diff mbox series

[FFmpeg-devel,2/3,v7] avformat/mov: add support for tile HEIF still images

Message ID 20240209222817.13543-2-jamrial@gmail.com
State New
Headers show
Series [FFmpeg-devel,1/3,v9] avformat: add a Tile Grid stream group type | expand

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yinshiyou/make_loongarch64 success Make finished
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andriy/make_x86 success Make finished
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Commit Message

James Almer Feb. 9, 2024, 10:28 p.m. UTC
Export each tile as its own stream, and the grid information as a Stream Group
of type TILE_GRID.
This also enables exporting other stream items like thumbnails, which may be
present in non tiled HEIF images too. For those, the primary stream will be
tagged with the default disposition.

Based on a patch by Swaraj Hota

Signed-off-by: James Almer <jamrial@gmail.com>
---
Now supporting Image Overlay derived images, by parsing the iovl item type.

 libavformat/avformat.c |   8 +
 libavformat/avformat.h |   6 +
 libavformat/dump.c     |   2 +
 libavformat/internal.h |   5 +
 libavformat/isom.h     |  15 +-
 libavformat/mov.c      | 484 +++++++++++++++++++++++++++++++++++++----
 6 files changed, 475 insertions(+), 45 deletions(-)
diff mbox series

Patch

diff --git a/libavformat/avformat.c b/libavformat/avformat.c
index f53ba4ce58..eb898223d2 100644
--- a/libavformat/avformat.c
+++ b/libavformat/avformat.c
@@ -119,6 +119,14 @@  void ff_remove_stream(AVFormatContext *s, AVStream *st)
     ff_free_stream(&s->streams[ --s->nb_streams ]);
 }
 
+void ff_remove_stream_group(AVFormatContext *s, AVStreamGroup *stg)
+{
+    av_assert0(s->nb_stream_groups > 0);
+    av_assert0(s->stream_groups[ s->nb_stream_groups - 1 ] == stg);
+
+    ff_free_stream_group(&s->stream_groups[ --s->nb_stream_groups ]);
+}
+
 /* XXX: suppress the packet queue */
 void ff_flush_packet_queue(AVFormatContext *s)
 {
diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index 97f68531ac..98954ce112 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -811,6 +811,12 @@  typedef struct AVIndexEntry {
  * The video stream contains still images.
  */
 #define AV_DISPOSITION_STILL_IMAGE          (1 << 20)
+/**
+ * The video stream is intended to be merged with another stream before
+ * presentation.
+ * Used for example to signal the stream contains a tile from a HEIF grid.
+ */
+#define AV_DISPOSITION_TILE                 (1 << 21)
 
 /**
  * @return The AV_DISPOSITION_* flag corresponding to disp or a negative error
diff --git a/libavformat/dump.c b/libavformat/dump.c
index 756db8c87e..6123ca58a5 100644
--- a/libavformat/dump.c
+++ b/libavformat/dump.c
@@ -657,6 +657,8 @@  static void dump_stream_format(const AVFormatContext *ic, int i,
         av_log(NULL, log_level, " (still image)");
     if (st->disposition & AV_DISPOSITION_NON_DIEGETIC)
         av_log(NULL, log_level, " (non-diegetic)");
+    if (st->disposition & AV_DISPOSITION_TILE)
+        av_log(NULL, log_level, " (tile)");
     av_log(NULL, log_level, "\n");
 
     dump_metadata(NULL, st->metadata, extra_indent, log_level);
diff --git a/libavformat/internal.h b/libavformat/internal.h
index c66f959e9f..5603ca1ab5 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -637,6 +637,11 @@  void ff_remove_stream(AVFormatContext *s, AVStream *st);
  * is not yet attached to an AVFormatContext.
  */
 void ff_free_stream_group(AVStreamGroup **pstg);
+/**
+ * Remove a stream group from its AVFormatContext and free it.
+ * The stream group must be the last stream group of the AVFormatContext.
+ */
+void ff_remove_stream_group(AVFormatContext *s, AVStreamGroup *stg);
 
