Separate A Channel from A Track

[niteghost]

Not sure where I should stick my question to which Category?
Have a bunch of Videos that have a Single Track with 2 languages [ Mandarin & Cantonese] - The default is a Mandarin and some
jumble up Cantonese in the background,when I played the video.

I can watch the Video with either VLC or Potplayer and select >> Audio stream >> Left Mono [ Cantonese].

Wha I really want is to REMOVE the Right Channel { Mandarin], so that when I play the Video, the default will be in
the Cantonese Language...Any suggestion? - Thanks.

[lingyi]

Are these VCDs or rips from VCDs? AFAIK, only VCDs had dual audio tracks (mono Mandarin/Cantonese one of the stereo tracks). DVDs have separate Mandarin/Cantonese stereo tracks.

If so, this thread details what you need to do: https://forum.videohelp.com/threads/193430-how-to-rip-a-VCD-with-2-audio-channels

[niteghost]

Are these VCDs or rips from VCDs? AFAIK, only VCDs had dual audio tracks (mono Mandarin/Cantonese one of the stereo tracks). DVDs have separate Mandarin/Cantonese stereo tracks.

If so, this thread details what you need to do: https://forum.videohelp.com/threads/193430-how-to-rip-a-VCD-with-2-audio-channels

I downloaded the whole bunch from a Chinese Sites,looks like thy are "Old Videos" probably VCD's but the file format are in RMVB format mostly.

I was elavted when I use Handbrake the previous version to convert,it did had an optin on the Audio Tab to set to "Left Mono or "Right Mono"
or the stay with the Default at "stereo ". I was able to convert at least 19 of the 40 files perfectly and then the next 20 or so
came out with a distorted audio.?

[jagabo]

ffmpeg has audio filters that can do that.

ffmpeg -i stereo.mp4 -map_channel 0.1.0 -c:v copy mono.mp4

[niteghost]

ffmpeg has audio filters that can do that.

ffmpeg -i stereo.mp4 -map_channel 0.1.0 -c:v copy mono.mp4

Hmmmmm...this program must be executed in the Command Line or CMD, how complicated is it?

[jagabo]

Once you get this set up it's trivially easy:

Download a "static build" of ffmpeg. Extract ffmpeg.exe and copy or move it to C:\Windows\System32. Then use Notepad to put this text

ffmpeg -i %1 -map_channel 0.1.0 -c:v copy "%~dpn1.mono.mp4"
pause

into a file called SL2M.BAT (or what ever you want to call it, maybe "Stereo Left to Mono.bat").

After that you can drag/drop any of your videos onto the batch file to mux the original video and encode the left channel of the source audio to aac, into a new file with the same base name pluse .mono.mp4. So, for example, MyFile.MKV will result in MyFile.mono.mp4. The original file is left untouched.

If you put that batch file in your SendTo folder you can right click on any video in Explorer and select Send To -> SL2M.bat from the context menu to perform the conversion. In Win10 you can get to the Send To folder by opening an Explorer window then, in the title bar, type SendTo, press Enter. Drag/drop the batch file there.

I don't have any rmvb files so I can't verify the video codec will work in MP4. You might have to use a different container, like MKV. You do that by changing the output extension in the batch file (change .mp4 at the end to .mkv or whatever you need).

The "Pause" in the batch file is to leave the CLI window open in case there is an error -- so you can see the error message. Once you verified that the batch file is working you can remove the Pause if you want, the CLI window will then close automatically.

[niteghost]

Once you get this set up it's trivially easy:

Download a "static build" of ffmpeg. Extract ffmpeg.exe and copy or move it to C:\Windows\System32. Then use Notepad to put this text

ffmpeg -i %1 -map_channel 0.1.0 -c:v copy "%~dpn1.mono.mp4"
pause

into a file called SL2M.BAT (or what ever you want to call it, maybe "Stereo Left to Mono.bat").

After that you can drag/drop any of your videos onto the batch file to mux the original video and encode the left channel of the source audio to aac, into a new file with the same base name pluse .mono.mp4. So, for example, MyFile.MKV will result in MyFile.mono.mp4. The original file is left untouched.

