Error in Variable bitrate (VBR) audio detected

[Russo]

I have got this error and don't understand

AVI: Variable bitrate (VBR) audio detected. VBR audio in AVI is
non-standard and you may encounter sync errors up to 43680ms when
attempting to extract WAV files or processing the audio in Direct Stream
Copy mode. Full Processing mode is recommended to decompress or recompress
the audio. (bitrate: 151.5 ± 32.3 kbps)

[mats.hogberg]

What do you not understand? Most applications have problem with VBR audio AVI. It shouldn't be used. Is this when loading it in VirtualDub? To fix it, extract audio, decode to wav, encode as CBR mp3 (or other codec) and replace the original audio.

/Mats

[Russo]

thx

I know it says to do that but first error like that wasn't sure

[jagabo]

Try using VirtualDubMod if your not already. It asks if you want to apply the fix or not. You can answer yes or no. Sometimes one works, sometimes the other, even without reencoding.

[Russo]

Having a hard time splitting the audio and video

[mats.hogberg]

Easiest is to load AVI in Goldwave, save wav.
Then you load the AVI in VirtualDub, and select WAV audio (and your new wav file from Goldwave)

/Mats

[Russo]

thx mats u are the man thx

[jagabo]

I usually do the following in VirtualDubMod if I need to export the audio as uncompressed WAV:

1) File -> Open Video File
2) Answer Yes or No if VBR error dialog pops up
3) Streams -> Stream List
4) Right click on stream, select Full Processing Mode
5) Right click on stream, select Conversion... if necessary
6) Press Save WAV

If you don't select Full Processing Mode for the audio stream will be saved with the existing codec in a WAV file. So if your source has VBR MP3 audio you will get a WAV file with VBR MP3 audio in it. Note that WAV and AVI are simply minor varations of the more general RIFF container.

[Spideray]

VirtualDubMod's header fix wont always fix the VBR without re-encoding (only about 1:10 chance) the trick is to remove the VBR audio with AVIMux-GUI then convert the the VBR to CBR using WinMP3Packer then add this new CBR audio to the modified AVI that you have removed the VBR track from in VirtualDubMod under the streams menu use direct stream copy. When split and audio converted you can use VirtualDubMod to re-mux use Direct Stream Copy again the will have the audio frames aligned with interleaves. this is a long winded process but will give the desired results, you can only recompress the video to DivX on another full processing pass when you can also alter the fps from Film (NTSC) to PAL if desired.

If you use the VirtualDub you can recompress the VBR audio to CBR using the LAME ACM MP3 codec (audio compression manager) without splitting and adding a new CBR track in my experience this will give you the best results even when the audio frames are split across interleaves.

The big problem with VBR audio is that most standalone DVD player/recorders with AVI support specifically Home Theatre DivX format require the audio to be at a CBR and the FOURCC of the video to be DX50 or DIVX to ensure no playback problems. Check out my Fixya tips here for conversion of AVI that will give you problems to those that won't.

http://www.fixya.com/support/r4096773-convert_ans_avi_mp3_vbr_cbr_virtualdub

If you play CBR audio AVI files on your PC you have many playback options usually a player that uses the libavcodecs like VLC Player, Mplayer and KMPlayer will play the file with no errors this can't be said for all players even the DivX player may suffer audio synch as VBR is not the standard as all will tell you even if the VBR audio is aligned with interleaves you may still have problems.

[Baldrick]

Bye bye.