avformat/{isom,mov,movenc}: add support for CMAF DASH roles

This information is coded in a standard MP4 KindBox and utilizes the
scheme and values as per the DASH role scheme defined in MPEG-DASH.
Other schemes are technically allowed, but where multiple schemes
define the same concepts, the DASH scheme should be utilized.

Such flagging is additionally utilized by the DASH-IF CMAF ingest
specification, enabling an encoder to inform the following component
of the roles of the incoming media streams.

A test is added for this functionality in a similar manner to the
matroska test.

Signed-off-by: Jan Ekström <jan.ekstrom@24i.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/libavformat/isom.c b/libavformat/isom.c
index 4df5440023..300ba927c2 100644
--- a/libavformat/isom.c
+++ b/libavformat/isom.c
@@ -430,3 +430,22 @@ void ff_mov_write_chan(AVIOContext *pb, int64_t channel_layout)
     }
     avio_wb32(pb, 0);              // mNumberChannelDescriptions
 }
+
+static const struct MP4TrackKindValueMapping dash_role_map[] = {
+    { AV_DISPOSITION_HEARING_IMPAIRED|AV_DISPOSITION_CAPTIONS,
+        "caption" },
+    { AV_DISPOSITION_COMMENT,
+        "commentary" },
+    { AV_DISPOSITION_VISUAL_IMPAIRED|AV_DISPOSITION_DESCRIPTIONS,
+        "description" },
+    { AV_DISPOSITION_DUB,
+        "dub" },
+    { AV_DISPOSITION_FORCED,
+        "forced-subtitle" },
+    { 0, NULL }
+};
+
+const struct MP4TrackKindMapping ff_mov_track_kind_table[] = {
+    { "urn:mpeg:dash:role:2011", dash_role_map },
+    { 0, NULL }
+};