On Fri, Jan 6, 2023 at 1:45 AM "zhilizhao(赵志立)" <quinkbl...@foxmail.com> wrote: > > > > > On Jan 6, 2023, at 01:34, Vignesh Venkatasubramanian > > <vigneshv-at-google....@ffmpeg.org> wrote: > > > > On Thu, Jan 5, 2023 at 1:45 AM "zhilizhao(赵志立)" <quinkbl...@foxmail.com> > > wrote: > >> > >> > >> > >>> On Jan 5, 2023, at 06:16, Vignesh Venkatasubramanian > >>> <vigneshv-at-google....@ffmpeg.org> wrote: > >>> > >>> The HEIF specification permits specifying the looping behavior of > >>> animated sequences by using the EditList (elst) box. The track > >>> duration will be set to the total duration of all the loops (or > >>> infinite) and the duration of a single loop will be set in the edit > >>> list box. > >>> > >>> The default behavior is to loop infinitely. > >>> > >>> Compliance verification: > >>> * This was added in libavif recently [1] and the files produced by > >>> ffmpeg after this change have EditList boxes similar to the ones > >>> produced by libavif (and avifdec is able to parse the loop count as > >>> intended). > >>> * ComplianceWarden is ok with the produced files. > >>> * Chrome is able to play back the produced files. > >>> > >>> Signed-off-by: Vignesh Venkatasubramanian <vigne...@google.com> > >>> --- > >>> libavformat/movenc.c | 35 +++++++++++++++++++++++++++++++---- > >>> libavformat/movenc.h | 1 + > >>> 2 files changed, 32 insertions(+), 4 deletions(-) > >>> > >>> diff --git a/libavformat/movenc.c b/libavformat/movenc.c > >>> index 36c76f7f60..8d31317838 100644 > >>> --- a/libavformat/movenc.c > >>> +++ b/libavformat/movenc.c > >>> @@ -3287,7 +3287,7 @@ static int mov_write_tkhd_tag(AVIOContext *pb, > >>> MOVMuxContext *mov, > >>> int64_t duration = av_rescale_rnd(calc_pts_duration(mov, track), > >>> mov->movie_timescale, > >>> track->timescale, > >>> AV_ROUND_UP); > >>> - int version = duration < INT32_MAX ? 0 : 1; > >>> + int version; > >>> int flags = MOV_TKHD_FLAG_IN_MOVIE; > >>> int group = 0; > >>> > >>> @@ -3295,6 +3295,14 @@ static int mov_write_tkhd_tag(AVIOContext *pb, > >>> MOVMuxContext *mov, > >>> size_t display_matrix_size; > >>> int i; > >>> > >>> + if (mov->mode == MODE_AVIF) > >>> + if (!mov->avif_loop_count) > >>> + duration = INT64_MAX; > >>> + else > >>> + duration *= mov->avif_loop_count; > >>> + > >>> + version = duration < INT32_MAX ? 0 : 1; > >>> + > >>> if (st) { > >>> if (mov->per_stream_grouping) > >>> group = st->index; > >>> @@ -3414,7 +3422,10 @@ static int mov_write_tapt_tag(AVIOContext *pb, > >>> MOVTrack *track) > >>> return update_size(pb, pos); > >>> } > >>> > >>> -// This box seems important for the psp playback ... without it the > >>> movie seems to hang > >>> +// This box is written in the following cases: > >>> +// * Seems important for the psp playback. Without it the movie seems > >>> to hang. > >>> +// * Used for specifying the looping behavior of animated AVIF (as > >>> specified > >>> +// in Section 9.6 of the HEIF specification ISO/IEC 23008-12). > >>> static int mov_write_edts_tag(AVIOContext *pb, MOVMuxContext *mov, > >>> MOVTrack *track) > >>> { > >>> @@ -3425,6 +3436,7 @@ static int mov_write_edts_tag(AVIOContext *pb, > >>> MOVMuxContext *mov, > >>> int entry_size, entry_count, size; > >>> int64_t delay, start_ct = track->start_cts; > >>> int64_t start_dts = track->start_dts; > >>> + int flags = 0; > >>> > >>> if (track->entry) { > >>> if (start_dts != track->cluster[0].dts || start_ct != > >>> track->cluster[0].cts) { > >>> @@ -3440,6 +3452,17 @@ static int mov_write_edts_tag(AVIOContext *pb, > >>> MOVMuxContext *mov, > >>> > >>> delay = av_rescale_rnd(start_dts + start_ct, mov->movie_timescale, > >>> track->timescale, AV_ROUND_DOWN); > >>> + > >>> + if (mov->mode == MODE_AVIF) { > >>> + delay = 0; > >>> + // Section 9.6.3 of ISO/IEC 23008-12: flags specifies repetition > >>> of the > >>> + // edit list as follows: (flags & 1) equal to 0 specifies that > >>> the edit > >>> + // list is not repeated, while (flags & 1) equal to 1 specifies > >>> that the > >>> + // edit list is repeated. > >>> + flags = mov->avif_loop_count != 1; > >>> + start_ct = 0; > >>> + } > >>> + > >>> version |= delay < INT32_MAX ? 