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Topic: Google Music WMA -> MP3 (Read 6499 times) previous topic - next topic
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Google Music WMA -> MP3

I recently moved my music collection to Google Music. For one of the CDs I uploaded, I have it on my PC in MP3 VBR V0, WMA Lossless, and FLAC. Google Music transcoded the WMA and FLAC to MP3 CBR 320 and I ended up with three copies of each song. Trying to determine which two to delete, I downloaded the three files for track one. I ABXed 8/10 with the two 320 kbps files. Thinking this was odd, and not knowing which was which, I chose the extremely unscientific route of downloading the two files from a different CD (this one, 320 transcoded by google from flac and VBR V0) and I couldn't ABX them (expected). Since the VBR V0 files were unmodified, I'd expect them to sound as good as flac (to my ears with my headphones, at least), so I came to the conclusion that Google is able to transcode the FLACs to high quality MP3s. Based on this, I have to assume that google is really bad a transcoding WMA to MP3.

Does this make any sense? Thoughts? Similar experiences?

Google Music WMA -> MP3

Reply #1
Since both of the transcoded files originated from lossless files and were presumably encoded with the same encoder, shouldn't they be identical?

Google Music WMA -> MP3

Reply #2
Since both of the transcoded files originated from lossless files and were presumably encoded with the same encoder, shouldn't they be identical?


That would be my guess as well, but they are different sizes and easy to ABX. That is why I came here with the question. Maybe google couldn't properly handle the WMA lossless file and screwed up the decoding.

Google Music WMA -> MP3

Reply #3
Since WMA seems to be Windows-only for the Google music client, and WMA lossless was only recently reverse engineered, it may be that they just have your local Windows machine convert the WMA lossless files to MP3 and then upload that. 

Actually, looking at the about page, it seems they include LAME, libfaad, libvorbis and libflac, so it seems likely they do at least some transcoding on your local machine.  I'm curious what the encoder is for the two different mp3s, perhaps one is done locally and the other remotely.

Google Music WMA -> MP3

Reply #4
Since WMA seems to be Windows-only for the Google music client, and WMA lossless was only recently reverse engineered, it may be that they just have your local Windows machine convert the WMA lossless files to MP3 and then upload that. 

Actually, looking at the about page, it seems they include LAME, libfaad, libvorbis and libflac, so it seems likely they do at least some transcoding on your local machine.  I'm curious what the encoder is for the two different mp3s, perhaps one is done locally and the other remotely.


I guess it makes sense for them to do the transcoding locally. They (and we) would save a lot of bandwidth. Although it didn't save me enough to stop the university I attend from sending me a letter for excessive uploading, it could save them some money.

They must at least decode the WMA locally, otherwise I can't see why they'd require a Windows computer to do it.  Do you think they use the Microsoft software on your computer for the transcoding?  Maybe they do the entire transcode with MS tools if you start as WMA. What encoder does Microsoft use when you rip CDs with WMP (you can do that right?) to MP3? Could that account for quality differences?

Google Music WMA -> MP3

Reply #5
fhg I believe.  Is that the encoder used for your files?

Google Music WMA -> MP3

Reply #6
fhg I believe.  Is that the encoder used for your files?


How would I check that? Is it in the metadata somewhere?

Edit:

If I open any of the three files in notepad++, obviously, I see a bunch of garbage with a small amount of text. They all contain part of a line that reads "LAME3.98.4" It appears to me that they were all done by lame, unless this is in the file for some strange compatibility reason.

Google Music WMA -> MP3

Reply #7
So, no one else has any thoughts? I'm still really curious how this could even happen.

 

Google Music WMA -> MP3

Reply #8
How would I check that? Is it in the metadata somewhere?


foobar2000 -> right click on a song -> Properties -> Properties tab -> Tool
or
foobar2000 -> right click on a song -> Properties -> <ENCODED BY>

Google Music WMA -> MP3

Reply #9
So, no one else has any thoughts? I'm still really curious how this could even happen.


Didn't you already figure out that its transcoding some of the files on your local machine and some on the remote server?

Google Music WMA -> MP3

Reply #10
How would I check that? Is it in the metadata somewhere?


foobar2000 -> right click on a song -> Properties -> Properties tab -> Tool
or
foobar2000 -> right click on a song -> Properties -> <ENCODED BY>




It appears only one of the files (the VBR I encoded with Lame) has record of the tool used. Am I looking in the wrong spot? None of them have an <ENCODED BY> tag.

So, no one else has any thoughts? I'm still really curious how this could even happen.


Didn't you already figure out that its transcoding some of the files on your local machine and some on the remote server?


I never said that. I am sorry for the confusion if I somehow implied it. I was merely guessing it was a possibility.

Google Music WMA -> MP3

Reply #11
I guess it makes sense for them to do the transcoding locally. They (and we) would save a lot of bandwidth.
I asked their support exactly that, and they confirmed that encoding takes place on the user's machine before uploading, unless the files are MP3 which should be transferred as-is (so you can upload proper VBR files instead of insane 320 CBR files). I never asked about WMA, though.
It's only audiophile if it's inconvenient.

Google Music WMA -> MP3

Reply #12
I guess it makes sense for them to do the transcoding locally. They (and we) would save a lot of bandwidth.
I asked their support exactly that, and they confirmed that encoding takes place on the user's machine before uploading, unless the files are MP3 which should be transferred as-is (so you can upload proper VBR files instead of insane 320 CBR files). I never asked about WMA, though.


I suspected as much. I can only guess it is true for the WMAs as well. I can't really see how they would mess up decoding the WMA, but encoding a decoded WMA or decoded FLAC should be identical. right?