On Wed, Mar 16, 2022 at 5:41 AM Lynne <d...@lynne.ee> wrote: > > 15 Mar 2022, 22:38 by vigneshv-at-google....@ffmpeg.org: > > > On Thu, Mar 3, 2022 at 3:58 PM Vignesh Venkatasubramanian > > <vigne...@google.com> wrote: > > > >> > >> Add support for parsing AVIF still images. This patches supports > >> AVIF still images that have exactly 1 item (i.e.) no alpha channel. > >> Essentially, we will have to parse the "iloc" box and populate > >> the mov index. > >> > >> With this patch, we can decode still AVIF images like so: > >> ffmpeg -i image.avif image.png > >> > >> Partially fixes trac ticket #7621 > >> > >> Signed-off-by: Vignesh Venkatasubramanian <vigne...@google.com> > >> --- > >> libavformat/isom.h | 1 + > >> libavformat/mov.c | 142 +++++++++++++++++++++++++++++++++++++++++++++ > >> 2 files changed, 143 insertions(+) > >> > >> diff --git a/libavformat/isom.h b/libavformat/isom.h > >> index 625dea8421..cc0a8e1ca9 100644 > >> --- a/libavformat/isom.h > >> +++ b/libavformat/isom.h > >> @@ -306,6 +306,7 @@ typedef struct MOVContext { > >> int have_read_mfra_size; > >> uint32_t mfra_size; > >> uint32_t max_stts_delta; > >> + int is_still_picture_avif; > >> } MOVContext; > >> > >> int ff_mp4_read_descr_len(AVIOContext *pb); > >> diff --git a/libavformat/mov.c b/libavformat/mov.c > >> index 68b6d7f075..d260024e47 100644 > >> --- a/libavformat/mov.c > >> +++ b/libavformat/mov.c > >> @@ -1126,6 +1126,7 @@ static int mov_read_ftyp(MOVContext *c, AVIOContext > >> *pb, MOVAtom atom) > >> c->isom = 1; > >> av_log(c->fc, AV_LOG_DEBUG, "ISO: File Type Major Brand: %.4s\n",(char > >> *)&type); > >> av_dict_set(&c->fc->metadata, "major_brand", type, 0); > >> + c->is_still_picture_avif = !strncmp(type, "avif", 4); > >> minor_ver = avio_rb32(pb); /* minor version */ > >> av_dict_set_int(&c->fc->metadata, "minor_version", minor_ver, 0); > >> > >> @@ -7173,6 +7174,146 @@ cleanup: > >> return ret; > >> } > >> > >> +static int rb_size(AVIOContext *pb, uint64_t* value, int size) > >> +{ > >> + if (size == 0) { > >> + *value = 0; > >> + } else if (size == 1) { > >> + *value = avio_r8(pb); > >> + } else if (size == 2) { > >> + *value = avio_rb16(pb); > >> + } else if (size == 4) { > >> + *value = avio_rb32(pb); > >> + } else if (size == 8) { > >> + *value = avio_rb64(pb); > >> + } else { > >> + return -1; > >> + } > >> + return size; > >> +} > >> + > >> +static int mov_read_iloc(MOVContext *c, AVIOContext *pb, MOVAtom atom) > >> +{ > >> + int version, offset_size, length_size, base_offset_size, index_size; > >> + int item_count, extent_count; > >> + uint64_t base_offset, extent_offset, extent_length; > >> + int i, j; > >> + uint8_t value; > >> + AVStream *st; > >> + MOVStreamContext *sc; > >> + > >> + if (!c->is_still_picture_avif) { > >> + // * For non-avif, we simply ignore the iloc box. > >> + // * For animated avif, we don't care about the iloc box as all > >> the > >> + // necessary information can be found in the moov box. > >> + return 0; > >> + } > >> + > >> + if (c->fc->nb_streams != 0) { > >> + av_log(c->fc, AV_LOG_INFO, "Duplicate iloc box found\n"); > >> + return 0; > >> + } > >> + > >> + st = avformat_new_stream(c->fc, NULL); > >> + if (!st) return AVERROR(ENOMEM); > >> + st->id = c->fc->nb_streams; > >> + sc = av_mallocz(sizeof(MOVStreamContext)); > >> + if (!sc) return AVERROR(ENOMEM); > >> + > >> + st->priv_data = sc; > >> + st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; > >> + st->codecpar->codec_id = AV_CODEC_ID_AV1; > >> + sc->ffindex = st->index; > >> + c->trak_index = st->index; > >> + st->avg_frame_rate.num = st->avg_frame_rate.den = 1; > >> + st->time_base.num = st->time_base.den = 1; > >> + st->nb_frames = 1; > >> + sc->time_scale = 1; > >> + sc = st->priv_data; > >> + sc->pb = c->fc->pb; > >> + sc->pb_is_copied = 1; > >> + > >> + version = avio_r8(pb); > >> + avio_rb24(pb); // flags. > >> + > >> + value = avio_r8(pb); > >> + offset_size = (value >> 4) & 0xF; > >> + length_size = value & 0xF; > >> + value = avio_r8(pb); > >> + base_offset_size = (value >> 4) & 0xF; > >> + index_size = (version == 0) ? 