[FFmpeg-devel] [PATCH 1/8] avformat/mpegts: add dvb ac3 descriptor metadata

[lance.lmwang at gmail.com]

From: Limin Wang <lance.lmwang at gmail.com>

Below is one metadata information for the ts with dvb ac3 descriptor audio:
 ./ffmpeg -i ac3_desc.ts
    ...
    Stream #0:1[0x294]: Audio: ac3 ([6][0][0][0] / 0x0006), 48000 Hz, 5.1(side), fltp, 448 kb/s
    Metadata:
      dvb.ac3_desc.component_type: 68
      dvb.ac3_desc.bsid: 6
      dvb.ac3_desc.mainid: 0

Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
---
 libavformat/mpegts.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index c6fd3e1..1ed7eaf 100644
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -2073,15 +2073,33 @@ int ff_parse_mpeg2_descriptor(AVFormatContext *fc, AVStream *st, int stream_type
         break;
     case 0x6a: /* ac-3_descriptor */
         {
-            int component_type_flag = get8(pp, desc_end) & (1 << 7);
+            uint8_t flags = get8(pp, desc_end);
+            uint8_t component_type_flag = flags & (1 << 7);
+            uint8_t bsid_flag           = flags & (1 << 6);
+            uint8_t mainid_flag         = flags & (1 << 5);
+            uint8_t asvc_flag           = flags & (1 << 4);
+
             if (component_type_flag) {
-                int component_type = get8(pp, desc_end);
+                uint8_t component_type = get8(pp, desc_end);
                 int service_type_mask = 0x38;  // 0b00111000
                 int service_type = ((component_type & service_type_mask) >> 3);
                 if (service_type == 0x02 /* 0b010 */) {
                     st->disposition |= AV_DISPOSITION_DESCRIPTIONS;
                     av_log(ts ? ts->stream : fc, AV_LOG_DEBUG, "New track disposition for id %u: %u\n", st->id, st->disposition);
                 }
+                av_dict_set_int(&st->metadata, "dvb.ac3_desc.component_type", component_type, 0);
+            }
+            if (bsid_flag) {
+                uint8_t bsid = get8(pp, desc_end);
+                av_dict_set_int(&st->metadata, "dvb.ac3_desc.bsid", bsid, 0);
+            }
+            if (mainid_flag) {
+                uint8_t mainid = get8(pp, desc_end);
+                av_dict_set_int(&st->metadata, "dvb.ac3_desc.mainid", mainid, 0);
+            }
+            if (asvc_flag) {
+                uint8_t asvc = get8(pp, desc_end);
+                av_dict_set_int(&st->metadata, "dvb.ac3_desc.asvc", asvc, 0);
             }
         }
         break;
-- 
1.8.3.1