Re: Are Google Play purchases transcodes?
Reply #3 – 2018-03-12 16:05:14
Your spectogram doesn't look that bad. The lowpass alone is a bad indicator to spot poor lossy encodings. Especially, Google-Play-MP3 may don't have that and OGG Vorbis doesn't have it too. ;-)
Do a time/frequency spectogram like Audacity can do on the audio track view. If you find there holes or blockieness in the high frequency, it is very likely having a lossy encoding. If there is a bigger gab between absolute silence and the lowest frequency amplitudes, the file is very lossy. I bought exactly two MP3s from google play with a long time period between the purchases... and requested refund both after first listen (I wrote into the request what was wrong with the files)! Bot appeared to be 320kbps but had very terrible artifacts making them unlistenable to me. They sounded like my old -V4 or -V5 encodings from a time where MP3 players had a half GB of disk space and I listened to that crap in school bus. So I started to inspect them. I barely remember that there was a meta tag where the encoding parameters were stored and these parameters didn't match high quality 320kbps at all. That was my key event to request refund. Looking at the spectogram I saw holes everywhere in it while there was no lowpass at all so much bitrate is wasted on extreme high frequencies which are hard to hear . I believe it is something like this: 1. Vendor delivers any format from ugly 96kbps to high-quality FLAC to google. 2. Google encoded all of them in the past to somewhat misconfigurated -V5 vbr mode with disabled lowpass filter. 3. Google bloated these crappy MP3s up to 320kbps a few years later which doesn't upgrade the quality. I never buy anymore MP3 files from that store.
Last Edit: 2018-03-12 16:12:05 by Franky666