libavformat/mvdec.c - manifest_repos/ffmpeg - Git at Google

 /*
  * Silicon Graphics Movie demuxer
  * Copyright (c) 2012 Peter Ross
  *
  * 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
  * Silicon Graphics Movie demuxer
  */

 #include "libavutil/channel_layout.h"
 #include "libavutil/eval.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/rational.h"

 #include "avformat.h"
 #include "internal.h"

 typedef struct MvContext {
     int nb_video_tracks;
     int nb_audio_tracks;

     int eof_count;        ///< number of streams that have finished
     int stream_index;     ///< current stream index
     int frame[2];         ///< frame nb for current stream

     int acompression;     ///< compression level for audio stream
     int aformat;          ///< audio format
 } MvContext;

 #define AUDIO_FORMAT_SIGNED 401

 static int mv_probe(const AVProbeData *p)
 {
     if (AV_RB32(p->buf) == MKBETAG('M', 'O', 'V', 'I') &&
         AV_RB16(p->buf + 4) < 3)
         return AVPROBE_SCORE_MAX;
     return 0;
 }

 static char *var_read_string(AVIOContext *pb, int size)
 {
     int n;
     char *str;

     if (size < 0 || size == INT_MAX)
         return NULL;

     str = av_malloc(size + 1);
     if (!str)
         return NULL;
     n = avio_get_str(pb, size, str, size + 1);
     if (n < size)
         avio_skip(pb, size - n);
     return str;
 }

 static int var_read_int(AVIOContext *pb, int size)
 {
     int v;
     char *s = var_read_string(pb, size);
     if (!s)
         return 0;
     v = strtol(s, NULL, 10);
     av_free(s);
     return v;
 }

 static AVRational var_read_float(AVIOContext *pb, int size)
 {
     AVRational v;
     char *s = var_read_string(pb, size);
     if (!s)
         return (AVRational) { 0, 0 };
     v = av_d2q(av_strtod(s, NULL), INT_MAX);
     av_free(s);
     return v;
 }

 static void var_read_metadata(AVFormatContext *avctx, const char *tag, int size)
 {
     char *value = var_read_string(avctx->pb, size);
     if (value)
         av_dict_set(&avctx->metadata, tag, value, AV_DICT_DONT_STRDUP_VAL);
 }

 static int set_channels(AVFormatContext *avctx, AVStream *st, int channels)
 {
     if (channels <= 0) {
         av_log(avctx, AV_LOG_ERROR, "Channel count %d invalid.\n", channels);
         return AVERROR_INVALIDDATA;
     }
     st->codecpar->channels       = channels;
     st->codecpar->channel_layout = (st->codecpar->channels == 1) ? AV_CH_LAYOUT_MONO
                                                                  : AV_CH_LAYOUT_STEREO;
     return 0;
 }

 /**
  * Parse global variable
  * @return < 0 if unknown
  */
 static int parse_global_var(AVFormatContext *avctx, AVStream *st,
                             const char *name, int size)
 {
     MvContext *mv = avctx->priv_data;
     AVIOContext *pb = avctx->pb;
     if (!strcmp(name, "__NUM_I_TRACKS")) {
         mv->nb_video_tracks = var_read_int(pb, size);
     } else if (!strcmp(name, "__NUM_A_TRACKS")) {
         mv->nb_audio_tracks = var_read_int(pb, size);
     } else if (!strcmp(name, "COMMENT") || !strcmp(name, "TITLE")) {
         var_read_metadata(avctx, name, size);
     } else if (!strcmp(name, "LOOP_MODE") || !strcmp(name, "NUM_LOOPS") ||
                !strcmp(name, "OPTIMIZED")) {
         avio_skip(pb, size); // ignore
     } else
         return AVERROR_INVALIDDATA;

     return 0;
 }

 /**
  * Parse audio variable
  * @return < 0 if unknown
  */
 static int parse_audio_var(AVFormatContext *avctx, AVStream *st,
                            const char *name, int size)
 {
     MvContext *mv = avctx->priv_data;
     AVIOContext *pb = avctx->pb;
     if (!strcmp(name, "__DIR_COUNT")) {
         st->nb_frames = var_read_int(pb, size);
     } else if (!strcmp(name, "AUDIO_FORMAT")) {
         mv->aformat = var_read_int(pb, size);
     } else if (!strcmp(name, "COMPRESSION")) {
         mv->acompression = var_read_int(pb, size);
     } else if (!strcmp(name, "DEFAULT_VOL")) {
         var_read_metadata(avctx, name, size);
     } else if (!strcmp(name, "NUM_CHANNELS")) {
         return set_channels(avctx, st, var_read_int(pb, size));
     } else if (!strcmp(name, "SAMPLE_RATE")) {
         st->codecpar->sample_rate = var_read_int(pb, size);
         avpriv_set_pts_info(st, 33, 1, st->codecpar->sample_rate);
     } else if (!strcmp(name, "SAMPLE_WIDTH")) {
         st->codecpar->bits_per_coded_sample = var_read_int(pb, size) * 8;
     } else
         return AVERROR_INVALIDDATA;

