Bethsoft VID demuxer and video decoder
authorNicholas Tung <ntung@ntung.com>
Sat, 7 Apr 2007 20:51:58 +0000 (20:51 +0000)
committerDiego Biurrun <diego@biurrun.de>
Sat, 7 Apr 2007 20:51:58 +0000 (20:51 +0000)
patch by Nicholas Tung, ntung ntung com

Originally committed as revision 8649 to svn://svn.ffmpeg.org/ffmpeg/trunk

Changelog
doc/ffmpeg-doc.texi
libavcodec/Makefile
libavcodec/allcodecs.c
libavcodec/avcodec.h
libavcodec/bethsoftvideo.c [new file with mode: 0644]
libavcodec/bethsoftvideo.h [new file with mode: 0644]
libavformat/Makefile
libavformat/allformats.c
libavformat/allformats.h
libavformat/bethsoftvid.c [new file with mode: 0644]

index 347acdcdc67208493e83384bfceefe4f4e4add77..2b64544214ae1a652bcbe977db48dd0042455266 100644 (file)
--- a/Changelog
+++ b/Changelog
@@ -78,6 +78,7 @@ version <next>
 - Gamecube movie (.THP) playback system
 - Blackfin optimizations
 - Interplay C93 demuxer and video decoder
 - Gamecube movie (.THP) playback system
 - Blackfin optimizations
 - Interplay C93 demuxer and video decoder
+- Bethsoft VID demuxer and video decoder
 
 version 0.4.9-pre1:
 
 
 version 0.4.9-pre1:
 
index 8c351c6374feb6552d54938b438b05494155f31d..55acced8b43c5a3c502d32e48a21beebb0e1f749 100644 (file)
@@ -905,6 +905,8 @@ different game cutscenes repacked for use with ScummVM.
 @tab Used on the Nintendo GameCube.
 @item C93 @tab    @tab X
 @tab Used in the game Cyberia from Interplay.
 @tab Used on the Nintendo GameCube.
 @item C93 @tab    @tab X
 @tab Used in the game Cyberia from Interplay.
+@item Bethsoft VID @tab    @tab X
+@tab Used in some games from Bethesda Softworks.
 @end multitable
 
 @code{X} means that encoding (resp. decoding) is supported.
 @end multitable
 
 @code{X} means that encoding (resp. decoding) is supported.
@@ -1015,6 +1017,7 @@ following image formats are supported:
 @item DXA Video              @tab     @tab  X @tab Codec originally used in Feeble Files game.
 @item AVID DNxHD             @tab     @tab  X @tab aka SMPTE VC3
 @item C93 Video              @tab     @tab  X @tab Codec used in Cyberia game.
 @item DXA Video              @tab     @tab  X @tab Codec originally used in Feeble Files game.
 @item AVID DNxHD             @tab     @tab  X @tab aka SMPTE VC3
 @item C93 Video              @tab     @tab  X @tab Codec used in Cyberia game.
+@item Bethsoft VID           @tab     @tab  X @tab Used in some games from Bethesda Softworks.
 @end multitable
 
