Apple Lossless streaming on Apple TV

Question

When streaming Apple Lossless files on on Apple TV, what is the maximum bitrate? I realize Apple TV can stream AAC and MP3 files at 320 kbps, but what about Apple Lossless file that can often provide up to 1,000 kbps? Does Apple TV support such high bitrates? (I know the sampling is always 16 bit / 48 kHz).

Answer 1

Hello. For some reason, your reply to my May 2 post, has disappeared, though I still have it in email. I've reposted in below.
First, let me thank you for taking the time to answer my questions. I'm confident that you've zeroed in on a solution. The clarity of your response is greatly appreciated.
Your points about compressed/lossy formats make sense. This explains the lower bitrates for those formats.
You also asked about the original source of my alac (Apple Lossless) files. As you may have guessed, the original files are typical itunes downloads, which I understand are usually MP3s at 256 kbps.
I had assumed that running them through the itunes converter would transform them into proper (16/44.1) lossless files with the associated bitrates ranging around 1,000 kbps -- with a much richer sound.
At first glance, it would appear that I was wrong. Merely upsampling the music has created larger files but without the added clarity, depth and soundstage. That's how I read your previous post. Again, correct me if I am wrong about this.
However, there is a twist.
As I mentioned, when I play these alac files through Apple TV -- through homesharing on my computer -- they sound no better than the 256k files. However, when I play the same files through the foobar2000 media streaming software, they sound much better and show the proper bitrates at around 1,000 kbps.
On this last question, my ears may be playing tricks on me, but I don't think so. I'm playing the files through a good system: an audiolab 8200CDQ pre-amp and 8200p power amp.
So, this has me stumped.
One last question: what is the point of having a program that upconverts MP3/AAC files to lossless if there is no improvement in sound quality. Why would you have a bigger file that sounds just as bad as the small one?
Regards
Here is your May 3 post, which has disappeared from the websit.
May 3
No problem. Sorry for the long reply.
I see what you mean about my equation. All 16/48 stereo signals would equate to 1536kbps. If you changed the sample rate to 44.1 (what CDs use) or something else, then the bitrate would change.
Now thats for uncompressed formats like WAV, AIFF, and PCM. And in the case of Airplay, the stream getting sent to the AppleTV is always uncompressed, no matter the the original format (aac, mp3, apple lossless, etc).
AAC files (and mp3, wma) are known as compressed formats: some fancy math equations are used to reduce the file size w/o your brain noticing the missing bits, so that initial stream (1536 kbps for instance) gets reduced to 320 kbps or lower in order to fit more songs on your device. the way this happens is really crazy but if you want to learn about it theres a magazine that did a good article. WARNING, its really technical!: http://www.soundonsound.com/sos/apr12/articles/lost-in-translation.htm
you seem to be able to hear the difference between compressed and uncompressed formats. many people do but many dont. It all depends on your hearing, sound equipment, etc. I was wondering if the reason your not hearing a difference btwn apple lossless and aac might be because of where the lossleess files came from. did you rip them from CD's or convert them from another format? If they didn't come from CD's, WAV, or AIFF files, you probably won't hear a difference, because you can't "upconvert" from something like AAC to Apple Lossless and get higher sound quality. If they came from CDs, then maybe the AAC versions are just really good quality to begin with and so you are having a hard time telling. That article has some examples of the same music in different formats, so you can test your ears and see if you notice a difference.
bE