     return 0;
 }

 /**
  * Parse video variable
  * @return < 0 if unknown
  */
 static int parse_video_var(AVFormatContext *avctx, AVStream *st,
                            const char *name, int size)
 {
     AVIOContext *pb = avctx->pb;
     if (!strcmp(name, "__DIR_COUNT")) {
         st->nb_frames = st->duration = var_read_int(pb, size);
     } else if (!strcmp(name, "COMPRESSION")) {
         char *str = var_read_string(pb, size);
         if (!str)
             return AVERROR_INVALIDDATA;
         if (!strcmp(str, "1")) {
             st->codecpar->codec_id = AV_CODEC_ID_MVC1;
         } else if (!strcmp(str, "2")) {
             st->codecpar->format = AV_PIX_FMT_ABGR;
             st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
         } else if (!strcmp(str, "3")) {
             st->codecpar->codec_id = AV_CODEC_ID_SGIRLE;
         } else if (!strcmp(str, "10")) {
             st->codecpar->codec_id = AV_CODEC_ID_MJPEG;
         } else if (!strcmp(str, "MVC2")) {
             st->codecpar->codec_id = AV_CODEC_ID_MVC2;
         } else {
             avpriv_request_sample(avctx, "Video compression %s", str);
         }
         av_free(str);
     } else if (!strcmp(name, "FPS")) {
         AVRational fps = var_read_float(pb, size);
         avpriv_set_pts_info(st, 64, fps.den, fps.num);
         st->avg_frame_rate = fps;
     } else if (!strcmp(name, "HEIGHT")) {
         st->codecpar->height = var_read_int(pb, size);
     } else if (!strcmp(name, "PIXEL_ASPECT")) {
         st->sample_aspect_ratio = var_read_float(pb, size);
         av_reduce(&st->sample_aspect_ratio.num, &st->sample_aspect_ratio.den,
                   st->sample_aspect_ratio.num, st->sample_aspect_ratio.den,
                   INT_MAX);
     } else if (!strcmp(name, "WIDTH")) {
         st->codecpar->width = var_read_int(pb, size);
     } else if (!strcmp(name, "ORIENTATION")) {
         if (var_read_int(pb, size) == 1101) {
             st->codecpar->extradata      = av_strdup("BottomUp");
             if (!st->codecpar->extradata)
                 return AVERROR(ENOMEM);
             st->codecpar->extradata_size = 9;
         }
     } else if (!strcmp(name, "Q_SPATIAL") || !strcmp(name, "Q_TEMPORAL")) {
         var_read_metadata(avctx, name, size);
     } else if (!strcmp(name, "INTERLACING") || !strcmp(name, "PACKING")) {
         avio_skip(pb, size); // ignore
     } else
         return AVERROR_INVALIDDATA;

     return 0;
 }

 static int read_table(AVFormatContext *avctx, AVStream *st,
                        int (*parse)(AVFormatContext *avctx, AVStream *st,
                                     const char *name, int size))
 {
     unsigned count;
     int i;

     AVIOContext *pb = avctx->pb;
     avio_skip(pb, 4);
     count = avio_rb32(pb);
     avio_skip(pb, 4);
     for (i = 0; i < count; i++) {
         char name[17];
         int size;

         if (avio_feof(pb))
             return AVERROR_EOF;

         avio_read(pb, name, 16);
         name[sizeof(name) - 1] = 0;
         size = avio_rb32(pb);
         if (size < 0) {
             av_log(avctx, AV_LOG_ERROR, "entry size %d is invalid\n", size);
             return AVERROR_INVALIDDATA;
         }
         if (parse(avctx, st, name, size) < 0) {
             avpriv_request_sample(avctx, "Variable %s", name);
             avio_skip(pb, size);
         }
     }
     return 0;
 }

