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Topic: Google play quality (Read 7525 times) previous topic - next topic
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Google play quality

Well I bought an album that is encoded 320k mp3. Foobar does not identify the encoder, However a hex editor shows lame 3.98.2. The other oddity I am not happy with is foobar say stereo = stereo which is not the default for lame 3.98.

Now these should be relatively small things but I have the suspicion i hear artifacts like metallic cymbal swooshing not unlike 128k WMA standard encodings. I cannot prove it as i don't have the original. Is google reliable (doesn't transcode) or use some bad methods ? The tampering of the default joint stereo only worsens my concerns.

Google play quality

Reply #1 –
I think mp3s are usually provided by the record company.  At least thats how Amazon and Apple do it.

Google play quality

Reply #2 –
Quote from: saratoga on
I think mp3s are usually provided by the record company.  At least thats how Amazon and Apple do it.

As far as I'm aware it doesn't work that way for Apple, unless something has recently changed. The record company needs to feed the originals (AIFF or WAV up to 24 bits/192 KHz) to iTunes Producer which handles the encoding to AAC and uploading to the iTunes Music Store. The record company doesn't get to choose settings or encoder.

Considering Google Play appears to be using different encoders and settings for different files I assume it may be that with Google Play record companies are able to provide their own MP3s to upload.
Every night with my star friends / We eat caviar and drink champagne
Sniffing in the VIP area / We talk about Frank Sinatra
Do you know Frank Sinatra? / He's dead

Google play quality

Reply #3 –
Reading tags from various webshops shows that encoding is often done by 3rd party company. Like for example comment field filled with "Encoded By Label Worx Limited". Additionally you can find adverts of companies calling their-self "content providers" - and description of what they do mostly includes mass transcoding of files for webshops.

Google play quality

Reply #4 –
Quote from: Maurits on
Quote from: saratoga on
I think mp3s are usually provided by the record company.  At least thats how Amazon and Apple do it.

As far as I'm aware it doesn't work that way for Apple, unless something has recently changed. The record company needs to feed the originals (AIFF or WAV up to 24 bits/192 KHz) to iTunes Producer which handles the encoding to AAC and uploading to the iTunes Music Store. The record company doesn't get to choose settings or encoder.


Is that actually true?  As in they check that the files followed the best practices document and reject them if they don't?

Google play quality

Reply #5 –
If I recall correctly from reading the "Mastered for iTunes" documentation, there is a Apple-provided program that is used to resample (if necessary) and convert to AAC.  However, the files are reviewed and rejected if there is audible clipping.  It wouldn't surprise me if iTunes uses a non-standard protocol that would need to be reverse-engineered to upload to the iTunes store, making it somewhat unlikely that there would be files that there were files encoded using an unauthorized encoder and/or setting.

EDIT: Upon further review, ignore this, I was wrong.

Google play quality

Reply #6 –
As far as I understand it the content owner doesn't encode and upload the files themselves. They supply the AIFF or WAV to iTunes Producer which encodes and uploads it, content owners don't provide compressed content. That's probably why I have never seen an iTunes Music Store AAC file that was not encoded using the QuickTime encoder at 256 kb/s VBR, the content owner doesn't choose the encoder or its settings. Sure, technically you could create a clipped file or an MP3, convert it back to WAV and then feed it to iTunes Producer which will convert it to AAC using Apple's settings.

iTunes Producer might be using some analytics technology to check if the WAVs that it's presented with show dubious characteristics (clipping, shoddy brick wall filters etc.) but I wouldn't know that. You'd need to create some outrageously mistreated WAV files and them to iTunes Producer to test that theory.
Every night with my star friends / We eat caviar and drink champagne
Sniffing in the VIP area / We talk about Frank Sinatra
Do you know Frank Sinatra? / He's dead

Google play quality

Reply #7 –
I don't think Amazon MP3s are provided by the label either. All my Amazon MP3 downloads are encoded by LAME 3.97 with the same settings:
Code: [Select]
-m j -V 0 -q 3 -lowpass 19.5 --vbr-old -b 32

Google play quality

Reply #8 –
my newest amazon (uk) purchases have been very strange indeed. until earlier this year, most of them were encoded with LAME 3.97 @ V0. but recently, i've bought 12 tracks (ok not many) but they are from 4 different releases and they report no codec profile/tool information in foobar at all. even the rest of my non-lame mp3 files at least report CBR. these amazon files show nothing. they must be using VBR though as one of them is 294kbps. 

