#11606(avcodec:new): avcodec/dvbsubenc: Broken dvb_encode_rle8
#11606: avcodec/dvbsubenc: Broken dvb_encode_rle8 ---------------------------------+--------------------------------------- Reporter: pbk | Type: defect Status: new | Priority: normal Component: avcodec | Version: unspecified Keywords: | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | ---------------------------------+--------------------------------------- The rle8 encoding (256 color table) is corrupted. The end of 8-bit/pixel_code_string shall be 2 zeroes (not one): Current code: *q++ = 0x00; *q++ = 0xf0; Correct code: *q++ = 0x00; *q++ = 0x00; *q++ = 0xf0; -- Ticket URL: <https://trac.ffmpeg.org/ticket/11606> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker
#11606: avcodec/dvbsubenc: Broken dvb_encode_rle8 -------------------------------------+----------------------------------- Reporter: pbk | Owner: (none) Type: defect | Status: new Priority: normal | Component: avcodec Version: unspecified | Resolution: Keywords: | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | -------------------------------------+----------------------------------- Comment (by waider): The current DVB SUB spec (https://www.etsi.org/deliver/etsi_en/300700_300799/300743/01.06.01_60/en_300...) on p62 in Table 44: 8-bit/pixel_code_string does indeed say `| 00000000 00000000 | end of 8-bit/pixel_code_string |` However the same spec on page 45 says
end_of_string_signal: A 7-bit field filled with '000 0000'. The presence of this field, i.e. next_bits(7) == '000 0000', signals the end of the 8-bit/pixel_code_string.
Do you have a reference for your quoted text ("The end of 8-bit/pixel_code_string shall be 2 zeroes") as I can't find it or anything quite like it in the above spec. -- Ticket URL: <https://trac.ffmpeg.org/ticket/11606#comment:1> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker
#11606: avcodec/dvbsubenc: Broken dvb_encode_rle8 -------------------------------------+----------------------------------- Reporter: pbk | Owner: (none) Type: defect | Status: new Priority: normal | Component: avcodec Version: unspecified | Resolution: Keywords: | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | -------------------------------------+----------------------------------- Comment (by pbk): Hi, I think you are missing following line in the Table 26: 8-bits per pixel code string: 8-bit_zero 8 bslbf So, the total zero bits are 16 (8 + 1 + 7). When I was developing my own ffmpeg TS muxer with ability to convert ttml/sgml/vwtt to DVB, I couldn't figure out what the hell is wrong. Subtitle rendering in both VLC anf MPC-HC was completely messed. After adding the missing zero byte to the end of the string, both players started to render the subtitles perfectly. -- Ticket URL: <https://trac.ffmpeg.org/ticket/11606#comment:2> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker
#11606: avcodec/dvbsubenc: Broken dvb_encode_rle8 -------------------------------------+----------------------------------- Reporter: pbk | Owner: (none) Type: defect | Status: new Priority: normal | Component: avcodec Version: unspecified | Resolution: Keywords: | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | -------------------------------------+----------------------------------- Comment (by Balling): Fix upcoming. https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20090/ -- Ticket URL: <https://trac.ffmpeg.org/ticket/11606#comment:3> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker
#11606: avcodec/dvbsubenc: Broken dvb_encode_rle8 -------------------------------------+----------------------------------- Reporter: pbk | Owner: (none) Type: defect | Status: closed Priority: normal | Component: avcodec Version: unspecified | Resolution: fixed Keywords: | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | -------------------------------------+----------------------------------- Changes (by Marton Balint): * resolution: => fixed * status: new => closed Comment: Fixed in 74f470c05c3ea76091b6d85d8fbf54ea3db1805b. -- Ticket URL: <https://trac.ffmpeg.org/ticket/11606#comment:4> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker
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