we're using mkvmerge to concat user uploaded audio into a single file (this is all done from code in a django website).
The command line looks like mkvmerge -o /path/to/output.webm -w /file/to/concat1.oga + /file/to/concat2.oga
(there can be hundreds of files, but that's not the issue).
It usually works well, except with a couple files, and we're trying to figure out the problem with these, so we can improve our code.
The error we get is:
Error: The track number 0 from the file '/path/to/file1.oga' cannot be appended to the track number 0 from the file '/path/to/file2.oga'. The formats do not match.
The two files are valid ogg/vorbis files, as shown by the output of ogginfo:
Processing file "/path/to/file1.oga"...
New logical stream (#1, serial: 32b21854): type vorbis
Vorbis headers parsed for stream 1, information follows...
Version: 0
Vendor: Xiph.Org libVorbis I 20101101 (Schaufenugget)
Channels: 1
Rate: 22050
Nominal bitrate: 45.111000 kb/s
Upper bitrate not set
Lower bitrate not set
User comments section follows...
ENCODER=libsndfile
TITLE=Tape1
Vorbis stream 1:
Total data length: 8453 bytes
Playback length: 0m:01.532s
Average bitrate: 44.126101 kb/s
Logical stream 1 ended
and ogginfo /path/to/file2.oga gives me:
Processing file "/path/to/file2.oga"...
New logical stream (#1, serial: 46c1e760): type vorbis
Vorbis headers parsed for stream 1, information follows...
Version: 0
Vendor: Xiph.Org libVorbis I 20101101 (Schaufenugget)
Channels: 1
Rate: 22050
Nominal bitrate: 58.000000 kb/s
Upper bitrate not set
Lower bitrate not set
User comments section follows...
TITLE=Tape2
Vorbis stream 1:
Total data length: 12121 bytes
Playback length: 0m:01.787s
Average bitrate: 54.234588 kb/s
Logical stream 1 ended
The only difference I can see is the bitrate, which from my understanding of the vorbis format, should not be an issue.
Any ideas on what the issue can be?