 static void read_index(AVIOContext *pb, AVStream *st)
 {
     uint64_t timestamp = 0;
     int i;
     for (i = 0; i < st->nb_frames; i++) {
         uint32_t pos  = avio_rb32(pb);
         uint32_t size = avio_rb32(pb);
         avio_skip(pb, 8);
         av_add_index_entry(st, pos, timestamp, size, 0, AVINDEX_KEYFRAME);
         if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
             timestamp += size / (st->codecpar->channels * 2LL);
         } else {
             timestamp++;
         }
     }
 }

 static int mv_read_header(AVFormatContext *avctx)
 {
     MvContext *mv = avctx->priv_data;
     AVIOContext *pb = avctx->pb;
     AVStream *ast = NULL, *vst = NULL; //initialization to suppress warning
     int version, i;
     int ret;

     avio_skip(pb, 4);

     version = avio_rb16(pb);
     if (version == 2) {
         uint64_t timestamp;
         int v;
         avio_skip(pb, 22);

         /* allocate audio track first to prevent unnecessary seeking
          * (audio packet always precede video packet for a given frame) */
         ast = avformat_new_stream(avctx, NULL);
         if (!ast)
             return AVERROR(ENOMEM);

         vst = avformat_new_stream(avctx, NULL);
         if (!vst)
             return AVERROR(ENOMEM);
         avpriv_set_pts_info(vst, 64, 1, 15);
         vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
         vst->avg_frame_rate    = av_inv_q(vst->time_base);
         vst->nb_frames         = avio_rb32(pb);
         v = avio_rb32(pb);
         switch (v) {
         case 1:
             vst->codecpar->codec_id = AV_CODEC_ID_MVC1;
             break;
         case 2:
             vst->codecpar->format = AV_PIX_FMT_ARGB;
             vst->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
             break;
         default:
             avpriv_request_sample(avctx, "Video compression %i", v);
             break;
         }
         vst->codecpar->codec_tag = 0;
         vst->codecpar->width     = avio_rb32(pb);
         vst->codecpar->height    = avio_rb32(pb);
         avio_skip(pb, 12);

         ast->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
         ast->nb_frames          = vst->nb_frames;
         ast->codecpar->sample_rate = avio_rb32(pb);
         if (ast->codecpar->sample_rate <= 0) {
             av_log(avctx, AV_LOG_ERROR, "Invalid sample rate %d\n", ast->codecpar->sample_rate);
             return AVERROR_INVALIDDATA;
         }
         avpriv_set_pts_info(ast, 33, 1, ast->codecpar->sample_rate);
         if (set_channels(avctx, ast, avio_rb32(pb)) < 0)
             return AVERROR_INVALIDDATA;

         v = avio_rb32(pb);
         if (v == AUDIO_FORMAT_SIGNED) {
             ast->codecpar->codec_id = AV_CODEC_ID_PCM_S16BE;
         } else {
             avpriv_request_sample(avctx, "Audio compression (format %i)", v);
         }

         avio_skip(pb, 12);
         var_read_metadata(avctx, "title", 0x80);
         var_read_metadata(avctx, "comment", 0x100);
         avio_skip(pb, 0x80);

         timestamp = 0;
         for (i = 0; i < vst->nb_frames; i++) {
             uint32_t pos   = avio_rb32(pb);
             uint32_t asize = avio_rb32(pb);
             uint32_t vsize = avio_rb32(pb);
             if (avio_feof(pb))
                 return AVERROR_INVALIDDATA;
             avio_skip(pb, 8);
             av_add_index_entry(ast, pos, timestamp, asize, 0, AVINDEX_KEYFRAME);
             av_add_index_entry(vst, pos + asize, i, vsize, 0, AVINDEX_KEYFRAME);
             timestamp += asize / (ast->codecpar->channels * 2LL);
         }
     } else if (!version && avio_rb16(pb) == 3) {
         avio_skip(pb, 4);

         if ((ret = read_table(avctx, NULL, parse_global_var)) < 0)
             return ret;

         if (mv->nb_audio_tracks < 0  || mv->nb_video_tracks < 0 ||
            (mv->nb_audio_tracks == 0 && mv->nb_video_tracks == 0)) {
             av_log(avctx, AV_LOG_ERROR, "Stream count is invalid.\n");
             return AVERROR_INVALIDDATA;
         }

