;
-}
-
-static av_cold int vmdvideo_decode_end(AVCodecContext *avctx)
-{
-    VmdVideoContext *s = avctx->priv_data;
-
-    av_frame_free(&s->prev_frame);
-    av_free(s->unpack_buffer);
-
-    return 0;
-}
-
-static av_cold int vmdvideo_decode_init(AVCodecContext *avctx)
-{
-    VmdVideoContext *s = avctx->priv_data;
-    int i;
-    unsigned int *palette32;
-    int palette_index = 0;
-    unsigned char r, g, b;
-    unsigned char *vmd_header;
-    unsigned char *raw_palette;
-
-    s->avctx = avctx;
-    avctx->pix_fmt = AV_PIX_FMT_PAL8;
-
-    /* make sure the VMD header made it */
-    if (s->avctx->extradata_size != VMD_HEADER_SIZE) {
-        av_log(s->avctx, AV_LOG_ERROR, "VMD video: expected extradata size of %d\n",
-            VMD_HEADER_SIZE);
-        return -1;
-    }
-    vmd_header = (unsigned char *)avctx->extradata;
-
-    s->unpack_buffer_size = AV_RL32(&vmd_header[800]);
-    if (s->unpack_buffer_size) {
-        s->unpack_buffer = av_malloc(s->unpack_buffer_size);
-        if (!s->unpack_buffer)
-            return AVERROR(ENOMEM);
-    }
-
-    /* load up the initial palette */
-    raw_palette = &vmd_header[28];
-    palette32 = (unsigned int *)s->palette;
-    for (i = 0; i < PALETTE_COUNT; i++) {
-        r = raw_palette[palette_index++] * 4;
-        g = raw_palette[palette_index++] * 4;
-        b = raw_palette[palette_index++] * 4;
-        palette32[i] = (r << 16) | (g << 8) | (b);
-    }
-
-    s->prev_frame = av_frame_alloc();
-    if (!s->prev_frame) {
-        vmdvideo_decode_end(avctx);
-        return AVERROR(ENOMEM);
-    }
-
-    return 0;
-}
-
-static int vmdvideo_decode_frame(AVCodecContext *avctx,
-                                 void *data, int *got_frame,
-                                 AVPacket *avpkt)
-{
-    const uint8_t *buf = avpkt->data;
-    int buf_size = avpkt->size;
-    VmdVideoContext *s = avctx->priv_data;
-    AVFrame *frame = data;
-    int ret;
-
-    s->buf = buf;
-    s->size = buf_size;
-
-    if (buf_size < 16)
-        return AVERROR_INVALIDDATA;
-
-    if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) {
-        av_log(s->avctx, AV_LOG_ERROR, "VMD Video: get_buffer() failed\n");
-        return ret;
-    }
-
-    if ((ret = vmd_decode(s, frame)) < 0)
-        return ret;
-
-    /* make the palette available on the way out */
-    memcpy(frame->data[1], s->palette, PALETTE_COUNT * 4);
-
-    /* shuffle frames */
-    av_frame_unref(s->prev_frame);
-    if ((ret = av_frame_ref(s->prev_frame, frame)) < 0)
-        return ret;
-
-    *got_frame      = 1;
-
-    /* report that the buffer was completely consumed */
-    return buf_size;
-}
-
-
-/*
- * Audio Decoder
- */
-
-#define BLOCK_TYPE_AUDIO    1
-#define BLOCK_TYPE_INITIAL  2
-#define BLOCK_TYPE_SILENCE  3
-
-typedef struct VmdAudioContext {
-    int out_bps;
-    int chunk_size;
-} VmdAudioContext;
-
-static const uint16_t vmdaudio_table[128] = {
-    0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
-    0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
-    0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
-    0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230,
-    0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280,
-    0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0,
-    0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320,
-    0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370,
-    0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0,
-    0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480,