0 : 1; > >>> > >>> entry_size = (version == 1) ? 20 : 12; > >>> @@ -3452,7 +3475,7 @@ static int mov_write_edts_tag(AVIOContext *pb, > >>> MOVMuxContext *mov, > >>> avio_wb32(pb, size - 8); > >>> ffio_wfourcc(pb, "elst"); > >>> avio_w8(pb, version); > >>> - avio_wb24(pb, 0); /* flags */ > >>> + avio_wb24(pb, flags); /* flags */ > >>> > >>> avio_wb32(pb, entry_count); > >>> if (delay > 0) { /* add an empty edit to delay presentation */ > >>> @@ -3469,7 +3492,7 @@ static int mov_write_edts_tag(AVIOContext *pb, > >>> MOVMuxContext *mov, > >>> avio_wb32(pb, -1); > >>> } > >>> avio_wb32(pb, 0x00010000); > >>> - } else { > >>> + } else if (mov->mode != MODE_AVIF) { > >>> /* Avoid accidentally ending up with start_ct = -1 which has got a > >>> * special meaning. Normally start_ct should end up positive or > >>> zero > >>> * here, but use FFMIN in case dts is a small positive integer > >>> @@ -3670,6 +3693,9 @@ static int mov_write_trak_tag(AVFormatContext *s, > >>> AVIOContext *pb, MOVMuxContext > >>> "Not writing any edit list even though one would have > >>> been required\n"); > >>> } > >>> > >>> + if (mov->is_animated_avif) > >>> + mov_write_edts_tag(pb, mov, track); > >>> + > >>> if (track->tref_tag) > >>> mov_write_tref_tag(pb, track); > >>> > >>> @@ -7761,6 +7787,7 @@ static const AVCodecTag codec_f4v_tags[] = { > >>> > >>> static const AVOption avif_options[] = { > >>> { "movie_timescale", "set movie timescale", offsetof(MOVMuxContext, > >>> movie_timescale), AV_OPT_TYPE_INT, {.i64 = MOV_TIMESCALE}, 1, INT_MAX, > >>> AV_OPT_FLAG_ENCODING_PARAM}, > >>> + { "loop", "Number of times to loop animated AVIF: 0 - infinite > >>> loop", offsetof(MOVMuxContext, avif_loop_count), AV_OPT_TYPE_INT, {.i64 = > >>> 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, 0 }, > >> > >> The code treat -loop 1 means playback 1 time. It can be misleading > >> to mean 2 times, playback 1 time then repeat/loop 1 time. That’s > >> how ‘-stream_loop’ option works. I’m not English native speaker, > >> I don’t know which one is correct. Better make the offset by 1 > >> clear. > >> > > > > libavif uses the term "repetitionCount" instead of "loop" to not have > > this ambiguity. > > > > The behavior of the "loop" parameter in this implementation is similar > > to WebP's "loop" parameter in ffmpeg (i.e.) loop means the number of > > times it will be played back (loop == 1 => 1 playback, loop == 2 => 2 > > playbacks and so on). > > LGTM then. > > > > >>> { NULL }, > >>> }; > >>> static const AVCodecTag codec_avif_tags[] = { > >>> diff --git a/libavformat/movenc.h b/libavformat/movenc.h > >>> index c6b3313deb..e85d83abdb 100644 > >>> --- a/libavformat/movenc.h > >>> +++ b/libavformat/movenc.h > >>> @@ -249,6 +249,7 @@ typedef struct MOVMuxContext { > >>> int64_t avif_extent_pos[2]; // index 0 is YUV and 1 is Alpha. > >>> int avif_extent_length[2]; // index 0 is YUV and 1 is Alpha. > >>> int is_animated_avif; > >>> + int avif_loop_count; > >>> } MOVMuxContext; > >>> > >>> #define FF_MOV_FLAG_RTP_HINT (1 << 0) > >>> -- > >>> 2.39.0.314.g84b9a713c41-goog > >>> > >>> _______________________________________________ > >>> 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". > >> > > > > > > -- > > Vignesh > > _______________________________________________ > > 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". > > _______________________________________________ > 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".
If there are no further comments, can this series of patches be merged please? -- Vignesh _______________________________________________ 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".