0 : (value & 0xF); > >> + if (index_size != 0) { > >> + return AVERROR_PATCHWELCOME; > >> + } > >> + item_count = (version < 2) ? avio_rb16(pb) : avio_rb32(pb); > >> + if (item_count > 1) { > >> + // For still AVIF images, we only support one item. Second item > >> will > >> + // generally be found for AVIF images with alpha channel. We don't > >> + // support them as of now. > >> + return AVERROR_PATCHWELCOME; > >> + } > >> + > >> + // Populate the necessary fields used by mov_build_index. > >> + sc->stsc_count = item_count; > >> + sc->stsc_data = av_malloc_array(item_count, sizeof(*sc->stsc_data)); > >> + if (!sc->stsc_data) { > >> + return AVERROR(ENOMEM); > >> + } > >> + sc->stsc_data[0].first = 1; > >> + sc->stsc_data[0].count = 1; > >> + sc->stsc_data[0].id = 1; > >> + sc->chunk_count = item_count; > >> + sc->chunk_offsets = av_malloc_array(item_count, > >> sizeof(*sc->chunk_offsets)); > >> + if (!sc->chunk_offsets) { > >> + return AVERROR(ENOMEM); > >> + } > >> + sc->sample_count = item_count; > >> + sc->sample_sizes = av_malloc_array(item_count, > >> sizeof(*sc->sample_sizes)); > >> + if (!sc->sample_sizes) { > >> + return AVERROR(ENOMEM); > >> + } > >> + sc->stts_count = item_count; > >> + sc->stts_data = av_malloc_array(item_count, sizeof(*sc->stts_data)); > >> + if (!sc->stts_data) { > >> + return AVERROR(ENOMEM); > >> + } > >> + sc->stts_data[0].count = 1; > >> + sc->stts_data[0].duration = 0; // Not used for still images. But > >> needed by mov_build_index. > >> + > >> + for (i = 0; i < item_count; ++i) { > >> + (version < 2) ? avio_rb16(pb) : avio_rb32(pb); // item_id; > >> + if (version > 0) { > >> + avio_rb16(pb); // construction_method. > >> + } > >> + avio_rb16(pb); // data_reference_index. > >> + if (rb_size(pb, &base_offset, base_offset_size) < 0) { > >> + return AVERROR_INVALIDDATA; > >> + } > >> + extent_count = avio_rb16(pb); > >> + if (extent_count > 1) { > >> + // For still AVIF images, we only support one extent item. > >> + return AVERROR_PATCHWELCOME; > >> + } > >> + for (j = 0; j < extent_count; ++j) { > >> + if (rb_size(pb, &extent_offset, offset_size) < 0 || > >> + rb_size(pb, &extent_length, length_size) < 0) { > >> + return AVERROR_INVALIDDATA; > >> + } > >> + sc->sample_sizes[0] = extent_length; > >> + sc->chunk_offsets[0] = base_offset + extent_offset; > >> + } > >> + } > >> + > >> + mov_build_index(c, st); > >> + > >> + // For still AVIF images, the iloc box contains all the necessary > >> + // information that would generally be provided by the moov box. So > >> simply > >> + // mark that we have found the moov box so that parsing can continue. > >> + c->found_moov = 1; > >> + > >> + return atom.size; > >> +} > >> + > >> static const MOVParseTableEntry mov_default_parse_table[] = { > >> { MKTAG('A','C','L','R'), mov_read_aclr }, > >> { MKTAG('A','P','R','G'), mov_read_avid }, > >> @@ -7272,6 +7413,7 @@ static const MOVParseTableEntry > >> mov_default_parse_table[] = { > >> { MKTAG('d','v','v','C'), mov_read_dvcc_dvvc }, > >> { MKTAG('d','v','w','C'), mov_read_dvcc_dvvc }, > >> { MKTAG('k','i','n','d'), mov_read_kind }, > >> +{ MKTAG('i','l','o','c'), mov_read_iloc }, > >> { 0, NULL } > >> }; > >> > >> -- > >> 2.35.1.616.g0bdcbb4464-goog > >> > > > > Ping on this patch please. > > > > Fix the coding style, please.
I am sorry, can you please be a bit more specific? I was trying to follow the code style that is consistent with the rest of the file. > _______________________________________________ > 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".