Blueray audio compliancy ?

[lutinor]

Hi all,

I seen on Sonic sound forge a warning message which said 'under 128kbps ac3' -> it's not dvd compliant but 'should work' in an hardware player.

Is there something like that on blueray or going under 128 is reliable ?

Thx in adv,

Max.

[mp3dom]

Bluray specs says:
"Mandatory player internal decoder support for ac3 streams bitrates of 64Kbps to 640Kbps".
So you're safe to use whatever bitrate you want.
Just for reference, dts mandatory decode for core starts from 192Kbps to 1509 Kbps.

Edit: Anyway the warning of SoundForge doesn't mean anything. I've looked into DVD specs and it says that the minimum allowed by ac3 is 64 Kbps (exactly as BD and it's the minimum value for an ac3 encoder). Also Scenarist accepts a 64Kbps ac3 file and compile without a warning. It's probably only a 'suggestion' to not have a poor quality audio file (you have another warning if you encode a 5.1 with a different bitrate than 448kbps).

[lutinor]

Bluray specs says:
"Mandatory player internal decoder support for ac3 streams bitrates of 64Kbps to 640Kbps".
So you're safe to use whatever bitrate you want.
Just for reference, dts mandatory decode for core starts from 192Kbps to 1509 Kbps.

Edit: Anyway the warning of SoundForge doesn't mean anything. I've looked into DVD specs and it says that the minimum allowed by ac3 is 64 Kbps (exactly as BD and it's the minimum value for an ac3 encoder). Also Scenarist accepts a 64Kbps ac3 file and compile without a warning. It's probably only a 'suggestion' to not have a poor quality audio file (you have another warning if you encode a 5.1 with a different bitrate than 448kbps).
Thx for the reply :)

For info here's what Sound forge pro 10 said :

The AC-3 file to be rendered may not be fully DVD compliant, or have the best possible quality.

- The recommended data rate for DVD compliant stereo AC-3 files is 192 Kbps.

[mp3dom]

The same warning that appear when encoding 5.1ch at 384kbps datarate which we know is in specs. Probably SF is referring to the second part of the message (not have the best possible quality).
On a BD there's anyway no reason to go below 192 kbps even for only speech recordings, considering the space available.

[lutinor]

The same warning that appear when encoding 5.1ch at 384kbps datarate which we know is in specs. Probably SF is referring to the second part of the message (not have the best possible quality).
On a BD there's anyway no reason to go below 192 kbps even for only speech recordings, considering the space available.
Depends, on this project i need to save any bit lol (426 little movies in 720x576) ^^