 unsigned int ff_codec_get_tag(const AVCodecTag *tags, enum AVCodecID id);
 
diff --git a/libavformat/isom.h b/libavformat/isom.h
index a4cca4c798..ade6d88faf 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -267,15 +267,24 @@  typedef struct MOVStreamContext {
 
 typedef struct HEIFItem {
     AVStream *st;
+    char *name;
     int item_id;
     int64_t extent_length;
     int64_t extent_offset;
-    int64_t size;
+    int tile_rows;
+    int tile_cols;
     int width;
     int height;
     int type;
+    int is_idat_relative;
 } HEIFItem;
 
+typedef struct HEIFGrid {
+    HEIFItem *item;
+    int16_t *tile_id_list;
+    int nb_tiles;
+} HEIFGrid;
+
 typedef struct MOVContext {
     const AVClass *class; ///< class for private options
     AVFormatContext *fc;
@@ -339,6 +348,10 @@  typedef struct MOVContext {
     int cur_item_id;
     HEIFItem *heif_item;
     int nb_heif_item;
+    HEIFGrid *heif_grid;
+    int nb_heif_grid;
+    int thmb_item_id;
+    int64_t idat_offset;
     int interleaved_read;
 } MOVContext;
 
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 42b0135987..02662bead0 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -185,6 +185,30 @@  static int mov_read_mac_string(MOVContext *c, AVIOContext *pb, int len,
     return p - dst;
 }
 
+static AVStream *get_curr_st(MOVContext *c)
+{
+    AVStream *st = NULL;
+
+    if (c->fc->nb_streams < 1)
+        return NULL;
+
+    for (int i = 0; i < c->nb_heif_item; i++) {
+        HEIFItem *item = &c->heif_item[i];
+
+        if (!item->st)
+            continue;
+        if (item->st->id != c->cur_item_id)
+            continue;
+
+        st = item->st;
+        break;
+    }
+    if (!st)
+        st = c->fc->streams[c->fc->nb_streams-1];
+
+    return st;
+}
+
 static int mov_read_covr(MOVContext *c, AVIOContext *pb, int type, int len)
 {
     AVStream *st;
@@ -1767,9 +1791,9 @@  static int mov_read_colr(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     uint16_t color_primaries, color_trc, color_matrix;
     int ret;
 
-    if (c->fc->nb_streams < 1)
+    st = get_curr_st(c);
+    if (!st)
         return 0;
-    st = c->fc->streams[c->fc->nb_streams - 1];
 
     ret = ffio_read_size(pb, color_parameter_type, 4);
     if (ret < 0)
@@ -2117,9 +2141,9 @@  static int mov_read_glbl(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     AVStream *st;
     int ret;
 
-    if (c->fc->nb_streams < 1)
+    st = get_curr_st(c);
+    if (!st)
         return 0;
-    st = c->fc->streams[c->fc->nb_streams-1];
 
     if ((uint64_t)atom.size > (1<<30))
         return AVERROR_INVALIDDATA;
@@ -4951,12 +4975,10 @@  static int heif_add_stream(MOVContext *c, HEIFItem *item)
     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
     st->codecpar->codec_id = mov_codec_id(st, item->type);
     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;
 
@@ -7809,11 +7831,18 @@  static int mov_read_pitm(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     return atom.size;
 }
 