-    0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700,
-    0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00,
-    0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000
-};
-
-static av_cold int vmdaudio_decode_init(AVCodecContext *avctx)
-{
-    VmdAudioContext *s = avctx->priv_data;
-
-    if (avctx->channels < 1 || avctx->channels > 2) {
-        av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
-        return AVERROR(EINVAL);
-    }
-    if (avctx->block_align < 1) {
-        av_log(avctx, AV_LOG_ERROR, "invalid block align\n");
-        return AVERROR(EINVAL);
-    }
-
-    avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO :
-                                                   AV_CH_LAYOUT_STEREO;
-
-    if (avctx->bits_per_coded_sample == 16)
-        avctx->sample_fmt = AV_SAMPLE_FMT_S16;
-    else
-        avctx->sample_fmt = AV_SAMPLE_FMT_U8;
-    s->out_bps = av_get_bytes_per_sample(avctx->sample_fmt);
-
-    s->chunk_size = avctx->block_align + avctx->channels * (s->out_bps == 2);
-
-    av_log(avctx, AV_LOG_DEBUG, "%d channels, %d bits/sample, "
-           "block align = %d, sample rate = %d\n",
-           avctx->channels, avctx->bits_per_coded_sample, avctx->block_align,
-           avctx->sample_rate);
-
-    return 0;
-}
-
-static void decode_audio_s16(int16_t *out, const uint8_t *buf, int buf_size,
-                             int channels)
-{
-    int ch;
-    const uint8_t *buf_end = buf + buf_size;
-    int predictor[2];
-    int st = channels - 1;
-
-    /* decode initial raw sample */
-    for (ch = 0; ch < channels; ch++) {
-        predictor[ch] = (int16_t)AV_RL16(buf);
-        buf += 2;
-        *out++ = predictor[ch];
-    }
-
-    /* decode DPCM samples */
-    ch = 0;
-    while (buf < buf_end) {
-        uint8_t b = *buf++;
-        if (b & 0x80)
-            predictor[ch] -= vmdaudio_table[b & 0x7F];
-        else
-            predictor[ch] += vmdaudio_table[b];
-        predictor[ch] = av_clip_int16(predictor[ch]);
-        *out++ = predictor[ch];
-        ch ^= st;
-    }
-}
-
-static int vmdaudio_decode_frame(AVCodecContext *avctx, void *data,
-                                 int *got_frame_ptr, AVPacket *avpkt)
-{
-    AVFrame *frame     = data;
-    const uint8_t *buf = avpkt->data;
-    const uint8_t *buf_end;
-    int buf_size = avpkt->size;
-    VmdAudioContext *s = avctx->priv_data;
-    int block_type, silent_chunks, audio_chunks;
-    int ret;
-    uint8_t *output_samples_u8;
-    int16_t *output_samples_s16;
-
-    if (buf_size < 16) {
-        av_log(avctx, AV_LOG_WARNING, "skipping small junk packet\n");
-        *got_frame_ptr = 0;
-        return buf_size;
-    }
-
-    block_type = buf[6];
-    if (block_type < BLOCK_TYPE_AUDIO || block_type > BLOCK_TYPE_SILENCE) {
-        av_log(avctx, AV_LOG_ERROR, "unknown block type: %d\n", block_type);
-        return AVERROR(EINVAL);
-    }
-    buf      += 16;
-    buf_size -= 16;
-
-    /* get number of silent chunks */
-    silent_chunks = 0;
-    if (block_type == BLOCK_TYPE_INITIAL) {
-        uint32_t flags;
-        if (buf_size < 4) {
-            av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
-            return AVERROR(EINVAL);
-        }
-        flags         = AV_RB32(buf);
-        silent_chunks = av_popcount(flags);
-        buf      += 4;
-        buf_size -= 4;
-    } else if (block_type == BLOCK_TYPE_SILENCE) {
-        silent_chunks = 1;
-        buf_size = 0; // should already be zero but set it just to be sure