 @code{X} means that encoding (resp. decoding) is supported.
 @end multitable
 
 @code{X} means that encoding (resp. decoding) is supported.
index a07879e962441ef8f36504f63c6b1c361f48c6f5..f29575967408ee8aeea7588f340e4c4e91007c82 100644 (file)
@@ -54,6 +54,7 @@ OBJS-$(CONFIG_ASV1_ENCODER)            += asv1.o
 OBJS-$(CONFIG_ASV2_DECODER)            += asv1.o
 OBJS-$(CONFIG_ASV2_ENCODER)            += asv1.o
 OBJS-$(CONFIG_AVS_DECODER)             += avs.o
 OBJS-$(CONFIG_ASV2_DECODER)            += asv1.o
 OBJS-$(CONFIG_ASV2_ENCODER)            += asv1.o
 OBJS-$(CONFIG_AVS_DECODER)             += avs.o
+OBJS-$(CONFIG_BETHSOFTVID_DECODER)     += bethsoftvideo.o
 OBJS-$(CONFIG_BMP_DECODER)             += bmp.o
 OBJS-$(CONFIG_BMP_ENCODER)             += bmpenc.o
 OBJS-$(CONFIG_C93_DECODER)             += c93.o
 OBJS-$(CONFIG_BMP_DECODER)             += bmp.o
 OBJS-$(CONFIG_BMP_ENCODER)             += bmpenc.o
 OBJS-$(CONFIG_C93_DECODER)             += c93.o
index be41c147f5ca2cc7c55b67ad9ab8b09304563250..5464dc7abc0e5dfbf5abe65ee0f3a6c0a6a8dffa 100644 (file)
@@ -58,6 +58,7 @@ void avcodec_register_all(void)
     REGISTER_ENCDEC (ASV1, asv1);
     REGISTER_ENCDEC (ASV2, asv2);
     REGISTER_DECODER(AVS, avs);
     REGISTER_ENCDEC (ASV1, asv1);
     REGISTER_ENCDEC (ASV2, asv2);
     REGISTER_DECODER(AVS, avs);
+    REGISTER_DECODER(BETHSOFTVID, bethsoftvid);
     REGISTER_ENCDEC (BMP, bmp);
     REGISTER_DECODER(C93, c93);
     REGISTER_DECODER(CAVS, cavs);
     REGISTER_ENCDEC (BMP, bmp);
     REGISTER_DECODER(C93, c93);
     REGISTER_DECODER(CAVS, cavs);
index 421171a183b643a2435778965875cecfd8e3a046..9fd2fb31ff25174b807232534433e0e58c745bdd 100644 (file)
@@ -161,6 +161,7 @@ enum CodecID {
     CODEC_ID_THP,
     CODEC_ID_SGI,
     CODEC_ID_C93,
     CODEC_ID_THP,
     CODEC_ID_SGI,
     CODEC_ID_C93,
+    CODEC_ID_BETHSOFTVID,
 