+static int mov_read_idat(MOVContext *c, AVIOContext *pb, MOVAtom atom)
+{
+    c->idat_offset = avio_tell(pb);
+    return 0;
+}
+
 static int mov_read_iloc(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 {
+    HEIFItem *heif_item;
     int version, offset_size, length_size, base_offset_size, index_size;
     int item_count, extent_count;
-    uint64_t base_offset, extent_offset, extent_length;
+    int64_t base_offset, extent_offset, extent_length;
     uint8_t value;
 
     if (c->found_moov) {
@@ -7832,17 +7861,20 @@  static int mov_read_iloc(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     base_offset_size = (value >> 4) & 0xF;
     index_size = !version ? 0 : (value & 0xF);
     if (index_size) {
-        av_log(c->fc, AV_LOG_ERROR, "iloc: index_size != 0 not supported.\n");
+        avpriv_report_missing_feature(c->fc, "iloc: index_size != 0");
         return AVERROR_PATCHWELCOME;
     }
     item_count = (version < 2) ? avio_rb16(pb) : avio_rb32(pb);
 
-    if (!c->heif_item) {
-        c->heif_item = av_calloc(item_count, sizeof(*c->heif_item));
-        if (!c->heif_item)
-            return AVERROR(ENOMEM);
-        c->nb_heif_item = item_count;
-    }
+    heif_item = av_realloc_array(c->heif_item, item_count, sizeof(*c->heif_item));
+    if (!heif_item)
+        return AVERROR(ENOMEM);
+    c->heif_item = heif_item;
+    if (item_count > c->nb_heif_item)
+        memset(c->heif_item + c->nb_heif_item, 0,
+               sizeof(*c->heif_item) * (item_count - c->nb_heif_item));
+    c->nb_heif_item = FFMAX(c->nb_heif_item, item_count);
+    c->cur_item_id = 0;
 
     av_log(c->fc, AV_LOG_TRACE, "iloc: item_count %d\n", item_count);
     for (int i = 0; i < item_count; i++) {
@@ -7852,7 +7884,7 @@  static int mov_read_iloc(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         if (avio_feof(pb))
             return AVERROR_INVALIDDATA;
         if (offset_type > 1) {
-            avpriv_request_sample(c->fc, "iloc offset type %d", offset_type);
+            avpriv_report_missing_feature(c->fc, "iloc offset type %d", offset_type);
             return AVERROR_PATCHWELCOME;
         }
         c->heif_item[i].item_id = item_id;
@@ -7863,13 +7895,15 @@  static int mov_read_iloc(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         extent_count = avio_rb16(pb);
         if (extent_count > 1) {
             // For still AVIF images, we only support one extent item.
-            av_log(c->fc, AV_LOG_ERROR, "iloc: extent_count > 1 not supported\n");
+            avpriv_report_missing_feature(c->fc, "iloc: extent_count > 1");
             return AVERROR_PATCHWELCOME;
         }
         for (int 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;
+            if (offset_type == 1)
+                c->heif_item[i].is_idat_relative = 1;
             c->heif_item[i].extent_length = extent_length;
             c->heif_item[i].extent_offset = base_offset + extent_offset;
             av_log(c->fc, AV_LOG_TRACE, "iloc: item_idx %d, offset_type %d, "
@@ -7884,7 +7918,7 @@  static int mov_read_iloc(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 
 static int mov_read_infe(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 {
-    char item_name[128];
+    AVBPrint item_name;
     int64_t size = atom.size;
     uint32_t item_type;
     int item_id;
@@ -7894,27 +7928,32 @@  static int mov_read_infe(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     avio_rb24(pb);  // flags.
     size -= 4;
 
-    if (version != 2) {
-        av_log(c->fc, AV_LOG_ERROR, "infe: version != 2 not supported\n");
+    if (version < 2) {
+        av_log(c->fc, AV_LOG_ERROR, "infe: version < 2 not supported\n");
         return AVERROR_PATCHWELCOME;
     }
 
-    item_id = avio_rb16(pb);
+    item_id = version > 2 ? avio_rb32(pb) : avio_rb16(pb);
     avio_rb16(pb); // item_protection_index
     item_type = avio_rl32(pb);
     size -= 8;
-    size -= avio_get_str(pb, INT_MAX, item_name, sizeof(item_name));
 