         if (mv->nb_audio_tracks > 1) {
             avpriv_request_sample(avctx, "Multiple audio streams support");
             return AVERROR_PATCHWELCOME;
         } else if (mv->nb_audio_tracks) {
             ast = avformat_new_stream(avctx, NULL);
             if (!ast)
                 return AVERROR(ENOMEM);
             ast->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
             if ((read_table(avctx, ast, parse_audio_var)) < 0)
                 return ret;
             if (mv->acompression == 100 &&
                 mv->aformat == AUDIO_FORMAT_SIGNED &&
                 ast->codecpar->bits_per_coded_sample == 16) {
                 ast->codecpar->codec_id = AV_CODEC_ID_PCM_S16BE;
             } else {
                 avpriv_request_sample(avctx,
                                       "Audio compression %i (format %i, sr %i)",
                                       mv->acompression, mv->aformat,
                                       ast->codecpar->bits_per_coded_sample);
                 ast->codecpar->codec_id = AV_CODEC_ID_NONE;
             }
             if (ast->codecpar->channels <= 0) {
                 av_log(avctx, AV_LOG_ERROR, "No valid channel count found.\n");
                 return AVERROR_INVALIDDATA;
             }
         }

         if (mv->nb_video_tracks > 1) {
             avpriv_request_sample(avctx, "Multiple video streams support");
             return AVERROR_PATCHWELCOME;
         } else if (mv->nb_video_tracks) {
             vst = avformat_new_stream(avctx, NULL);
             if (!vst)
                 return AVERROR(ENOMEM);
             vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
             if ((ret = read_table(avctx, vst, parse_video_var))<0)
                 return ret;
         }

         if (mv->nb_audio_tracks)
             read_index(pb, ast);

         if (mv->nb_video_tracks)
             read_index(pb, vst);
     } else {
         avpriv_request_sample(avctx, "Version %i", version);
         return AVERROR_PATCHWELCOME;
     }

     return 0;
 }

 static int mv_read_packet(AVFormatContext *avctx, AVPacket *pkt)
 {
     MvContext *mv = avctx->priv_data;
     AVIOContext *pb = avctx->pb;
     AVStream *st = avctx->streams[mv->stream_index];
     const AVIndexEntry *index;
     int frame = mv->frame[mv->stream_index];
     int64_t ret;
     uint64_t pos;

     if (frame < st->internal->nb_index_entries) {
         index = &st->internal->index_entries[frame];
         pos   = avio_tell(pb);
         if (index->pos > pos)
             avio_skip(pb, index->pos - pos);
         else if (index->pos < pos) {
             if (!(pb->seekable & AVIO_SEEKABLE_NORMAL))
                 return AVERROR(EIO);
             ret = avio_seek(pb, index->pos, SEEK_SET);
             if (ret < 0)
                 return ret;
         }
         ret = av_get_packet(pb, pkt, index->size);
         if (ret < 0)
             return ret;

         pkt->stream_index = mv->stream_index;
         pkt->pts          = index->timestamp;
         pkt->flags       |= AV_PKT_FLAG_KEY;

         mv->frame[mv->stream_index]++;
         mv->eof_count = 0;
     } else {
         mv->eof_count++;
         if (mv->eof_count >= avctx->nb_streams)
             return AVERROR_EOF;

         // avoid returning 0 without a packet
         return AVERROR(EAGAIN);
     }

     mv->stream_index++;
     if (mv->stream_index >= avctx->nb_streams)
         mv->stream_index = 0;

     return 0;
 }

 static int mv_read_seek(AVFormatContext *avctx, int stream_index,
                         int64_t timestamp, int flags)
 {
     MvContext *mv = avctx->priv_data;
     AVStream *st = avctx->streams[stream_index];
     int frame, i;

     if ((flags & AVSEEK_FLAG_FRAME) || (flags & AVSEEK_FLAG_BYTE))
         return AVERROR(ENOSYS);

     if (!(avctx->pb->seekable & AVIO_SEEKABLE_NORMAL))
         return AVERROR(EIO);

     frame = av_index_search_timestamp(st, timestamp, flags);
     if (frame < 0)
         return AVERROR_INVALIDDATA;

     for (i = 0; i < avctx->nb_streams; i++)
         mv->frame[i] = frame;
     return 0;
 }

 AVInputFormat ff_mv_demuxer = {
     .name           = "mv",
     .long_name      = NULL_IF_CONFIG_SMALL("Silicon Graphics Movie"),
     .priv_data_size = sizeof(MvContext),
     .read_probe     = mv_probe,
     .read_header    = mv_read_header,
     .read_packet    = mv_read_packet,
     .read_seek      = mv_read_seek,
 };
	/*
	* Silicon Graphics Movie demuxer
	* Copyright (c) 2012 Peter Ross
	*
	* 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
	* Silicon Graphics Movie demuxer
	*/

