Unsupported Audio Type is actually MP3

[yetanotherid]

I'd been re-encoding some AVIs when I bumped into this problem again so thought I'd ask if anyone knows why.
The original AVIs were created (I'm 90% sure) using AutoGK. When trying to re-encode them some worked fine, while with others AutoGK claimed they contained an unsupported audio type. According to AutoGK, the audio in the AVIs it was happy with is "112 Kbps CBR MP3 2ch". The unspported audio is listed as "112 Kbps MPEG-1/2 L3 2ch".

When I opened each AVI with Gspot it saw the audio in all the AVIs as "MPEG-1 Layer 3".

I then tried opening the AVIs with VirtualDubMod and it demuxed the AVIs with the unsupported audio as MP3s without a problem. When I tried to reload them into the AVI using VDM though it wasn't quite as happy. This is a picture of the warning dialogue:

http://i29.tinypic.com/256e6u8.jpg

When I continued VDM decided the MP3 audio was "MPEG-1 L1" rather than "MPEG-1 L3", 32000hz instead of 44100hz, around 9 minutes long instead of 23 minutes, and that it was a VBR MP3, which it wasn't. Foobar2000 had no problem correctly identifying and playing the MP3. Media Player Classic correctly identified the "unsupported" MP3 audio in the problem AVIs.

Rather than re-encode the audio I opened MP3DirectCut and resaved the MP3 as a new file. MP3DirectCut didn't offer up any warnings and the new MP3 then loaded into VDM as it should and became supported audio in the AVI.

I can only assume there's nothing wrong with the audio data as such, but something going on with an MP3 header which is confusing AutoGK and VDM. Anyone with any other ideas, or who knows why AutoGK/VDM aren't identifying those MP3s correctly?

FYI I'm using AutoGK 2.55 although I'm pretty sure I uninstalled the version of AviSynth which was installed with AutoGK and installed a slightly older version. That's because the version which AutoGK 2.55 installed was giving me errors when trying to re-encode AVIs. If memory serves me correctly, AVI wasn't a file type the newer version of AviSynth supported.

[buzzqw]

afaik is a MPA , mpeg audio file, aka mpeg layer 2 (not layer 3, mp3)

no avi should be muxed with mpa audio

BHH

[Midzuki]

no avi should be muxed with mpa audio

AVI files with constant-bitrate MP2 run nicely in Media Player Classic, in
Windows Media Player, and in Mplayer as well.

Sadly there exists only one MP2 ACM codec,
which doesn't want to work in VirtualDub.

[buzzqw]

i will reformulate

no avi should be muxed with mp2 vbr/abr (or ogg audio...)

even if is playable...

BHH

[yetanotherid]

Thanks guys but I'm still a little confused, because....
These particular AVIs were ones I made myself. They were created after recording an old VHS tape to the PC. The tape itself consisted of half a dozen different episodes. I'm virtually 100% sure I made them by converting the entire tape to either mpeg or AVI (with uncompressed video), then converting the mpeg or AVI to a new AVI containing XviD, and then I used VirtualDubMod to split the new XviD AVI into individual episodes. Even if I split the video before I converted it, which I doubt, I would have used the same program to convert each one to XviD, and I can't think of a reason why that wouldn't have been AutoGK. However I did it though, there's no reason why the audio in each of the AVIs in question shouldn't be of the same type.

Plus there's the fact that it's only AutoGK and VDM which don't seem to want to accept that some of the AVIs contain MP3 audio. GSpot, Media Player Classic and Foobar2000 all identified the demuxed audio as MP3.

After I posted I also had a thought regarding the other times I'd had this problem. I'm pretty sure there's been times when I've converted a video to an uncompressed AVI using either Super or AnyVideoConverter, then used AutoGK to convert that to XviD. Only I'd had to convert the audio to a wave file because when I'd converted it to MP3 I'd bumped into this same problem. I'll have to do a test conversion with Super and AnyVideoConverter later to see if I'm remembering correctly, but I'm sure that when I use one of those programs to convert the audio in a video to MP3, AutoGK sees it as MPEG-1/2 L3 2ch and tells me it's unsupported.

Is MPEG-1/2 L3 2ch audio not an MP3?

Thanks.

[Midzuki]

Is MPEG-1/2 L3 2ch audio not an MP3?

MPEG-1 layer III sample frequencies (kHz): 32 48 44.1
bitrates (kbps): 32 40 48 56 64 80 96 112 128 160 192 224 256 320

MPEG-2 layer III sample frequencies (kHz): 16 24 22.05
bitrates (kbps): 8 16 24 32 40 48 56 64 80 96 112 128 144 160

MPEG-2.5 layer III sample frequencies (kHz): 8 12 11.025
bitrates (kbps): 8 16 24 32 40 48 56 64

BTW, why use SUPER or AnyVideoConverter? :(

[buzzqw]

never use SUPER or AnyVideoC

try avidemux, it's a lot more powerfull

BHH

[yetanotherid]

Okay Midzuki, I'll admit it. I have no idea if you answered my question. :-)

Thanks buzzqw, I'll give avidemux a shot.