-    }
-
-    /* ensure output buffer is large enough */
-    audio_chunks = buf_size / s->chunk_size;
-
-    /* drop incomplete chunks */
-    buf_size     = audio_chunks * s->chunk_size;
-
-    /* get output buffer */
-    frame->nb_samples = ((silent_chunks + audio_chunks) * avctx->block_align) /
-                        avctx->channels;
-    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
-        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
-        return ret;
-    }
-    output_samples_u8  =            frame->data[0];
-    output_samples_s16 = (int16_t *)frame->data[0];
-
-    /* decode silent chunks */
-    if (silent_chunks > 0) {
-        int silent_size = FFMIN(avctx->block_align * silent_chunks,
-                                frame->nb_samples * avctx->channels);
-        if (s->out_bps == 2) {
-            memset(output_samples_s16, 0x00, silent_size * 2);
-            output_samples_s16 += silent_size;
-        } else {
-            memset(output_samples_u8,  0x80, silent_size);
-            output_samples_u8 += silent_size;
-        }
-    }
-
-    /* decode audio chunks */
-    if (audio_chunks > 0) {
-        buf_end = buf + (buf_size & ~(avctx->channels > 1));
-        while (buf + s->chunk_size <= buf_end) {
-            if (s->out_bps == 2) {
-                decode_audio_s16(output_samples_s16, buf, s->chunk_size,
-                                 avctx->channels);
-                output_samples_s16 += avctx->block_align;
-            } else {
-                memcpy(output_samples_u8, buf, s->chunk_size);
-                output_samples_u8  += avctx->block_align;
-            }
-            buf += s->chunk_size;
-        }
-    }
-
-    *got_frame_ptr = 1;
-
-    return avpkt->size;
-}
-
-
-/*
- * Public Data Structures
- */
-
-AVCodec ff_vmdvideo_decoder = {
-    .name           = "vmdvideo",
-    .long_name      = NULL_IF_CONFIG_SMALL("Sierra VMD video"),
-    .type           = AVMEDIA_TYPE_VIDEO,
-    .id             = AV_CODEC_ID_VMDVIDEO,
-    .priv_data_size = sizeof(VmdVideoContext),
-    .init           = vmdvideo_decode_init,
-    .close          = vmdvideo_decode_end,
-    .decode         = vmdvideo_decode_frame,
-    .capabilities   = CODEC_CAP_DR1,
-};
-
-AVCodec ff_vmdaudio_decoder = {
-    .name           = "vmdaudio",
-    .long_name      = NULL_IF_CONFIG_SMALL("Sierra VMD audio"),
-    .type           = AVMEDIA_TYPE_AUDIO,
-    .id             = AV_CODEC_ID_VMDAUDIO,
-    .priv_data_size = sizeof(VmdAudioContext),
-    .init           = vmdaudio_decode_init,
-    .decode         = vmdaudio_decode_frame,
-    .capabilities   = CODEC_CAP_DR1,
-};
diff --git a/libavcodec/vmdvideo.c b/libavcodec/vmdvideo.c
new file mode 100644 (file)
index 0000000..aaeff43
--- /dev/null
@@ -0,0 +1,467 @@
+/*
+ * Sierra VMD video decoder
+ *
+ * This file is part of Libav.
+ *
+ * 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.
+ *
+ * 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * Sierra VMD video decoder
+ * by Vladimir "VAG" Gneushev (vagsoft at mail.ru)
+ * for more information on the Sierra VMD format, visit:
+ *   http://www.pcisys.net/~melanson/codecs/
+ *
+ * The video decoder outputs PAL8 colorspace data. The decoder expects
+ * a 0x330-byte VMD file header to be transmitted via extradata during
+ * codec initialization. Each encoded frame that is sent to this decoder
+ * is expected to be prepended with the appropriate 16-byte frame
+ * information record from the VMD file.