If you put that batch file in your SendTo folder you can right click on any video in Explorer and select Send To -> SL2M.bat from the context menu to perform the conversion. In Win10 you can get to the Send To folder by opening an Explorer window then, in the title bar, type SendTo, press Enter. Drag/drop the batch file there.

I don't have any rmvb files so I can't verify the video codec will work in MP4. You might have to use a different container, like MKV. You do that by changing the output extension in the batch file (change .mp4 at the end to .mkv or whatever you need).

The "Pause" in the batch file is to leave the CLI window open in case there is an error -- so you can see the error message. Once you verified that the batch file is working you can remove the Pause if you want, the CLI window will then close automatically.

Thanks for the instructions for the setup.I will give it a try with the RMVB files.

[niteghost]

Once you get this set up it's trivially easy:

Download a "static build" of ffmpeg. Extract ffmpeg.exe and copy or move it to C:\Windows\System32. Then use Notepad to put this text

ffmpeg -i %1 -map_channel 0.1.0 -c:v copy "%~dpn1.mono.mp4"
pause

into a file called SL2M.BAT (or what ever you want to call it, maybe "Stereo Left to Mono.bat").

After that you can drag/drop any of your videos onto the batch file to mux the original video and encode the left channel of the source audio to aac, into a new file with the same base name pluse .mono.mp4. So, for example, MyFile.MKV will result in MyFile.mono.mp4. The original file is left untouched.

If you put that batch file in your SendTo folder you can right click on any video in Explorer and select Send To -> SL2M.bat from the context menu to perform the conversion. In Win10 you can get to the Send To folder by opening an Explorer window then, in the title bar, type SendTo, press Enter. Drag/drop the batch file there.

I don't have any rmvb files so I can't verify the video codec will work in MP4. You might have to use a different container, like MKV. You do that by changing the output extension in the batch file (change .mp4 at the end to .mkv or whatever you need).

The "Pause" in the batch file is to leave the CLI window open in case there is an error -- so you can see the error message. Once you verified that the batch file is working you can remove the Pause if you want, the CLI window will then close automatically.

Thanks for the instructions for the setup.I will give it a try with the RMVB files.

Yes, you are quite right, it is easier than it looks, I tried to highlight 2 or 3 files to Drag and Drop into the .Bat file but it seem to process
1 file at a time?... Also, can I specify a different Output folder for the converted files?......what am I doing wrong?

BTW. it came out perfectly the quality of the audio and video- Thanks.

[sneaker]

I tried to highlight 2 or 3 files to Drag and Drop into the .Bat file but it seem to process
1 file at a time?... Also, can I specify a different Output folder for the converted files?

You can adapt for multiple files and an output folder:

 
PUSHD %~dp0
mkdir "output_folder"
if [%1]==[] goto :eof
:loop
ffmpeg -i %1 -map_channel 0.1.0 -c:v copy "output_folder\%~dpn1.mono.mp4"
shift
if not [%1]==[] goto loop

[niteghost]

I tried to highlight 2 or 3 files to Drag and Drop into the .Bat file but it seem to process
1 file at a time?... Also, can I specify a different Output folder for the converted files?

You can adapt for multiple files and an output folder:

 
PUSHD %~dp0
mkdir "output_folder"
if [%1]==[] goto :eof
:loop
ffmpeg -i %1 -map_channel 0.1.0 -c:v copy "output_folder\%~dpn1.mono.mp4"
shift
if not [%1]==[] goto loop

Thanks, I will try that later .

[niteghost]

[QUOTE=niteghost;2581671]

Once you get this set up it's trivially easy:

Download a "static build" of ffmpeg. Extract ffmpeg.exe and copy or move it to C:\Windows\System32. Then use Notepad to put this text

ffmpeg -i %1 -map_channel 0.1.0 -c:v copy "%~dpn1.mono.mp4"
pause

into a file called SL2M.BAT (or what ever you want to call it, maybe "Stereo Left to Mono.bat").

After that you can drag/drop any of your videos onto the batch file to mux the original video and encode the left channel of the source audio to aac, into a new file with the same base name pluse .mono.mp4. So, for example, MyFile.MKV will result in MyFile.mono.mp4. The original file is left untouched.

