HydrogenAudio

Lossless Audio Compression => Lossless / Other Codecs => Topic started by: skamp on 2012-06-25 09:19:17

Title: Comparison of compression ratios between FLAC --best and TAK -p4
Post by: skamp on 2012-06-25 09:19:17
This post (http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=95670&view=findpost&p=799992) made me wonder whether I had over-estimated TAK's compression capabilities, so I decided to run a benchmark on my entire music collection.

I used caudec to transcode my 5,074 FLACs (--best, version 1.2.1) to TAK (-p4, version 2.2.0), one album at a time. All songs are CD audio (16 bit / 44.1 kHz, stereo). I measured the size in bytes of all the files comprising the album, as WAV, FLAC and TAK files. I then calculated the compression ratio of the FLACs and the TAKs compared to the WAVs, as a percentage. Finally, I calculated the difference in ratios between FLAC and TAK: that value (also a percentage of the WAV file) is always negative, meaning TAK compressed better than FLAC in all cases. Here are the results (http://pastebin.com/raw.php?i=TkwG3jVt), as a CSV file.

On average, TAK compressed 2.19% better than FLAC. Here's a list of the top 10 albums where the difference was the most significant:


Note: I used -p4 with TAK simply because I forgot about the existence about -p4m. I later tried it on a couple albums though, and while TAK -p4 is faster than FLAC --best, TAK -p4m is slower. Improvement in compression is unlikely to be much larger than 0.2%, from what I can tell.
Title: Comparison of compression ratios between FLAC --best and TAK -p4
Post by: Porcus on 2012-06-25 10:46:45
I then calculated the compression ratio of the FLACs and the TAKs compared to the WAVs, as a percentage. Finally, I calculated the difference in ratios between FLAC and TAK: that value (also a percentage of the WAV file)


You've miscalculated a bit (see below). To correct this, calculate the ratio TAKbitrate/FLACbitrate, subtract 1 and then multiply by 100 %. You will probably get negative 3 point something.

Your figure measures an improvement of 2.19 percentage points (http://en.wikipedia.org/wiki/Percentage_point), not 2.19 percents.
Percents: improvement over what-to-improve (i.e. the FLAC file).
Percentage points: difference between percents.
The most crucial point is that all comparisons use the same yardstick (and I suppose that most should, and most will, choose the percents).
Title: Comparison of compression ratios between FLAC --best and TAK -p4
Post by: skamp on 2012-06-25 11:13:23
TAKs are on average 96.48% the size of the FLACs, so that's a 3.52% improvement over FLAC. That figure looks better indeed.

Edit: I've never used a spreadsheet in my life, so if you have some Excel-fu, feel free to download the CSV and calculate correct individual values for the "compression improvement" column by using the bytesize columns.
Title: Comparison of compression ratios between FLAC --best and TAK -p4
Post by: lvqcl on 2012-06-25 11:17:23
WAV bytes, sum: 227851632252
FLAC bytes, sum: 141786750976
TAK bytes, sum: 136796209152

(TAK/FLAC)-1 = -3.52%

{too slow again  }
Title: Comparison of compression ratios between FLAC --best and TAK -p4
Post by: skamp on 2012-06-25 11:31:39
Revised CSV (http://pastebin.com/raw.php?i=N8CchEV8) with the last column showing the compression improvement of TAK over FLAC, in %. My BASH-fu is stronger than my spreadsheet-fu