Nouvelle Collection
2014-Mar-17 20:50 UTC
[flac-dev] More than 150 MB / second encoding + "nanozip"
Thanks for the info. I will look at encode.ru . In the meantime I discovered "nanozip" : http://www.nanozip.net/ On http://compressionratings.com/sort.cgi?aud1.brief+4nf_pf, the result is amazing : 100 MB compressed in ... 0.44 sec ! with compressed size = 60% of the original size ! i.e. ratio = similar to FLAC, and very very fast... nanozip 0.09a -m.5g -cf ***** 63 710 155 bytes 60.2 % 0.44 sec 0.44 sec Unfortunately, "nanozip" is closed source. Do you have any idea on the algorithm behind that makes this possible ? 2014-03-17 21:22 GMT+01:00 <neheb at hushmail.com>:> flac -0 would work. I was under the impression that it just packed and did > not compress but that was wrong. For FLACCL as well. > > FLACCL is faster and compresses better. My test file was encoded in 10 > seconds using FLACCL and 26 using regular FLAC. If GPU is not possible, > you're probably SOL. > > FLACCL -0 --fast-gpu --no-md5: 805893523 bytes - 10.687 seconds > FLAC -0: 838208659 bytes - 27.170 seconds //no idea how to remove the MD5 > checksum from the encode. The MD5 function is not SSE-accelerated and is > pretty slow. > > One other variant is to use a general purpose compressor(maybe LZ4 or even > Zhuff) and apply a filter to get the size down. I tried this and got > miserable results, mainly because the filter that i used was slow. You may > want to post on http://encode.ru if you wish to take this path. The site > is not in Russian despite the last two letters. > > On 3/17/2014 at 10:08 AM, "Nouvelle Collection" < > nouvellecollection at gmail.com> wrote: > > > >Hello neheb, > > > >Thanks for your answer. > >Unfortunately, I won't be able to use something that needs a GPU, > >because > >some users may not have a GPU on their computer. > >What's the fastest option when running "standard FLAC" in order to > >have > >fastest compression time ? > > > >> As an aside: the author of LZ4 has also created Zhuff which is > >basically > >LZ4 with an entropy coder. Encoding > >> speeds are slightly slower but decompression is much faster. > >Compresses > >better as well. > >> See: http://fastcompression.blogspot.com/p/zhuff.html > >Very cool ! I tried it and I think it will probably fit my needs. > >I just need to find a Python-Zhuff binding :) > > > >Best regards > > > > > > > > > > > >2014-03-17 1:11 GMT+01:00 <neheb at hushmail.com>: > > > >> FLACCL might work: http://www.cuetools.net/wiki/FLACCL > >> > >> The problems with it are: slow initialization time. The OpenCL > >kernel must > >> be compiled during the first run. Which leads me to the second > >drawback. > >> > >> It requires a GPU. Core i5s include an integrated GPU which can > >be > >> utilized. > >> > >> The latest version of FLACCL is at: > >> http://www.cuetools.net/install/CUETools_2.1.5.zip > >> > >> Recommended command line would probably be: -1 --lax --no-md5 -- > >fast-gpu > >> > >> --slow-gpu may produce faster results on your end. Needs to be > >tested. -1 > >> could also be increased if needed. --no-md5 could also be > >removed but the > >> code that calculates the MD5 hash is slow. I also think that an > >MD5 hash of > >> the audio data is pointless since FLAC includes CRCs for every > >block. > >> > >> Also, there is currently a bug in the flac.cl kernel which > >sometimes > >> produces wrong encodes at higher compression levels. The fixed > >kernel can > >> be downloaded from: > >> > >http://sourceforge.net/p/cuetoolsnet/code/ci/default/tree/CUETools. > >Codecs.FLACCL/flac.cl?format=raw > >> > >> For a slightly smaller size, you can change the line "cbits > >min(cbits, > >> clz(order + 1) + 1 - shared.task.obits);" to "cbits = min(cbits, > >clz(order) > >> + 1 - shared.task.obits);". I checked with the author to make > >sure this is > >> correct. > >> > >> Also: BIG NOTE: The best results that I could get on my machine > >was around > >> 110MB/s (based on my own calculations). It may or may not be > >acceptable for > >> your purposes. > >> > >> As an aside: the author of LZ4 has also created Zhuff which is > >basically > >> LZ4 with an entropy coder. Encoding speeds are slightly slower > >but > >> decompression is much faster. Compresses better as well. See: > >> http://fastcompression.blogspot.com/p/zhuff.html > >> > >> On 3/16/2014 at 10:27 AM, "Nouvelle Collection" < > >> nouvellecollection at gmail.com> wrote: > >> > > >> >Hello, > >> > > >> >Is there some version of FLAC that allows very very fast > >encoding > >> >(i.e. > >> >able to process at least 150 MB / second of .wav input data on a > >> >standard > >> >computer : laptop computer, Core i5/i7, Windows 7 64 bit, 8 GB > >> >RAM) ? > >> >(It's ok to have a compression ratio which is a little bit lower > >> >than > >> >traditionnal FLAC) > >> > > >> >I'm looking for something which is between FLAC (very good > >ratio, > >> >slower > >> >than LZ4) and LZ4 (very very fast compression : 400 MB / sec, > >> >but lower > >> >compression ratio than FLAC because it's not dedicated to > >audio). > >> > > >> >Best regards. > >> > >> > >-------------- next part -------------- An HTML attachment was scrubbed... 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