If you put that batch file in your SendTo folder you can right click on any video in Explorer and select Send To -> SL2M.bat from the context menu to perform the conversion. In Win10 you can get to the Send To folder by opening an Explorer window then, in the title bar, type SendTo, press Enter. Drag/drop the batch file there.

I don't have any rmvb files so I can't verify the video codec will work in MP4. You might have to use a different container, like MKV. You do that by changing the output extension in the batch file (change .mp4 at the end to .mkv or whatever you need).

The "Pause" in the batch file is to leave the CLI window open in case there is an error -- so you can see the error message. Once you verified that the batch file is working you can remove the Pause if you want, the CLI window will then close automatically.

No. it does not work for RMVB video files?

[jagabo]

No. it does not work for RMVB video files?

What exactly do you mean? You seem to indicate it worked for a single file in post #8:

BTW. it came out perfectly the quality of the audio and video

Can you upload an rmvb file that isn't working? I don't have any to test.

[niteghost]

No. it does not work for RMVB video files?

What exactly do you mean? You seem to indicate it worked for a single file in post #8:

BTW. it came out perfectly the quality of the audio and video

Can you upload an rmvb file that isn't working? I don't have any to test.

Sorry about the confusion,it worked for video files with MKV containers but NOT for RMVB, I tested the code with MKV first.

screenshot with MKV files:

http://www.imagebam.com/image/3daacc1342564033


Screenshot of RMVB files:


http://www.imagebam.com/image/cda9ec1342566119


Here I UPLOADED a RMVB file, if you want to try it


http://www.filefactory.com/file/3zedlm5qszft/East.Fall.West.01.rmvb





Hope that clears up the confusion... Thanks again.

[jagabo]

The "0.1.0" in the ffmpeg command line means file 0, stream 1, channel 0. You're working with only one file file 0 is correct. Media files usually have the video stream before the audio stream. So stream 0 is usually the video and stream 1 the audio. But your RMVB file has them reversed -- 0 is the audio, 1 is the video. So you need to change that to "0.0.0".

I managed to find one RMBV file in my collection of odds and ends. Like the file in your image it has RV40 video and Cook audio. The next problem you'll run into is that RV40 video can't be put into an MP4 container (at least ffmpeg won't do it). Unfortunately, ffmpeg doesn't include an RMVB muxer so the new file can't be RMVB either. You can use MKV though.

The command line I gave you doesn't specify what audio codec to use. When making MP4 files ffmpeg will default to AAC. But when using MKV it defaults to Vorbis. If that's a problem for you you can specify what audio codec to use. For AAC:

ffmpeg -i %1 -map_channel 0.0.0 -c:v copy -c:a aac "%~dpn1.mono.mkv"

Other audio encoders you might want to use: ac3, mp2, mp3.

You can specify a bitrate with "-b:a 160k" (replace 160k with the bitrate you want). For example:

ffmpeg -i %1 -map_channel 0.0.0 -c:v copy -c:a mp3 -b:a 160k "%~dpn1.mono.mkv"

[niteghost]

The "0.1.0" in the ffmpeg command line means file 0, stream 1, channel 0. You're working with only one file file 0 is correct. Media files usually have the video stream before the audio stream. So stream 0 is usually the video and stream 1 the audio. But your RMVB file has them reversed -- 0 is the audio, 1 is the video. So you need to change that to "0.0.0".

I managed to find one RMBV file in my collection of odds and ends. Like the file in your image it has RV40 video and Cook audio. The next problem you'll run into is that RV40 video can't be put into an MP4 container (at least ffmpeg won't do it). Unfortunately, ffmpeg doesn't include an RMVB muxer so the new file can't be RMVB either. You can use MKV though.

The command line I gave you doesn't specify what audio codec to use. When making MP4 files ffmpeg will default to AAC. But when using MKV it defaults to Vorbis. If that's a problem for you you can specify what audio codec to use. For AAC:

ffmpeg -i %1 -map_channel 0.0.0 -c:v copy -c:a aac "%~dpn1.mono.mkv"

Other audio encoders you might want to use: ac3, mp2, mp3.

