5 Nov
2013
5 Nov
'13
11:19 p.m.
hermann meyer wrote:
I would save a internal audio buffer to file on exit,
to reuse it after
e new start.
Currently I use stdio fopen/fwrite/fread and save the binary data from
the array.
That works well.
Now I've started to play with libsndfile, first I use SF_FORMAT_WAV |
SF_FORMAT_FLOAT which work as nice as stdio. The file size is the same
then with plain binary data.
To save some bytes on the disk I tried SF_FORMAT_FLAC | SF_FORMAT_PCM_24
which reduce the size nearly to the half. The drawback is that the
floats in the internal buffer could go out of the range from -1.0 <->
1.0 which leads to crackles when the buffer get refiled. As long the
values are in range, flac works very well.
Yes, and so it should.
I tried it with the sf_command (sndfile,
SFC_SET_NORM_FLOAT, NULL, SF_TRUE)
for write and read, but that didn't help.
No, it won't.
What you need to do is scale your data to the range [-1.0, 1.0] before
you write it to the file.
Yes, I use sf_write_float to write/read the flac file,
even if flac
didn't support floats. When I understand the libsndfile api right,
libsndfile will handle that.
Yes, that is correct.
So my quetion will be, which is the common format to
write flac file
with libsndfile,
Writing float is fine, you just need to ensure that the data is in
range [-1.0, 1.0] first.
and is there a way to write values out of range into a
flac file?
No, there isn't.
Erik
--
----------------------------------------------------------------------
Erik de Castro Lopo
http://www.mega-nerd.com/