Help with Multi-Stream .ogg Please =)

[Straylit]

I have a series of multi-stream .ogg files. I've been tasked with taking each file and separating the streams within each into their own files. 11 of the files have imported and exported perfectly, but the two largest ones have not.

When importing these two files, I will get the prompt "Select Stream(s) to import." when I select them all, I am supposed to be getting the green progress bar for the import. Instead, the window just closes and nothing happens. I have tried literally everything I can think of, including opening these files in another program, but nothing seems to read them, despite them showing up in the same format as all the files I've successfully dealt with.

Is there a limit to how many streams/tracks Audacity can process? One of these multi-stream files states that it's 16 hours long and 617mb, the other is 4 hours long and 82mb, and they seem to be trying to import on the order of thousands and thousands of streams. The other files were all 500-1500 tracks each. I understand if the import would take a long time, or even if it crashed, but the "Import Stream(s) dialogue menu just closes and everything reverts to the default as if I had just opened the program.

Is this something Audacity can't do?

[Gale Andrews]

I don't know about whether there is a limit to the number of streams, I'm afraid. I see no comment in the code about it, other than a comment that only the first logical stream is opened (which is only still true for Audacity 1.2).

If no other programs will read these files they could be corrupted. However I think you can also assume Audacity support for multi-stream files is imperfect. I have a multi-stream OGG file I was given a while ago that has about 40 streams and is about three hours long. Audacity hangs whether you select one stream or all, and if you use FFmpeg to import the file, it does not list all the streams. VLC and Foobar manage the file OK and can convert it to FLAC (which is lossless). I would try that solution. I would not convert to WAV because the files will exceed the 2 GB or 4 GB WAV size limit (depending on the application).

If you want to upload somewhere the smallest example you have of a multi-stream OGG file that imports correctly, and one that doesn't, that might assist us. You could try http://www.megaupload.com/ for example (maximum 1024 MB).

Thanks


Gale

[Straylit]

Imports Correctly: http://www.megaupload.com/?d=FEJK0MPT

Won't Import: http://www.megaupload.com/?d=EMQ0W595

Both VLC and Foobar will open the files, but there's literally nothing there. You play them and nothing happens. VLC and Foobar also won't play or properly identify the ones that DO work in Audacity either.

I used SUPER which says that both are 16bit pcm, 80kbps 44100hz .ogg files, but it won't play or handle the files either. Soundforge can't read them, ffmpeg can't read them. I don't know of any other software to try.

I appreciate any assistance, thanks a bunch!

[Gale Andrews]

Thanks for the files.

I confirm Audacity just does nothing on opening the list of streams from the longer file.

VLC won't play that longer file.

I tried an old Foobar version 1.0.2.1 and the current 1.1.7. They behave oddly with that longer OGG, hanging first time, but second time opening the file apparently OK. It would appear that OGG has 1245 streams. I converted it to a long single FLAC file (297 MB) using Foobar 1.0.2.1. If Foobar sees the last stream correctly, it seems to be a 150 minute file and the FLAC of it imports OK into Audacity.

However clearly you want a tool that splits the streams into separate tracks. Although Foobar should be able to do that, it sees each stream as the same file name and seems to have no way to differentiate each file, so you can't save separate files automatically.

I also tried OggCutter and Musicutter to see if cutting the file in half would help Audacity to open it but they would not cut the file.

My feeling would be to ask on the Hydrogenaudio Forums for advice. There ought to be tools which can cut OGGs losslessly at the logical stream, and if not a HexEditor ought to be able to do it if you knew enough about where to cut and the header to paste after the cut. All I can find out about is the OggS "page breaks" which are in all OGGs whether they have multiple streams or not.



Gale

[Straylit]

After a bit of work, I managed to locate and configure a program that successfully split the remaining files.

It's called OGMDemuxer and can be found at http://www.videohelp.com/tools/OGMDemuxer.

I figured I would post my results and reference this program here in case anyone else runs into a similar issue. Thanks for the help Gale.

[Gale Andrews]

Many thanks for the link, though I changed it to point to videohelp.com so that if anyone needs help with that tool they should be able to get help there.

Sorry Audacity was not more useful with the largest files. I don't see any obvious structural differences between the one that opened and the one that didn't so I assume Audacity as you suggest is just choking on the sheer number of streams.


Gale