You can specify a bitrate with "-b:a 160k" (replace 160k with the bitrate you want). For example:

ffmpeg -i %1 -map_channel 0.0.0 -c:v copy -c:a mp3 -b:a 160k "%~dpn1.mono.mkv"

Tested the first line of code, came out great,now if I can incorporate that code that enables me to specify how many files in a folder to process and
able to specify a designated output folder to house the converted files will be PERFECT !!

Thanks fpr ll the effort,you're the RIGHT person to help me. !!


Screenshot of Converted files :


http://www.imagebam.com/image/a42b931342573175

[jagabo]

Sneaker showed how to step through files if you drag/drop more than one.

If you want to process all the RMVB files in a folder, and put them in a subfolder, put a batch file in that folder with this:

mkdir mono
for %%F in (*.rmvb) do (
    ffmpeg -i "%%~dpnxF" -map_channel 0.0.0 -c:v copy -c:a aac -b:a 160k "mono\%%~nF.mkv"
)
pause

Then double click on the bat file. All the new files will be in the "mono" subfolder. Note that the -y at the start of the command line stops ffmpeg from asking you if you want to overwrite any existing files.

[niteghost]

Sneaker showed how to step through files if you drag/drop more than one.

If you want to process all the RMVB files in a folder, and put them in a subfolder, put a batch file in that folder with this:

mkdir mono
for %%F in (*.rmvb) do (
    ffmpeg -i "%%~dpnxF" -map_channel 0.0.0 -c:v copy -c:a aac -b:a 160k "mono\%%~nF.mkv"
)
pause

Then double click on the bat file. All the new files will be in the "mono" subfolder. Note that the -y at the start of the command line stops ffmpeg from asking you if you want to overwrite any existing files.

Sorry, I'm really new to this way of converting files and absolutely NO idea about the parameters, you guys
are setting. I highlighted a bunch of RMVB files and drag it into the Code that you provided, ito the .BAT file and it seems to
process the files but I cannot find the subdirectory or the files that were converted?

[niteghost]

The "0.1.0" in the ffmpeg command line means file 0, stream 1, channel 0. You're working with only one file file 0 is correct. Media files usually have the video stream before the audio stream. So stream 0 is usually the video and stream 1 the audio. But your RMVB file has them reversed -- 0 is the audio, 1 is the video. So you need to change that to "0.0.0".

I managed to find one RMBV file in my collection of odds and ends. Like the file in your image it has RV40 video and Cook audio. The next problem you'll run into is that RV40 video can't be put into an MP4 container (at least ffmpeg won't do it). Unfortunately, ffmpeg doesn't include an RMVB muxer so the new file can't be RMVB either. You can use MKV though.

The command line I gave you doesn't specify what audio codec to use. When making MP4 files ffmpeg will default to AAC. But when using MKV it defaults to Vorbis. If that's a problem for you you can specify what audio codec to use. For AAC:

ffmpeg -i %1 -map_channel 0.0.0 -c:v copy -c:a aac "%~dpn1.mono.mkv"

Other audio encoders you might want to use: ac3, mp2, mp3.

You can specify a bitrate with "-b:a 160k" (replace 160k with the bitrate you want). For example:

ffmpeg -i %1 -map_channel 0.0.0 -c:v copy -c:a mp3 -b:a 160k "%~dpn1.mono.mkv"

Tested the first line of code, came out great,now if I can incorporate that code that enables me to specify how many files in a folder to process and
able to specify a designated output folder to house the converted files will be PERFECT !!

Thanks fpr ll the effort,you're the RIGHT person to help me. !!


Screenshot of Converted files :


http://www.imagebam.com/image/a42b931342573175

Frustrating !!,,,It worked 3 times, did not changed anything?
Now, the CMD window does not even appear when I dragged the fourtg file in?

What did I do wrong?

