[vlc-commits] mux: mp4: add esds comments

[Francois Cartegnie]

vlc | branch: master | Francois Cartegnie <fcvlcdev at free.fr> | Fri Feb  8 18:08:15 2019 +0100| [505fd6b69a1e8f8ae2f0b94ecd34b44fcda0b365] | committer: Francois Cartegnie

mux: mp4: add esds comments

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=505fd6b69a1e8f8ae2f0b94ecd34b44fcda0b365
---

 modules/mux/mp4/libmp4mux.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/modules/mux/mp4/libmp4mux.c b/modules/mux/mp4/libmp4mux.c
index 67a80326e5..1c13ea1b01 100644
--- a/modules/mux/mp4/libmp4mux.c
+++ b/modules/mux/mp4/libmp4mux.c
@@ -553,19 +553,20 @@ static bo_t *GetESDS(mp4mux_trackinfo_t *p_track)
     if (i_bitrate_max <= 1)
         i_bitrate_max = 0x7fffffff;
 
-    /* ES_Descr ISO/IEC 14496-1 8.3.3 */
+    /* ES_Descriptor ISO/IEC 14496-1 */
     bo_add_mp4_tag_descr(esds, 0x03, 3 + 5 + 13 + i_decoder_specific_info_size + 5 + 1);
     bo_add_16be(esds, p_track->i_track_id);
     bo_add_8   (esds, 0x1f);      // flags=0|streamPriority=0x1f
 
-    /* DecoderConfigDescr ISO/IEC 14496-1 8.3.4 */
+    /* DecoderConfigDescr ISO/IEC 14496-1
+        http://mp4ra.org/#/object_types */
     bo_add_mp4_tag_descr(esds, 0x04, 13 + i_decoder_specific_info_size);
 
     uint8_t i_object_profile_indication;
     switch(p_track->fmt.i_codec)
     {
     case VLC_CODEC_MP4V:
-        i_object_profile_indication = 0x20;
+        i_object_profile_indication = 0x20; /* Visual 14496-2 */
         break;
     case VLC_CODEC_MPGV:
         if(p_track->fmt.i_original_fourcc == VLC_CODEC_MP1V)
@@ -576,7 +577,7 @@ static bo_t *GetESDS(mp4mux_trackinfo_t *p_track)
         /* fallthrough */
     case VLC_CODEC_MP2V:
         /* MPEG-I=0x6b, MPEG-II = 0x60 -> 0x65 */
-        i_object_profile_indication = 0x65;
+        i_object_profile_indication = 0x65; /* Visual 13818-2 422 Profile */
         break;
     case VLC_CODEC_MP1V:
         /* MPEG-I=0x6b, MPEG-II = 0x60 -> 0x65 */
@@ -584,15 +585,16 @@ static bo_t *GetESDS(mp4mux_trackinfo_t *p_track)
         break;
     case VLC_CODEC_MP4A:
         /* FIXME for mpeg2-aac == 0x66->0x68 */
-        i_object_profile_indication = 0x40;
+        i_object_profile_indication = 0x40; /* Audio 14496-3 */
         break;
     case VLC_CODEC_MP3:
     case VLC_CODEC_MPGA:
         i_object_profile_indication =
-            p_track->fmt.audio.i_rate < 32000 ? 0x69 : 0x6b;
+            p_track->fmt.audio.i_rate < 32000 ? 0x69 /* Audio 13818-3 */
+                                              : 0x6b;/* Audio 11172-3 */
         break;
     case VLC_CODEC_DTS:
-        i_object_profile_indication = 0xa9;
+        i_object_profile_indication = 0xa9; /* Core Substream */
         break;
     default:
         i_object_profile_indication = 0xFE; /* No profile specified */