From a8da11514347255f49e44d249075a1289ce250c9 Mon Sep 17 00:00:00 2001 From: John-Paul Stewart Date: Fri, 31 Dec 2021 20:11:47 -0500 Subject: [PATCH] avformat/mvdec: make audio stream conditional Only allocate an audio stream if there is one in the data. Silicon Graphics movie format will contain default values (16 bit samples, 2 audio channels, 22050 Hz sample rate) even when no audio is present in the file. This confuses FFmpeg into thinking such an audio stream is present with 0 samples in it. There is a flag value in the format to indicate whether or not audio is present. This patch checks that and behaves accordingly. Signed-off-by: John-Paul Stewart Reviewed-by: Andreas Rheinhardt Reviewed-by: Peter Ross --- libavformat/mvdec.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/libavformat/mvdec.c b/libavformat/mvdec.c index ea955d2b11..0f0474141b 100644 --- a/libavformat/mvdec.c +++ b/libavformat/mvdec.c @@ -45,6 +45,10 @@ typedef struct MvContext { int aformat; ///< audio format } MvContext; +/* these magic numbers are defined in moviefile.h on Silicon Grahpics IRIX */ +#define MOVIE_SOUND 1 +#define MOVIE_SILENT 2 + #define AUDIO_FORMAT_SIGNED 401 static int mv_probe(const AVProbeData *p) @@ -305,18 +309,25 @@ static int mv_read_header(AVFormatContext *avctx) avio_skip(pb, 10); + fps = av_d2q(av_int2double(avio_rb64(pb)), INT_MAX); + /* allocate audio track first to prevent unnecessary seeking * (audio packet always precede video packet for a given frame) */ + v = avio_rb16(pb); + if (v == MOVIE_SOUND) { + /* movie has sound so allocate an audio stream */ ast = avformat_new_stream(avctx, NULL); if (!ast) return AVERROR(ENOMEM); + } else if (v != MOVIE_SILENT) + return AVERROR_INVALIDDATA; + + avio_skip(pb, 2); vst = avformat_new_stream(avctx, NULL); if (!vst) return AVERROR(ENOMEM); - fps = av_d2q(av_int2double(avio_rb64(pb)), INT_MAX); avpriv_set_pts_info(vst, 64, fps.den, fps.num); - avio_skip(pb, 4); vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; vst->avg_frame_rate = fps; vst->duration = vst->nb_frames = avio_rb32(pb); @@ -338,6 +349,7 @@ static int mv_read_header(AVFormatContext *avctx) vst->codecpar->height = avio_rb32(pb); avio_skip(pb, 12); + if (ast) { ast->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; ast->nb_frames = vst->nb_frames; ast->codecpar->sample_rate = avio_rb32(pb); @@ -373,6 +385,8 @@ static int mv_read_header(AVFormatContext *avctx) return AVERROR_INVALIDDATA; avio_skip(pb, 8); + } else + avio_skip(pb, 24); /* skip meaningless audio metadata */ var_read_metadata(avctx, "title", 0x80); var_read_metadata(avctx, "comment", 0x100); @@ -386,9 +400,11 @@ static int mv_read_header(AVFormatContext *avctx) if (avio_feof(pb)) return AVERROR_INVALIDDATA; avio_skip(pb, 8); + if (ast) { 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 * (uint64_t)bytes_per_sample); + } + av_add_index_entry(vst, pos + asize, i, vsize, 0, AVINDEX_KEYFRAME); } } else if (!version && avio_rb16(pb) == 3) { avio_skip(pb, 4);