[jagabo]

There's a bug in Sneaker's batch file. I believe he intended for the bat file to be in the same folder as the video files, and and the new files would go to a subfolder called "output_folder" from there. But the output name spec is built incorrectly. Say your source file is in D:\Videos\Filename.rmvb". "output_folder\%~dpn1.mono.mp4" builds a name like "output_folder\D:\Videos\Filename.mono.mp4" Changing the output spec to "%~dp1output_folder\%~n1.mono.mp4" or "output_folder\%~n1.mono.mp4" should work.

If you want the batch file to work with the batch file in a different folder than the video files (in your SendTo folder, for example) you can modify the code to look like:

PUSHD %~dp0
if [%1]==[] goto :eof
:loop
mkdir "%~dp1output_folder"
ffmpeg -i %1 -map_channel 0.1.0 -c:v copy "%~dp1output_folder\%~n1.mono.mp4"
shift
if not [%1]==[] goto loop

That will work regardless of where the batch file is located. Output_folder will be created in the folder where each source video is.

[niteghost]

If you want the batch file to work with the batch file in a different folder than the video files (in your SendTo folder, for example) you can modify the code to look like:

PUSHD %~dp0
if [%1]==[] goto :eof
:loop
mkdir "%~dp1output_folder"
ffmpeg -i %1 -map_channel 0.1.0 -c:v copy "%~dp1output_folder\%~n1.mono.mp4"
shift
if not [%1]==[] goto loop

That will work regardless of where the batch file is located. Output_folder will be created in the folder where each source video is.

Unfortunately, I just tried your code but when the converted file that was put into the Output_folder, does not play at all.


A couple of screenshots are shown below :



http://www.imagebam.com/image/6abaec1342593432




http://www.imagebam.com/image/74b76f1342593512

[niteghost]

If you want the batch file to work with the batch file in a different folder than the video files (in your SendTo folder, for example) you can modify the code to look like:

PUSHD %~dp0
if [%1]==[] goto :eof
:loop
mkdir "%~dp1output_folder"
ffmpeg -i %1 -map_channel 0.1.0 -c:v copy "%~dp1output_folder\%~n1.mono.mp4"
shift
if not [%1]==[] goto loop

That will work regardless of where the batch file is located. Output_folder will be created in the folder where each source video is.

Unfortunately, I just tried your code but when the converted file that was put into the Output_folder, does not play at all.


A couple of screenshots are shown below :



http://www.imagebam.com/image/6abaec1342593432




http://www.imagebam.com/image/74b76f1342593512

UPDATE :

I made a chage in your Code instead of MP4, I use MKV and it worked !! - I dragged in 3 to 4 at a time..

Thanks much.

[jagabo]

Ah, yes, rv40 video can't be put in an MP4 file.

[niteghost]

Ah, yes, rv40 video can't be put in an MP4 file.

It seems to run very well the first time, then I tried a different folder with 20 RMVB files , it created the output_folder, and just did the #13 file, even though
I highlighted the 20 files and dragged them into the .BAT file.

I end up doing them individually...........sigh !! with your Original Code:


ffmpeg -i %1 -map_channel 0.0.0 -c:v copy -c:a aac "%~dpn1.mono.mkv"

[jagabo]

When you drag/drop files onto a batch file Windows builds a command line with a list of all the files you selected. There is a limit to the length of a command line. So there's a limit to the number of files you can convert that way.

Another way of handling many files is to put the names in a text file (with notepad, for example), one name per line. Then use that text file as an input to ffmpeg.

[niteghost]

When you drag/drop files onto a batch file Windows builds a command line with a list of all the files you selected. There is a limit to the length of a command line. So there's a limit to the number of files you can convert that way.

Another way of handling many files is to put the names in a text file (with notepad, for example), one name per line. Then use that text file as an input to ffmpeg.

Well, I'm happy and grateful even though I have to drag individual file one at a time,was just curious it worked before when I
dagged in 3 to 4 or more simultaneously it created the Output_folder and deposited the converted files in the folder. Tanks anyway for all the great help
and patience. Eternally Grateful Bro.

[niteghost]

Sneaker showed how to step through files if you drag/drop more than one.

