ALAC files play at 32kHZ, not 96kHZ

[Red5TX]

Hey all, I have seen a few posts about Poweramp not being able to play ALAC files over a certain size/speed/sample rate.  I can't find anything recent about whether this have been addressed or not.  I have a few HD Tracks at 96kHZ/24bit.  When I upload the FLAC version of the song to my phone, everything works perfectly.  When I convert the same to ALAC (so that I can play across my network using Air Play) and upload those to the phone, Poweramp thinks that they files at 32kHZ and they play soooooooo slowly.  I have checked and iTunes reports the ALAC files being at 96k, so I do not think it is the converter (I am using dbPoweramp Music Converter - for what it is worth).

 

Any ideas what might be going on?

 

Red

[Magadaner]

Current Poweramp has 144khz limit for flacs. Such flacs generally resampled by Poweramp to device output sampling rate (44.1 / 48 khz). Also, such high rate files are not generally recommended for portable devices (due to x4-x5 cpu/battery consumption).

[Red5TX]

That's interesting.  Thanks for the help.  But there is no limit on FLAC files in Poweramp, is there?  Is there a reason that FLACs of different speeds are supported by ALACs are not?  I get that ALAC and FLACs take up a lot of space, but that is the beauty of having a 64 GB mobile device.  Do FLACs eat up the battery as bad as the ALACs?

 

Red

[KurianOfBorg]

There is a bug in almost all ALAC converter implementations which uses a 16-bit integer to store the sample rate. This overflow causes all these files to play back at 30464 Hz. To maintain compatibility, current players should detect this and play the file back at 96000 Hz.

 

I suggest you use refalac to encode high sample rate files to M4A ALAC. This outputs valid M4A files that play back properly. However multichannel ALAC is not very useful at this time because even iTunes cannot play it back. Only stereo ALAC is reliable. There are too any file corrupting bugs with multichannel / high sample rate ALAC software.