	#include "libavutil/channel_layout.h"
	#include "libavutil/eval.h"
	#include "libavutil/intreadwrite.h"
	#include "libavutil/rational.h"

	#include "avformat.h"
	#include "internal.h"

	typedef struct MvContext {
	int nb_video_tracks;
	int nb_audio_tracks;

	int eof_count; ///< number of streams that have finished
	int stream_index; ///< current stream index
	int frame[2]; ///< frame nb for current stream

	int acompression; ///< compression level for audio stream
	int aformat; ///< audio format
	} MvContext;

	#define AUDIO_FORMAT_SIGNED 401

	static int mv_probe(const AVProbeData *p)
	{
	if (AV_RB32(p->buf) == MKBETAG('M', 'O', 'V', 'I') &&
	AV_RB16(p->buf + 4) < 3)
	return AVPROBE_SCORE_MAX;
	return 0;
	}

	static char var_read_string(AVIOContext pb, int size)
	{
	int n;
	char *str;

	if (size < 0 \|\| size == INT_MAX)
	return NULL;

	str = av_malloc(size + 1);
	if (!str)
	return NULL;
	n = avio_get_str(pb, size, str, size + 1);
	if (n < size)
	avio_skip(pb, size - n);
	return str;
	}

	static int var_read_int(AVIOContext *pb, int size)
	{
	int v;
	char *s = var_read_string(pb, size);
	if (!s)
	return 0;
	v = strtol(s, NULL, 10);
	av_free(s);
	return v;
	}

	static AVRational var_read_float(AVIOContext *pb, int size)
	{
	AVRational v;
	char *s = var_read_string(pb, size);
	if (!s)
	return (AVRational) { 0, 0 };
	v = av_d2q(av_strtod(s, NULL), INT_MAX);
	av_free(s);
	return v;
	}

	static void var_read_metadata(AVFormatContext avctx, const char tag, int size)
	{
	char *value = var_read_string(avctx->pb, size);
	if (value)
	av_dict_set(&avctx->metadata, tag, value, AV_DICT_DONT_STRDUP_VAL);
	}

	static int set_channels(AVFormatContext avctx, AVStream st, int channels)
	{
	if (channels <= 0) {
	av_log(avctx, AV_LOG_ERROR, "Channel count %d invalid.\n", channels);
	return AVERROR_INVALIDDATA;
	}
	st->codecpar->channels = channels;
	st->codecpar->channel_layout = (st->codecpar->channels == 1) ? AV_CH_LAYOUT_MONO
	: AV_CH_LAYOUT_STEREO;
	return 0;
	}

	/**
	* Parse global variable
	* @return < 0 if unknown
	*/
	static int parse_global_var(AVFormatContext avctx, AVStream st,
	const char *name, int size)
	{
	MvContext *mv = avctx->priv_data;
	AVIOContext *pb = avctx->pb;
	if (!strcmp(name, "__NUM_I_TRACKS")) {
	mv->nb_video_tracks = var_read_int(pb, size);
	} else if (!strcmp(name, "__NUM_A_TRACKS")) {
	mv->nb_audio_tracks = var_read_int(pb, size);
	} else if (!strcmp(name, "COMMENT") \|\| !strcmp(name, "TITLE")) {
	var_read_metadata(avctx, name, size);
	} else if (!strcmp(name, "LOOP_MODE") \|\| !strcmp(name, "NUM_LOOPS") \|\|
	!strcmp(name, "OPTIMIZED")) {
	avio_skip(pb, size); // ignore
	} else
	return AVERROR_INVALIDDATA;

