TMpgEng Express and Audio Encoding

Good evening afterdawn addicts!

Question: Sitting here with my TMpgEnc open and have been encoding to dvd a bit, playing around and I'm curious about audio encoding. What's a good way to go? MPEG-1 or AC-3 Dolby? I've been reading that in theory, NTSC should use AC-3, but then what bitrate should I look at? Does it matter? And then what should I look at for channel mode: stereo or dual channel?

Anyhoo, thanks for checkin this out and happy new year's to you.

Ry

 

Tmpgenc sucks at encoding audio, however...
Stereo AC3 is dvd spec.

 

First, MPEG-1 is VCD MPEG (a video compressed 1150 kbps CBR), not an audio format.
The alternative audio format is MP2 (mpeg Layer 2), ofter called MPA (MPEG audio).

My suggestion is: avoid using TMPGenc to make conversions.
If you alteady have an AVI with AC3 audio (2 channels: Dolby; 5+1 channels: Dolby Surround), simply load it with VirtualDubMod, do Stream__Stream List and demux the AC3 stream.
If the AVI has MP3 audio (often they have), load the AVI with VirtualDub, make Audio__Full Processing Mode and Save WAV.
(Often the VirtualDubMod's commad 'Save WAV' doesn't work and simply demuxes the audio stream).

Later you'll use the WAV or the AC3 stream when you author the DVD. The authoring applications load a M2V video and an audio (.AC3, .MPA which is, in truth, another name for .MP2 file, .DTS or .WAV).

Ah, the stream must be sampled 48 kHz. AC3 streams always are (they are DVD compliant, either if they have 5+1 or 2 channels), sometimes you'll need to transcode (44.1 kHz -> 48 kHz) the WAV stream because the sampling rate of the MP3 audio was 44.1 kHz [(S)VCD] instead of 48 kHz.
Some auhoring application can transcode the audio (DVD Lab does it). Otherwise, a good audio encoder can make it.

Last: remember that garbage in = garbage out. Avoid try using the WAV stream extracted from a, say, 96-128 kbps MP3 audio to make a 384 kbps AC3 stream. You won't get great results, even if you manage to make a correct AC3 stream from that.

 

Thanks for the input aldaco. Gotta love that GIGO rule hey? If I had a dollar for every time I heard that from one of my professors. Heh