DVDLab pro & AC3 Files

[tygrus2000]

i noticed the other day I tried to bring a high bitrate AC3 5.1 file I created into a DVD project and DVD Lab crashes on compile and muxing.

The file I used was AC3 5.1 640 kbps and my overall project (video +audio) was 9675 kbps - well under the 9800 limit.

Does DVD lab have limitations on the bit rate of audio files?

thx.

Tygrus

[equinox137]

Not that I know of, but I've never heard of an AC3 5.1 having such a high bitrate as 640kbps. The highest I've seen even a commercial AC3 5.1 go is 448 kbps. On the other hand, you can also use uncompressed WAV at 1536 kbps, so I don't think there's a bitrate limit.

[BJ_M]

9675 kbps is really to high for burned dvd's.. just asking for problems ..


you should use 448 as max because the multiplexer will have buffer underflows at the bit rate you used as it is non standard ...

[reboot]

How did you get the AC3 file?

[Safesurfer]

I think the maximum legal data rate for AC3 in the DVD spec is 448kbps, that's probably why DVDLab is crashing.

[GeorgeW]

From the DVDDemystified site:

<<<
Dolby Digital is multi-channel digital audio, using lossy AC-3 coding technology from PCM source with a sample rate of 48 kHz at up to 24 bits. The bitrate is 64 kbps to 448 kbps, with 384 or 448 being the normal rate for 5.1 channels and 192 being the typical rate for stereo (with or without surround encoding). (Most Dolby Digital decoders support up to 640 kbps, so non-standard discs with 640 kbps tracks play on many players.) The channel combinations are (front/surround): 1/0, 1+1/0 (dual mono), 2/0, 3/0, 2/1, 3/1, 2/2, and 3/2. The LFE channel is optional with all 8 combinations. For details see ATSC document A/52 <www.atsc.org/document.html>. Dolby Digital is the format used for audio tracks on almost all DVDs.

>>>

[JimJohnD]

If you are encoding AC3 5.1 @ 48K then bitrate to audio bandwith looks like:

224 = 9.05 khz
256 = 12.42 khz
320 = 15.8 khz
384 = 18.05 khz
448, 512, 576 and 640 all = 20.3 khz

So there isn't any reason to go above 448KHZ for 5.1 as far as bandwidth is concerned.

[tygrus2000]

I made the file with the program Audio DVD Creator that is advertised on this site. Maybe I have to tone it back to 448.

I was trying to see if the surround effect increases with audio bitrate.

[reboot]

No...

[BJ_M]

nope