Highest bitrate for AC-3 2.0?

[Anonymous344]

Hi,

does anyone know how high I can encode AC3 2.0 and stay within the DVD standard? I know that 5.1 cannot go above 448 kbps and that 2.0 is usually encoded at 192 kbps, but can I produce, for example, a 224 kbps or 256 kbps AC-3 2.0 file without it causing problems with players?

Thank you.

[guns1inger]

192kbps is at the very low end for commercial discs, although I have seen less professional material using 128 kbps, which is MP3 territory. I use 224 or 256 most of the time. 384 for stereo is probably higher than most source will required, with 448 being complete overkill. However if you have the space and the audio is the most important thing, you might opt for the higher bitrates, or even PCM (1536 kbps)

[dannyboy48888]

spec wise you can go up to 48khz at 640kbps. realistilty 384kbps should be fine for stereo audio. author a test clip and test on the dvd player in question. I have yet to run across one that did not play 640kbps stero, but you never know. And yes 5.1 can go up to 640kbps, the key is to keep the total container bitrate below 8mbps (saftey reasons) so just lower the max video bitrate accordingly

[ron spencer]

what is your source audio? Is it music? Does it NEED bandwidth. If it is just talking (like home movies), anything about 192 is a waste of space and takes from video.

[Anonymous344]

Thanks, guys! You gave me the information I needed. I'm most grateful.

[guns1inger]

As has been discussed elsewhere, regardless of the playability, 640 kbps AC3 is out of spec for DVD. That your player can handle it is beside the point. It is not allowed under the DVD specification, and any discs that is authored with it must be considered out of spec.

[Anonymous344]

Yes; that's what I thought about 640 kbps. I'm just glad that if I wanted to, I could go to 384 kbps and not be out of spec and have trouble with the file playing on people's players, though I'll probably stick to 256 or 224. Thanks, guns1inger.

[lordsmurf]

192kbps is at the very low end for commercial discs, although I have seen less professional material using 128 kbps, which is MP3 territory. I use 224 or 256 most of the time. 384 for stereo is probably higher than most source will required, with 448 being complete overkill. However if you have the space and the audio is the most important thing, you might opt for the higher bitrates, or even PCM (1536 kbps)

384-448 stereo is a transparent compression, best used for restored audio, so as not to reintroduce errors that were just filtered out, or add new ones to already-marginal audio.

[dannyboy48888]

my bad guns1inger, half awake. i was thinking of the max ac3 limit itself is 640kbps, but yes youre are right it is 'out of spec' for 100% conformance