[Speex-dev] Delays estimation in Speex algorithms

[John Ridges]

JM,

I also need to know the precise delays from Speex but I used the 
SPEEX_GET_LOOKAHEAD control requests to determine them (plus the 
"speex_resampler_get_output_latency" function from the resampler). The 
returned values from the Speex lookahead request don't seem to match 
with the values you gave Alexander. Am I doing this wrong? Thanks,

John Ridges


speex-dev-request at xiph.org wrote:
>
> Alexander Chemeris a ?crit :
>   
>> I want to do a careful measure of mic-to-net and net-to-spkr delays
>> in sip media engine and to make it really precise I need to know
>> delays, introduced by Speex algorithms. In particular, I'm interested
>> in delays of:
>> 1) encoder in NB, WB and UWB modes,
>>     
>
> NB: 25 ms, WB: ~28 ms, UWB: ~30 ms
>
>   
>> 2) decoder (I guess it should be 0?)
>>     
>
> 5 ms
>
>   
>> 3) resampler. I think it varies depending on input rate to output rate
>> ratio. Any generic formula or at least values for specific ratios available?
>>     
>
> The higher the quality, the higher the delay
>
>   
>> 4) AEC
>>     
>
> 0 ms
>
>   
>> 5) preprocessor
>>     
>
> 1 frame extra delay (i.e. you get back the last frame you sent the last
> time)
>
> 	Jean-Marc
>
>
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