Unable to remove subtitles with ffmpeg

[the_steve_randolph]

So ... "If ffmpeg can't detect the subs, you can't "remove" or stream copy them with ffmpeg" - is it clear now ?

Yes, and, THAT is the purpose of this thread. WHY is ffmpeg not finding these subtitles? Other apps are not seeing them either.

Hi, since it seem like an weird issue, if using VLC Media Player, if you have for example an folder named "Subtitles" in the same directory as the video, and allso if the subtitle name have the same name as the video it will appear as an subtitle stream within vlc! If maybe you have many folders and videos in this directory that the video is inside maybe you used the same name as an subtitle without knowing and have an folder with many subtitles!

For me it say:
Stream 0
Codec: Text subtitles with various Tags (subt)
Language: \subtitles\subtitlename
Type: Subtitle

This is from vlc, the folder named "Subtitles" is in the same directory as the avi video and in this directory the subtitle have the same name as the video, VLC Media Player picked the subtitle up by itself! The subtitle allso show up as an subtitle track that can be disabled!

Thanks, but, I have already eliminated that as to what is causing my issue.

[the_steve_randolph]

-bsf:v filter_units=remove_types=6

works with a h264 (avc) video (tested).
For mpeg4 (divx, xvid) you seem to be out of luck.
I would still experiment with other numbers.

The error message I posted above said:

Codec 'mpeg4' (12) is not supported by the bitstream filter 'filter_units'.  Supported codecs
are: av1 (226) h264 (2) hevc (173) mpeg2video (2) vp9 (167)

That indicates to me that "mpeg4" and "filter_units" are not compatible at all - regardless of the types value. Then the issue would seem to be to figure out how to access EAI-608 data in a mpeg4 file, right?

[the_steve_randolph]

I found this thread answer that provided a solution to removing the close captioning: https://forum.videohelp.com/threads/390217-Deleting-CEA-608-(EIA-608)-captions-from-a-...le#post2561602

Is Selur still around? Maybe he can explain how to remove EIA-608 closed captioning in a mpeg4 video with ffmpeg.

[Selur]

closed caption subtitles are normal streams.
To remove them with ffmpeg you can simply passthrough all the other streams,...

ffmpeg -i "Path to input file" -c:v copy -c:a copy "path to output file"

[the_steve_randolph]

closed caption subtitles are normal streams.
To remove them with ffmpeg you can simply passthrough all the other streams,...

ffmpeg -i "Path to input file" -c:v copy -c:a copy "path to output file"

Dang it - that was too easy! {muttering stuff under my breath} Thanks again Selur!

[the_steve_randolph]

closed caption subtitles are normal streams.
To remove them with ffmpeg you can simply passthrough all the other streams,...

ffmpeg -i "Path to input file" -c:v copy -c:a copy "path to output file"

Dang it - that was too easy! {muttering stuff under my breath} Thanks again Selur!

Oops, I think that I spoke too soon. The ffmepg above does seemingly remove the EIA-608 subtitle data in the video stream. But, the resulting file still has a subtitle track visible in VLC. When I originally viewed the input file in VLC, there were two subtitles displayed at the same time - one apparently from the video stream and one from a subtitle track soft-coded into the file. Looking at the resulting output file, VLC still shows a subtitle track in the "Subtitles" dropdown and in the Tools > Codec information as "Stream 2" (that Codec information is the same as what I reported in a previous post). When I do a ffprobe on the output file, it does not show any information about any subtitles. But when I do this command:

d:ffmpeg -f lavfi -i movie=in.mp4[out0+subcc] -vn -an -codec:s subrip in.srt

the resulting SRT output file is empty and the console display shows this:

Output #0, srt, to in.srt
  Metadata:
    encoder  :  Lavf60.5.100
  Stream #0:0:  Subtitle: subrip
    Metadata:
      encoder  :  Lavc60.10.100 subrip
Stream mapping:
  Stream #0:1 -> #0:0 (eia_608 (cc_dec) -> subrip (native))

So, it looks like the EIA-608 subtitles (aka closed captioning) is in two different streams. The typical "-sn" and "map 0 -0: s:0" {yes, space inserted to avoid emoji} don't remove the remaining track/stream

[Selur]

a. Share a sample of your source which includes subtitles. (not an empy subtitle stream)
b. write down what you want to do (I thought you wanted to remove the subtitles, now wou wan to do some conversion?)
side note: make sure you have no subtiles files lying next to your video file whenusing vlc otherwise it may show those external subtitles in its subtitle list.