     /* various PCM "codecs" */
     CODEC_ID_PCM_S16LE= 0x10000,
 
     /* various PCM "codecs" */
     CODEC_ID_PCM_S16LE= 0x10000,
@@ -2252,6 +2253,7 @@ extern AVCodec amr_wb_decoder;
 extern AVCodec asv1_decoder;
 extern AVCodec asv2_decoder;
 extern AVCodec avs_decoder;
 extern AVCodec asv1_decoder;
 extern AVCodec asv2_decoder;
 extern AVCodec avs_decoder;
+extern AVCodec bethsoftvid_decoder;
 extern AVCodec bmp_decoder;
 extern AVCodec c93_decoder;
 extern AVCodec cavs_decoder;
 extern AVCodec bmp_decoder;
 extern AVCodec c93_decoder;
 extern AVCodec cavs_decoder;
diff --git a/libavcodec/bethsoftvideo.c b/libavcodec/bethsoftvideo.c
new file mode 100644 (file)
index 0000000..a597437
--- /dev/null
@@ -0,0 +1,139 @@
+/*
+ * Bethesda VID video decoder
+ * Copyright (C) 2007 Nicholas Tung
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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,
+ * 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
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file bethsoftvideo.c
+ * @brief Bethesda Softworks VID Video Decoder
+ * @author Nicholas Tung [ntung (at. ntung com] (2007-03)
+ * @sa http://wiki.multimedia.cx/index.php?title=Bethsoft_VID
+ * @sa http://www.svatopluk.com/andux/docs/dfvid.html
+ */
+
+#include "common.h"
+#include "dsputil.h"
+#include "bethsoftvideo.h"
+#include "bytestream.h"
+
+typedef struct BethsoftvidContext {
+    AVFrame frame;
+} BethsoftvidContext;
+
+static int bethsoftvid_decode_init(AVCodecContext *avctx)
+{
+    BethsoftvidContext *vid = avctx->priv_data;
+    vid->frame.reference = 1;
+    vid->frame.buffer_hints = FF_BUFFER_HINTS_VALID |
+        FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
+    avctx->pix_fmt = PIX_FMT_PAL8;    // palette in vid->frame.data[1]
+    av_log(avctx, AV_LOG_DEBUG, "[bethsoftvid video decoder] init\n");
+    return 0;
+}
+
+static void set_palette(AVFrame * frame, uint8_t * palette_buffer)
+{
+    uint32_t * palette = (uint32_t *)frame->data[1];
+    int a;
+    for(a = 0; a < VID_PALETTE_NUMCOLORS; a++)
+    {
+        palette[a] = AV_RB24(&palette_buffer[a * 3]) * 4;    // multiply all colors by 4
+    }
+    frame->palette_has_changed = 1;
+}
+
+static int bethsoftvid_decode_frame(AVCodecContext *avctx,
+                              void *data, int *data_size,
+                              uint8_t *buf, int buf_size)
+{
+    BethsoftvidContext * vid = avctx->priv_data;
+    char block_type;
+    uint8_t * destination;
+    uint8_t * frame_end;
+    int line_remaining = avctx->width;          // number of bytes remaining on a line
+    const int wrap_to_next_line = vid->frame.linesize[0] - avctx->width;
+    uint8_t rle_num_bytes;
+    int yoffset;
+
+    av_log(avctx, AV_LOG_DEBUG, "[bethsoftvid video decoder] decoding frame\n");
+
+    // reget buffer will copy old data, good for simple difference frames
+    if (avctx->reget_buffer(avctx, &vid->frame)) {
+        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
+        return -1;
+    }
+    destination = vid->frame.data[0];
+    frame_end = vid->frame.data[0] + vid->frame.linesize[0] * avctx->height;
+
+    switch(block_type = *buf++)
+    {
+        case PALETTE_BLOCK: set_palette(&vid->frame, buf); return 0;
+        case VIDEO_YOFFSET_DIFFERENCE_FRAME_BLOCK:
+            yoffset = bytestream_get_le16(&buf);
+            if(yoffset >= avctx->height) { return -1; }
+            destination += vid->frame.linesize[0] * yoffset;
+    }
+
+    // main code
+    while((rle_num_bytes = *buf++))
+    {
+        int length = rle_num_bytes & 0x7f;
+
+        // copy any bytes starting at the current position, and ending at the frame width
+        while(length > line_remaining)
+        {
+            if(rle_num_bytes < 0x80) { bytestream_get_buffer(&buf, destination, line_remaining); }
+            else if(block_type == VIDEO_FULL_FRAME_BLOCK) { memset(destination, buf[0], line_remaining); }
+            length -= line_remaining;      // decrement the number of bytes to be copied
+            destination += line_remaining + wrap_to_next_line;    // skip over extra bytes at end of frame
