Deleting CEA-608 (EIA-608) captions from a H.264 video file

[Sviests]

Hi,everyone.

I have a H.264 type file (with .mkv as a container) that has some closed captions (CEA-608 aka EIA-608) and they're appearing in middle of the screen so i need to permanently remove them. I have tried various of options,but seems that most software are not detecting it,while VLC,MPC-HC does and plays them.
Here's a screen of VLC that shows that there are captions (streams 2-5):


I have tried CCextractor , Subtitle Edit , MKVToolinx even VideoRedo had option to remove NAL units,but none of them are able to pick those captions up or exported the file still having those captions.

For example,CCextractor kept returning

No captions were found in input.

The closest i got was with FFMPEG.
Apparently it has a bitstream filter called filter_units so you can either pass or reject NAL units by it's type.I found also this:

EIA-608 and similar closed captioning standards, the captions are embedded directly in the video bitstream as user data. H.264 bitstreams are stored as a sequence of NAL (network abstraction layer) units. Each unit has a type; user data is stored in a NAL unit of the supplemental enhancement information (SEI) type.

The latest H.264 spec table (table 7.1 page 86) says that SEI type is 6,so my code would be:

ffmpeg -i input.mkv -codec copy -bsf:v 'filter_units=remove_types=6' output.mkv

But apparently it doesn't recognize filter_units at all,here's what FFMPEG returns (error in red color):

C:\Users\Sviests\Desktop\ffmpeg\bin>ffmpeg -i input.mkv
v -codec copy -bsf:v "filter_units=remove_types=6" output.mkv
ffmpeg version N-90264-g80798e3857 Copyright (c) 2000-2018 the FFmpeg developers

  built with gcc 7.3.0 (GCC)
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --e
nable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libblur
ay --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-
libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enab
le-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-li
bvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --en
able-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-
libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enabl
e-libspeex --enable-libxvid --enable-libmfx --enable-amf --enable-ffnvcodec --en
able-cuvid --enable-d3d11va --enable-nvenc --enable-dxva2 --enable-avisynth
  libavutil      56.  8.100 / 56.  8.100
  libavcodec     58. 14.100 / 58. 14.100
  libavformat    58. 10.100 / 58. 10.100
  libavdevice    58.  2.100 / 58.  2.100
  libavfilter     7. 12.100 /  7. 12.100
  libswscale      5.  0.102 /  5.  0.102
  libswresample   3.  0.101 /  3.  0.101
  libpostproc    55.  0.100 / 55.  0.100
Input #0, matroska,webm, from 'input.mkv':
  Metadata:
    encoder         : libebml v1.3.6 + libmatroska v1.4.9
    creation_time   : 2018-09-10T16:37:05.000000Z
  Duration: 01:39:15.03, start: 0.000000, bitrate: 14218 kb/s
    Stream #0:0: Video: h264 (High), yuv420p(tv, bt709, progressive), 1920x1080
[SAR 1:1 DAR 16:9], Closed Captions, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (de
fault)
    Metadata:
      BPS-eng         : 13576112
      DURATION-eng    : 01:39:15.033000000
      NUMBER_OF_FRAMES-eng: 142778
      NUMBER_OF_BYTES-eng: 10105774524
      _STATISTICS_WRITING_APP-eng: mkvmerge v26.0.0 ('In The Game') 64-bit
      _STATISTICS_WRITING_DATE_UTC-eng: 2018-09-10 16:37:05
      _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
    Stream #0:1(eng): Audio: eac3, 48000 Hz, 5.1(side), fltp, 640 kb/s
    Metadata:
      title           : English Surround 5.1 - E-AC3
      BPS-eng         : 640000
      DURATION-eng    : 01:39:14.976000000
      NUMBER_OF_FRAMES-eng: 186093
      NUMBER_OF_BYTES-eng: 476398080
      _STATISTICS_WRITING_APP-eng: mkvmerge v26.0.0 ('In The Game') 64-bit
      _STATISTICS_WRITING_DATE_UTC-eng: 2018-09-10 16:37:05
      _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
    Stream #0:2: Video: mjpeg, yuvj440p(pc, bt470bg/unknown/unknown), 450x600 [S
AR 72:72 DAR 3:4], 90k tbr, 90k tbn, 90k tbc
Unknown bitstream filter filter_units

I hope i made it as clear as possible, i would appreciate any type of help.