-    av_log(c->fc, AV_LOG_TRACE, "infe: item_id %d, item_type %s, item_name %s\n",
-           item_id, av_fourcc2str(item_type), item_name);
+    av_bprint_init(&item_name, 0, AV_BPRINT_SIZE_UNLIMITED);
+    ret = ff_read_string_to_bprint_overwrite(pb, &item_name, size);
+    if (ret < 0) {
+        av_bprint_finalize(&item_name, NULL);
+        return ret;
+    }
 
-    // Skip all but the primary item until support is added
-    if (item_id != c->primary_item_id)
-        return 0;
+    av_log(c->fc, AV_LOG_TRACE, "infe: item_id %d, item_type %s, item_name %s\n",
+           item_id, av_fourcc2str(item_type), item_name.str);
 
+    size -= ret + 1;
     if (size > 0)
         avio_skip(pb, size);
 
+    if (ret)
+        av_bprint_finalize(&item_name, &c->heif_item[c->cur_item_id].name);
     c->heif_item[c->cur_item_id].item_id = item_id;
     c->heif_item[c->cur_item_id].type    = item_type;
 
@@ -7925,9 +7964,6 @@  static int mov_read_infe(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         if (ret < 0)
             return ret;
         break;
-    default:
-        av_log(c->fc, AV_LOG_TRACE, "infe: ignoring item_type %s\n", av_fourcc2str(item_type));
-        break;
     }
 
     c->cur_item_id++;
@@ -7937,6 +7973,7 @@  static int mov_read_infe(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 
 static int mov_read_iinf(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 {
+    HEIFItem *heif_item;
     int entry_count;
     int version, ret;
 
@@ -7954,13 +7991,14 @@  static int mov_read_iinf(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     avio_rb24(pb);  // flags.
     entry_count = version ? avio_rb32(pb) : avio_rb16(pb);
 
-    if (!c->heif_item) {
-        c->heif_item = av_calloc(entry_count, sizeof(*c->heif_item));
-        if (!c->heif_item)
-            return AVERROR(ENOMEM);
-        c->nb_heif_item = entry_count;
-    }
-
+    heif_item = av_realloc_array(c->heif_item, entry_count, sizeof(*c->heif_item));
+    if (!heif_item)
+        return AVERROR(ENOMEM);
+    c->heif_item = heif_item;
+    if (entry_count > c->nb_heif_item)
+        memset(c->heif_item + c->nb_heif_item, 0,
+               sizeof(*c->heif_item) * (entry_count - c->nb_heif_item));
+    c->nb_heif_item = FFMAX(c->nb_heif_item, entry_count);
     c->cur_item_id = 0;
 
     for (int i = 0; i < entry_count; i++) {
@@ -7977,11 +8015,124 @@  static int mov_read_iinf(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     return 0;
 }
 