	return 0;
	}

	/**
	* Parse audio variable
	* @return < 0 if unknown
	*/
	static int parse_audio_var(AVFormatContext avctx, AVStream st,
	const char *name, int size)
	{
	MvContext *mv = avctx->priv_data;
	AVIOContext *pb = avctx->pb;
	if (!strcmp(name, "__DIR_COUNT")) {
	st->nb_frames = var_read_int(pb, size);
	} else if (!strcmp(name, "AUDIO_FORMAT")) {
	mv->aformat = var_read_int(pb, size);
	} else if (!strcmp(name, "COMPRESSION")) {
	mv->acompression = var_read_int(pb, size);
	} else if (!strcmp(name, "DEFAULT_VOL")) {
	var_read_metadata(avctx, name, size);
	} else if (!strcmp(name, "NUM_CHANNELS")) {
	return set_channels(avctx, st, var_read_int(pb, size));
	} else if (!strcmp(name, "SAMPLE_RATE")) {
	st->codecpar->sample_rate = var_read_int(pb, size);
	avpriv_set_pts_info(st, 33, 1, st->codecpar->sample_rate);
	} else if (!strcmp(name, "SAMPLE_WIDTH")) {
	st->codecpar->bits_per_coded_sample = var_read_int(pb, size) * 8;
	} else
	return AVERROR_INVALIDDATA;

	return 0;
	}

	/**
	* Parse video variable
	* @return < 0 if unknown
	*/
	static int parse_video_var(AVFormatContext avctx, AVStream st,
	const char *name, int size)
	{
	AVIOContext *pb = avctx->pb;
	if (!strcmp(name, "__DIR_COUNT")) {
	st->nb_frames = st->duration = var_read_int(pb, size);
	} else if (!strcmp(name, "COMPRESSION")) {
	char *str = var_read_string(pb, size);
	if (!str)
	return AVERROR_INVALIDDATA;
	if (!strcmp(str, "1")) {
	st->codecpar->codec_id = AV_CODEC_ID_MVC1;
	} else if (!strcmp(str, "2")) {
	st->codecpar->format = AV_PIX_FMT_ABGR;
	st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
	} else if (!strcmp(str, "3")) {
	st->codecpar->codec_id = AV_CODEC_ID_SGIRLE;
	} else if (!strcmp(str, "10")) {
	st->codecpar->codec_id = AV_CODEC_ID_MJPEG;
	} else if (!strcmp(str, "MVC2")) {
	st->codecpar->codec_id = AV_CODEC_ID_MVC2;
	} else {
	avpriv_request_sample(avctx, "Video compression %s", str);
	}
	av_free(str);
	} else if (!strcmp(name, "FPS")) {
	AVRational fps = var_read_float(pb, size);
	avpriv_set_pts_info(st, 64, fps.den, fps.num);
	st->avg_frame_rate = fps;
	} else if (!strcmp(name, "HEIGHT")) {
	st->codecpar->height = var_read_int(pb, size);
	} else if (!strcmp(name, "PIXEL_ASPECT")) {
	st->sample_aspect_ratio = var_read_float(pb, size);
	av_reduce(&st->sample_aspect_ratio.num, &st->sample_aspect_ratio.den,
	st->sample_aspect_ratio.num, st->sample_aspect_ratio.den,
	INT_MAX);
	} else if (!strcmp(name, "WIDTH")) {
	st->codecpar->width = var_read_int(pb, size);
	} else if (!strcmp(name, "ORIENTATION")) {
	if (var_read_int(pb, size) == 1101) {
	st->codecpar->extradata = av_strdup("BottomUp");
	if (!st->codecpar->extradata)
	return AVERROR(ENOMEM);
	st->codecpar->extradata_size = 9;
	}
	} else if (!strcmp(name, "Q_SPATIAL") \|\| !strcmp(name, "Q_TEMPORAL")) {
	var_read_metadata(avctx, name, size);
	} else if (!strcmp(name, "INTERLACING") \|\| !strcmp(name, "PACKING")) {
	avio_skip(pb, size); // ignore
	} else
	return AVERROR_INVALIDDATA;

	return 0;
	}

	static int read_table(AVFormatContext avctx, AVStream st,
	int (parse)(AVFormatContext avctx, AVStream *st,
	const char *name, int size))
	{
	unsigned count;
	int i;

	AVIOContext *pb = avctx->pb;
	avio_skip(pb, 4);
	count = avio_rb32(pb);
	avio_skip(pb, 4);
	for (i = 0; i < count; i++) {
	char name[17];
	int size;

	if (avio_feof(pb))
	return AVERROR_EOF;

	avio_read(pb, name, 16);
	name[sizeof(name) - 1] = 0;
	size = avio_rb32(pb);
	if (size < 0) {
	av_log(avctx, AV_LOG_ERROR, "entry size %d is invalid\n", size);
	return AVERROR_INVALIDDATA;
	}
	if (parse(avctx, st, name, size) < 0) {
	avpriv_request_sample(avctx, "Variable %s", name);
	avio_skip(pb, size);
	}
	}
	return 0;
	}

