Should set "number of frames" to bytes 24-27 of IVF header, not duration. It is described by [1]. Also confirm it by parsing IVF files in [2].
[1] Duck IVF - MultimediaWiki https://wiki.multimedia.cx/index.php/Duck_IVF [2] webm/vp8-test-vectors - Git at Google https://chromium.googlesource.com/webm/vp8-test-vectors Signed-off-by: Jianhui Dai <jianhui.j....@intel.com> --- libavformat/ivfenc.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/libavformat/ivfenc.c b/libavformat/ivfenc.c index 47b4efbcd1..88399099d4 100644 --- a/libavformat/ivfenc.c +++ b/libavformat/ivfenc.c @@ -72,7 +72,8 @@ static int ivf_write_header(AVFormatContext *s) avio_wl16(pb, par->height); avio_wl32(pb, s->streams[0]->time_base.den); avio_wl32(pb, s->streams[0]->time_base.num); - avio_wl64(pb, 0xFFFFFFFFFFFFFFFFULL); // length is overwritten at the end of muxing + avio_wl32(pb, 0xFFFFFFFF); // "number of frames" is overwritten at the end of muxing + avio_wl32(pb, 0); // unused return 0; } @@ -99,16 +100,12 @@ static int ivf_write_trailer(AVFormatContext *s) AVIOContext *pb = s->pb; IVFEncContext *ctx = s->priv_data; - if ((pb->seekable & AVIO_SEEKABLE_NORMAL) && - (ctx->frame_cnt > 1 || (ctx->frame_cnt == 1 && ctx->last_pkt_duration))) { + // overwrite the "number of frames" + if ((pb->seekable & AVIO_SEEKABLE_NORMAL)) { int64_t end = avio_tell(pb); avio_seek(pb, 24, SEEK_SET); - // overwrite the "length" field (duration) - avio_wl32(pb, ctx->last_pkt_duration ? - ctx->sum_delta_pts + ctx->last_pkt_duration : - ctx->frame_cnt * ctx->sum_delta_pts / (ctx->frame_cnt - 1)); - avio_wl32(pb, 0); // zero out unused bytes + avio_wl32(pb, ctx->frame_cnt); avio_seek(pb, end, SEEK_SET); } -- 2.25.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
