[Flac-dev] Re: FLAC: same features as WavPack

Justin Frankel justin at blorp.com
Fri Mar 30 15:00:59 PDT 2007


To clarify, I am one of the REAPER developers.

To say that FLAC itself is not broken is sort of meaningless--FLAC 
itself is just a specification. So yes, it is just libFLAC that is 
broken. I have spent QUITE a bit of time trying to sort out why it fails 
on 24 bit mode.. If there are some specific alignment requirements of 
samples, please point me to the documentation of them, but we have 
experimented with many-- and indeed we aren't doing things TERRIBLY 
wrong, as it does at least preserve the samples.

Perhaps it's just a little endian or OS issue. You don't need to be 
overly defensive of FLAC--this isn't a criticism, it's just a request 
for clarification/fixing of an issue that a lot of people seem to 
experience.

-Justin



Brian Willoughby wrote:
> Hi Justin,
>
> I am using flac on the Mac OS X command-line with AIFF input files.  
> In fact, you can use my Mac installer for flac to get everything you 
> need for working 24-bit files in FLAC.  You can also build flac from 
> the open-source project to get the same thing.
>
> It sounds like you're using libFLAC, and the REAPER programmers are 
> unable to get it working with 24-bit.  Have you tried changing the 
> alignment of the samples to follow the libFLAC requirements?  It's not 
> easy to get it right, but it is possible.
>
> I have written my own software which uses libFLAC, and it took a while 
> to get the setup calls correct.  I am able to play 24-bit files, but I 
> can't remember if I have encoded any.  It might be interesting for me 
> to use my own tools to encode 24-bit and see if I have any problems.
>
> I think you need to try a little harder.  It's not really fair to go 
> around saying that FLAC is broken for 24-bit files when it really is 
> only broken in your software, and not when you use the tools that come 
> with FLAC.  The working tools are open-source, so perhaps the REAPER 
> programmers should look at that to see how to do it right.
>
> I'm sorry if this seems harsh, but there are a log of non-programmers 
> here who are getting confused about the difference between the 
> official FLAC and stuff from third-party software that might be 
> broken.  FLAC itself is not broken.
>
> Brian Willoughby
> Sound Consulting
>
>
> On Mar 30, 2007, at 14:35, Justin Frankel wrote:
>
> Brian Willoughby wrote:
>> Hi Justin,
>>
>> Are you saying that 24-bit support does not work for you?  Which 
>> version of FLAC are you using?  What platform?  What kind of files 
>> are you trying to compress?
>
> We're using FLAC 1.1.2, and we're compressing any kinds of PCM audio. 
> The software that we make that uses it is REAPER, www.reaper.fm.
>
> We sent some messages back in august, as did other people, that FLAC 
> is using the verbatim block type or whatnot.. if you like I can dig up 
> the emails, but at some point there was a reply from Josh Coalson 
> saying something about a bug in the rice encoder...
>
>> I am not any kind of official spokesperson for FLAC, but this alleged 
>> report about 24-bit problems surfaced in Aug 2006.  However, I have 
>> been successfully using 24-bit FLAC since June of 2004, and I have 
>> never seen a single problem.  The largest FLAC-compressed files are 
>> 69% of the original 24-bit file, and I have never seen one end up 
>> larger than the original.  In other words, I have never been able to 
>> reproduce the problem.  I have recorded about 90 live shows in 24-bit 
>> format, up to 18 channels multitrack, and have successfully 
>> compressed over 75 GB of 24-bit audio with absolutely no errors.
>>
>
> Which version of FLAC are you using, and on what platform(s)?
>
>> Why would you tell people to use WavPack when FLAC is flawless?
>
> Because FLAC in 24 bit mode doesnt work with our application!  We also 
> posted our encoder setup calls etc, and I believe we heard back that 
> it should be fine. And everything works hunky dory in 16 bit mode..
>
> -Justin



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