The ffmpeg code read and wrote a 64bit duration field (in timebase units) in the ivf header, where the libvpx and chromium code instead use a 32bit frame count field, and then 32bits of unused (reserved?) space.
Switch ffmpeg to match the behaviour of libvpx & chromium. Note that libvpx writes 0 to the frame count field when initially writing the header then seeks back and overwrites it with the real frame count. ffmpeg used to write 0xFFFFFFFF - I've changed the behaviour to match libvpx. References: https://github.com/webmproject/libvpx/blob/v1.8.1/ivfenc.c#L16 Which is called from: https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1191 (initial header) https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1209 (rewrite with frame count) And the chromium parser: https://chromium.googlesource.com/chromium/src/media/+/1681b9abff73fe0e3d0932aefdab4f039a284d1a/filters/ivf_parser.h --- libavformat/ivfdec.c | 3 ++- libavformat/ivfenc.c | 11 ++++------- 2 files changed, 6 insertions(+), 8 deletions(-) diff --git a/libavformat/ivfdec.c b/libavformat/ivfdec.c index 40ae464b76..2eaa5164ff 100644 --- a/libavformat/ivfdec.c +++ b/libavformat/ivfdec.c @@ -53,7 +53,8 @@ static int read_header(AVFormatContext *s) st->codecpar->height = avio_rl16(s->pb); time_base.den = avio_rl32(s->pb); time_base.num = avio_rl32(s->pb); - st->duration = avio_rl64(s->pb); + st->nb_frames = avio_rl32(s->pb); + avio_skip(s->pb, 4); // 32 bits unused st->need_parsing = AVSTREAM_PARSE_HEADERS; diff --git a/libavformat/ivfenc.c b/libavformat/ivfenc.c index adf72117e9..85ca6045ba 100644 --- a/libavformat/ivfenc.c +++ b/libavformat/ivfenc.c @@ -22,8 +22,7 @@ #include "libavutil/intreadwrite.h" typedef struct IVFEncContext { - unsigned frame_cnt; - uint64_t last_pts, sum_delta_pts; + uint32_t frame_cnt; } IVFEncContext; static int ivf_write_header(AVFormatContext *s) @@ -53,7 +52,8 @@ 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); + avio_wl32(pb, 0); // frame count + avio_wl32(pb, 0); // unused return 0; } @@ -66,10 +66,7 @@ static int ivf_write_packet(AVFormatContext *s, AVPacket *pkt) avio_wl32(pb, pkt->size); avio_wl64(pb, pkt->pts); avio_write(pb, pkt->data, pkt->size); - if (ctx->frame_cnt) - ctx->sum_delta_pts += pkt->pts - ctx->last_pts; ctx->frame_cnt++; - ctx->last_pts = pkt->pts; return 0; } @@ -83,7 +80,7 @@ static int ivf_write_trailer(AVFormatContext *s) size_t end = avio_tell(pb); avio_seek(pb, 24, SEEK_SET); - avio_wl64(pb, ctx->frame_cnt * ctx->sum_delta_pts / (ctx->frame_cnt - 1)); + avio_wl32(pb, ctx->frame_cnt); avio_seek(pb, end, SEEK_SET); } -- 2.21.0 _______________________________________________ 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".