+            line_remaining = avctx->width;
+            if(destination == frame_end) { goto end; }
+        }
+
+        // copy any remaining bytes after / if line overflows
+        if(rle_num_bytes < 0x80) { bytestream_get_buffer(&buf, destination, length); }
+        else if(block_type == VIDEO_FULL_FRAME_BLOCK) { memset(destination, *buf++, length); }
+        line_remaining -= length;
+        destination += length;
+    }
+    end:
+
+    *data_size = sizeof(AVFrame);
+    *(AVFrame*)data = vid->frame;
+
+    return buf_size;
+}
+
+static int bethsoftvid_decode_end(AVCodecContext *avctx)
+{
+    BethsoftvidContext * vid = avctx->priv_data;
+    av_log(avctx, AV_LOG_DEBUG, "[bethsoftvid video decoder] closing\n");
+    if(vid->frame.data[0]) { avctx->release_buffer(avctx, &vid->frame); }
+    return 0;
+}
+
+AVCodec bethsoftvid_decoder = {
+    .name = "bethsoftvid",
+    .type = CODEC_TYPE_VIDEO,
+    .id = CODEC_ID_BETHSOFTVID,
+    .priv_data_size = sizeof(BethsoftvidContext),
+    .init = bethsoftvid_decode_init,
+    .close = bethsoftvid_decode_end,
+    .decode = bethsoftvid_decode_frame,
+};
diff --git a/libavcodec/bethsoftvideo.h b/libavcodec/bethsoftvideo.h
new file mode 100644 (file)
index 0000000..036175a
--- /dev/null
@@ -0,0 +1,9 @@
+#define VID_PALETTE_NUMCOLORS 256
+
+enum BethsoftVidBlockType
+{
+    PALETTE_BLOCK = 0x02,
+    FIRST_AUDIO_BLOCK = 0x7c, AUDIO_BLOCK = 0x7d,
+    VIDEO_FULL_FRAME_BLOCK = 0x03, VIDEO_DIFFERENCE_FRAME_BLOCK = 0x01, VIDEO_YOFFSET_DIFFERENCE_FRAME_BLOCK = 0x04,
+    FINISHED_BLOCK = 0x14,
+};
index 4e18f72657355727ae3a2d7a651d370310754441..b58069b5323c9c7823686fe2b955775dc0e638b0 100644 (file)
@@ -28,6 +28,7 @@ OBJS-$(CONFIG_AVI_DEMUXER)               += avidec.o riff.o
 OBJS-$(CONFIG_AVI_MUXER)                 += avienc.o riff.o
 OBJS-$(CONFIG_AVISYNTH)                  += avisynth.o
 OBJS-$(CONFIG_AVS_DEMUXER)               += avs.o vocdec.o voc.o riff.o
 OBJS-$(CONFIG_AVI_MUXER)                 += avienc.o riff.o
 OBJS-$(CONFIG_AVISYNTH)                  += avisynth.o
 OBJS-$(CONFIG_AVS_DEMUXER)               += avs.o vocdec.o voc.o riff.o
+OBJS-$(CONFIG_BETHSOFTVID_DEMUXER)       += bethsoftvid.o
 OBJS-$(CONFIG_C93_DEMUXER)               += c93.o
 OBJS-$(CONFIG_CRC_MUXER)                 += crc.o
 OBJS-$(CONFIG_FRAMECRC_MUXER)            += crc.o
 OBJS-$(CONFIG_C93_DEMUXER)               += c93.o
 OBJS-$(CONFIG_CRC_MUXER)                 += crc.o
 OBJS-$(CONFIG_FRAMECRC_MUXER)            += crc.o
index 3cfe8726618633fb1099683151ba587ba468bd3e..9e1f76533ef6c6136d10cb7268a0839bb05d4782 100644 (file)
@@ -58,6 +58,7 @@ void av_register_all(void)
     av_register_input_format(&avisynth_demuxer);
 #endif
     REGISTER_DEMUXER (AVS, avs);
     av_register_input_format(&avisynth_demuxer);
 #endif
     REGISTER_DEMUXER (AVS, avs);
+    REGISTER_DEMUXER (BETHSOFTVID, bethsoftvid);
     REGISTER_DEMUXER (C93, c93);
     REGISTER_MUXER   (CRC, crc);
     REGISTER_DEMUXER (DAUD, daud);
     REGISTER_DEMUXER (C93, c93);
     REGISTER_MUXER   (CRC, crc);
     REGISTER_DEMUXER (DAUD, daud);
index 3e0cb6b9806fd98865995a06e286cf6f1d053a40..a3ba464376ff729418012415d519a5198e8e9a62 100644 (file)
@@ -32,6 +32,7 @@ extern AVInputFormat audio_demuxer;
 extern AVInputFormat avi_demuxer;
 extern AVInputFormat avisynth_demuxer;
 extern AVInputFormat avs_demuxer;
 extern AVInputFormat avi_demuxer;
 extern AVInputFormat avisynth_demuxer;
 extern AVInputFormat avs_demuxer;
+extern AVInputFormat bethsoftvid_demuxer;
 extern AVInputFormat c93_demuxer;
 extern AVInputFormat daud_demuxer;
 extern AVInputFormat dc1394_demuxer;
 extern AVInputFormat c93_demuxer;
 extern AVInputFormat daud_demuxer;
 extern AVInputFormat dc1394_demuxer;
diff --git a/libavformat/bethsoftvid.c b/libavformat/bethsoftvid.c
new file mode 100644 (file)
index 0000000..7ea4835
--- /dev/null
@@ -0,0 +1,234 @@
+/*
+ * Bethsoft VID format Demuxer
+ * Copyright (c) 2007 Nicholas Tung
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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,
