avformat/mov: Rework the AVIF parser to handle multiple items

Stores the item ids of all the items found in the file and
processes the primary item at the end of the meta box. This patch
does not change any behavior. It sets up the code for parsing
alpha channel (and possibly images with 'grid') in follow up
patches.

Reviewed-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Signed-off-by: Vignesh Venkatasubramanian <vigneshv@google.com>
Signed-off-by: James Zern <jzern@google.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/libavformat/isom.h b/libavformat/isom.h
index f05c2d9c28..9d8646d2ea 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -318,6 +318,12 @@ typedef struct MOVContext {
     uint32_t max_stts_delta;
     int is_still_picture_avif;
     int primary_item_id;
+    struct {
+        int item_id;
+        int extent_length;
+        int64_t extent_offset;
+    } *avif_info;
+    int avif_info_size;
 } MOVContext;
 
 int ff_mp4_read_descr_len(AVIOContext *pb);