Converting AC3 to WAV then back to AC3 quality loss?

[xycer]

ok, the source is AC3 448kbps but i want to make it 256kbps so i can make the video quality a little better. The way i figured to do it was to extract the audio to WAV using virtualdubmod and converting it back to AC3 (256khz though) using ffmpegGUI. Will there be any noticable audio quality loss by extracting the audio to wav then back to AC3 (other than the fact that im reducing the quality from 448kbps to 256kbps) or is there a better way to do this?

[celtic_druid]

No loss from converting to wav, however re-encoding to AC3 there will be a loss. Why not convert directly with ffmpeg?

[Soopafresh]

I don't think the size is going to change all that much for you to notice a big difference in your higher video bitrate.

[johns0]

Its better to extract to wav and normalize the sound before you encode to ac3 cause if you directly encode ac3 to ac3 with ffmpeggui the audio will sound lower than before.

[xycer]

nvm, i tried extracting to WAV format in full processing mode but it wouldnt do it (i forget the error message) it will do it in direct stream mode but i heard i should do it in full proc. mode. I also tried encoding it directly using ffmpegGUI but the output was very small and i dont think it worked right.

when youre extracting the audio to WAV, are you supposed to do it in full processing mode or does it matter if you choose direct stream copy?

[xycer]

also, does any1 know the actual quality of dolby digital ac3 sound on real DVDs? (256, 448 etc).

[lordsmurf]

also, does any1 know the actual quality of dolby digital ac3 sound on real DVDs? (256, 448 etc).

Most stereo is 192-256, more channels 384+

[yoda313]

Hello,

Ditto to Lordsmurfs rating.

The documentaries will be 192 or lower to save space. Many older movies tend to be 384.

Newer Dolby tracks will be 448. Like Star Wars, Lord of the Rings, etc.

DTS starts at 754.

Kevin

[xycer]

thanks guys. when you guys do AVI to DVD transfers, what audio quality do you usually use?