avformat/mov: parse ISO-14496-12 ChannelLayout

Only support chnl version 0 now.

Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>

1 files changed, 84 insertions, 1 deletions

diff --git a/libavformat/mov.c b/libavformat/mov.c
index 14528bdcaa..057fd872b1 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -940,6 +940,88 @@ static int mov_read_chan(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     return 0;
 }
 
+static int mov_read_chnl(MOVContext *c, AVIOContext *pb, MOVAtom atom)
+{
+    int64_t end = av_sat_add64(avio_tell(pb), atom.size);
+    int stream_structure;
+    int version, flags;
+    int ret = 0;
+    AVStream *st;
+
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+
+    version = avio_r8(pb);
+    flags   = avio_rb24(pb);
+    if (version != 0 || flags != 0) {
+        av_log(c->fc, AV_LOG_ERROR,
+               "Unsupported 'chnl' box with version %d, flags: %#x",
+               version, flags);
+        return AVERROR_INVALIDDATA;
+    }
+
+    stream_structure = avio_r8(pb);
+
+    // stream carries channels
+    if (stream_structure & 1) {
+        int layout = avio_r8(pb);
+
+        av_log(c->fc, AV_LOG_TRACE, "'chnl' layout %d\n", layout);
+        if (!layout) {
+            uint8_t *positions = av_malloc(st->codecpar->ch_layout.nb_channels);
+
+            if (!positions)
+                return AVERROR(ENOMEM);
+            for (int i = 0; i < st->codecpar->ch_layout.nb_channels; i++) {
+                int speaker_pos = avio_r8(pb);
+
+                av_log(c->fc, AV_LOG_TRACE, "speaker_position %d\n", speaker_pos);
+                if (speaker_pos == 126) { // explicit position
+                    avpriv_request_sample(c->fc, "explicit position");
+                    av_freep(&positions);
+                    return AVERROR_PATCHWELCOME;
+                } else {
+                    positions[i] = speaker_pos;
+                }
+            }
+
+            ret = ff_mov_get_layout_from_channel_positions(positions,
+                    st->codecpar->ch_layout.nb_channels,
+                    &st->codecpar->ch_layout);
+            av_freep(&positions);
+            if (ret) {
+                av_log(c->fc, AV_LOG_ERROR,
+                        "get channel layout from speaker positions failed, %s\n",
+                        av_err2str(ret));
+                return ret;
+            }
+        } else {
+            uint64_t omitted_channel_map = avio_rb64(pb);
+
+            if (omitted_channel_map) {
+                avpriv_request_sample(c->fc, "omitted_channel_map 0x%" PRIx64 " != 0",
+                                      omitted_channel_map);
+                return AVERROR_PATCHWELCOME;
+            }
+            ff_mov_get_channel_layout_from_config(layout, &st->codecpar->ch_layout);
+        }
+    }
+
+    // stream carries objects
+    if (stream_structure & 2) {
+        int obj_count = avio_r8(pb);
+        av_log(c->fc, AV_LOG_TRACE, "'chnl' with object_count %d\n", obj_count);
+    }
+
+    if (avio_tell(pb) != end) {
+        av_log(c->fc, AV_LOG_WARNING, "skip %" PRId64 " bytes of unknown data inside chnl\n",
+                end - avio_tell(pb));
+        avio_seek(pb, end, SEEK_SET);
+    }
+    return ret;
+}
+
 static int mov_read_wfex(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 {
     AVStream *st;
@@ -7817,7 +7899,8 @@ static const MOVParseTableEntry mov_default_parse_table[] = {
 { MKTAG('w','i','d','e'), mov_read_wide }, /* place holder */
 { MKTAG('w','f','e','x'), mov_read_wfex },
 { MKTAG('c','m','o','v'), mov_read_cmov },
-{ MKTAG('c','h','a','n'), mov_read_chan }, /* channel layout */
+{ MKTAG('c','h','a','n'), mov_read_chan }, /* channel layout from quicktime */
+{ MKTAG('c','h','n','l'), mov_read_chnl }, /* channel layout from ISO-14496-12 */
 { MKTAG('d','v','c','1'), mov_read_dvc1 },
 { MKTAG('s','g','p','d'), mov_read_sgpd },
 { MKTAG('s','b','g','p'), mov_read_sbgp },