+ */
+
+#include <string.h>
+
+#include "libavutil/common.h"
+#include "libavutil/intreadwrite.h"
+
+#include "avcodec.h"
+#include "internal.h"
+#include "bytestream.h"
+
+#define VMD_HEADER_SIZE 0x330
+#define PALETTE_COUNT 256
+
+typedef struct VmdVideoContext {
+
+    AVCodecContext *avctx;
+    AVFrame *prev_frame;
+
+    const unsigned char *buf;
+    int size;
+
+    unsigned char palette[PALETTE_COUNT * 4];
+    unsigned char *unpack_buffer;
+    int unpack_buffer_size;
+
+    int x_off, y_off;
+} VmdVideoContext;
+
+#define QUEUE_SIZE 0x1000
+#define QUEUE_MASK 0x0FFF
+
+static void lz_unpack(const unsigned char *src, int src_len,
+                      unsigned char *dest, int dest_len)
+{
+    unsigned char *d;
+    unsigned char *d_end;
+    unsigned char queue[QUEUE_SIZE];
+    unsigned int qpos;
+    unsigned int dataleft;
+    unsigned int chainofs;
+    unsigned int chainlen;
+    unsigned int speclen;
+    unsigned char tag;
+    unsigned int i, j;
+    GetByteContext gb;
+
+    bytestream2_init(&gb, src, src_len);
+    d = dest;
+    d_end = d + dest_len;
+    dataleft = bytestream2_get_le32(&gb);
+    memset(queue, 0x20, QUEUE_SIZE);
+    if (bytestream2_get_bytes_left(&gb) < 4)
+        return;
+    if (bytestream2_peek_le32(&gb) == 0x56781234) {
+        bytestream2_get_le32(&gb);
+        qpos = 0x111;
+        speclen = 0xF + 3;
+    } else {
+        qpos = 0xFEE;
+        speclen = 100;  /* no speclen */
+    }
+
+    while (dataleft > 0 && bytestream2_get_bytes_left(&gb) > 0) {
+        tag = bytestream2_get_byteu(&gb);
+        if ((tag == 0xFF) && (dataleft > 8)) {
+            if (d + 8 > d_end || bytestream2_get_bytes_left(&gb) < 8)
+                return;
+            for (i = 0; i < 8; i++) {
+                queue[qpos++] = *d++ = bytestream2_get_byteu(&gb);
+                qpos &= QUEUE_MASK;
+            }
+            dataleft -= 8;
+        } else {
+            for (i = 0; i < 8; i++) {
+                if (dataleft == 0)
+                    break;
+                if (tag & 0x01) {
+                    if (d + 1 > d_end || bytestream2_get_bytes_left(&gb) < 1)
+                        return;
+                    queue[qpos++] = *d++ = bytestream2_get_byte(&gb);
+                    qpos &= QUEUE_MASK;
+                    dataleft--;
+                } else {
+                    chainofs = bytestream2_get_byte(&gb);
+                    chainofs |= ((bytestream2_peek_byte(&gb) & 0xF0) << 4);
+                    chainlen = (bytestream2_get_byte(&gb) & 0x0F) + 3;
+                    if (chainlen == speclen) {
+                        chainlen = bytestream2_get_byte(&gb) + 0xF + 3;
+                    }
+                    if (d + chainlen > d_end)
+                        return;
+                    for (j = 0; j < chainlen; j++) {
+                        *d = queue[chainofs++ & QUEUE_MASK];
+                        queue[qpos++] = *d++;
+                        qpos &= QUEUE_MASK;
+                    }
+                    dataleft -= chainlen;
+                }
+                tag >>= 1;
+            }
+        }
+    }
+}
+
+static int rle_unpack(const unsigned char *src, unsigned char *dest,
+    int src_count, int src_size, int dest_len)
+{
+    unsigned char *pd;
+    int i, l, used = 0;
+    unsigned char *dest_end = dest + dest_len;
+    GetByteContext gb;
+    uint16_t run_val;
+
+    bytestream2_init(&gb, src, src_size);
+    pd = dest;
+    if (src_count & 1) {
+        if (bytestream2_get_bytes_left(&gb) < 1)
