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

libavformat/cafdec.c

@@ -29,6 +29,7 @@
 #include "internal.h"
 #include "riff.h"
 #include "isom.h"
+#include "mov_chan.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/intfloat.h"
 #include "libavutil/dict.h"
@@ -266,6 +267,11 @@ static int read_header(AVFormatContext *s)
             found_data = 1;
             break;
 
+        case MKBETAG('c','h','a','n'):
+            if ((ret = ff_mov_read_chan(s, st, size)) < 0)
+                return ret;
+            break;
+
         /* magic cookie chunk */
         case MKBETAG('k','u','k','i'):
             if (read_kuki_chunk(s, size))

libavformat/mov.c

@@ -575,10 +575,6 @@ static int mov_read_dec3(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 static int mov_read_chan(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 {
     AVStream *st;
-    uint8_t av_unused version;
-    uint32_t av_unused flags;
-    uint32_t layout_tag, bitmap, num_descr, label_mask;
-    int i;
 
     if (c->fc->nb_streams < 1)
         return 0;
@@ -587,40 +583,7 @@ static int mov_read_chan(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     if (atom.size < 16)
         return 0;
 
-    version = avio_r8(pb);
-    flags   = avio_rb24(pb);
-
-    layout_tag = avio_rb32(pb);
-    bitmap     = avio_rb32(pb);
-    num_descr  = avio_rb32(pb);
-
-    if (atom.size < 16ULL + num_descr * 20ULL)
-        return 0;
-
-    av_dlog(c->fc, "chan: size=%ld version=%u flags=%u layout=%u bitmap=%u num_descr=%u\n",
-            atom.size, version, flags, layout_tag, bitmap, num_descr);
-
-    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 = ff_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);
+    ff_mov_read_chan(c->fc, st, atom.size - 4);
 
     return 0;
 }

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;
+}

libavformat/mov_chan.h

@@ -29,6 +29,7 @@
 #include <stdint.h>
 
 #include "libavcodec/avcodec.h"
+#include "avformat.h"
 
 /**
  * Get the channel layout for the specified channel layout tag.
@@ -39,14 +40,6 @@
  */
 uint64_t ff_mov_get_channel_layout(uint32_t tag, uint32_t bitmap);
 
-/**
- * Get the channel layout for the specified channel label.
- *
- * @param[in]  label   channel label
- * @return             channel layout mask fragment
- */
-uint32_t ff_mov_get_channel_label(uint32_t label);
-
 /**
  * Get the channel layout tag for the specified codec id and channel layout.
  * If the layout tag was not found, use a channel bitmap if possible.
@@ -60,4 +53,14 @@ uint32_t ff_mov_get_channel_layout_tag(enum CodecID codec_id,
                                        uint64_t channel_layout,
                                        uint32_t *bitmap);
 
+/**
+ * Read 'chan' tag from the input stream.
+ *
+ * @param s     AVFormatContext
+ * @param st    The stream to set codec values for
+ * @param size  Remaining size in the 'chan' tag
+ * @return      0 if ok, or negative AVERROR code on failure
+ */
+int ff_mov_read_chan(AVFormatContext *s, AVStream *st, int64_t size);
+
 #endif /* AVFORMAT_MOV_CHAN_H */