Changing Video File's Soundtrack format

[fl]

A friend created a video using a Zoom camera, which is capable of recording 24 bit PCM audio along with a high-def picture, as a QuickTime .MOV file. When he supplied this video to his client, there were playback issues, and I suspect that having uncompressed PCM audio was the source of the problems.

I suggested that he Start Pyramix, then instead of creating a new Project, that he Import the Video, and let Pyramix do the rest, which it does nicely, creating an eight Mono Strip Mixer and then importing the Video, displaying the visuals on a Video track and the stereo audio on two of the Audio Tracks. Subsequent modifications to the Track line-up and Mixer simplify things.

Selecting the three Tracks and then asking Pyramix to Wrap the file, and changing the destination's File Name so that the suffix is no longer .MOV but rather .MP4, and then proceeding with the Wrapping, yields a file which has its audio encoded as AAC, an automatic function of Pyramix, yielding a video which I suspect will play more nicely with the client's media player.

My question - I know that Pyramix will automatically convert the sound components of any project converted and re-wrapped like this, to AAC, but is there anywhere where bitrate and/or Samplerate can be altered? Were I to replace the existing soundtrack entirely with a mix of my own recordings of the same material, is there any way I can control the bitrate and samplerate of the resulting two-track soundtrack? What if I wanted to create a video with an .mp3 soundtrack? Can this be selected somewhere?

I don't suppose that Rendering the files/Clips in the Timeline to AAC or MP3, would give me this control, since the Wrapping will be sourced from the Mixer's Master Bus...

As I understand it, whenever a compressed audio file, like Ogg Vorbis, AAC, MP3, or FLAC is loaded into the Tracks in a Timeline, they are automatically converted to WAV files, to enable smoother, less processor demanding playback, so even if I go to the extent of converting my files to AAC, they'll still be WAV by the time they play through the Mixer, correct? What if I called the Mixdown window and chose LC AAC as the output format, then cancelled this operation to attempt the re-wrapping once again?

Is there any setting or preference which can be set which will determine a Video's Soundtrack Format, Bitrate, Samplerate and other Properties, when it's Wrapped in Pyramix?

I'm using Native version 11.0.4, and I don't own VCube or any additional video codec keys..., are any necessary for what I want to do?