Audacity Forum

I've set the default sample format to 32 bit float in preferences (that's the standard). Now mp3, 16 bit wav files and 16 bit flac are imported to 32 float tracks. I think that is the way it should be. Ogg files, however, and files that are imported through Quicktime (m4a, mp4, or mov) always appear as 16 bit integer tracks.

That's probably the reason why 24 bit Apple lossless files fail to import completely. (Using Mac OSX 10.4.11 on a G5 processor).

george13 wrote:I've set the default sample format to 32 bit float in preferences (that's the standard). Now mp3, 16 bit wav files and 16 bit flac are imported to 32 float tracks. I think that is the way it should be. Ogg files, however, and files that are imported through Quicktime (m4a, mp4, or mov) always appear as 16 bit integer tracks.

Hi, thanks for the report. Piecing together this and other reports then, it seems we have
all imports via FFmpeg (Windows and Mac) and QuickTime (Mac) at 16-bit resolution, and all
OGG imports via the native importer at 16-bit resolution irrespective of quality settings. I've asked on our developers' list if there are any reasons for this.

george13 wrote:That's probably the reason why 24 bit Apple lossless files fail to import completely. (Using Mac OSX 10.4.11 on a G5 processor).

Do you mean they are of shorter length than they should be (for example, 2 minutes instead of 3 minutes) or some other symptom? Do they import properly if you set quality to 16-bit?

Generally, definite bugs are better reported to feedback_AT_audacityteam_DOT_org rather than here, because there is no guarantee they will be picked up otherwise.


Thanks

Gale

Hi,

Sorry for being unclear, I meant to say those 24 bit Apple lossless files aren't imported at all. Nothing appears on the timeline, no error message either.

I understand ogg supports only 16 bit, but when you import a file into Audacity you probably want to work with it, eq or change the volume. Then it would be good to start with a 32 bit track for the added precision. But no major bug, anyway.

Generally, definite bugs are better reported to feedback_AT_audacityteam_DOT_org rather than here, because there is no guarantee they will be picked up otherwise.

I'll do that, thanks.

george13 wrote:I meant to say those 24 bit Apple lossless files aren't imported at all. Nothing appears on the timeline, no error message either. I understand ogg supports only 16 bit, but when you import a file into Audacity you probably want to work with it, eq or change the volume. Then it would be good to start with a 32 bit track for the added precision. But no major bug, anyway.

Thanks. Clearly the 24-bit Apple Lossless files need to be handled better than that. While QuickTime supports 24-bit, not all codecs it supports do, so it depends if our QuickTime importer can accommodate this problem. It's the same issue for imports via FFmpeg. The libav* interface does now support sample formats greater than 16-bit, but not all codecs FFmepg supports do. As for OGG, it seems at the moment that as the format does not support more than 16-bit, we cannot open it at higher resolution. The current known limitations have been documented in the Manual, anyway.



Gale

george13 wrote:I've set the default sample format to 32 bit float in preferences (that's the standard). Now mp3, 16 bit wav files and 16 bit flac are imported to 32 float tracks. I think that is the way it should be. Ogg files, however, and files that are imported through Quicktime (m4a, mp4, or mov) always appear as 16 bit integer tracks.

That's probably the reason why 24 bit Apple lossless files fail to import completely. (Using Mac OSX 10.4.11 on a G5 processor).

Hi George,

How did you create the 24-bit Apple Lossless files? (I have Tiger and Leopard so can use either...)

Leland

Hi,

I used Max (http://sbooth.org/Max/), but you can also use iTunes.

The next nightly build (at the bottom) from:

http://audacity.homerow.net/index.php?dir=mac

should now allow importing Apple Lossless (and others) files that contain samples sizes greater than 16 and sample rates greater than 64k. It will also import the individual channels multi-channel files separately instead of mixing them.

Leland