[speex-dev] input format

X-Fixer x-fixer at narod.ru
Sat Feb 22 02:57:28 PST 2003

>> - any sample rate (should be set with speex_encoder_ctl), but prefered
>> are 8/16/32 kHz. but what modes should I use for a given rate?

JMV> 8 kHz is narrowband (speex_nb_mode), 16 kHz is wideband (speex_wb_mode)
JMV> and 32 kHz is ultra-wideband (speex_uwb_mode)

but are other sample rates supported? I ask because ACM does a bad job
for resampling and I want to accept any possible sample rate. (and so:
what's best mode for an arbitrary sample rate?)

>> also
>> - what bit rates are allowed?

JMV> Too many to list here: from around 2 kbps to 44 kbps

JMV> complexity means: take more (or less) CPU to do a better job at
JMV> encoding. It doesn't change the bit-rate, but it has a (small) effect on
JMV> quality. Of course, the quality of the encoding is mainly controlled by
JMV> the "quality" parameter (which has a direct effect on bit-rate).

user should be able to select quality for encoding and the best way
for it (I think) is to specify it in kbps. so, how should I set up
quality/bps (since there are controls for both) to get a proper bps?

>> also, to have a "legal" ACM codec one should register at microsoft
>> (get MID, PID and format tag). is this somehow possible? I mean Xiph
>> is a solid organization.

JMV> Might want to contact Emmett Plant <emmettfish at mac.com> about that
JMV> (contact me again if you don't get an answer).

ok, I'll do that when I get codec working.

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