+            return 0;
+        *pd++ = bytestream2_get_byteu(&gb);
+        used++;
+    }
+
+    do {
+        if (bytestream2_get_bytes_left(&gb) < 1)
+            break;
+        l = bytestream2_get_byteu(&gb);
+        if (l & 0x80) {
+            l = (l & 0x7F) * 2;
+            if (pd + l > dest_end || bytestream2_get_bytes_left(&gb) < l)
+                return bytestream2_tell(&gb);
+            bytestream2_get_buffer(&gb, pd, l);
+            pd += l;
+        } else {
+            if (pd + l > dest_end || bytestream2_get_bytes_left(&gb) < 2)
+                return bytestream2_tell(&gb);
+            run_val = bytestream2_get_ne16(&gb);
+            for (i = 0; i < l; i++) {
+                AV_WN16(pd, run_val);
+                pd += 2;
+            }
+            l *= 2;
+        }
+        used += l;
+    } while (used < src_count);
+
+    return bytestream2_tell(&gb);
+}
+
+static int vmd_decode(VmdVideoContext *s, AVFrame *frame)
+{
+    int i;
+    unsigned int *palette32;
+    unsigned char r, g, b;
+
+    GetByteContext gb;
+
+    unsigned char meth;
+    unsigned char *dp;   /* pointer to current frame */
+    unsigned char *pp;   /* pointer to previous frame */
+    unsigned char len;
+    int ofs;
+
+    int frame_x, frame_y;
+    int frame_width, frame_height;
+
+    frame_x = AV_RL16(&s->buf[6]);
+    frame_y = AV_RL16(&s->buf[8]);
+    frame_width = AV_RL16(&s->buf[10]) - frame_x + 1;
+    frame_height = AV_RL16(&s->buf[12]) - frame_y + 1;
+    if (frame_x < 0 || frame_width < 0 ||
+        frame_x >= s->avctx->width ||
+        frame_width > s->avctx->width ||
+        frame_x + frame_width > s->avctx->width) {
+        av_log(s->avctx, AV_LOG_ERROR,
+               "Invalid horizontal range %d-%d\n",
+               frame_x, frame_width);
+        return AVERROR_INVALIDDATA;
+    }
+    if (frame_y < 0 || frame_height < 0 ||
+        frame_y >= s->avctx->height ||
+        frame_height > s->avctx->height ||
+        frame_y + frame_height > s->avctx->height) {
+        av_log(s->avctx, AV_LOG_ERROR,
+               "Invalid vertical range %d-%d\n",
+               frame_x, frame_width);
+        return AVERROR_INVALIDDATA;
+    }
+
+    if ((frame_width == s->avctx->width && frame_height == s->avctx->height) &&
+        (frame_x || frame_y)) {
+
+        s->x_off = frame_x;
+        s->y_off = frame_y;
+    }
+    frame_x -= s->x_off;
+    frame_y -= s->y_off;
+
+    /* if only a certain region will be updated, copy the entire previous
+     * frame before the decode */
+    if (s->prev_frame->data[0] &&
+        (frame_x || frame_y || (frame_width != s->avctx->width) ||
+        (frame_height != s->avctx->height))) {
+
+        memcpy(frame->data[0], s->prev_frame->data[0],
+            s->avctx->height * frame->linesize[0]);
+    }
+
+    /* check if there is a new palette */
+    bytestream2_init(&gb, s->buf + 16, s->size - 16);
+    if (s->buf[15] & 0x02) {
+        bytestream2_skip(&gb, 2);
+        palette32 = (unsigned int *)s->palette;
+        if (bytestream2_get_bytes_left(&gb) >= PALETTE_COUNT * 3) {
+            for (i = 0; i < PALETTE_COUNT; i++) {
+                r = bytestream2_get_byteu(&gb) * 4;
+                g = bytestream2_get_byteu(&gb) * 4;
+                b = bytestream2_get_byteu(&gb) * 4;
+                palette32[i] = (r << 16) | (g << 8) | (b);
+            }
+        } else {
+            av_log(s->avctx, AV_LOG_ERROR, "Incomplete palette\n");
+            return AVERROR_INVALIDDATA;
