Speex dev - Dec 2011 - Decoding only a certain frame results in different values than when decoding the entire file

And how many frames does Speex need to "recover"?
Or is that not predictable?

Greetings,
Hermann


Am 23.12.2011 19:17, schrieb Steve Checkoway:
>
> On Dec 23, 2011, at 10:03 , Hermann Weber wrote:
>
>> I found out something:
>>
>> The more frames I decode before the frame that I actually want to
>> decode, the better the quality becomes.
>> For example when I basically want to decode frame #100, I read frame
#80
>> to #100, and then frame 100 has the quality that I need.
>>
>> Why? Is there any information on this behaviour?
>
>
> Speex is a stateful encoder. As it encodes the audio, the state 
> changes. As it decodes, the state changes. You're trying to start 
> somewhere in the middle with the initial state rather than with the 
> state it would have if you started from the beginning and decoded it 
> all. As you've noticed, it can recover from lost frames over time.
>
> This is just repeating what Lakhdar Bourokba already said though.
>
> As for your question about the header, it really depends on how you're 
> saving the encoded file.
>
>
>
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On Dec 23, 2011, at 10:54, Hermann Weber <hermie.weber at gmx.de> wrote:
> And how many frames does Speex need to "recover"?
> Or is that not predictable?
No idea. My guess is not predictable. You have all of the data, why not decode
it all?

-- 
Steve Checkoway

My file is 3 hours long, so decoding takes around 5 minutes on an 
average computer.
That is a bit too long unfortunately...


Am 23.12.2011 20:38, schrieb Steve Checkoway:
> On Dec 23, 2011, at 10:54, Hermann Weber<hermie.weber at gmx.de> 
wrote:
>
>> And how many frames does Speex need to "recover"?
>> Or is that not predictable?
> No idea. My guess is not predictable. You have all of the data, why not
decode it all?
>