+static int mov_read_iref_dimg(MOVContext *c, AVIOContext *pb, int version)
+{
+    HEIFItem *item = NULL;
+    HEIFGrid *grid;
+    int entries, i;
+    int from_item_id = version ? avio_rb32(pb) : avio_rb16(pb);
+
+    for (int i = 0; i < c->nb_heif_grid; i++) {
+        if (c->heif_grid[i].item->item_id == from_item_id) {
+            av_log(c->fc, AV_LOG_ERROR, "More than one 'dimg' box "
+                                        "referencing the same 'grid'\n");
+            return AVERROR_INVALIDDATA;
+        }
+    }
+    for (int i = 0; i < c->nb_heif_item; i++) {
+        if (c->heif_item[i].item_id != from_item_id)
+            continue;
+        item = &c->heif_item[i];
+
+        switch (item->type) {
+        case MKTAG('g','r','i','d'):
+        case MKTAG('i','o','v','l'):
+            break;
+        default:
+            avpriv_report_missing_feature(c->fc, "Derived item of type %s",
+                                          av_fourcc2str(item->type));
+            return 0;
+        }
+        break;
+    }
+    if (!item) {
+        av_log(c->fc, AV_LOG_ERROR, "Missing grid information\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    grid = av_realloc_array(c->heif_grid, c->nb_heif_grid + 1U,
+                            sizeof(*c->heif_grid));
+    if (!grid)
+        return AVERROR(ENOMEM);
+    c->heif_grid = grid;
+    grid = &grid[c->nb_heif_grid++];
+
+    entries = avio_rb16(pb);
+    grid->tile_id_list = av_malloc_array(entries, sizeof(*grid->tile_id_list));
+    if (!grid->tile_id_list)
+        return AVERROR(ENOMEM);
+    /* 'to' item ids */
+    for (i = 0; i < entries; i++)
+        grid->tile_id_list[i] = version ? avio_rb32(pb) : avio_rb16(pb);
+    grid->nb_tiles = entries;
+    grid->item = item;
+
+    av_log(c->fc, AV_LOG_TRACE, "dimg: from_item_id %d, entries %d\n",
+           from_item_id, entries);
+
+    return 0;
+}
+
+static int mov_read_iref_thmb(MOVContext *c, AVIOContext *pb, int version)
+{
+    int entries;
+    int to_item_id, from_item_id = version ? avio_rb32(pb) : avio_rb16(pb);
+
+    entries = avio_rb16(pb);
+    if (entries > 1) {
+        avpriv_request_sample(c->fc, "thmb in iref referencing several items");
+        return AVERROR_PATCHWELCOME;
+    }
+    /* 'to' item ids */
+    to_item_id = version ? avio_rb32(pb) : avio_rb16(pb);
+
+    if (to_item_id != c->primary_item_id)
+        return 0;
+
+    c->thmb_item_id = from_item_id;
+
+    av_log(c->fc, AV_LOG_TRACE, "thmb: from_item_id %d, entries %d\n",
+           from_item_id, entries);
+
+    return 0;
+}
+
 static int mov_read_iref(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 {
-    avio_rb32(pb);  /* version and flags */
+    int version = avio_r8(pb);
+    avio_rb24(pb); // flags
     atom.size -= 4;
-    return mov_read_default(c, pb, atom);
+
+    if (version > 1) {
+        av_log(c->fc, AV_LOG_WARNING, "Unknown iref box version %d\n", version);
+        return 0;
+    }
+
+    while (atom.size) {
+        uint32_t type, size = avio_rb32(pb);
+        int64_t next = avio_tell(pb);
+
+        if (size < 14 || next < 0 || next > INT64_MAX - size)
+            return AVERROR_INVALIDDATA;
+
+        next += size - 4;
+        type = avio_rl32(pb);
+        switch (type) {
+        case MKTAG('d','i','m','g'):
+            mov_read_iref_dimg(c, pb, version);
+            break;
+        case MKTAG('t','h','m','b'):
+            mov_read_iref_thmb(c, pb, version);
+            break;
+        default:
+            av_log(c->fc, AV_LOG_DEBUG, "Unknown iref type %s size %"PRIu32"\n",
+                   av_fourcc2str(type), size);
+        }
+
+        atom.size -= size;
+        avio_seek(pb, next, SEEK_SET);
+    }
+    return 0;
 }
 
 static int mov_read_ispe(MOVContext *c, AVIOContext *pb, MOVAtom atom)
@@ -8104,10 +8255,6 @@  static int mov_read_iprp(MOVContext *c, AVIOContext *pb, MOVAtom atom)
             av_log(c->fc, AV_LOG_TRACE, "ipma: property_index %d, item_id %d, item_type %s\n",
                    index + 1, item_id, av_fourcc2str(ref->type));
 