	static void read_index(AVIOContext pb, AVStream st)
	{
	uint64_t timestamp = 0;
	int i;
	for (i = 0; i < st->nb_frames; i++) {
	uint32_t pos = avio_rb32(pb);
	uint32_t size = avio_rb32(pb);
	avio_skip(pb, 8);
	av_add_index_entry(st, pos, timestamp, size, 0, AVINDEX_KEYFRAME);
	if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
	timestamp += size / (st->codecpar->channels * 2LL);
	} else {
	timestamp++;
	}
	}
	}

	static int mv_read_header(AVFormatContext *avctx)
	{
	MvContext *mv = avctx->priv_data;
	AVIOContext *pb = avctx->pb;
	AVStream ast = NULL, vst = NULL; //initialization to suppress warning
	int version, i;
	int ret;

	avio_skip(pb, 4);

	version = avio_rb16(pb);
	if (version == 2) {
	uint64_t timestamp;
	int v;
	avio_skip(pb, 22);

	/* allocate audio track first to prevent unnecessary seeking
	* (audio packet always precede video packet for a given frame) */
	ast = avformat_new_stream(avctx, NULL);
	if (!ast)
	return AVERROR(ENOMEM);

	vst = avformat_new_stream(avctx, NULL);
	if (!vst)
	return AVERROR(ENOMEM);
	avpriv_set_pts_info(vst, 64, 1, 15);
	vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
	vst->avg_frame_rate = av_inv_q(vst->time_base);
	vst->nb_frames = avio_rb32(pb);
	v = avio_rb32(pb);
	switch (v) {
	case 1:
	vst->codecpar->codec_id = AV_CODEC_ID_MVC1;
	break;
	case 2:
	vst->codecpar->format = AV_PIX_FMT_ARGB;
	vst->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
	break;
	default:
	avpriv_request_sample(avctx, "Video compression %i", v);
	break;
	}
	vst->codecpar->codec_tag = 0;
	vst->codecpar->width = avio_rb32(pb);
	vst->codecpar->height = avio_rb32(pb);
	avio_skip(pb, 12);

	ast->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
	ast->nb_frames = vst->nb_frames;
	ast->codecpar->sample_rate = avio_rb32(pb);
	if (ast->codecpar->sample_rate <= 0) {
	av_log(avctx, AV_LOG_ERROR, "Invalid sample rate %d\n", ast->codecpar->sample_rate);
	return AVERROR_INVALIDDATA;
	}
	avpriv_set_pts_info(ast, 33, 1, ast->codecpar->sample_rate);
	if (set_channels(avctx, ast, avio_rb32(pb)) < 0)
	return AVERROR_INVALIDDATA;

	v = avio_rb32(pb);
	if (v == AUDIO_FORMAT_SIGNED) {
	ast->codecpar->codec_id = AV_CODEC_ID_PCM_S16BE;
	} else {
	avpriv_request_sample(avctx, "Audio compression (format %i)", v);
	}

	avio_skip(pb, 12);
	var_read_metadata(avctx, "title", 0x80);
	var_read_metadata(avctx, "comment", 0x100);
	avio_skip(pb, 0x80);

	timestamp = 0;
	for (i = 0; i < vst->nb_frames; i++) {
	uint32_t pos = avio_rb32(pb);
	uint32_t asize = avio_rb32(pb);
	uint32_t vsize = avio_rb32(pb);
	if (avio_feof(pb))
	return AVERROR_INVALIDDATA;
	avio_skip(pb, 8);
	av_add_index_entry(ast, pos, timestamp, asize, 0, AVINDEX_KEYFRAME);
	av_add_index_entry(vst, pos + asize, i, vsize, 0, AVINDEX_KEYFRAME);
	timestamp += asize / (ast->codecpar->channels * 2LL);
	}
	} else if (!version && avio_rb16(pb) == 3) {
	avio_skip(pb, 4);

	if ((ret = read_table(avctx, NULL, parse_global_var)) < 0)
	return ret;

	if (mv->nb_audio_tracks < 0 \|\| mv->nb_video_tracks < 0 \|\|
	(mv->nb_audio_tracks == 0 && mv->nb_video_tracks == 0)) {
	av_log(avctx, AV_LOG_ERROR, "Stream count is invalid.\n");
	return AVERROR_INVALIDDATA;
	}

