Any way to raise volume of an exported video without re-rendering whole file?

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Level 7

21,066 points

Any way to raise volume of an exported video without re-rendering whole file?

I have been given some videos where the audio is too low even when the TV/computer amplifier is set to maximum.

If I put them in FCP X and raise the volume it takes ages to re-render/export them . . . I am virtually exporting the complete video again.

Am I missing something . . . is there a way to alter the volume speedily?

I can do it in Avidemux . . . a one hour video takes less than 20 seconds to reprocess but I would prefer to use FCP X if that's possible.

iMac 27″ 5K, macOS 11.5

Posted on May 26, 2022 5:22 AM

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Answer 1

Best reply

Tom Wolsky

Level 10

151,058 points

May 27, 2022 4:41 AM in response to Ian R. Brown

Click the + button in the lower left and select New Setting. In the dialog select QuickTime. Select the new custom preset in left sidebar, and in the Video tab of the inspector check Enable video pass-through.

Bring in the clip to process. Drag the preset onto the job. Select the preset you've applied to the clip. In the Audio inspector use Add Audio Effect. Dynamic Range will give you an option to increase the Gain.

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Answer 2

terryb

Level 4

2,175 points

May 26, 2022 10:59 AM in response to Ian R. Brown

I'm not aware of a way to re-export in this way from FCP.

You could also do it pretty quickly in ffmpeg:

+ 10dB

ffmpeg -i inputfile -vcodec copy -af "volume=10dB" outputfile

+ 200%

ffmpeg -i inputfile -vcodec copy -af "volume=2.0" outputfile

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Answer 3

Ian R. Brown Author

Level 7

21,066 points

May 26, 2022 11:31 AM in response to terryb

Thanks. I have a strong hunch that it probably can't be done in FCP.

I won't use ffmpeg as it's yet another app to learn and store on my computer and Avidemux is so quick and easy.

Incidentally I think it was you who put me on to Avidemux a year ago . . . quite a useful little app.

Correction: It was Matti Haveri. You suggested ffprobe in conjunction with finding I, B and P frames.

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Answer 4

Ian R. Brown Author

Level 7

21,066 points

May 27, 2022 1:45 AM in response to Alchroma

I don't understand . . . how would I swap the new audio file with the existing one in the video?

As things stand, I open the video file in Avidemux, type in the number of decibels I want to raise or lower the volume by and hit Save. A new hour long video will be encoded in about 20 seconds. Nothing could be quicker or easier.

I wondered why I couldn't do it in FCP or any other normal editing app.

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Answer 5

May 27, 2022 2:42 AM in response to Ian R. Brown

Pass through video is not supported in FCP. But then, it is not supported in Compressor, nor in HandBrake, which I was about to recommend for the job. That came as a surprise for me. It turns out that people have been asking for this for a long time.

I think that, FCP being a video editor, it makes sense, but I would expect Compressor or HanBrake would do it. Glad that you have a solution that works, and quickly.

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Answer 6

Ian R. Brown Author

Level 7

21,066 points

May 27, 2022 6:15 AM in response to Tom Wolsky

You have cracked it once again!

The crucial thing I had forgotten was pressing that little + sign to get started.

Yes, it works perfectly except the encoding time (45 seconds) is twice as long as Avidemux . . . what's that about looking gift horses . . . ?

I tried it in FCP exporting the Compressor preset but it looks as though it would have taken ages (2% after a minute) as the file was not a "normal" one.

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