In Copy mode, Avidemux will just copy the audio source (external, internal, etc) to the output file. The only processing that works in copy mode is audio shift to correct for desynced audio.

• DRC: Use compressor code from Audacity. Amplify low sound level.
• Timeshift: Change the audio/video synchronisation. The unit is millisecond.

• None: Makes no changes to the audio
• Resample to: Change the sampling frequency. Needed for some formats that need a given frequency (such as DVD which needs 48(nbsp)kHz).

These filters must be used with a manual video framerate change as the filters change the synchronisation.

• Film to PAL: To be used when you changed the framerate of a video that was 23.976, changed to 25.
• PAL to Film: To be used when you changed the framerate of a video that was 25, changed to 23.976.

An option to dynamics increase or decrease the overall volume of the audio. Check the Gain enable this option.

• Automatic (max -3(nbsp)dB)
• Manual (dB): Put in the manual amount you want to raise or lower the value. This is an amplification level, so it is quite powerful.

The mixer will change the number of channels that you hear. The most common usage is to go from 5.1 sound to stereo. You will probably want Dolby Pro Logic II downmixing. Beware that to be efficient, Dolby Pro Logic audio must not be encoded with a low bitrate (~(nbsp)<(nbsp)160(nbsp)kb/s).