Thanks beforehand.

[poisondeathray]

It seems to work ok here ; vlc, mediainfo, ffmpeg report the 608 streams gone , and ffmpeg no longer reports closed caption for the video stream

1) check if your ffmpeg binary has filter_units available as a bitstream filter; it might not have been compiled with it

ffmpeg -bsfs

2) is there a typo in you console copy/paste ? there seems to be an extra "v" after input.mkv . Maybe double check your actual command line

[Sviests]

That extra v was just a typo while copy/pasting here.

ffmpeg -bsfs returned:

Bitstream filters:
aac_adtstoasc
chomp
dump_extra
dca_core
extract_extradata
h264_metadata
h264_mp4toannexb
h264_redundant_pps
hevc_metadata
hevc_mp4toannexb
imxdump
mjpeg2jpeg
mjpegadump
mp3decomp
mpeg2_metadata
mpeg4_unpack_bframes
mov2textsub
noise
null
remove_extra
text2movsub
trace_headers
vp9_raw_reorder
vp9_superframe
vp9_superframe_split

Edit: I updated binaries,filter_units is now there,let's see if it works this time.

[poisondeathray]

I don't see it in your list

Here is my list. I'm using a windows binary from zeraone
https://ffmpeg.zeranoe.com/builds/

Bitstream filters:
aac_adtstoasc
chomp
dump_extra
dca_core
eac3_core
extract_extradata
filter_units
h264_metadata
h264_mp4toannexb
h264_redundant_pps
hapqa_extract
hevc_metadata
hevc_mp4toannexb
imxdump
mjpeg2jpeg
mjpegadump
mp3decomp
mpeg2_metadata
mpeg4_unpack_bframes
mov2textsub
noise
null
remove_extra
text2movsub
trace_headers
vp9_metadata
vp9_raw_reorder
vp9_superframe
vp9_superframe_split

[Sviests]

It's all good now. Worked like a charm. Just needed to update some binaries (apparently i thought i had the latest version,heh).
Anyway,this can be locked now, thanks!

[timucin]

Hi. I want to remove closed captions frm mkv file. how can I remove them?

[Selur]

use mkvtoolnix

[timucin]

mkvtoolnix can't see closed captions.

[Selur]

Then a simple remux with mkvtoolnix should remove them,... doesn't it?

[timucin]

what's the difference between mkvtoolnix and simple mkvtoolnix? as I said mkv doesn't work.

[Selur]

You wrote that mvktoolnix doesn't see the captions, in which case it won't passthrough the captions on remuxing and thus removing the captions which is what you wanted.

...so i need to permanently remove them.

what's the difference between mkvtoolnix and simple mkvtoolnix?

??

[timucin]

To be more clear: I want to remove closed captions on white collar tv show see pic 1. But when add the mkv to mkvtoolnix they can not seen see pic 2. Not the question is: how to remove them?

[Selur]

But when add the mkv to mkvtoolnix they can not seen see pic 2.

Which is exactly why mvktoolnix should remove the files on remuxing.

