I have .mpg file that I want to lower the bitrate of the audio. I know I have to demux, etc. My question: Can I lower the bitrate of my audio stream directly in one step, or do I have to convert it into a .wav file first, then reencode it into a .mp2 file? Also, will reencoding the audio lower its quality (aside from the lower bitrate) as similar to the more you reencode video, the worse its quality gets?

Thanks