"Using FLAC binary : /Users/Marcus/flac/test/../src/flac/flac Original file size 441044 bytes. Compression level 1, file size 421393 bytes. Compression level 2, file size 421393 bytes. Compression level 3, file size 373613 bytes. Compression level 4, file size 369517 bytes. Compression level 5, file size 369517 bytes. Compression level 6, file size 369517 bytes. Compression level 7, file size 369517 bytes. Compression level 8, file size 366411 bytes. ---------------- " So, basically compression levels 1 & 2 result in the same file size, 4-7 also result in the same file size, now is it just a coincidence, considering the test files are small, or should the compression levels be rewritten, to something like compression level 1, 2, and 3 (not corresponding to the current one two and three ofc.) -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/flac-dev/attachments/20130312/06e187c9/attachment.htm
On 2013-03-12, at 12:11 , Marcus Johnson wrote:> now is it just a coincidence, > considering the test files are smallIt is, testing on a >6mn piece (Endless, Nameless from Nirvana's Nevermind, 6:21) using flac 1.2.1 on OSX 10.6 I get the following: 71495116 base.wav 54517574 level-0.flac 53440982 level-1.flac 53159360 level-2.flac 50965333 level-3.flac 49735714 level-4.flac 49437135 level-5.flac 49427599 level-6.flac 49411090 level-7.flac 49281659 level-8.flac sizes in bytes, the flac file names correspond to the flac "compression level" flag, everything else left stock.
Marcus Johnson wrote:> So, basically compression levels 1 & 2 result in the same file size, 4-7 > also result in the same file size, now is it just a coincidence,That is the results for that particular file, a file that was already part of the FLAC test suite called "noisy-sine.wav". For another file chosen randomly from my SSD I get: Original file size 18345736 bytes. Compression level 1, file size 10405054 bytes. Compression level 2, file size 10405054 bytes. Compression level 3, file size 9409515 bytes. Compression level 4, file size 9397416 bytes. Compression level 5, file size 9397414 bytes. Compression level 6, file size 9397414 bytes. Compression level 7, file size 9367585 bytes. Compression level 8, file size 9332497 bytes. For this example, 1 & 2 are still the same, but 4-7 give three different results. Whats happening is that each different increasing compression level adds a new compression method to the set of compression methods. In the case where two successive compression levels result in the same output file size, it means that the added compression method didn't help compressing that particular file. It may still help the compression of another different file.> considering the test files are small, or should the compression levels be > rewritten, to something like compression level 1, 2, and 3 > (not corresponding to the current one two and three ofc.)No, they should stay as they are. Erik -- ---------------------------------------------------------------------- Erik de Castro Lopo http://www.mega-nerd.com/
On Tue, Mar 12, 2013 at 12:36:29PM +0100, catch-all at masklinn.net wrote:> > > now is it just a coincidence, > > It is, testing on a >6mn piece (Endless, Nameless from Nirvana's > Nevermind, 6:21)Does that track have a long period of silence in the middle? (...checks Discogs...) Nope: "Endless, Nameless" comes after 10 minutes silence after the end of "Something In The Way", and all are indexed on the CD as track 12. I'm just mentioning this because I'm pretty sure that FLAC doesn't compress as tightly as it could when the source file has lots of absolute silence in it. -- -Dec. --- (no microsoft products were used to create this message)