[Flac-dev] Re: nice idea

[Miroslav Lichvar]

On Sun, Oct 20, 2002 at 11:50:12PM -0700, Josh Coalson wrote:
> Interesting, looks like the best case is ~ 0.75% increase in
> compression for 18% increase in encode time.  The compression
> increase is similar to my old brute force test but much faster.
> The question is, is it worth it from the user's point of view?

Here is another test. I've rewritten my brute force util, it is much
faster (these 2 albums took about 8 hours) and decrease of compression
ratio isn't very big. First is one of "worse" albums, where previously
was no improvement and second one is the "best" album from my previous
test.

tr.    raw          flac -8              flac-vbs -8 (bf)      diff
----------------------------------------------------------------------
01     42465360     32921806 (0.7753)    32797052 (0.7723)     0.00294
02     49309680     35592614 (0.7218)    35360927 (0.7171)     0.00470
03     44892624     31174614 (0.6944)    30756995 (0.6851)     0.00930
04     48933360     35896765 (0.7336)    35544467 (0.7264)     0.00720
05     46223856     32552195 (0.7042)    31966877 (0.6916)     0.01266
06     54512304     38597716 (0.7081)    38183807 (0.7005)     0.00759
07     62233920     47307456 (0.7602)    47103582 (0.7569)     0.00328
08     50081136     35248709 (0.7038)    34802683 (0.6949)     0.00891
09     46722480     34866768 (0.7463)    34649209 (0.7416)     0.00466
10    105181440     66135505 (0.6288)    65403955 (0.6218)     0.00696
11     42140784     31847746 (0.7557)    31632150 (0.7506)     0.00512
12     39497136     26761582 (0.6776)    26599003 (0.6734)     0.00412
13     41717424     29667034 (0.7111)    29427846 (0.7054)     0.00573
14     60982656     41929582 (0.6876)    41659950 (0.6831)     0.00442
15     41465760     29593363 (0.7137)    29311228 (0.7069)     0.00680
1-15  776359920    550093455 (0.7086)   545199731 (0.7023)     0.00630

01     30964080     21620551 (0.6982)    21329002 (0.6888)     0.00942
02     38984400     26756131 (0.6863)    26376519 (0.6766)     0.00974
03     33831168     26303654 (0.7775)    26101924 (0.7715)     0.00596
04     56497392     37413032 (0.6622)    36704124 (0.6497)     0.01255
05     25756752     19550862 (0.7591)    19305960 (0.7495)     0.00951
06     30611280     15424648 (0.5039)    15245573 (0.4980)     0.00585
07     36637104     23893567 (0.6522)    23538606 (0.6425)     0.00969
08     35258832     24666148 (0.6996)    24323401 (0.6899)     0.00972
09     24587808     18761332 (0.7630)    18574225 (0.7554)     0.00761
10     29470560     21236888 (0.7206)    20987622 (0.7122)     0.00846
11     44111760     27948908 (0.6336)    27319813 (0.6193)     0.01426
12     23138976     18018696 (0.7787)    17821689 (0.7702)     0.00851
13     44027088     32130608 (0.7298)    31623073 (0.7183)     0.01153
14     49570752     34641760 (0.6988)    34184309 (0.6896)     0.00923
1-14  503447952    348366785 (0.6920)   343435840 (0.6822)     0.00979


So there is still big room for improvement. And i believe this test
don't show us maximum, what we can get from variable blocksizes. If
anyone want to help me to find the right procedure, my hacks are here:
  http://phoenix.inf.upol.cz/~lichvarm/flac-vbs/flac-bf.cc
  http://phoenix.inf.upol.cz/~lichvarm/flac-vbs/flac-vbs.patch

-- 
Miroslav Lichvar