[FFmpeg-devel] [PATCH] avformat/mov: get heif image rotation from irot box

[Hacene Bouaroua]

parse irot box to get the transformative heif
item rotation angle.

Signed-off-by: Hacene Bouaroua <hbouaroua at freebox.fr>
---
  libavformat/avformat.h |  5 +++++
  libavformat/isom.h     |  1 +
  libavformat/mov.c      | 25 +++++++++++++++++++++++++
  3 files changed, 31 insertions(+)

diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index 8afdcd9fd0..615650ddcb 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -1077,6 +1077,11 @@ typedef struct AVStreamGroupTileGrid {
       * final image before presentation.
       */
      int height;
+    /**
+     * the angle which the reconstructed image is initially rotated
+     * (in anti-clockwise direction) in units of degrees.
+     */
+    int rotation;
  } AVStreamGroupTileGrid;
   enum AVStreamGroupParamsType {
diff --git a/libavformat/isom.h b/libavformat/isom.h
index c0a5788e08..757e3f8738 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -277,6 +277,7 @@ typedef struct HEIFItem {
      int64_t extent_offset;
      int width;
      int height;
+    int rotation;
      int type;
      int is_idat_relative;
  } HEIFItem;
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 45eca74d1d..5f04e68f88 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -8398,6 +8398,27 @@ static int mov_read_ispe(MOVContext *c, 
AVIOContext *pb, MOVAtom atom)
      return 0;
  }
  +static int mov_read_irot(MOVContext *c, AVIOContext *pb, MOVAtom atom)
+{
+    uint32_t angle;
+
+    angle = avio_r8(pb);
+
+    av_log(c->fc, AV_LOG_TRACE, "irot: item_id %d, angle %u\n",
+           c->cur_item_id, angle);
+
+    for (int i = 0; i < c->nb_heif_item; i++) {
+        if (c->heif_item[i].item_id == c->cur_item_id) {
+            // angle * 90 specifies the angle (in anti-clockwise direction)
+            // in units of degrees.
+            c->heif_item[i].rotation  = angle * 90;
+            break;
+        }
+    }
+
+    return 0;
+}
+
  static int mov_read_iprp(MOVContext *c, AVIOContext *pb, MOVAtom atom)
  {
      typedef struct MOVAtoms {
@@ -8615,6 +8636,7 @@ static const MOVParseTableEntry 
mov_default_parse_table[] = {
  { 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','r','o','t'), mov_read_irot },
  { MKTAG('i','p','r','p'), mov_read_iprp },
  { MKTAG('i','i','n','f'), mov_read_iinf },
  { MKTAG('a','m','v','e'), mov_read_amve }, /* ambient viewing 
environment box */
@@ -9315,6 +9337,9 @@ static int read_image_grid(AVFormatContext *s, 
const HEIFGrid *grid,
      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);
  +    /* rotation */
+    tile_grid->rotation = item->rotation;
+
      av_log(c->fc, AV_LOG_TRACE, "grid: grid_rows %d grid_cols %d 
output_width %d output_height %d\n",
             tile_rows, tile_cols, tile_grid->width, tile_grid->height);
  -- 2.34.1