Support detecting and demuxing EIA-608 subtitles in mov.

The format is slightly proprietary.
DVDs use a format of
code byte (0x00, 0x01, 0xfe or 0xff), two data bytes
MOV uses instead
cdat/cdt2 atom, two data bytes
Auto-detecting and supporting both in one decoder is trivial,
so a single codec ID is used.
Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>

libavcodec/avcodec.h

@@ -414,6 +414,7 @@ enum CodecID {
     CODEC_ID_DVB_TELETEXT,
     CODEC_ID_SRT,
     CODEC_ID_MICRODVD   = MKBETAG('m','D','V','D'),
+    CODEC_ID_EIA_608    = MKBETAG('c','6','0','8'),
 
     /* other specific kind of codecs (generally used for attachments) */
     CODEC_ID_FIRST_UNKNOWN = 0x18000,           ///< A dummy ID pointing at the start of various fake codecs.

libavcodec/version.h

@@ -21,7 +21,7 @@
 #define AVCODEC_VERSION_H
 
 #define LIBAVCODEC_VERSION_MAJOR 54
-#define LIBAVCODEC_VERSION_MINOR  13
+#define LIBAVCODEC_VERSION_MINOR  14
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \

libavformat/isom.c

@@ -287,6 +287,7 @@ const AVCodecTag ff_codec_movaudio_tags[] = {
 const AVCodecTag ff_codec_movsubtitle_tags[] = {
     { CODEC_ID_MOV_TEXT, MKTAG('t', 'e', 'x', 't') },
     { CODEC_ID_MOV_TEXT, MKTAG('t', 'x', '3', 'g') },
+    { CODEC_ID_EIA_608,  MKTAG('c', '6', '0', '8') },
     { CODEC_ID_NONE, 0 },
 };
 

libavformat/mov.c

@@ -1222,7 +1222,9 @@ int ff_mov_read_stsd_entries(MOVContext *c, AVIOContext *pb, int entries)
                 id = ff_codec_get_id(ff_codec_bmp_tags, format);
             if (id > 0)
                 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
-            else if (st->codec->codec_type == AVMEDIA_TYPE_DATA){
+            else if (st->codec->codec_type == AVMEDIA_TYPE_DATA ||
+                     (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE &&
+                      st->codec->codec_id == CODEC_ID_NONE)){
                 id = ff_codec_get_id(ff_codec_movsubtitle_tags, format);
                 if (id > 0)
                     st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;