+        }
+        s->size -= PALETTE_COUNT * 3 + 2;
+    }
+
+    if (!s->size)
+        return 0;
+
+    /* originally UnpackFrame in VAG's code */
+    if (bytestream2_get_bytes_left(&gb) < 1)
+        return AVERROR_INVALIDDATA;
+    meth = bytestream2_get_byteu(&gb);
+    if (meth & 0x80) {
+        if (!s->unpack_buffer_size) {
+            av_log(s->avctx, AV_LOG_ERROR,
+                   "Trying to unpack LZ-compressed frame with no LZ buffer\n");
+            return AVERROR_INVALIDDATA;
+        }
+        lz_unpack(gb.buffer, bytestream2_get_bytes_left(&gb),
+                  s->unpack_buffer, s->unpack_buffer_size);
+        meth &= 0x7F;
+        bytestream2_init(&gb, s->unpack_buffer, s->unpack_buffer_size);
+    }
+
+    dp = &frame->data[0][frame_y * frame->linesize[0] + frame_x];
+    pp = &s->prev_frame->data[0][frame_y * s->prev_frame->linesize[0] + frame_x];
+    switch (meth) {
+    case 1:
+        for (i = 0; i < frame_height; i++) {
+            ofs = 0;
+            do {
+                len = bytestream2_get_byte(&gb);
+                if (len & 0x80) {
+                    len = (len & 0x7F) + 1;
+                    if (ofs + len > frame_width ||
+                        bytestream2_get_bytes_left(&gb) < len)
+                        return AVERROR_INVALIDDATA;
+                    bytestream2_get_buffer(&gb, &dp[ofs], len);
+                    ofs += len;
+                } else {
+                    /* interframe pixel copy */
+                    if (ofs + len + 1 > frame_width || !s->prev_frame->data[0])
+                        return AVERROR_INVALIDDATA;
+                    memcpy(&dp[ofs], &pp[ofs], len + 1);
+                    ofs += len + 1;
+                }
+            } while (ofs < frame_width);
+            if (ofs > frame_width) {
+                av_log(s->avctx, AV_LOG_ERROR,
+                       "VMD video: offset > width (%d > %d)\n",
+                       ofs, frame_width);
+                return AVERROR_INVALIDDATA;
+            }
+            dp += frame->linesize[0];
+            pp += s->prev_frame->linesize[0];
+        }
+        break;
+
+    case 2:
+        for (i = 0; i < frame_height; i++) {
+            bytestream2_get_buffer(&gb, dp, frame_width);
+            dp += frame->linesize[0];
+            pp += s->prev_frame->linesize[0];
+        }
+        break;
+
+    case 3:
+        for (i = 0; i < frame_height; i++) {
+            ofs = 0;
+            do {
+                len = bytestream2_get_byte(&gb);
+                if (len & 0x80) {
+                    len = (len & 0x7F) + 1;
+                    if (bytestream2_peek_byte(&gb) == 0xFF) {
+                        int slen = len;
+                        bytestream2_get_byte(&gb);
+                        len = rle_unpack(gb.buffer, &dp[ofs],
+                                         len, bytestream2_get_bytes_left(&gb),
+                                         frame_width - ofs);
+                        ofs += slen;
+                        bytestream2_skip(&gb, len);
+                    } else {
+                        bytestream2_get_buffer(&gb, &dp[ofs], len);
+                        ofs += len;
+                    }
+                } else {
+                    /* interframe pixel copy */
+                    if (ofs + len + 1 > frame_width || !s->prev_frame->data[0])
+                        return AVERROR_INVALIDDATA;
+                    memcpy(&dp[ofs], &pp[ofs], len + 1);
+                    ofs += len + 1;