-            // Skip properties referencing items other than the primary item until support is added
-            if (item_id != c->primary_item_id)
-                continue;
-
             c->cur_item_id = item_id;
 
             ret = mov_read_default(c, &ref->b.pub,
@@ -8236,6 +8383,7 @@  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','d','a','t'), mov_read_idat },
 { MKTAG('i','r','e','f'), mov_read_iref },
 { MKTAG('i','s','p','e'), mov_read_ispe },
 { MKTAG('i','p','r','p'), mov_read_iprp },
@@ -8745,7 +8893,12 @@  static int mov_read_close(AVFormatContext *s)
 
     av_freep(&mov->aes_decrypt);
     av_freep(&mov->chapter_tracks);
+    for (i = 0; i < mov->nb_heif_item; i++)
+        av_freep(&mov->heif_item[i].name);
     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);
 
     return 0;
 }
@@ -8885,6 +9038,224 @@  fail:
     return ret;
 }
 
+static int read_image_grid(AVFormatContext *s, AVStreamGroup *stg,
+                           AVStreamGroupTileGrid *tile_grid, HEIFGrid *grid)
+{
+    MOVContext *c = s->priv_data;
+    HEIFItem *item = grid->item;
+    int64_t offset = 0, pos = avio_tell(s->pb);
+    int x = 0, y = 0, i = 0;
+    int ret, flags, size;
+
+    if (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL)) {
+        av_log(c->fc, AV_LOG_INFO, "grid box with non seekable input\n");
+        return AVERROR_PATCHWELCOME;
+    }
+    if (item->is_idat_relative) {
+        if (!c->idat_offset) {
+            av_log(c->fc, AV_LOG_ERROR, "missing idat box required by the image grid\n");
+            return AVERROR_INVALIDDATA;
+        }
+        offset = c->idat_offset;
+    }
+
+    avio_seek(s->pb, item->extent_offset + offset, SEEK_SET);
+
+    avio_r8(s->pb);    /* version */
+    flags = avio_r8(s->pb);
+
+    item->tile_rows = avio_r8(s->pb) + 1;
+    item->tile_cols = avio_r8(s->pb) + 1;
+    /* actual width and height of output image */
+    tile_grid->width  = (flags & 1) ? avio_rb32(s->pb) : avio_rb16(s->pb);
+    tile_grid->height = (flags & 1) ? avio_rb32(s->pb) : avio_rb16(s->pb);
+
+    av_log(c->fc, AV_LOG_TRACE, "grid: grid_rows %d grid_cols %d output_width %d output_height %d\n",
+           item->tile_rows, item->tile_cols, tile_grid->width, tile_grid->height);
+
+    avio_seek(s->pb, pos, SEEK_SET);
+
+    size = grid->item->tile_rows * grid->item->tile_cols;
+    for (int i = 0; i < grid->item->tile_cols; i++)
+        tile_grid->coded_width  += stg->streams[i]->codecpar->width;
+    for (int i = 0; i < size; i += grid->item->tile_cols)
+        tile_grid->coded_height += stg->streams[i]->codecpar->height;
+
+    tile_grid->offsets = av_calloc(grid->nb_tiles, sizeof(*tile_grid->offsets));
+    if (!tile_grid->offsets)
+        return AVERROR(ENOMEM);
+
+    while (y < tile_grid->coded_height) {
+        int left_col = i;
+
+        while (x < tile_grid->coded_width) {
+            if (i == grid->nb_tiles) {
+                ret = AVERROR(EINVAL);
+                goto fail;
+            }
+
+            tile_grid->offsets[i].x = x;
+            tile_grid->offsets[i].y = y;
+
+            x += stg->streams[i++]->codecpar->width;
+        }
+
+        if (x > tile_grid->coded_width) {
+            avpriv_request_sample(s, "Non uniform HEIF tiles");
+            ret = AVERROR_PATCHWELCOME;
+            goto fail;
+        }
+
+        x  = 0;
+        y += stg->streams[left_col]->codecpar->height;
+    }
+
+    if (y > tile_grid->coded_height || i != grid->nb_tiles) {
+        avpriv_request_sample(s, "Non uniform HEIF tiles");
+        ret = AVERROR_PATCHWELCOME;
+        goto fail;
+    }
+
+    return 0;
+fail:
+    av_freep(&tile_grid->offsets);
+
+    return ret;
+}
+
+static int read_image_overlay(AVFormatContext *s, AVStreamGroupTileGrid *tile_grid,
+                              HEIFGrid *grid)
+{
+    MOVContext *c = s->priv_data;
+    HEIFItem *item = grid->item;
+    uint16_t canvas_fill_value[4];
+    int64_t offset = 0, pos = avio_tell(s->pb);
+    int flags;
+
+    if (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL)) {
+        av_log(c->fc, AV_LOG_INFO, "iovl box with non seekable input\n");
+        return AVERROR_PATCHWELCOME;
+    }
