[FFmpeg-trac] #7694(avcodec:new): Decoding EIA-608 closed captions in MP4 (created by Final Cut Pro) not working
FFmpeg
trac at avcodec.org
Wed Jan 23 08:33:58 EET 2019
#7694: Decoding EIA-608 closed captions in MP4 (created by Final Cut Pro) not
working
------------------------------------+--------------------------------------
Reporter: fumoboy007 | Type: defect
Status: new | Priority: normal
Component: avcodec | Version: git-master
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
------------------------------------+--------------------------------------
= Summary of the bug
I created an MP4 using Final Cut Pro that contains EIA-608 closed
captions. (The closed captions are muxed by Final Cut Pro as a separate
stream from the video.) I tried playing this file using `ffplay`, VLC, and
my own video application that uses the FFmpeg libraries; the closed
captions are not shown.
More specifically, `avcodec_decode_subtitle2` always returns `0` into
`got_sub_ptr`.
= How to reproduce
Download the attached sample file and then run the following command:
{{{
% ffplay FFmpeg\ EIA-608\ Bug.m4v
ffplay version 4.1 Copyright (c) 2003-2018 the FFmpeg developers
built with Apple LLVM version 10.0.0 (clang-1000.11.45.5)
configuration: --prefix=/usr/local/Cellar/ffmpeg/4.1_1 --enable-shared
--enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-
avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay
--enable-gpl --enable-libmp3lame --enable-libopus --enable-libsnappy
--enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264
--enable-libx265 --enable-libxvid --enable-lzma --enable-libfreetype
--enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-
libopencore-amrwb --enable-librtmp --enable-libspeex --enable-videotoolbox
libavutil 56. 22.100 / 56. 22.100
libavcodec 58. 35.100 / 58. 35.100
libavformat 58. 20.100 / 58. 20.100
libavdevice 58. 5.100 / 58. 5.100
libavfilter 7. 40.101 / 7. 40.101
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 3.100 / 5. 3.100
libswresample 3. 3.100 / 3. 3.100
libpostproc 55. 3.100 / 55. 3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'FFmpeg EIA-608 Bug.m4v':
Metadata:
major_brand : M4V
minor_version : 1
compatible_brands: M4V M4A mp42isom
creation_time : 2019-01-23T06:04:07.000000Z
Duration: 00:00:09.44, start: 0.000000, bitrate: 4165 kb/s
Stream #0:0(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz,
stereo, fltp, 124 kb/s (default)
Metadata:
creation_time : 2019-01-23T06:04:07.000000Z
handler_name : Core Media Audio
Stream #0:1(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv,
bt709, progressive), 960x540 [SAR 1:1 DAR 16:9], 4034 kb/s, 25 fps, 25
tbr, 25 tbn, 50 tbc (default)
Metadata:
creation_time : 2019-01-23T06:04:07.000000Z
handler_name : Core Media Video
Stream #0:2(eng): Subtitle: eia_608 (c608 / 0x38303663), 960x540, 0
kb/s (default)
Metadata:
creation_time : 2019-01-23T06:04:07.000000Z
handler_name : Core Media Closed Caption
}}}
I have also attached an SCC file (generated by Final Cut Pro) that
contains only the closed captions.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/7694>
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