+ * 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
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file bethsoftvid.c
+ * @brief Bethesda Softworks VID (.vid) file demuxer
+ * @author Nicholas Tung [ntung (at. ntung com] (2007-03)
+ * @sa http://wiki.multimedia.cx/index.php?title=Bethsoft_VID
+ * @sa http://www.svatopluk.com/andux/docs/dfvid.html
+ */
+
+#include "avformat.h"
+#include "bethsoftvideo.h"
+
+typedef struct BVID_DemuxContext
+{
+    int nframes;
+    /** delay value between frames, added to individual frame delay.
+     * custom units, which will be added to other custom units (~=16ms according
+     * to free, unofficial documentation) */
+    int bethsoft_global_delay;
+
+    /** video presentation time stamp.
+     * delay = 16 milliseconds * (global_delay + per_frame_delay) */
+    int64_t video_pts;
+
+    int is_finished;
+
+} BVID_DemuxContext;
+
+static int vid_probe(AVProbeData *p)
+{
+    // little endian VID tag, file starts with "VID\0"
+    if (p->buf_size < 4 || AV_RL32(p->buf) != MKTAG('V', 'I', 'D', 0))
+        return 0;
+
+    return AVPROBE_SCORE_MAX;
+}
+
+static int vid_read_header(AVFormatContext *s,
+                            AVFormatParameters *ap)
+{
+    BVID_DemuxContext *vid = s->priv_data;     // permanent data outside of function
+    ByteIOContext *pb = &s->pb;                // io to file
+    AVStream *stream;
+
+    /* load main header. Contents:
+    *    bytes: 'V' 'I' 'D'
+    *    int16s: always_512, nframes, width, height, delay, always_14
+    */
+    url_fseek(pb, 5, SEEK_CUR);
+    vid->nframes = get_le16(pb);
+
+    // FFmpeg central code will use this; don't need to return or anything
+    // initialize the bethsoft codec
+    stream = av_new_stream(s, 0);
+    if (!stream) { return AVERROR_NOMEM; }
+    av_set_pts_info(stream, 32, 1, 60);     // 16 ms increments, i.e. 60 fps
+    stream->codec->codec_type = CODEC_TYPE_VIDEO;
+    stream->codec->codec_id = CODEC_ID_BETHSOFTVID;
+    stream->codec->width = get_le16(pb);
+    stream->codec->height = get_le16(pb);
+    stream->codec->pix_fmt = PIX_FMT_PAL8;
+    vid->bethsoft_global_delay = get_le16(pb);
+    get_le16(pb);
+
+    // done with video codec, set up audio codec
+    stream = av_new_stream(s, 0);
+    if (!stream) { return AVERROR_NOMEM; }
+    stream->codec->codec_type = CODEC_TYPE_AUDIO;
+    stream->codec->codec_id = CODEC_ID_PCM_U8;
+    stream->codec->channels = 1;
+    stream->codec->sample_rate = 11025;
+    stream->codec->bits_per_sample = 8;
+    stream->codec->bit_rate = stream->codec->channels * stream->codec->sample_rate * stream->codec->bits_per_sample;
+
+    return 0;
+}
+
+#define BUFFER_PADDING_SIZE 1000
+static int read_frame(BVID_DemuxContext *vid, ByteIOContext *pb, AVPacket *pkt,
+                      uint8_t block_type, AVFormatContext *s, int npixels)
+{
+    uint8_t * vidbuf_start = NULL;
+    int vidbuf_nbytes = 0;
+    int rle_num_bytes;
+    int bytes_copied = 0;
+    int position;
+    size_t vidbuf_capacity;
+
+    vidbuf_start = av_malloc(vidbuf_capacity = BUFFER_PADDING_SIZE);
+    if(!vidbuf_start) { return AVERROR_NOMEM; }
+
+    // save the file position for the packet, include block type
+    position = url_ftell(pb) - 1;
+
+    // set the block type for the decoder
+    vidbuf_start[vidbuf_nbytes++] = block_type;
+
+    // get the video delay (next int16), and set the presentation time
+    vid->video_pts += vid->bethsoft_global_delay + get_le16(pb);
+
+    // set the y offset if it exists (decoder header data should be in data section)
+    if(block_type == VIDEO_YOFFSET_DIFFERENCE_FRAME_BLOCK)
+    {
+        if(get_buffer(pb, &vidbuf_start[vidbuf_nbytes], 2) != 2) { return AVERROR_IO; }
+        vidbuf_nbytes += 2;
+    }
+
+    do
+    {
+        vidbuf_start = av_fast_realloc(vidbuf_start, &vidbuf_capacity, vidbuf_nbytes + BUFFER_PADDING_SIZE);
+        if(!vidbuf_start) { return AVERROR_NOMEM; }
+
+        rle_num_bytes = get_byte(pb);
+        vidbuf_start[vidbuf_nbytes++] = rle_num_bytes;
+
+        if(rle_num_bytes > 0x80) // rle sequence
+        {
