Feb 2, 2011 9:47 AM
FLAC is overrated.
I've seen a fair share of Blu-Ray rip releases with FLAC audio, and while I generally don't have any problem with FLAC, I just found a release where using FLAC is really a stupid choice.
For you who don't know already, FLAC stands for Free Lossless Audio Codec, and as it says, it's a lossless audio compression codec. Since it's lossless, the size will get rather large than usual lossy compression (AAC, Vorbis, MP3 etc.)
Usually, for a standard Blu-Ray rip 24 minutes episode, a stereo FLAC track will be around 100-110MB, and usually the video track for 720p will get around 300-600MB (though, the ones with FLAC are usually at least 400MB). Usually I'm fine with the FLAC size here, since it's only 14%-20% of the total size. After all, transcoding to AAC q=0.7 (where for my ears, the difference with lossless FLAC is non-existent) only cuts off 40MB per episode, less than 10% of the original size, so I just leave them be.
But I found a stupid 720p Blu-ray release with dual audio 5.1 FLAC tracks. This is really stupid because:
- For a standard 24 minutes episode, one 5.1 FLAC track is 220-250MB.
- Two tracks, so they're both 440-500MB.
- The filesizes of the actual release are around 700-900MB per episode.
So what does that mean? That means the freaking audio takes over half the filesize. That's stupid. Transcoding both tracks to Vorbis q=7 gives ~90MB each tracks, to a total of ~180MB. That cuts off ~280MB off each episode, which is quite large, more than 30% of the original size.
Encoding to Vorbis q=7, I don't hear any difference at all. Actually, q=6 and I still can't hear the difference, but maybe that's just my sound setup. And my ears are quite sensitive compared to my RL friends.
There are a lot of people who claim they can "hear the difference clearly, the compression artifacts are pretty noticeable", but I'd bet if take a FLAC track, transcode it to AAC q=0.7 , reencode it back to FLAC, then ask them to differentiate with the original FLAC track, most of them won't even be able to guess it correctly.
/rant.
For you who don't know already, FLAC stands for Free Lossless Audio Codec, and as it says, it's a lossless audio compression codec. Since it's lossless, the size will get rather large than usual lossy compression (AAC, Vorbis, MP3 etc.)
Usually, for a standard Blu-Ray rip 24 minutes episode, a stereo FLAC track will be around 100-110MB, and usually the video track for 720p will get around 300-600MB (though, the ones with FLAC are usually at least 400MB). Usually I'm fine with the FLAC size here, since it's only 14%-20% of the total size. After all, transcoding to AAC q=0.7 (where for my ears, the difference with lossless FLAC is non-existent) only cuts off 40MB per episode, less than 10% of the original size, so I just leave them be.
But I found a stupid 720p Blu-ray release with dual audio 5.1 FLAC tracks. This is really stupid because:
- For a standard 24 minutes episode, one 5.1 FLAC track is 220-250MB.
- Two tracks, so they're both 440-500MB.
- The filesizes of the actual release are around 700-900MB per episode.
So what does that mean? That means the freaking audio takes over half the filesize. That's stupid. Transcoding both tracks to Vorbis q=7 gives ~90MB each tracks, to a total of ~180MB. That cuts off ~280MB off each episode, which is quite large, more than 30% of the original size.
Encoding to Vorbis q=7, I don't hear any difference at all. Actually, q=6 and I still can't hear the difference, but maybe that's just my sound setup. And my ears are quite sensitive compared to my RL friends.
There are a lot of people who claim they can "hear the difference clearly, the compression artifacts are pretty noticeable", but I'd bet if take a FLAC track, transcode it to AAC q=0.7 , reencode it back to FLAC, then ask them to differentiate with the original FLAC track, most of them won't even be able to guess it correctly.
/rant.
Posted by
RedSuisei
| Feb 2, 2011 9:47 AM |
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