[FFmpeg-devel] [PATCH] avformat/mov: Add support for demuxing still HEIC images

[Vignesh Venkatasubramanian]

They are similar to AVIF images (both use the HEIF container).
The only additional work needed is to parse the hvcC box and put
it in the extradata.

With this patch applied, ffmpeg (when built with an HEVC decoder)
is able to decode the files in
https://github.com/nokiatech/heif/tree/gh-pages/content/images

Partially fixes trac ticket #6521.

Signed-off-by: Vignesh Venkatasubramanian <vigneshv at google.com>
---
 libavformat/isom.h |  2 ++
 libavformat/mov.c  | 38 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/libavformat/isom.h b/libavformat/isom.h
index 3d375d7a46..b30b9da65e 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -327,6 +327,8 @@ typedef struct MOVContext {
         int64_t extent_offset;
     } *avif_info;
     int avif_info_size;
+    int64_t hvcC_offset;
+    int hvcC_size;
     int interleaved_read;
 } MOVContext;
 
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 1996e0028c..cec9cb5fe1 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -1218,7 +1218,8 @@ 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);
+    c->is_still_picture_avif = !strncmp(type, "avif", 4) ||
+                               !strncmp(type, "mif1", 4);
     minor_ver = avio_rb32(pb); /* minor version */
     av_dict_set_int(&c->fc->metadata, "minor_version", minor_ver, 0);
 
@@ -4911,6 +4912,16 @@ static int avif_add_stream(MOVContext *c, int item_id)
     st->priv_data = sc;
     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
     st->codecpar->codec_id = AV_CODEC_ID_AV1;
+    if (c->hvcC_offset >= 0) {
+        int ret;
+        int64_t pos = avio_tell(c->fc->pb);
+        st->codecpar->codec_id = AV_CODEC_ID_HEVC;
+        avio_seek(c->fc->pb, c->hvcC_offset, SEEK_SET);
+        ret = ff_get_extradata(c->fc, st->codecpar, c->fc->pb, c->hvcC_size);
+        if (ret < 0)
+            return ret;
+        avio_seek(c->fc->pb, pos, SEEK_SET);
+    }
     sc->ffindex = st->index;
     c->trak_index = st->index;
     st->avg_frame_rate.num = st->avg_frame_rate.den = 1;
@@ -4953,6 +4964,8 @@ static int avif_add_stream(MOVContext *c, int item_id)
 
 static int mov_read_meta(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 {
+    c->hvcC_offset = -1;
+    c->hvcC_size = 0;
     while (atom.size > 8) {
         uint32_t tag;
         if (avio_feof(pb))
@@ -7826,6 +7839,28 @@ static int mov_read_iloc(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     return atom.size;
 }
 
+static int mov_read_iprp(MOVContext *c, AVIOContext *pb, MOVAtom atom)
+{
+    int size = avio_rb32(pb);
+    if (avio_rl32(pb) != MKTAG('i','p','c','o'))
+        return AVERROR_INVALIDDATA;
+    size -= 8;
+    while (size > 0) {
+        int sub_size, sub_type;
+        sub_size = avio_rb32(pb);
+        sub_type = avio_rl32(pb);
+        sub_size -= 8;
+        size -= sub_size + 8;
+        if (sub_type == MKTAG('h','v','c','C')) {
+            c->hvcC_offset = avio_tell(pb);
+            c->hvcC_size = sub_size;
+            break;
+        }
+        avio_skip(pb, sub_size);
+    }
+    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 },
@@ -7933,6 +7968,7 @@ static const MOVParseTableEntry mov_default_parse_table[] = {
 { MKTAG('p','c','m','C'), mov_read_pcmc }, /* PCM configuration box */
 { MKTAG('p','i','t','m'), mov_read_pitm },
 { MKTAG('e','v','c','C'), mov_read_glbl },
+{ MKTAG('i','p','r','p'), mov_read_iprp },
 { 0, NULL }
 };
 
-- 
2.42.0.515.g380fc7ccd1-goog