Cu Selur

[the_steve_randolph]

a. Share a sample of your source which includes subtitles. (not an empy subtitle stream)
b. write down what you want to do (I thought you wanted to remove the subtitles, now wou wan to do some conversion?)
side note: make sure you have no subtiles files lying next to your video file whenusing vlc otherwise it may show those external subtitles in its subtitle list.

Cu Selur

The code in the previous post were just to show that all of the subtitle streams in the file are EIA_608. The original file plays two exact same subtitles in VLC - one set from a track listed in the "Subtitles" dropdown. When I disable that track, there is still one set that remains. From the various things I have tried here, at one point I was able to play the file with no subtitles at all. As you may know me and my projects from the past, I am trying to learn more about ffmpeg - as opposed to just simply removing the subtitles. The basic switches shown in the previous post don't work, and, that is why I started this thread.

I have never uploaded a file before, so, I will need to do a couple of things before uploading. And, looking at several copies I have left from this process, I am having a little bit of trouble nailing down exactly what seems to be happening at each step/try.

[the_steve_randolph]

OK, I am close to losing my mind. It seems that VLC is automatically picking up and using a subtitles file called "IN-XXX.SRT" for a video called "IN.MP4". I will post again after consulting with my shrink.

[Selur]

*gig* autoloading subtitles,..

[ProWo]

closed caption subtitles are normal streams.
To remove them with ffmpeg you can simply passthrough all the other streams,...

ffmpeg -i "Path to input file" -c:v copy -c:a copy "path to output file"

Not true. The EIA608/708 captions are encoded into the SEI with the videostream and are invisible to ffmpeg.
So a simple remux doesn't remove the captions.

[ProWo]

@ the_steve_randolph

As a last resort (for your mpeg4 video):
Re-encode it with x264 and then use
-bsf:v filter_units=remove_types=6
with streamcopy.

[Selur]

if you reencode shouldn't you lose the sei unit info of the source anyways
=> like I wrote: " a. Share a sample of your source which includes subtitles. (not an empy subtitle stream)"

[ProWo]

if you reencode shouldn't you lose the sei unit info of the source anyways

Tested, nope. They are still here.

[the_steve_randolph]

*gig* autoloading subtitles,..

Yep. I just now went back at looked at all of the previous messages in this thread. Only one or two mentioned the subfolder issue, but, not what I ended up discovering. My original file was named something like MACHINE.AVI. Originally I had a file named something like MACHINE.SRT. Thinking that VLC was "autoloading" that SRT, I changed it to MACHINE-XXX.SRT - but it STILL "autoloaded" it (but I did not realize it at the time). And, during my processing/testing, to save a few keystrokes I shortened the name of the output file to M.MP4. That STILL found MACHINE-XXX.SRT! Of couse, that means that it would also "autoload" a file from a totally different video named MACHINE_SOUNDS.SRT. Yes, I am mad and embarrassed by it, but, what is probably the most annoying is that I don't know who I am mad at the most.

I am in the process of going back and replicating what I found and I will make a post here to provide the "solution" and a recap of what was discovered. Again, thanks for your help.

[the_steve_randolph]

@ the_steve_randolph

As a last resort (for your mpeg4 video):
Re-encode it with x264 and then use
-bsf:v filter_units=remove_types=6
with streamcopy.