+    if (item->is_idat_relative) {
+        if (!c->idat_offset) {
+            av_log(c->fc, AV_LOG_ERROR, "missing idat box required by the image overlay\n");
+            return AVERROR_INVALIDDATA;
+        }
+        offset = c->idat_offset;
+    }
+
+    avio_seek(s->pb, item->extent_offset + offset, SEEK_SET);
+
+    avio_r8(s->pb);    /* version */
+    flags = avio_r8(s->pb);
+
+    for (int i = 0; i < 4; i++)
+        canvas_fill_value[i] = avio_rb16(s->pb);
+    av_log(c->fc, AV_LOG_TRACE, "iovl: canvas_fill_value { %u, %u, %u, %u }\n",
+           canvas_fill_value[0], canvas_fill_value[1],
+           canvas_fill_value[2], canvas_fill_value[3]);
+    for (int i = 0; i < 4; i++)
+        tile_grid->background[i] = canvas_fill_value[i];
+
+    /* actual width and height of output image */
+    tile_grid->width        =
+    tile_grid->coded_width  = (flags & 1) ? avio_rb32(s->pb) : avio_rb16(s->pb);
+    tile_grid->height       =
+    tile_grid->coded_height = (flags & 1) ? avio_rb32(s->pb) : avio_rb16(s->pb);
+    av_log(c->fc, AV_LOG_TRACE, "iovl: output_width %d, output_height %d\n",
+           tile_grid->width, tile_grid->height);
+
+    tile_grid->offsets = av_calloc(grid->nb_tiles, sizeof(*tile_grid->offsets));
+    if (!tile_grid->offsets)
+        return AVERROR(ENOMEM);
+
+    for (int i = 0; i < grid->nb_tiles; i++) {
+        tile_grid->offsets[i].x = (flags & 1) ? avio_rb32(s->pb) : avio_rb16(s->pb);
+        tile_grid->offsets[i].y = (flags & 1) ? avio_rb32(s->pb) : avio_rb16(s->pb);
+        av_log(c->fc, AV_LOG_TRACE, "iovl: horizontal_offset[%d] %d, vertical_offset[%d] %d\n",
+               i, tile_grid->offsets[i].x, i, tile_grid->offsets[i].y);
+    }
+
+    avio_seek(s->pb, pos, SEEK_SET);
+
+    return 0;
+}
+
+static int mov_parse_tiles(AVFormatContext *s)
+{
+    MOVContext *mov = s->priv_data;
+
+    for (int i = 0; i < mov->nb_heif_grid; i++) {
+        AVStreamGroup *stg = avformat_stream_group_create(s, AV_STREAM_GROUP_PARAMS_TILE_GRID, NULL);
+        AVStreamGroupTileGrid *tile_grid;
+        HEIFGrid *grid = &mov->heif_grid[i];
+        int err, loop = 1;
+
+        if (!stg)
+            return AVERROR(ENOMEM);
+
+        stg->id = grid->item->item_id;
+        tile_grid = stg->params.tile_grid;
+
+        for (int j = 0; j < grid->nb_tiles; j++) {
+            int tile_id = grid->tile_id_list[j];
+
+            for (int k = 0; k < mov->nb_heif_item; k++) {
+                const HEIFItem *item = &mov->heif_item[k];
+                AVStream *st = item->st;
+
+                if (item->item_id != tile_id)
+                    continue;
+                if (!st) {
+                    av_log(s, AV_LOG_WARNING, "HEIF item id %d from grid id %d doesn't "
+                                              "reference a stream\n",
+                           tile_id, grid->item->item_id);
+                    ff_remove_stream_group(s, stg);
+                    loop = 0;
+                    break;
+                }
+
+                st->codecpar->width  = item->width;
+                st->codecpar->height = item->height;
+
+                err = avformat_stream_group_add_stream(stg, st);
+                if (err == AVERROR(EEXIST))
+                    return AVERROR_INVALIDDATA;
+                else if (err < 0)
+                    return err;
+
+                st->disposition |= AV_DISPOSITION_TILE;
+                break;
+            }
+
+            if (!loop)
+                break;
+        }
+
+        if (!loop)
+            continue;
+
+        switch (grid->item->type) {
+        case MKTAG('g','r','i','d'):
+            err = read_image_grid(s, stg, tile_grid, grid);
+            break;
+        case MKTAG('i','o','v','l'):
+            err = read_image_overlay(s, tile_grid, grid);
+            break;
+        default:
+            av_assert0(0);
+        }
+        if (err < 0)
+            return err;
+
+
+        if (grid->item->name)
+            av_dict_set(&stg->metadata, "title", grid->item->name, 0);
+    }
+
+    return 0;
+}
+
 static int mov_read_header(AVFormatContext *s)
 {
     MOVContext *mov = s->priv_data;
@@ -8901,6 +9272,8 @@  static int mov_read_header(AVFormatContext *s)
 
