Pass the composition and ancillary ID for DVB subtitles via extradata instead

of sub_id, this allows detecting when that information is not available and
just decode everything.
In addition extradata is required for many codecs and thus in contrast to
sub_id generally already passed on by any programs using libav*.
Also ask for a sample if we encounter a stream with multiple/changing IDs.

Originally committed as revision 24238 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 11 insertions, 4 deletions

diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index d9ee987e1d..b1600901e2 100644
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -860,7 +860,6 @@ static void pmt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len
     const uint8_t *p, *p_end, *desc_list_end, *desc_end;
     int program_info_length, pcr_pid, pid, stream_type;
     int desc_list_len, desc_len, desc_tag;
-    int comp_page, anc_page;
     char language[4];
     uint32_t prog_reg_desc = 0; /* registration descriptor */
 
@@ -981,9 +980,17 @@ static void pmt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len
                 language[2] = get8(&p, desc_end);
                 language[3] = 0;
                 get8(&p, desc_end);
-                comp_page = get16(&p, desc_end);
-                anc_page = get16(&p, desc_end);
-                st->codec->sub_id = (anc_page << 16) | comp_page;
+                if (st->codec->extradata) {
+                    if (st->codec->extradata_size == 4 && memcmp(st->codec->extradata, p, 4))
+                        av_log_ask_for_sample(ts->stream, "DVB sub with multiple IDs\n");
+                } else {
+                    st->codec->extradata = av_malloc(4 + FF_INPUT_BUFFER_PADDING_SIZE);
+                    if (st->codec->extradata) {
+                        st->codec->extradata_size = 4;
+                        memcpy(st->codec->extradata, p, 4);
+                    }
+                }
+                p += 4;
                 av_metadata_set2(&st->metadata, "language", language, 0);
                 break;
             case 0x0a: /* ISO 639 language descriptor */