+            if(block_type == VIDEO_FULL_FRAME_BLOCK) { vidbuf_start[vidbuf_nbytes++] = get_byte(pb); }
+            bytes_copied += rle_num_bytes - 0x80;
+        }
+        else if(rle_num_bytes) // plain sequence
+        {
+            if(get_buffer(pb, &vidbuf_start[vidbuf_nbytes], rle_num_bytes) != rle_num_bytes)
+                return AVERROR_IO;
+            vidbuf_nbytes += rle_num_bytes;
+            bytes_copied += rle_num_bytes;
+        }
+        if(bytes_copied == npixels) // sometimes no stop character is given, need to keep track of bytes copied
+        {
+            // may contain a 0 byte even if read all pixels
+            if(get_byte(pb)) { url_fseek(pb, -1, SEEK_CUR); }
+            break;
+        }
+        if(bytes_copied > npixels) { return -1; }    // error
+    } while(rle_num_bytes);
+
+    // copy data into packet
+    if(av_new_packet(pkt, vidbuf_nbytes)) { return AVERROR_NOMEM; }
+    memcpy(pkt->data, vidbuf_start, vidbuf_nbytes);
+    av_free(vidbuf_start);
+
+    pkt->pos = position;
+    pkt->stream_index = 0;  // use the video decoder, which was initialized as the first stream
+    pkt->pts = vid->video_pts;
+
+    vid->nframes--;  // used to check if all the frames were read
+    return vidbuf_nbytes;
+}
+
+static int vid_read_packet(AVFormatContext *s,
+                           AVPacket *pkt)
+{
+    BVID_DemuxContext *vid = s->priv_data;     // permanent data outside of function
+    ByteIOContext *pb = &s->pb;                // io to file
+    unsigned char block_type;                  // block type
+    int audio_length;
+    int ret_value;
+
+    av_log(s, AV_LOG_DEBUG, "[bethsoftvid demuxer read_packet]");
+
+    if(vid->is_finished || url_feof(pb)) { return AVERROR_IO; }
+
+    block_type = get_byte(pb);
+    switch(block_type)
+    {
+        case PALETTE_BLOCK:
+            av_log(s, AV_LOG_DEBUG, "palette block.\n");
+            url_fseek(pb, -1, SEEK_CUR);     // include block type
+            ret_value = av_get_packet(pb, pkt, 3 * VID_PALETTE_NUMCOLORS + 1);
+            if(ret_value != 3 * VID_PALETTE_NUMCOLORS + 1) { av_free_packet(pkt); return AVERROR_IO; }
+            pkt->stream_index = 0;
+            return ret_value;
+
+        case FIRST_AUDIO_BLOCK:
+            av_log(s, AV_LOG_DEBUG, "first ");
+            get_le16(pb); //    some unused constant
+            // soundblaster DAC used for sample rate, as on specification page (link above)
+            s->streams[1]->codec->sample_rate = 1000000 / (256 - get_byte(pb));
+            s->streams[1]->codec->bit_rate = s->streams[1]->codec->channels * s->streams[1]->codec->sample_rate * s->streams[1]->codec->bits_per_sample;
+        case AUDIO_BLOCK:
+            av_log(s, AV_LOG_DEBUG, "audio block.\n");
+            audio_length = get_le16(pb);
+            ret_value = av_get_packet(pb, pkt, audio_length);
+            pkt->stream_index = 1;
+            return (ret_value != audio_length ? AVERROR_IO : ret_value);
+
+        case VIDEO_DIFFERENCE_FRAME_BLOCK: av_log(s, AV_LOG_DEBUG, "non-");
+        case VIDEO_YOFFSET_DIFFERENCE_FRAME_BLOCK: av_log(s, AV_LOG_DEBUG, "offset ");
+        case VIDEO_FULL_FRAME_BLOCK: av_log(s, AV_LOG_DEBUG, "video block.\n");
+            return read_frame(vid, pb, pkt, block_type, s,
+                              s->streams[0]->codec->width * s->streams[0]->codec->height);
+
+        case FINISHED_BLOCK:
+            if(vid->nframes != 0)
+                av_log(s, AV_LOG_VERBOSE, "reached terminating character but not all frames read.\n");
+            vid->is_finished = 1;
+            av_log(s, AV_LOG_DEBUG, "terminating block.\n");
+            return AVERROR_IO;
+        default:
+            av_log(s, AV_LOG_ERROR, "unknown block (character = %c, decimal = %d, hex = %x)!!!\n",
+                   block_type, block_type, block_type); return -1;
+    }
+
+    return 0;
+}
+
+AVInputFormat bethsoftvid_demuxer = {
+    "bethsoftvid",
+    "Bethesda Softworks 'Daggerfall' VID format",
+    sizeof(BVID_DemuxContext),
+    vid_probe,
+    vid_read_header,
+    vid_read_packet,
+};