AVI audio becomes out of sync in Vegas Pro 9.0

[Thunderhead2772]

when editing AVI files with the audio codec "0x0055 MPEG-1 Layer 3" in Vegas Pro 9.0e, certain sections of audio will go out of sync or skip after a certain amount of time of Vegas running. also this is while editing/playing on the timeline, not the rendered video that has the problem.

i tried remuxing to mp4 with ffmpeg, and with mp4box, but then i cant import it at all for some reason

heres a mediainfo of the AVI. and this happens for all AVI videos with these codecs

Format                           : AVI
Format/Info                      : Audio Video Interleave
File size                        : 99.9 MiB
Duration                         : 11mn 36s
Overall bit rate mode            : Variable
Overall bit rate                 : 1 203 Kbps
Writing application              : VirtualDubMod 1.5.4.1 (build 2178/release)
Writing library                  : VirtualDubMod build 2178/release

Video
ID                               : 0
Format                           : MPEG-4 Visual
Format settings, BVOP            : 1
Format settings, QPel            : No
Format settings, GMC             : No warppoints
Format settings, Matrix          : Default (H.263)
Muxing mode                      : Packed bitstream
Codec ID                         : DX50
Codec ID/Hint                    : DivX 5
Duration                         : 11mn 36s
Bit rate                         : 1 056 Kbps
Width                            : 512 pixels
Height                           : 384 pixels
Display aspect ratio             : 4:3
Frame rate                       : 29.970 fps
Color space                      : YUV
Chroma subsampling               : 4:2:0
Bit depth                        : 8 bits
Scan type                        : Progressive
Compression mode                 : Lossy
Bits/(Pixel*Frame)               : 0.179
Stream size                      : 87.7 MiB (88%)
Writing library                  : DivX 5.1.1 (Maupiti) (UTC 2003-11-19)

Audio
ID                               : 1
Format                           : MPEG Audio
Format version                   : Version 1
Format profile                   : Layer 3
Mode                             : Joint stereo
Mode extension                   : MS Stereo
Codec ID                         : 55
Codec ID/Hint                    : MP3
Duration                         : 11mn 36s
Bit rate mode                    : Variable
Bit rate                         : 133 Kbps
Channel(s)                       : 2 channels
Sampling rate                    : 48.0 KHz
Compression mode                 : Lossy
Stream size                      : 11.1 MiB (11%)
Alignment                        : Aligned on interleaves
Interleave, duration             : 24 ms (0.72 video frame)
Interleave, preload duration     : 219 ms
Writing library                  : LAME3.90.3

[poisondeathray]

vbr mp3 can give vegas (and other programs) problems.

convert to the audio to wave. you could use vdub in direct stream copy for the video, and uncompress the audio ; or you could use ffmpeg, or avidemux

[Thunderhead2772]

what would be the ffmpeg command for converting the audio in the AVI file and putting it into a new avi file?

[poisondeathray]

ffmpeg -i input.avi -vcodec copy -acodec pcm_s16le output.avi

but normal long GOP xvid/divx isn't the best to edit either; you would be better off using an I-frame format

[Thunderhead2772]

well it seems to work now. but it like doubled the file size :/ 99.9mb to 216 mb

are there any other audio codecs to convert to that wont bloat the file?

[poisondeathray]

cbr mp3 should have less problems, but it's lossy (re-encoding mp3 to mp3). Then the size is dependent on the bitrate you choose (filesize = bitrate x running time)

my advice is : if you want fewer headaches, use uncompressed audio all the time with NLE's like vegas