[FFmpeg-trac] #1482(undetermined:new): FFMPEG fails to create a SRT file when extracting Subtitles

[FFmpeg]

#1482: FFMPEG fails to create a SRT file when extracting Subtitles
-------------------------------------+-------------------------------------
             Reporter:  ramitbhalla  |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
              Version:  git-master   |  undetermined
             Keywords:  cc           |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
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Comment (by reimar):

 A far larger sample size will be needed to reverse-engineer this format
 properly, but for reference below hack to MPlayer makes it mostly display
 correctly (using -sid 0 -subcc 1).
 However how the whole rollup, rollon, number of lines etc. pp. is encoded
 in the format is still quite unclear to me.
 {{{
 Index: sub/sub_cc.c
 ===================================================================
 --- sub/sub_cc.c        (revision 35108)
 +++ sub/sub_cc.c        (working copy)
 @@ -376,11 +381,26 @@

  void subcc_process_data(const uint8_t *inputdata, unsigned int len)
  {
 +       int newline = 0;
         int mov_mode = len >= 10 &&
                        memcmp(inputdata, mov_cc_signature_1,
 sizeof(mov_cc_signature_1)) == 0;
         if(!subcc_enabled) return;
         if(!initialized) subcc_init();

 +       cc_mode = CC_ROLLUP;
 +       if (len < 2) return;
 +       newline = (inputdata[1] & 0xf0) == 0x30;
 +       inputdata += 2;
 +       len -= 2;
 +       channel = 0;
 +       while (len >= 2 && (inputdata[0] & 0x60)) {
 +               cc_decode_EIA608(inputdata[0] | (inputdata[1] << 8));
 +               if (!(inputdata[1] & 0x60)) break;
 +               inputdata += 2;
 +               len -= 2;
 +       }
 +       if (newline) append_char('\n');
 +       return;
         if (mov_mode) {
                 mov_subcc_decode(inputdata, len);
                 return;
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1482#comment:19>
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