AIFF files will not play on iPod, will on iTunes

[toog]

I'm using Audacity 2.0.3.0 from the .dmg on a Mac Pro hex core with 24 GB RAM. Audacity is installed on a SSD boot drive and the data is stored on a RAID 0 combination of conventional HD's. Using OS X 10.6.8.

I record streaming radio, my saved projects (.aup) are anywhere from seven to twelve hours long, sometimes I will save them in halves. The files are ~7-17 GB. I export selections from the projects in AIFF that are ~80 minutes long. The stream is mp3, 128 Kbps. I record on a Windows PC running Windows Seven, using Real Player, for logistical reasons. Then drag them to the Mac over the network. That way I can record on the PC while I edit on the Mac, and also do not have to relay on that stinking, crash-prone, Adobe shock wave flash player. Adobe, are you listening!?

I'm just an audio lay person, although I am a rocket scientist,....really. I export in AIFF so as to have a file I can edit without loss of quality before I export a final section for listening, which I want to be as good as possible. I understand that I'm not starting with the gold standard of recording, nevertheless... I drag the files into iTunes, where they play just fine. I import them into my iPod, and while it's plugged into the computer it plays the files. However, once the iPod is disconnected, the AIFF files will not play on the iPod.

If I export from Audacity in WAV or AAC, no problems. Same with if I convert the AIFF files to either of those two while in iTunes. I called Apple tech support and was escalated twice, ultimately, to a senior tech spec., who didn't have an answer, but would like to know what I find out. AIFF should be compatible with the iPod. In fact, some of the earlier AIFF files I created in Audacity will play on the iPod, but after trying to play, several times, those which will not, the early files will no longer play either. But, if I reset the iPod they will play again. Restoring does not help, except doing so will provide the same fix for the early AIFF files as a reset.

I realize I can work around the issue by not using AIFF, however, inquiring minds want to know....

Any thoughts?

Thanks guys,

G

[kozikowski]

All AIFF files will fail to play on a stand-alone iPod? Short, long, it doesn't make any difference?

If you prepare your work in WAV, open it in iTunes and use iTunes to convert to AIFF, do those play? I think you can use QuickTime Pro to convert as well if you have that. I'm wondering if it makes a difference who makes the AIFF file.

Open the AIFF in QuickTime and Command-I invoke the INFO panel. What does that say?

Koz

[toog]

All AIFF files will fail to play on a stand-alone iPod? Short, long, it doesn't make any difference?

No, I exported one song, ~38 MB, in AIFF from Audacity, which would not play in the iPod. The larger file I am using (from which the prior song was culled) is ~850 MB.

If you prepare your work in WAV, open it in iTunes and use iTunes to convert to AIFF, do those play?

Yes, converting a WAV exported file to AIFF in iTunes results in a file that plays on the iPod, both the small and large files. In fact, if I convert an AIFF file in iTunes to AIFF, that will play also. In the get info section, iTunes, the extensions of the converted files change from AIFF to AIF. However, just going into the iTunes folder on the HD and changing the extension to one F does not alter its playability. In some cases, on an Apple PC, extensions can get a little funky, so it was worth a try.

I'm wondering if it makes a difference who makes the AIFF file.

Does not seem so. I converted both the small and long files from WAV to AIFF, and AIFF to AIFF, using WavePad, and they all played in iTunes and on the iPod.

Open the AIFF in QuickTime and Command-I invoke the INFO panel. What does that say?

In all cases the Quicktime format was : Linear PCM, 16 bit big-endian signed integer, 2 channels, 44100 Hz. That includes conversions in WavePad and iTunes.

G

[kozikowski]

--- I'm wondering if it makes a difference who makes the AIFF file.---
Does not seem so.

Yes, it does. Only AIFF files from Audacity fail, right?
Koz

[toog]

Correct. I answered in the context that we already knew that Audacity AIFF would not play and, so, were there anyone else's AIFF files that would not play.

So far, only AIFF files created by exporting selection, in Audacity, will not play.

Am I the only one to whom this has happened?

G

[kozikowski]

Now you have to wait until one of us has time to stop what we're doing, drag out the iPod, connect it, etc. etc. etc.

Koz

[kozikowski]

I made a nice AIFF file in Audacity 2.0.3 and it plays perfectly on both an iPod Touch and an older mechanical, spinning hard drive iPod.

This is the file I made.

http://www.kozco.com/tech/clips/millerGuitar2.aiff

Koz

[Gale Andrews]

Open the AIFF in QuickTime and Command-I invoke the INFO panel. What does that say?

In all cases the Quicktime format was : Linear PCM, 16 bit big-endian signed integer, 2 channels, 44100 Hz. That includes conversions in WavePad and iTunes.

If the iPod is on battery when unplugged from the computer, that is probably the problem - it will struggle with the extra calculations for any format that is unexpected in any way, or a file that has an unusual bit rate/depth or sample rate.

I was about to suggest the AIFF was unexpected compared to Audacity's because I thought AIFF's written by Apple applications are actually little-endian and have been for some years even on PPC machines ( see http://en.wikipedia.org/wiki/Audio_Inte ... ile_Format ). However an AIFF converted in iTunes does appear to be big-endian according to QuickTime Player just like an Audacity-exported AIFF. I only see one character difference in the header between an iTunes AIFF and Audacity AIFF.

If you wanted to satisfy curiosity you could install FFmpeg ( http://manual.audacityteam.org/o/man/fa ... html#macff ). When you export from Audacity, choose "Custom FFmpeg Export" and click "Options...". Choose "aiff" in the formats list and "pcm_s16le" in the codecs list. Click OK, add ".aiff" (without quotes) to the end of the file name, then export. This will give you a 16-bit little-endian AIFF instead of the normal big-endian.

What other differences could there be between an Audacity-created file and an iTunes created file? Does your Audacity-exported AIFF file have metadata? Does the order of the metadata change after conversion to AIFF in iTunes? You can check in a hex editor.

my saved projects (.aup) are anywhere from seven to twelve hours long

Please be careful. 13.5 hours is the maximum amount of audio that you can save in a 44100 Hz project, and less than that at higher sample rates. See http://wiki.audacityteam.org/wiki/Relea ... e_Projects .


Gale

[toog]

Thanks guys for the response.

The guitar section played.

I save my long projects in sections.

Like everyone, I only have so much time. I'll get to the other suggestions in the next couple of days.

Thanks again,

G

[Gale Andrews]

The guitar section played.

In the iPod without the cable connected?

Koz's guitar track has no metadata (Artist, Genre and so on). Perhaps your files have metadata.

Any AIFF saved by iTunes will have Normalisation (NORM) and Gapless (PGAP) information added to the file.

If Audacity exports an iTunes-created AIFF file containing NORM and PGAP data, it duplicates the Normalisation information towards the top of the file (but removing the "NORM" designation from both instances) and removes the Gapless (PGAP) information entirely. This could be quite sufficient to upset iPod running on battery.


Gale