I have downloaded an mp3 from http://www.brokenheartfoundation.org.uk/hawk/track03.mp3

It plays correctly in iTunes 7 on a Mac but for some reason iTunes refuses to even sync it to my iPod. The other 3 mp3s you can download from the same site plays and syncs fine.

Any ideas why? Is this mp3 broken (beyond that it is encoded a ridiculously low bitrate and in mono)?

damn, this sounds awful! :-(

I can confirm that the file isn't syncable... latest iTunes OS X and first gen iPod Nano.

the downloaded mp3 is an mpeg-2, layer 3 file actually not an mpeg-1 layer3! (created with iTunes 4.9; mono, 10,025KHz and 24 Kbps (VBR)) that's supposedly why the iPod won't play them.


edit: this site tells us, that "From a purely file format point-of-view, there is no such thing as an "MP3 file". We have MPEG-1 files, MPEG-2 files, and MPEG-4 files, but no MPEG-3 files as there is no such thing as MPEG-3. The "MPEG-3" designation was skipped. Next is MPEG-7, followed by MPEG-21.

What we commonly call an "MP3 file" (that is, a file with a ".mp3" extension) is, from a strictly file format point-of-view, actually an MPEG-1 file or an MPEG-2 file which just happens to contain MPEG Layer III audio data (as opposed to MPEG Layer I audio data or MPEG Layer II audio data). (...) Which type of file, MPEG-1 or MPEG-2, a given (properly named) .mp3 file is, is dependent upon the encoding parameters chosen at the time the file was created. The parameters which determine whether the MP3 encoding software will produce an MPEG-1 file or an MPEG-2 file are the sampling rate (measured in kHz or kilohertz - thousands of cycles per second), the datarate (or bitrate, measured in kbps or kilo bits per second - thousands of bits per second), and the number of audio channels (one channel for monaural or two channels for stereophonic)."

so the iPod should play them, as long as apple thinks the same way. they state in the iPod specs:

"Audio formats supported: AAC (16 to 320 Kbps), Protected AAC (from iTunes Store), MP3 (16 to 320 Kbps), MP3 VBR".


2nd edit: I tested a file which I have transcoded via iTunes that has a bitrate of 24 kbps (VBR), is encoded in mono, has a sampling-rate of 11,025 KHz and uses mpeg-2, layer 3 encoding. this file is syncable..

conclusion:

the problem must be something else.. it has nothing to do whether it is mpeg-2, layer 3 or an mpeg-1, layer 3.



3rd edit: a little suggestion.. you could have tested and done a google-search on your own.

What should I have tested/searched for? I knew it was an Mpeg2 Layer-3 file, what we in everyday speech call an mp3.

well, you could have encoded one file and test it. then you would have known that the file must be corrupt, because the self-made file is syncable and plays in iTunes.

but - you are welcome! :-P

No, we don't. MP3 is MPEG-1 Audio Layer 3. Fact. See http://wiki.hydrogenaudio.org/index.php?title=MP3

the site I referred to tells something different:




so.. what is the consensus? who is we and what is an mp3 anyway?

after reading my linked site it seems to me that mpeg-2, layer 3 is just an encoding option which was added later to the mpeg-1 standard and can be considered as an extension to it - for low bitrates/sampling rates and mono-encoding.


could someone, a LAME-developer for instance, clear this up?

It isn't broken. It is a 24kbps 11.025kHz MPEG-2.5 Layer-III file. MPEG-2.5 isn't an official MPEG standard (only MPEG-1, MPEG-2, MPEG-4, ... etc are) and this is most probably the reason why not all programs want to play this file - it is simply a non-standard MP3 file and not always supported.

This is about correct. MPEG-2 Layer 3 is mp3 too, it just extends the specifications by adding sample rates of 16 kHz, 22.05 kHz and 24 kHz as well as the possibility to encode up to 5.1 channels to the existing MPEG-1 standard, featuring flawless backwards compatibility. The above-mentioned MPEG-2.5 supports additional sample rates of 8 kHz, 11,025 kHz and 12 kHz, but it's a proprietary development by Fraunhofer IIS and therefore unsupported by the majority of mp3 decoders.