[speex-dev] Speex bitrate
miguel.gomes at netcabo.pt
Fri Mar 19 06:35:12 PST 2004
I'm using speex to encode wav files. How does the --bitrate n option (use bit-rate n or lower) afects the quality and time of the encoding?
If I don't use that option how speex determines the bitrate to use in encoding?
Thanks in advance
De: owner-speex-dev at xiph.org em nome de Chris Flerackers
Enviada: qui 18-03-2004 14:52
Para: speex-dev at xiph.org
Assunto: Re: [speex-dev] denoise.c missing from 1.1.4 archive
I was indeed using Visual C++ to compile speex.
I made the following changes and now it compiles:
- Remove denoise.c from project
- Add jitter.c, lbr_48k_tables.c, lmdf.c, preprocess.c to project
- Add the following to quant_lsp.c in the floating point case
#define M_PI 3.14159265358979323846 /* pi */
- Replace inline with __inline in lsp.c line 105
static inline spx_word16_t spx_cos(spx_word16_t x)
According to msdn: The inline keyword is available only in C++.
The __inline and __forceinline keywords are available in both C and C++.
When compiling in debug mode, I also get 530 warnings about double to
float conversions. In release mode I don't get these warnings because the
warning level is set to 1. Do these conversions impact performance? I think
it is because you use e.g. 16000.0 instead of 16000.0f but I'm wondering
if this causes computations to be done using doubles and then converted to
instead of working with floats all the time. If 32 bit float precision is
it is better to use .0f everywhere?
----- Original Message -----
From: "Jean-Marc Valin" <Jean-Marc.Valin at USherbrooke.ca>
To: "speex" <speex-dev at xiph.org>; "Chris Flerackers"
<cflerackers at androme.be>
Sent: Wednesday, March 17, 2004 6:01 PM
Subject: Re: [speex-dev] denoise.c missing from 1.1.4 archive
> I just downloaded http://www.speex.org/download/speex-1.1.4.tar.gz and
> tried to build it but the file denoise.c seems to be missing from the
> Can you fix this or is it better to get everything from cvs?
You're using Windows, right? The project file is simply out of date. The
denoise.c file has been renamed to preprocess.c
> Another question, when will a stable version of 1.1 be released. I'm
> in the preprocess features but I would also like a stable encoder/decoder
So far, I'd say that the quality of 1.1.4 is probably higher than 1.0.3.
It is considered unstable because I don't do the same amount of testing
and I'm still changing many things. I think 1.2 (the next stable
version) might take a couple months (can't be more precise). In the mean
time, I'm considering back-porting the preprocessor to 1.0.x. I'll do
that when I have time, but you can probably even do it yourself. All you
have to do is change "short" for "float" at a couple places (or if
you're lazy, the version in 1.1.1 might work directly).
Jean-Marc Valin, M.Sc.A., ing. jr.
Université de Sherbrooke, Québec, Canada
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