[CELT-dev] CELT 0.6.0 released, submitted as IETF draft

[John Ridges]

Actually I think the API you've defined is a good one (I can't think of 
a better interface offhand). The only thing I'm a little disappointed 
about is that the bit-rate doesn't decrease as dramatically as I'd like 
when there is essentially very quite audio (like it does in Speex), but 
I also realize that as a full-fidelity codec even soft audio might 
require a relatively high bit-rate to make sure it's faithfully 
reproduced. So I'll just work with whatever miracles you folks can pull 
off with the VBR. I have a #define that sets the VBR as a percentage of 
the maximum bit-rate. Right now I have it set to 50%, but maybe in the 
future I can set it closer to 100%.

Regards,

John Ridges


Jean-Marc Valin wrote:
> John Ridges a écrit :
>   
>> I found where I was off by a factor of two, so, yes, VBR does appear to
>> work exactly the way you describe. In the future do you think you'll
>> keep it working this way or do you have plans to change its behavior as
>> it gets more advanced (I've noticed that it rarely gives you a bit-rate
>> below the target bit-rate)? Tha
>>     
>
> Do you mean "working this way" as in the API or as the way it changes
> the bit-stream. The latter will definitely improve with time. The API
> may or may not change depending on the feedback we get. Is the current
> API sufficient for you or would you prefer something different?
>
> Cheers,
>
> 	Jean-Marc
>
>
>   
>> John Ridges
>>
>>
>> Jean-Marc Valin wrote:
>>     
>>> Hi John,
>>>
>>> The way VBR currently works is that you control the (approximate)
>>> bit-rate target with CELT_SET_VBR_RATE and then the argument you pass to
>>> the encoder is just the *maximum* bit-rate allowed. So if the maximum
>>> isn't important, you just pass a large value there and control the rate
>>> with CELT_SET_VBR_RATE.
>>>
>>> Cheers,
>>>
>>>     Jean-Marc
>>>
>>> John Ridges a écrit :
>>>  
>>>       
>>>> Congrats JM. I've been looking forward to 0.6.0 for a while now, and
>>>> I've just integrated it into my app and it works great. I have just one
>>>> question though. I realize that the VBR implementation is brand-new and
>>>> isn't finished yet, but I would like to use it and was wondering if you
>>>> could give us all some idea of how you envision the VBR eventually
>>>> working (in other words, how the VBR parameter would affect the
>>>> bit-rate). Right now it appears to give me about half the bit-rate I ask
>>>> for when encoding silence, bit will sometimes increase up to around the
>>>> full bit-rate on occasion depending on the audio.
>>>>
>>>> Thanks,
>>>>
>>>> John Ridges
>>>>
>>>> celt-dev-request at xiph.org wrote:
>>>>    
>>>>         
>>>>> Message: 1
>>>>> Date: Sun, 05 Jul 2009 20:37:40 -0400
>>>>> From: Jean-Marc Valin <jean-marc.valin at usherbrooke.ca>
>>>>> Subject: [CELT-dev] CELT 0.6.0 released, submitted as IETF draft
>>>>> To: celt-dev <celt-dev at xiph.org>
>>>>> Message-ID: <4A514754.4020101 at usherbrooke.ca>
>>>>> Content-Type: text/plain; charset=ISO-8859-1
>>>>>
>>>>> Hi everyone,
>>>>>
>>>>> I'm pleased to announce version 0.6.0 of CELT, with many quality
>>>>> improvements. This includes better stereo coupling, better handling of
>>>>> transients, and better handling of highly tonal signals. In addition,
>>>>> packet loss robustness has been improved through the optional use of
>>>>> independent (intra) frames. CELT now supports a larger dynamic range,
>>>>> suitable for encoding 24-bit audio (float version only). There is
>>>>> also a
>>>>> very early VBR implementation.
>>>>>
>>>>> Now, 0.6.0 is also the version that just got submitted as an "IPR-free
>>>>> codec" Internet draft:
>>>>> http://www.ietf.org/internet-drafts/draft-valin-celt-codec-00.txt
>>>>>
>>>>> For those who aren't aware of it, there is an ongoing discussion about
>>>>> creating an IETF working group for standardising unencumbered audio
>>>>> codecs that everyone can use. There will be a BoF at the next IETF
>>>>> meeting (26-31 July) in Stockholm to discuss that. I encourage those
>>>>> interested in taking part in the mailing list discussion (
>>>>> https://www.ietf.org/mailman/listinfo/codec ) and/or attending the BoF
>>>>> in Stockholm. I will be co-chairing this BoF with Jason Fischl from
>>>>> Skype.
>>>>>
>>>>> Cheers,
>>>>>
>>>>>     Jean-Marc
>>>>>
>>>>>
>>>>>         
>>>>>           
>>>>     
>>>>         
>>>   
>>>       
>>
>>     
>
>
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