Downmix an M4V made with Handbrake

[loninappleton]

Having tried the prescribed Videohelp methods of preparing a dvd for Auto GK and also having failed to get an encode from RipIt4Me, I looked up some tips on Lifehacker which recommended Handbrake. My Handbrake needed upgrading so I did that first

The encode to M4V, the default in Handbrake, gave a fine and reasonably sized encode of a 2 hour dvd main movie.

The problem I found was only seeing a sound record mode of 6:1 audio. No chance to use the normalizing capabilities of AGK or Goldwave filters which I also use.

Can MeGui or PGCDemux get the audio demultiplexed, then downmixed (which I saw/read FFMpeg is good at) and then go on to knocking out the loud parts (for latenight viewing) with Goldwave?

My question here is how do the Videohelp procedures I know from MP3 audio translate to this standard M4V made with Handbrake? That is: separating the audio, adjusting it then remuxing the audio to video with VirtualDubMod.

It should be clear that there is nothing "basically" or "essentially" about the process so please avoid saying such.

[loninappleton]

I have found this lead. Will see how far I get with MKVMerge/ MKVToolNix as suggested by hello_hello


http://forum.doom9.org/archive/index.php/t-164099.html

[loninappleton]

Some progress but still just trying things.

To review. I began with Mymovie.m4v made in Handbrake

Then obtained mkv from MKV toolnix

Following this I used the advice in the thread above and Dl'ed the latest FFCoder from videohelp. This was confusing because the prog that downloads is called 1.3.0 but is shown to be a 2.2 beta on the description.

FFCoder opens the MKV. Right Click and the AC3 2 ch 48000 audio is shown with the video file.

I requested to extract the AC3 audio to .WAV

This .wav I dropped into the Levelator which suppresses all sound effects and enhances speech dialog. Levelator is free and I have used it many times before to good effect:

http://web.archive.org/web/20130729204551id_/http://www.conversationsnetwork.org/levelator/

What surprised me in all this is that Handbrake (I guess) showed 6 ch audio but the output is AC3 2 ch 48000 and much easier to work with.

[loninappleton]

Using Levelator and a procedure for Goldwave I now have a .wav file ready to remux to the video.

I am now confused.

The original Handbrake m4v was converted to mkv with its ac3 audio in MKVToolnix and inspected in FFCoder.

I have .wav file to remux with the video. My only experience with this is in Virtual Dub.

I do not know how to put Humpty back together again. I'll inspect FFCoder to see if there is a reversal process available.

[loninappleton]

to this point I have used Winff, a GUI for FFmpeg if I understand that right.

I was able to encode from m4v to avi from this.

I have made my new audio file and the times match within a second.

But after several tries with WinFF thwe picture remains distorted. I tried anamorphic preset but it gave a wrong pixel size error. Selecting wide screen did not improve the picture which remains pinched. I do not know if there are settings other than the presets to correct this.

Making a standard MS compatible AVI takes a very long time but that is the only remaining thing to try in presets.