2Lame VBR audio & SVCD

[HockeyStick]

Hi everyone,
As some of you may have already notice in previous post, i've had i hard time finding the right settings to get good mp2 audio with SVCD (squealing noise in silent scenes) even at 224kbps. So i've test near all settings possible with AZID---»SSRC---»2Lame, and i found that i can get excellent results with the "experimental" VBR audio setting in 2Lame (i've try the maximum of "15").
Now, i've mux the resulting mp2 file with the video, but no audio was present when i played back with WinDVD (the mp2 file played very well in WinAmp).
So i don't think VBR audio is compatible with SVCD, or is there a way to get it work?

regards,
HockeyStick

[Gabriel_Bouvigne]

Sorry, but vbr is not part of vcd specs.

[Shabubu]

I've heard that alot, but acording to the VCDImager documentation it VBR audio is a part of the SVCD spec, the big question is who is right, and regardless of that do the players support them.

Page 10 of VCDImager manual

"1.3.4 Super Video CD 1.0

With the upcoming ......

..... The following new features building upon the Video CD 2.0 secification are:


-Use of MPEG-2 encoding instead of MPEG-1 for video stream
-Allowed VBR Encoding of MPEG-1 audio stream.
-Higer resolutions ......"

Cofirmed again in section 1.5.2

[Spawn]

VBR MPEG Layer 2 audio is part of the SVCD specs. Months ago I made vbr mp2 streams that playback perfectly by themselves, however they fail when multiplexed with audio (Silence; as you noted).

I believe this is an issue with BBMpeg not supporting vbr mp2 audio.

-Spawn

[Gabriel_Bouvigne]

Oh yes, my mistake

It's not part of vcd, but yes it's part of svcd

[HockeyStick]

Spawn-
You may be right about that issue with bbMPEG(it's the one i use), i will try to mux with TMPGenc instead and give you some feedback.
Or, is there a better prog for multiplex?
thanks

[symonjfox]

Unfortunately BBMpeg can't handle VBR MP2 files. I know that TMPGenc can do it.

You can't listen to any sound in WinDVD or PowerDVD because they can't play low bitrates (I tried a SVCD with audio @ 96 kbs that play well in my DVD player, but it doesn't with those programs).

There's an issue about using VBR MP2 with SVCDs: SVCDs have a TOTAL BITRATE LIMIT. If you use a bitrate higher that limit, some players (like mine) freeze and skip to next scene lower that limit. Now: if we have a CBR audio, the video can be VBR but we know that will be the right Max Bitrate for it. If we use a VBR audio, we can't know what is the max used bitrate. In Toolame or Besweet I can't set a max bitrate option, so else in a 112 kbs average bitrate, there should be a frame with 224 or 320 kbs. Usually, the bitrate (both video and audio) will jump up when there's a scene like an explosion or a shot, some action scenes, and so on. Those scenes increase both VIDEO and AUDIO bitrate, so the probability of going out of range is very high.

I explained bad, but I hope you understood.