     mov->fc = s;
     mov->trak_index = -1;
+    mov->thmb_item_id = -1;
+    mov->primary_item_id = -1;
     /* .mov and .mp4 aren't streamable anyway (only progressive download if moov is before mdat) */
     if (pb->seekable & AVIO_SEEKABLE_NORMAL)
         atom.size = avio_size(pb);
@@ -8923,20 +9296,43 @@  static int mov_read_header(AVFormatContext *s)
     av_log(mov->fc, AV_LOG_TRACE, "on_parse_exit_offset=%"PRId64"\n", avio_tell(pb));
 
     if (mov->found_iloc) {
+        if (mov->nb_heif_grid) {
+            err = mov_parse_tiles(s);
+            if (err < 0)
+                return err;
+        }
+
         for (i = 0; i < mov->nb_heif_item; i++) {
             HEIFItem *item = &mov->heif_item[i];
             MOVStreamContext *sc;
             AVStream *st;
+            int64_t offset = 0;
 
-            if (!item->st)
+            if (!item->st) {
+                if (item->item_id == mov->thmb_item_id) {
+                    av_log(s, AV_LOG_ERROR, "HEIF thumbnail doesn't reference a stream\n");
+                    return AVERROR_INVALIDDATA;
+                }
                 continue;
+            }
+            if (item->is_idat_relative) {
+                if (!mov->idat_offset) {
+                    av_log(s, AV_LOG_ERROR, "Missing idat box for item %d\n", item->item_id);
+                    return AVERROR_INVALIDDATA;
+                }
+                offset = mov->idat_offset;
+            }
 
             st = item->st;
             sc = st->priv_data;
             st->codecpar->width  = item->width;
             st->codecpar->height = item->height;
+
             sc->sample_sizes[0]  = item->extent_length;
-            sc->chunk_offsets[0] = item->extent_offset;
+            sc->chunk_offsets[0] = item->extent_offset + offset;
+
+            if (item->item_id == mov->primary_item_id)
+                st->disposition |= AV_DISPOSITION_DEFAULT;
 
             mov_build_index(mov, st);
         }