AC-3 question

StormMarc wrote on 8/3/2005, 1:14 PM

Is it safe to encode AC-3 files at higher bitrates if I have the room? I'm used to encoding at 192 and do not want to mess up my compatability with DVD players but would like to get higher quality.

Also does would using PCM audio lower my compatability rates?

Thanks,

Marc

Comments

B_JM wrote on 8/3/2005, 1:44 PM

PCM would not lower compatability unless you went over a bit rate total of about 8000

you can encode to a higher bitrate BUT use standard bit rates of 224 or 448 as some players choke on others ...

PeterWright wrote on 8/3/2005, 7:09 PM

As most of my DVDs have video content around half an hour or less, I always use PCM audio, to maximise quality, since space is not an issue.

I am not aware of any compatibility issues so far. If I need a 5.1 surround mix, of course, I would have to use AC3.

StormMarc wrote on 8/4/2005, 11:09 AM

Peter,

When using PCM audio, what is the highest bitrate you will use to encode the video?

Thanks

Chienworks wrote on 8/4/2005, 11:15 AM

Bitrates don't apply to PCM. Bitrates are a measure of compression, and PCM is uncompressed.

However, you can calculate how many bits per second an uncompressed file will be. 48KHz 16 bit stereo will use 1,536,000 bits every second (1500Kbps). You cannot adjust this because there is no compression factor, so there is no "highest" amount, or "lowest" or "average" either.

B_JM wrote on 8/4/2005, 11:18 AM

I believe he was asking what was the highest max. VIDEO bitrate to use when using LPCM ..

the answer would be ~6450

Chienworks wrote on 8/4/2005, 11:25 AM

Ahhh. Good catch. Thanks.

StormMarc wrote on 8/4/2005, 12:34 PM

So basically there is a trade off in that you can not have 8000 CBR video if using PCM audio. Ok I think I've got it now.

Thanks,

Marc