1. open file in mvktoolnix
2. set 'Destination file' to a file with a different name
3. press 'Start muxing'
-> new file shouldn't contain the captions (mkvtoolnix doesn't detect the captions thus it won't remux them)

[timucin]

did exactly what you've said. the result is negative see pic.
[Attachment 50356 - Click to enlarge]

[Selur]

can you share a !small! sample of such a file so I can look into it?
(you can cut/split the file using mkvtoolnix)

[timucin]

I dont have suitable software to split the video. I searched on google but coudn't find it. But I downloaded the movie from this link: http://links.snahp.it/8fEsK5HrAVZEL0zs7cguIMr5YKrukX3Ahiz. the main page is https://snahp.it/?p=45676

[Selur]

Like I wrote:

you can cut/split the file using mkvtoolnix

the the options under Output->splitting

[timucin]

thank you. I didn't know that I can do it with mkvtool. here's a sample, you can check the subtitles: https://www.dropbox.com/s/6ech65kq282nv0n/white%20collar-001.mkv?dl=0

[timucin]

Like I wrote:

you can cut/split the file using mkvtoolnix

the the options under Output->splitting

or you can download from here: https://mega.nz/#!ik1SVAjJ!WhDfwH3NlDO8mqjltZ02-16g88865a4S7P50MxAn_Wo

[Selur]

got the file

[timucin]

[Selur]

some first impressions:
a. extracing the streams with mkvtoolnix and remuxing the raw streams does kind of remove the captions (vlc still shows them in the subtitle list, but shows nothing if they are selected)
b. same happens when using:

ffmpeg.exe -i "PATH TO INPUT" -c copy -bsf:v h264_mp4toannexb "PATH TO OUTPUT"

-> doing some further testing.

[timucin]

may be. waiting... not urgent.

[Selur]

ffmpeg -i "PATH TO INPUT" -bsf:v "filter_units=remove_types=6" -c copy "PATH TO OUTPUT"

removes the captions for me

Cu Selur

[timucin]

ffmpeg-i "PATH TO INPUT" -bsf:v "filter_units=remove_types=6" -c copy "PATH TO OUTPUT"

I don't know anything about these codes. I only know using softwares like mkvtoolnix

[Selur]

ffmpeg is a command line took you can download from for example: https://ffmpeg.zeranoe.com/builds/
extracting ffmpeg.exe into a folder of your choice, for example: "E:\ffmpeg.exe" you could call:

"E:\ffmpeg.exe" -i "E:\Input\input.mkv" -bsf:v "filter_units=remove_types=6" -c copy "E:\Output\output.mkv"

in a Windows Command Prompt to process an input file names "E:\Input\input.mkv" and create and output file named "E:\Output\output.mkv".

[timucin]

looks little bit confusing. will try it in my free time. thank you a lot. I'll write later.

[Selur]

I'll create a modified version of Hybrid with a small step by step for you end send you a link in an hour or so, then you have a gui which will do more easily.

Cu Selur

[Selur]

Modified Hybrid and released a new version (2019.09.30.1) you can download over at http://selur.de/downloads

After downloading and installing Hybrid, do the following:

1. Start Hybrid
2. set default output and temp paths (under Config->Path->Default XXX path)
3. save those settings as defaults, press 'Config->Save->All->Save selected' (right lower corner)
4. enable "Config->Automation->Passthrough streams->Subtitle" in case you want to keep the normal subtitles (if you don't want to keep any subtitles don't do this)
5. enable "Base->Subtitle" and "Subtitle->Import->Delete subtitle after muxing" for Hybrid to delete extracted and muxed subtitles.
6. enable "Congig->Input->Extraction->Stream extraction with ffmpeg"
7. Set "Base->Processing->Video" to "passthrough"
8. Set "Base->Processing->Audio" to "passthrough all"
9. Set "Base->Default container" to 'mkv'
10. In case you set a default output folder which isn't the input folder enable 'Base->Generate' otherwise set the output file ('Base->Output File')
11. Load your file ("Base->Open File"; upper right corner)
12. Create a job for Hybrid by pressing "Base->Add to queue" (lower right corner)
13. Start the processing ("Jobs->Queue->Play"; upper left corner)

Once the process is done the output should contain no captions.
Note that you can do multiple files at once by selecting them and then drag&dropping them onto the input line in the Base-tab.

Cu Selur

[teddee]

Selur, you are a champion! This worked perfectly for me.