avformat/mov: fix setting tile grid stream offsets when a stream is referenced more than once

The amount of tiles does not necessarely need to match the amount of streams referenced
in the grid, as there could be duplicates.
Don't silently ignore EEXIST return codes from avformat_stream_group_add_stream() and
instead store the index of the duplicate stream.

Signed-off-by: James Almer <jamrial@gmail.com>

2 files changed, 18 insertions, 5 deletions

diff --git a/libavformat/isom.h b/libavformat/isom.h
index f18b15bbff..767babf749 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -299,6 +299,7 @@ typedef struct HEIFGrid {
     HEIFItem *item;
     HEIFItem **tile_item_list;
     int16_t *tile_id_list;
+    unsigned *tile_idx_list;
     int nb_tiles;
 } HEIFGrid;
 
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 93e1cebe65..a881acf99d 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -9020,8 +9020,9 @@ static int mov_read_iref_dimg(MOVContext *c, AVIOContext *pb, int version)
 
     entries = avio_rb16(pb);
     grid->tile_id_list = av_malloc_array(entries, sizeof(*grid->tile_id_list));
+    grid->tile_idx_list = av_calloc(entries, sizeof(*grid->tile_idx_list));
     grid->tile_item_list = av_calloc(entries, sizeof(*grid->tile_item_list));
-    if (!grid->tile_id_list || !grid->tile_item_list)
+    if (!grid->tile_id_list || !grid->tile_item_list || !grid->tile_idx_list)
         return AVERROR(ENOMEM);
     /* 'to' item ids */
     for (i = 0; i < entries; i++)
@@ -9918,6 +9919,7 @@ static int mov_read_close(AVFormatContext *s)
     av_freep(&mov->heif_item);
     for (i = 0; i < mov->nb_heif_grid; i++) {
         av_freep(&mov->heif_grid[i].tile_id_list);
+        av_freep(&mov->heif_grid[i].tile_idx_list);
         av_freep(&mov->heif_grid[i].tile_item_list);
     }
     av_freep(&mov->heif_grid);
@@ -10170,7 +10172,7 @@ static int read_image_grid(AVFormatContext *s, const HEIFGrid *grid,
             if (i == tile_grid->nb_tiles)
                 return AVERROR_INVALIDDATA;
 
-            tile_grid->offsets[i].idx        = i;
+            tile_grid->offsets[i].idx        = grid->tile_idx_list[i];
             tile_grid->offsets[i].horizontal = x;
             tile_grid->offsets[i].vertical   = y;
 
@@ -10261,7 +10263,7 @@ static int read_image_iovl(AVFormatContext *s, const HEIFGrid *grid,
     }
 
     for (int i = 0; i < tile_grid->nb_tiles; i++) {
-        tile_grid->offsets[i].idx        = grid->tile_item_list[i]->st->index;
+        tile_grid->offsets[i].idx        = grid->tile_idx_list[i];
         tile_grid->offsets[i].horizontal = (flags & 1) ? avio_rb32(s->pb) : avio_rb16(s->pb);
         tile_grid->offsets[i].vertical   = (flags & 1) ? avio_rb32(s->pb) : avio_rb16(s->pb);
         av_log(c->fc, AV_LOG_TRACE, "iovl: stream_idx[%d] %u, "
@@ -10313,10 +10315,20 @@ static int mov_parse_tiles(AVFormatContext *s)
                 }
 
                 grid->tile_item_list[j] = item;
+                grid->tile_idx_list[j] = stg->nb_streams;
 
                 err = avformat_stream_group_add_stream(stg, st);
-                if (err < 0 && err != AVERROR(EEXIST))
-                    return err;
+                if (err < 0) {
+                    int l;
+                    if (err != AVERROR(EEXIST))
+                        return err;
+
+                    for (l = 0; l < stg->nb_streams; l++)
+                        if (stg->streams[l]->index == st->index)
+                            break;
+                    av_assert0(l < stg->nb_streams);
+                    grid->tile_idx_list[j] = l;
+                }
 
                 if (item->item_id != mov->primary_item_id)
                     st->disposition |= AV_DISPOSITION_DEPENDENT;