+                }
+            } while (ofs < frame_width);
+            if (ofs > frame_width) {
+                av_log(s->avctx, AV_LOG_ERROR,
+                       "VMD video: offset > width (%d > %d)\n",
+                       ofs, frame_width);
+                return AVERROR_INVALIDDATA;
+            }
+            dp += frame->linesize[0];
+            pp += s->prev_frame->linesize[0];
+        }
+        break;
+    }
+    return 0;
+}
+
+static av_cold int vmdvideo_decode_end(AVCodecContext *avctx)
+{
+    VmdVideoContext *s = avctx->priv_data;
+
+    av_frame_free(&s->prev_frame);
+    av_free(s->unpack_buffer);
+
+    return 0;
+}
+
+static av_cold int vmdvideo_decode_init(AVCodecContext *avctx)
+{
+    VmdVideoContext *s = avctx->priv_data;
+    int i;
+    unsigned int *palette32;
+    int palette_index = 0;
+    unsigned char r, g, b;
+    unsigned char *vmd_header;
+    unsigned char *raw_palette;
+
+    s->avctx = avctx;
+    avctx->pix_fmt = AV_PIX_FMT_PAL8;
+
+    /* make sure the VMD header made it */
+    if (s->avctx->extradata_size != VMD_HEADER_SIZE) {
+        av_log(s->avctx, AV_LOG_ERROR, "VMD video: expected extradata size of %d\n",
+            VMD_HEADER_SIZE);
+        return -1;
+    }
+    vmd_header = (unsigned char *)avctx->extradata;
+
+    s->unpack_buffer_size = AV_RL32(&vmd_header[800]);
+    if (s->unpack_buffer_size) {
+        s->unpack_buffer = av_malloc(s->unpack_buffer_size);
+        if (!s->unpack_buffer)
+            return AVERROR(ENOMEM);
+    }
+
+    /* load up the initial palette */
+    raw_palette = &vmd_header[28];
+    palette32 = (unsigned int *)s->palette;
+    for (i = 0; i < PALETTE_COUNT; i++) {
+        r = raw_palette[palette_index++] * 4;
+        g = raw_palette[palette_index++] * 4;
+        b = raw_palette[palette_index++] * 4;
+        palette32[i] = (r << 16) | (g << 8) | (b);
+    }
+
+    s->prev_frame = av_frame_alloc();
+    if (!s->prev_frame) {
+        vmdvideo_decode_end(avctx);
+        return AVERROR(ENOMEM);
+    }
+
+    return 0;
+}
+
+static int vmdvideo_decode_frame(AVCodecContext *avctx,
+                                 void *data, int *got_frame,
+                                 AVPacket *avpkt)
+{
+    const uint8_t *buf = avpkt->data;
+    int buf_size = avpkt->size;
+    VmdVideoContext *s = avctx->priv_data;
+    AVFrame *frame = data;
+    int ret;
+
+    s->buf = buf;
+    s->size = buf_size;
+
+    if (buf_size < 16)
+        return AVERROR_INVALIDDATA;
+
+    if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) {
+        av_log(s->avctx, AV_LOG_ERROR, "VMD Video: get_buffer() failed\n");
+        return ret;
+    }
+
+    if ((ret = vmd_decode(s, frame)) < 0)
+        return ret;
+
+    /* make the palette available on the way out */
+    memcpy(frame->data[1], s->palette, PALETTE_COUNT * 4);
+
+    /* shuffle frames */
+    av_frame_unref(s->prev_frame);
+    if ((ret = av_frame_ref(s->prev_frame, frame)) < 0)
+        return ret;
+
+    *got_frame      = 1;
+
+    /* report that the buffer was completely consumed */
+    return buf_size;
+}
+
+AVCodec ff_vmdvideo_decoder = {
+    .name           = "vmdvideo",
+    .long_name      = NULL_IF_CONFIG_SMALL("Sierra VMD video"),
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_VMDVIDEO,
+    .priv_data_size = sizeof(VmdVideoContext),
+    .init           = vmdvideo_decode_init,
+    .close          = vmdvideo_decode_end,
+    .decode         = vmdvideo_decode_frame,
+    .capabilities   = CODEC_CAP_DR1,
+};