Jean-Marc Valin <jean-marc.valin at usherbrooke.ca> writes:
> On 2010-04-03 22:52, Randy Yates wrote:
>> Jean-Marc Valin<jean-marc.valin at usherbrooke.ca> writes:
>>
>>> Quality and bit-rate are different ways of specifying exactly the
same
>>> thing. Complexity is orthogonal.
>>
>> That clears it up - thanks. Is this in the manual?
>
> Have a look and tell me.
Jean-Marc,
In your 1.2 Beta 3 manual, on p. 7, you discuss quality:
Quality (variable)
Speex is a lossy codec, which means that it achives compression at the
expense of fidelity of the input speech signal. Unlike some other
speech codecs, it is possible to control the tradeoff made between
quality and bit-rate. The Speex encoding process is controlled most of
the time by a quality parameter that ranges from 0 to 10. In constant
bit-rate (CBR) operation, the quality parameter is an integer, while
for variable bit-rate (VBR), the parameter is a float.
The sentence "Unlike some other speech codecs, it is possible to control
the tradeoff made between quality and bit-rate" implies to me that they
are NOT the same thing.
So, while you do discuss these terms in your manual, what you state
there seems to contradict what you've stated here in this mailing list.
--Randy
>
> Jean-Marc
>
>> --Randy
>>
>>>
>>> Jean-Marc
>>>
>>> On 2010-04-03 08:28, Randy Yates wrote:
>>>> Jean-Marc: I know you're seeing these - how about a
response?
>>>>
>>>> --Randy
>>>>
>>>> Randy Yates<yates at ieee.org> writes:
>>>>
>>>>> If I understand these terms correctly, you cannot specify
simultaneously
>>>>> all three, e.g., high quality, low bitrate, and low
complexity.
>>>>>
>>>>> It seems that specifying any two implies the third. For
example,
>>>>> specifying a high quality and low bitrate will necessarily
require a
>>>>> high complexity.
>>>>>
>>>>> Am I correct? If not, can someone please explain how these
parameters
>>>>> interact?
>>>>
>>> _______________________________________________
>>> Speex-dev mailing list
>>> Speex-dev at xiph.org
>>> http://lists.xiph.org/mailman/listinfo/speex-dev
>>>
>>
--
Randy Yates % "Bird, on the wing,
Digital Signal Labs % goes floating by
mailto://yates at ieee.org % but there's a teardrop in his
eye..."
http://www.digitalsignallabs.com % 'One Summer Dream', *Face The Music*,
ELO