If you want to process all the RMVB files in a folder, and put them in a subfolder, put a batch file in that folder with this:

mkdir mono
for %%F in (*.rmvb) do (
    ffmpeg -i "%%~dpnxF" -map_channel 0.0.0 -c:v copy -c:a aac -b:a 160k "mono\%%~nF.mkv"
)
pause

Then double click on the bat file. All the new files will be in the "mono" subfolder. Note that the -y at the start of the command line stops ffmpeg from asking you if you want to overwrite any existing files.

Hmmm.........seems like some RMVB files worked and some not - I hink I will give it a rest now.

[niteghost]

Here is a folder with a folder with the RMVB files

Screenshots of source file:

http://www.imagebam.com/image/e32ccc1342679743

Screenshot of the Mono folder:

http://www.imagebam.com/image/4b4a9d1342679778


Screenshots of CMD window:

http://www.imagebam.com/image/54a4581342679797


http://www.imagebam.com/image/b7d0d91342679827



Not sure why this particular source RMVB folder does not work?

[jagabo]

The fourth image shows the problem: "stream #0.0 is not an audio stream". Right above that you can see that stream 0 is video, stream 1 is audio. Some of your videos have the audio as stream 0, some as stream 1. I don't know how to make ffmpeg automatically detect which is the audio stream to prevent this error. But you could try using two ffmepg commands, one for stream 0, one for stream 1:

mkdir mono
for %%F in (*.rmvb) do (
    ffmpeg -i "%%~dpnxF" -map_channel 0.0.0 -c:v copy -c:a aac -b:a 160k "mono\%%~nF.mkv"
    ffmpeg -i "%%~dpnxF" -map_channel 0.1.0 -c:v copy -c:a aac -b:a 160k "mono\%%~nF.mkv"
)
pause

One will faild and do nothing. The other will succeed.

[niteghost]

The fourth image shows the problem: "stream #0.0 is not an audio stream". Right above that you can see that stream 0 is video, stream 1 is audio. Some of your videos have the audio as stream 0, some as stream 1. I don't know how to make ffmpeg automatically detect which is the audio stream to prevent this error. But you could try using two ffmepg commands, one for stream 0, one for stream 1:

mkdir mono
for %%F in (*.rmvb) do (
    ffmpeg -i "%%~dpnxF" -map_channel 0.0.0 -c:v copy -c:a aac -b:a 160k "mono\%%~nF.mkv"
    ffmpeg -i "%%~dpnxF" -map_channel 0.1.0 -c:v copy -c:a aac -b:a 160k "mono\%%~nF.mkv"
)
pause

One will faild and do nothing. The other will succeed.

Yep !! That DID IT !! - I'm haoping this "Final " Code that you provided here can be a "Universal " script to convert ANY RMVB

video files,REGARGLESS how the stream of the Video or audio are arranged??


Screenshot of the perfectly converted RMVB fiiles with the Leeft Mono in the MONO output File :





Thanks again for your support and patience...

[niteghost]

The fourth image shows the problem: "stream #0.0 is not an audio stream". Right above that you can see that stream 0 is video, stream 1 is audio. Some of your videos have the audio as stream 0, some as stream 1. I don't know how to make ffmpeg automatically detect which is the audio stream to prevent this error. But you could try using two ffmepg commands, one for stream 0, one for stream 1:

mkdir mono
for %%F in (*.rmvb) do (
    ffmpeg -i "%%~dpnxF" -map_channel 0.0.0 -c:v copy -c:a aac -b:a 160k "mono\%%~nF.mkv"
    ffmpeg -i "%%~dpnxF" -map_channel 0.1.0 -c:v copy -c:a aac -b:a 160k "mono\%%~nF.mkv"
)
pause

One will faild and do nothing. The other will succeed.

Yep !! That DID IT !! - I'm haoping this "Final " Code that you provided here can be a "Universal " script to convert ANY RMVB

video files,REGARGLESS how the stream of the Video or audio are arranged??


Screenshot of the perfectly converted RMVB fiiles with the Leeft Mono in the MONO output File :





Thanks again for your support and patience...

Which part of the above code that suppress Righ Mono making the Left Mono as default?


I have a bunch of RMVB files that I need to suppress the Left Mono now, the oppsosite to this?


Thanks.