File Conversion

[Paianis 488]

Very minor point, almost nitpicking but:

 

I tend to upload FLACs at 24/96KHz. That's fine, by the looks of things the filesize of the FLAC on the site is about the same as the master I've got on my PC, so the sampling rate was retained. However, the ALAC seems to be much smaller and I can only assume it has been downsampled to 16/44.1KHz (CD quality). It just makes more sense to me to have the sampling rate identical for both formats (unless iTunes/iPods don't support it, in which case keep it as it is).

[Planty 1,052]

isn't 44khz the peak of what humans can hear? so a sampling rate above that you wouldn't be able to tell the difference (except in rare cases) and it would take up for memory to produce?

[Paianis 488]

That's not the point. If the source is 24/96, and the site's FLAC is 24/96...why can't the ALAC be 24/96.

 

24/96 makes more sense for recording onto analogue formats such as audio tape, rather than listening through a DAC. Still very good for archival purposes though, and its a standard for professional recording studios.

[Jack "Fox" Grayson 27]

@: I downloaded one of your songs in ALAC and it turns out it's 16/96, even though ALAC does seem to support 24-bit samples.  That might be part of why the ALAC file is significantly smaller, but I'm not sure.

[Twilight Sparkle ✨ 8,520]

ALAC appears to support 24/96, but the FLAC -> ALAC encode isn't preserving the bit depth for some reason. It might be an issue with ffmpeg's ALAC encoder, because there's nothing in the encode command that tells it to drop the bit depth. I'll flag this on our bug tracker to look into further.

 

Perhaps relevant, it seems that iDevices might have some trouble with studio-quality ALAC files. I'll see what I can do to test this myself, because if they have trouble with 24/96 ALAC's and that's all that Pony.fm offers, it'll require people to transcode them anyway to get them onto their iPod (which sort of defeats the point of offering it in the first place, since FLAC is already more than suitable for archival quality).

 

Thanks for the heads-up on this, Paspie.

[Paianis 488]

ffmpeg raises a few more questions for me: for Vorbis files, are you using the encoder that is built-in to ffmpeg, or the official 'libvorbis' one which is discrete from ffmpeg but is far more polished and mature?

 

Thanks for taking the ALAC thing into consideration though. From the looks of things 24/48 is the max that iPods can handle, may that would be a practical compromise.

 

(I hope I'm not sounding like I ought to be an official site supervisor, lol)

Edited July 6, 2013 by Paspie

[Twilight Sparkle ✨ 8,520]

ffmpeg raises a few more questions for me: for Vorbis files, are you using the encoder that is built-in to ffmpeg, or the official 'libvorbis' one which is discrete from ffmpeg but is far more polished and mature?

 

We roll with libvorbis for those. I agree that ffmpeg's built-in encoder produces rather lackluster results, so there's no reason not to use the official library.

 

 

(I hope I'm not sounding like I ought to be an official site supervisor, lol)

 

I really appreciate your feedback, Paspie. You don't need to have a staff title to start or take part in a technical discussion about Pony.fm. I had no idea this bit depth issue on ALAC files existed until you pointed it out. Please don't hesitate to speak up about any other thoughts you have or things you notice with Pony.fm!