Say I have a video file with contained audio file. So a container with audio and video codecs.
If I'm applying an operation in ffmpeg that will re-encode the video, such as applying filters or changing the container (assume it supports the audio codec) or video codec or whatever, does this also re-encode or affect the audio of the output file in any way?
Does the audio codec just automatically get a kinda pseudo -c copy command applied and translated over to new video file?
I'm trying to understand whether I need to specify a -c copy for the audio every-time I do an operation to the video part. Whether for the purpose of speeding up the operation or for avoiding quality-loss.
Like when setting an audio input and a video input and combining you need to specify a -c copy to get it to simply combine them. But I'm just a bit confused if you need to worry about it once the audio codec is already safely in the container and I'm applying operations to this video afterthefact.