flac dev - Feb 2013 - Commonly getting FLAC__STREAM_ENCODER_VERIFY_MISMATCH_IN_AUDIO_DATA on valid audio

Erik de Castro Lopo <mle+la <at> mega-nerd.com> writes:
> 
> Collin wrote:
> 
> > Has anyone encountered a similar problem, or are there any known
issues that
> > could explain this?
> 
> No known issues of this kind, but I would like to see a repeatable test
> case so I can investigate further.
> 
> Cheers,
> Erik

It turns out it was an error on my part; sorry for the trouble. I misunderstood
the format libflac was expecting my samples in. I found the wording in the
documentation very confusing.

My audio file has 2 channels and 16-bit samples, so I have to pull out each
individual sample, push it into a FLAC__int32, and fix endian-ness before I can
pass it to libflac.

The documentation made me think that libflac just wanted me to shove my 2-byte
sample into a FLAC__int32. I wasn't aware that it wanted me to extend the
sign,
as well.

Collin wrote:
> It turns out it was an error on my part; sorry for the trouble. I
misunderstood
> the format libflac was expecting my samples in. I found the wording in the
> documentation very confusing.
> 
> My audio file has 2 channels and 16-bit samples, so I have to pull out each
> individual sample, push it into a FLAC__int32, and fix endian-ness before I
can
> pass it to libflac.
> 
> The documentation made me think that libflac just wanted me to shove my
2-byte
> sample into a FLAC__int32. I wasn't aware that it wanted me to extend
the sign,
> as well.
At some stage it might make sense for us to make the FLAC API a little
more user/programmer friendly. Something to match libsndfile's ease of
use.

Erik
-- 
----------------------------------------------------------------------
Erik de Castro Lopo
http://www.mega-nerd.com/

2013/2/8 Erik de Castro Lopo <mle+la at
mega-nerd.com>:
> Collin wrote:
>
>> It turns out it was an error on my part; sorry for the trouble. I
misunderstood
>> the format libflac was expecting my samples in. I found the wording in
the
>> documentation very confusing.
>>
>> My audio file has 2 channels and 16-bit samples, so I have to pull out
each
>> individual sample, push it into a FLAC__int32, and fix endian-ness
before I can
>> pass it to libflac.
>>
>> The documentation made me think that libflac just wanted me to shove my
2-byte
>> sample into a FLAC__int32. I wasn't aware that it wanted me to
extend the sign,
>> as well.
>
> At some stage it might make sense for us to make the FLAC API a little
> more user/programmer friendly. Something to match libsndfile's ease of
> use.
That would be great!
I was actually starting my small ?project? with libsndfile, but it was
done in a way that I didn't agree with, and since I only work with
FLAC files (mostly 24 bits) I decided to try to go with libflac
instead, which seems to let me do things the way I want more than
libsndfile.

For example, when loading an audiofile with libsndfile, all the
samples are converted to floating point numbers, which is what I want
anyway, but the conversion is done by dividing the integers from the
file with pow(2,bps-1), but when converting back, they multiply with
pow(2,bps-1)-1, so if you just read and then write, you end up with a
slightly lower volume (not that you can hear any difference if you do
it only a few times, but still, it isn't right, AND it is very easy to
do it right, so why don't they?)?


Johnny Rosenberg, the beginner
>
> Erik
> --
> ----------------------------------------------------------------------
> Erik de Castro Lopo
> http://www.mega-nerd.com/
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