avformat: move 'chan' tag parsing to mov_chan.c to share with the CAF demuxer

1 files changed, 45 insertions, 1 deletions

diff --git a/libavformat/mov_chan.c b/libavformat/mov_chan.c
index edd5f6c4da..c0b57119d1 100644
--- a/libavformat/mov_chan.c
+++ b/libavformat/mov_chan.c
@@ -477,7 +477,7 @@ uint64_t ff_mov_get_channel_layout(uint32_t tag, uint32_t bitmap)
     return layout_map[i].layout;
 }
 
-uint32_t ff_mov_get_channel_label(uint32_t label)
+static uint32_t mov_get_channel_label(uint32_t label)
 {
     if (label == 0)
         return 0;
@@ -542,3 +542,47 @@ uint32_t ff_mov_get_channel_layout_tag(enum CodecID codec_id,
 
     return tag;
 }
+
+int ff_mov_read_chan(AVFormatContext *s, AVStream *st, int64_t size)
+{
+    AVIOContext *pb = s->pb;
+    uint32_t layout_tag, bitmap, num_descr, label_mask;
+    int i;
+
+    if (size < 12)
+        return AVERROR_INVALIDDATA;
+
+    layout_tag = avio_rb32(pb);
+    bitmap     = avio_rb32(pb);
+    num_descr  = avio_rb32(pb);
+
+    av_dlog(s, "chan: layout=%u bitmap=%u num_descr=%u\n",
+            layout_tag, bitmap, num_descr);
+
+    if (size < 12ULL + num_descr * 20ULL)
+        return 0;
+
+    label_mask = 0;
+    for (i = 0; i < num_descr; i++) {
+        uint32_t label;
+        label     = avio_rb32(pb);          // mChannelLabel
+        avio_rb32(pb);                      // mChannelFlags
+        avio_rl32(pb);                      // mCoordinates[0]
+        avio_rl32(pb);                      // mCoordinates[1]
+        avio_rl32(pb);                      // mCoordinates[2]
+        if (layout_tag == 0) {
+            uint32_t mask_incr = mov_get_channel_label(label);
+            if (mask_incr == 0) {
+                label_mask = 0;
+                break;
+            }
+            label_mask |= mask_incr;
+        }
+    }
+    if (layout_tag == 0)
+            st->codec->channel_layout = label_mask;
+    else
+        st->codec->channel_layout = ff_mov_get_channel_layout(layout_tag, bitmap);
+
+    return 0;
+}