command line: use vlc to save video with modified brightness

[quickk]

Hi everyone,

I'm trying to figure out how to use vlc to save a video with modified brightness, gamma, and contrast values. Looking at the documentation, I found that the following code can play the video with the attributes that I want:

Code: Select all

vlc --contrast .9 --brightness .9 --gamma 3 test.mov

but I can't figure out how to then save the file with these modified attributes. I looked through the documentation, and there's an overwhelming amount of options, and I really don't know what to do. I don't want to transcode, just save the same file with these slight modifications.

Any help will be greatly appreciated!

[Arite]

This should probably be in the General VLC media player Troubleshooting forum section.

Those will work for playback providing you have enabled the adjust video-filter module (one method is to go to "Tools >> Effects and Filters" and check "Image adjust" in the "Video Effects" tab).

However to do it using the commandline you need to use "--video-filter adjust". For reference the complete commandline for playing the video with those settings is:

Code: Select all

vlc --video-filter adjust --contrast .9 --brightness .9 --gamma 3 test.mov

Equally to use the "adjust" video filter for transcoding you need to enable it using the --sout-transcode-vfilter command line option. So, for example to encode your test.mov to, for example, a MP4 file you could do:

Code: Select all

vlc --sout=#transcode{vcodec=h264,vb=0,scale=0,acodec=mpga,ab=128,channels=2,samplerate=44100}:file{dst=out.mp4} --sout-transcode-vfilter adjust --contrast .9 --brightness .9 --gamma 3 --sout-keep test.mov

Where "out.mp4" is your destination.

The --sout command specifies the encoding options/destination etc, --sout-transcode-vfilter says to use the "adjust" video filer module when transcoding, and the --contrast --brightness and --gamma settings set what the adjustment values should be. --sout-keep keeps the stream open across multiple playlist items (not required for one file).

Arite.

[quickk]

Thank you Arite for your help. The code you posted worked pretty well, except for the fact that the output video is a bit jumpy. I suspect that this is due to the fact that the input video does not have the usual frame rate, but is instead the output of a high speed camera with 1000fps.

A related question: is it possible to apply the video filters without any transcoding? Suppose I have an avi file on input and I want to keep everything the same so that I still have an avi file on output (except with the applied filters).

[Arite]

Thank you Arite for your help. The code you posted worked pretty well, except for the fact that the output video is a bit jumpy. I suspect that this is due to the fact that the input video does not have the usual frame rate, but is instead the output of a high speed camera with 1000fps.

You can customise the sout settings.

A related question: is it possible to apply the video filters without any transcoding? Suppose I have an avi file on input and I want to keep everything the same so that I still have an avi file on output (except with the applied filters).

Yeh - I saw you said you didn't want to trancode after writing my previous post . Below is a way to setup the default brightness, contrast settings etc.

I don't want to transcode, just save the same file with these slight modifications.

Ah OK - well you need to transcode the file if you want it permanently set with those settings. If you just want VLC to use those adjustment settings by default go to:
Tools >> Preferences >> (Select "All" for "Show settings") >> Video >> Filters

And check the "Image properties filter". This will enable the filter by default. Then go to:
Video >> Filters >> Image adjust

And set the Image contrast, brightness etc. to the levels you want. Then every time you open VLC it will use those settings by default.

If you don't enable "Image properties filter" the settings will still be stored - so you could just enable "Image adjust" in the "Effects and Filters" dialog box (or use "--video-filter adjust" in commandline when you want to use it).

Arite.