	if (mv->nb_audio_tracks > 1) {
	avpriv_request_sample(avctx, "Multiple audio streams support");
	return AVERROR_PATCHWELCOME;
	} else if (mv->nb_audio_tracks) {
	ast = avformat_new_stream(avctx, NULL);
	if (!ast)
	return AVERROR(ENOMEM);
	ast->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
	if ((read_table(avctx, ast, parse_audio_var)) < 0)
	return ret;
	if (mv->acompression == 100 &&
	mv->aformat == AUDIO_FORMAT_SIGNED &&
	ast->codecpar->bits_per_coded_sample == 16) {
	ast->codecpar->codec_id = AV_CODEC_ID_PCM_S16BE;
	} else {
	avpriv_request_sample(avctx,
	"Audio compression %i (format %i, sr %i)",
	mv->acompression, mv->aformat,
	ast->codecpar->bits_per_coded_sample);
	ast->codecpar->codec_id = AV_CODEC_ID_NONE;
	}
	if (ast->codecpar->channels <= 0) {
	av_log(avctx, AV_LOG_ERROR, "No valid channel count found.\n");
	return AVERROR_INVALIDDATA;
	}
	}

	if (mv->nb_video_tracks > 1) {
	avpriv_request_sample(avctx, "Multiple video streams support");
	return AVERROR_PATCHWELCOME;
	} else if (mv->nb_video_tracks) {
	vst = avformat_new_stream(avctx, NULL);
	if (!vst)
	return AVERROR(ENOMEM);
	vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
	if ((ret = read_table(avctx, vst, parse_video_var))<0)
	return ret;
	}

	if (mv->nb_audio_tracks)
	read_index(pb, ast);

	if (mv->nb_video_tracks)
	read_index(pb, vst);
	} else {
	avpriv_request_sample(avctx, "Version %i", version);
	return AVERROR_PATCHWELCOME;
	}

	return 0;
	}

	static int mv_read_packet(AVFormatContext avctx, AVPacket pkt)
	{
	MvContext *mv = avctx->priv_data;
	AVIOContext *pb = avctx->pb;
	AVStream *st = avctx->streams[mv->stream_index];
	const AVIndexEntry *index;
	int frame = mv->frame[mv->stream_index];
	int64_t ret;
	uint64_t pos;

	if (frame < st->internal->nb_index_entries) {
	index = &st->internal->index_entries[frame];
	pos = avio_tell(pb);
	if (index->pos > pos)
	avio_skip(pb, index->pos - pos);
	else if (index->pos < pos) {
	if (!(pb->seekable & AVIO_SEEKABLE_NORMAL))
	return AVERROR(EIO);
	ret = avio_seek(pb, index->pos, SEEK_SET);
	if (ret < 0)
	return ret;
	}
	ret = av_get_packet(pb, pkt, index->size);
	if (ret < 0)
	return ret;

	pkt->stream_index = mv->stream_index;
	pkt->pts = index->timestamp;
	pkt->flags \|= AV_PKT_FLAG_KEY;

	mv->frame[mv->stream_index]++;
	mv->eof_count = 0;
	} else {
	mv->eof_count++;
	if (mv->eof_count >= avctx->nb_streams)
	return AVERROR_EOF;

	// avoid returning 0 without a packet
	return AVERROR(EAGAIN);
	}

	mv->stream_index++;
	if (mv->stream_index >= avctx->nb_streams)
	mv->stream_index = 0;

	return 0;
	}

	static int mv_read_seek(AVFormatContext *avctx, int stream_index,
	int64_t timestamp, int flags)
	{
	MvContext *mv = avctx->priv_data;
	AVStream *st = avctx->streams[stream_index];
	int frame, i;

	if ((flags & AVSEEK_FLAG_FRAME) \|\| (flags & AVSEEK_FLAG_BYTE))
	return AVERROR(ENOSYS);

	if (!(avctx->pb->seekable & AVIO_SEEKABLE_NORMAL))
	return AVERROR(EIO);

	frame = av_index_search_timestamp(st, timestamp, flags);
	if (frame < 0)
	return AVERROR_INVALIDDATA;

	for (i = 0; i < avctx->nb_streams; i++)
	mv->frame[i] = frame;
	return 0;
	}

	AVInputFormat ff_mv_demuxer = {
	.name = "mv",
	.long_name = NULL_IF_CONFIG_SMALL("Silicon Graphics Movie"),
	.priv_data_size = sizeof(MvContext),
	.read_probe = mv_probe,
	.read_header = mv_read_header,
	.read_packet = mv_read_packet,
	.read_seek = mv_read_seek,
	};