Google play quality

Reply #9 –
Quote from: Maurits on
iTunes Producer might be using some analytics technology to check if the WAVs that it's presented with show dubious characteristics (clipping, shoddy brick wall filters etc.) but I wouldn't know that. You'd need to create some outrageously mistreated WAV files and them to iTunes Producer to test that theory.
You mean, you need to provide files which are pretty much commonplace in today's rock and pop music mastering. At least "I'm with You" mastered by the infamous Vlad "the Impaler" Meller shows clipping in both the CD and "Mastered for iTunes" release:
Interestingly enough, the mastering "engineers" seemingly attenuated the signal by about 1.0 dB before encoding the AAC. So the iTunes producer may have very well rejected the file due to excessive clipping, but they might have circumvented this by attenuating. Either way, even the iTunes release shows excessive clipping. Like Walter Sobchack would say: "f***ing amateurs".

EDIT: To make sure, when encoded to AAC and decoded back to PCM, the flat clipping peaks turn into the more wavy structure. From the shape of the signal it is still pretty obvious that this still is just lossy encoded clipping. You can try it yourself.
It's only audiophile if it's inconvenient.

Google play quality

Reply #10 –
Quote from: Kohlrabi on
Interestingly enough, the mastering "engineers" seemingly attenuated the signal by about 1.0 dB before encoding the AAC. So the iTunes producer may have very well rejected the file due to excessive clipping, but they might have circumvented this by attenuating.

I see this on CD releases also, often only -0.1 or -0.05dB. All songs have exactly the same peak volume down to many digits in a way no limiter can do but a simple volume change after the damage is done.
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!

Google play quality

Reply #11 –
Quote from: Kohlrabi on
At least "I'm with You" mastered by the infamous Vlad "the Impaler" Meller shows clipping in both the CD and "Mastered for iTunes" release:

Quote
EDIT: To make sure, when encoded to AAC and decoded back to PCM, the flat clipping peaks turn into the more wavy structure. From the shape of the signal it is still pretty obvious that this still is just lossy encoded clipping. You can try it yourself.


Yeah I was wondering that too. At first I thought it might have been passed through a software "de-clipper". I've seen some programs claiming to be able to recover dynamics lost through hard limiting, but I doubt they can really recover something damaged like that. Certainly the process of lossy encoding could explain it also.

Google play quality

Reply #12 –
Quote from: Kohlrabi on
"I'm with You" mastered by the infamous Vlad "the Impaler" Meller shows clipping in both the CD and "Mastered for iTunes" release


What is the timescale on that terrible clipping?

Google play quality

Reply #13 –
Quote from: dhromed on
What is the timescale on that terrible clipping?
I didn't find the exact position of that screenshot, since I didn't save the timestamp info. But there is a lot of other obvious clipping about, one bad case shows about 3.2 ms, so roughly 150 samples.
It's only audiophile if it's inconvenient.
 

Google play quality

Reply #14 –
  Here's a Foobar snapshot of my Google Music Store purchased mp3 profiles.  Seems to be a mixed bag of mostly unidentified encoders.  I haven't delved into it trying to identify the encoders further since I mostly use the Google Store for the free 20000 song cloud storage, special deal price offers, free music downloads, and for the occasional download-only music offerings and hard-to-find songs/albums.  As I've mentioned before, I prefer buying the cd and converting from lossless to whatever lossy format fits my need.

As far as stereo vs. joint-stereo, I haven't encountered any tracks that are in normal stereo; nor have I run into any other glaring quality issues within my limited download/purchased collection.  In other words, I've been happy with Google Music purchases so far.

[edit] For whatever reason, my snapshot isn't being included with my post.  In a nutshell, Foobar identifies roughly 14% of my Google folder as being encoded by various lame encoder versions with 99.9% of all mp3's as 320 kbps cbr.