I am willing to try that, but, "re-encode it with x264" is again above my paygrade. I understand what a codec is and in general what it does, but, I have no knowledge of the features/problems with a specific codec or how to manipulate them. As stated before, the purpose of this thread/project is to learn more about ffmpeg. Over time, I have taken a lot of notes about things I don't quite understand with the hope of understanding at some point in the future. As stated in a post just a few minutes ago, I am in the process of replicating everything and I will be making a final post very soon. Again, thanks for your help.

[Selur]

Like I wrote: share a sample of your source which has subtitles in it, so others can test and suggest stuff.

[ProWo]

I am willing to try that, but, "re-encode it with x264" is again above my paygrade.

A fast recode commandline:

ffmpeg.exe -i "your_mpeg4_with_path" -map 0:v:0 -c:v libx264 -crf 20 output.mp4

This recodes the videostream only.

[the_steve_randolph]

Like I wrote: share a sample of your source which has subtitles in it, so others can test and suggest stuff.

This is the first time I have tried to upload a file, so, hopefully it works.

*************** Edited: this is NOT the correct file

[ProWo]

This is the first time I have tried to upload a file, so, hopefully it works.

This isn't a mpeg4 video with EIA 608 captions, but a h264 video with hardcoded subtitles.
This hardcoded subs cannot be removed.
You should upload the original mpeg4 sample with captions..

[the_steve_randolph]

This is the first time I have tried to upload a file, so, hopefully it works.

This isn't a mpeg4 video with EIA 608 captions, but a h264 video with hardcoded subtitles.
This hardcoded subs cannot be removed.
You should upload the original mpeg4 sample with captions..

Yes, I have uploaded the wrong file.

[the_steve_randolph]

Like I wrote: share a sample of your source which has subtitles in it, so others can test and suggest stuff.

I am working on that. In the meantime, I have downloaded the most recent version of Hybrid (Windows ver. 2024.01.12.1) from the "software/Hybrid" folder on this site. But, when I tried to run it, it gave me this error message:

Found no activationattributeNameFilter for key (FieldMatch)! (let Selur know)

[the_steve_randolph]

This is the first time I have tried to upload a file, so, hopefully it works.

This isn't a mpeg4 video with EIA 608 captions, but a h264 video with hardcoded subtitles.
This hardcoded subs cannot be removed.
You should upload the original mpeg4 sample with captions..

This appears to be the correct file:

[ProWo]

This is the first time I have tried to upload a file, so, hopefully it works.

This isn't a mpeg4 video with EIA 608 captions, but a h264 video with hardcoded subtitles.
This hardcoded subs cannot be removed.
You should upload the original mpeg4 sample with captions..

This appears to be the correct file:

No this is the wrong file again.
A h264 video with hardcoded subtitles, as above.

[the_steve_randolph]

No this is the wrong file again.
A h264 video with hardcoded subtitles, as above.

OK, I have talked with my shrink and he said yes - I am losing my mind. He thinks we might have identified it early, but, it also might only last a few more days. So, now it is a race against time for me to locate, clip, and, upload the proper file. Wish me luck cats and dogs!

[the_steve_randolph]

OK, I downloaded the file that I attached to post #53. Then, I execute this command:

ffmpeg -f lavfi -i movie=clip_of_orig_downloaded_again.avi[out0+subcc]

and this is the output I get:

ffmpeg version N-101923-gc012f9b265 Copyright (c) 2000-2021 the FFmpeg developers
  built with gcc 9.3-win32 (GCC) 20200320
  configuration: --prefix=/ffbuild/prefix --pkg-config-flags=--static --pkg-config=pkg-config --cross-prefix=x86_64-w64-mingw32- --arch=x86_64 --target-os=mingw32 --enable-gpl --enable-version3 --disable-debug --disable-w32threads --enable-pthreads --enable-iconv --enable-libxml2 --enable-zlib --enable-libfreetype --enable-libfribidi --enable-gmp --enable-lzma --enable-fontconfig --enable-libvorbis --enable-opencl --enable-libvmaf --enable-vulkan --enable-amf --enable-libaom --enable-avisynth --enable-libdav1d --enable-libdavs2 --enable-ffnvcodec --enable-cuda-llvm --enable-libglslang --enable-libgme --enable-libass --enable-libbluray --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvpx --enable-libwebp --enable-lv2 --enable-libmfx --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librav1e --enable-librubberband --enable-schannel --enable-sdl2 --enable-libsoxr --enable-libsrt --enable-libsvtav1 --enable-libtwolame --enable-libuavs3d --enable-libvidstab --enable-libx264 --enable-libx265 --enable-libxavs2 --enable-libxvid --enable-libzimg --extra-cflags=-DLIBTWOLAME_STATIC --extra-cxxflags= --extra-ldflags=-pthread --extra-libs=-lgomp
  libavutil      56. 72.100 / 56. 72.100
  libavcodec     58.136.100 / 58.136.100
  libavformat    58. 78.100 / 58. 78.100
  libavdevice    58. 14.100 / 58. 14.100
  libavfilter     7.111.100 /  7.111.100
  libswscale      5. 10.100 /  5. 10.100
  libswresample   3. 10.100 /  3. 10.100
  libpostproc    55. 10.100 / 55. 10.100
[h264 @ 000002bb7a1c7bc0] Application has requested 29 threads. Using a thread count greater than 16 is not recommended.
Input #0, lavfi, from 'movie=clip_of_orig_downloaded_again.avi[out0+subcc]':
  Duration: N/A, start: 0.080000, bitrate: N/A
  Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 512x384 [SAR 1:1 DAR 4:3], 25 tbr, 25 tbn, 25 tbc
  Stream #0:1: Subtitle: eia_608
At least one output file must be specified

That command is the only one I can seem to find that identifies the eia_608 stream. I am still getting conflicting views when I play my various copies on various players. Yes, ultimately I want to hardcode the subtitles into the video stream. When playing the videos, it seems that the smaller gray subtitles are the closed captioning and the more stark white subtitles are burned in.

[the_steve_randolph]

No this is the wrong file again.
A h264 video with hardcoded subtitles, as above.

Clearly I am having issues with finding the right file. But, coming at it from another angle, is there a player out there that does identify EIA 608 closed captioning AND can turn it on or off?

[zing269]

OK, I downloaded the file that I attached to post #53. Then, I execute this command:

ffmpeg -f lavfi -i movie=clip_of_orig_downloaded_again.avi[out0+subcc]

.
.
.
That command is the only one I can seem to find that identifies the eia_608 stream.

I think that code is creating an empty cc stream. Using the same command against a file that I know does not have an eia_608 stream also shows a subtitle stream.

Input #0, lavfi, from 'movie=test.avi[out0+subcc]':
  Duration: N/A, start: 0.500000, bitrate: N/A
    Stream #0:0: Video: rawvideo (I420 / 0x30323449),
    Stream #0:1: Subtitle: eia_608

[ProWo]

Clearly I am having issues with finding the right file. But, coming at it from another angle, is there a player out there that does identify EIA 608 closed captioning AND can turn it on or off?

VLC player, Tools, Media information, Codec.


[Attachment 77121 - Click to enlarge]

[the_steve_randolph]

Clearly I am having issues with finding the right file. But, coming at it from another angle, is there a player out there that does identify EIA 608 closed captioning AND can turn it on or off?

VLC player, Tools, Media information, Codec.

OK, I seem to be unable to find my original file that had the EIA 608 closed captioning. Seeing this post, I have a few questions:

1. can you upload a clip of that file with the EIA 608 closed captioning so that I have something to work with?
2. where in VLC can I turn on or off those EIA 608 closed captions?
3. what switch in ffmpeg would show me that the file contains EAI 608 closed captions?
4. what ffmpeg command can be used to extract the closed captioning into a text-based subtitles file?
5. what ffmpeg command can be used to eliminate the EIA 608 closed captions?