[vorbis] bit rate

Karthik M karthik at siptech.co.in
Mon Sep 22 23:52:31 PDT 2003



codebooks define how a (binary) file is organized.  An application may
have to read the codebook first to correctly read the contents of the data
file.

To see how vorbis implements codebooks, take a look at vorbis/codebook.c

> thanks for your answers,
>
> i am reading the specifications, and i  don't understand it all, i have
> one
> other question:
>
> i undestand the bitpacking operation.
> but what about the codebook thing?
> is it made for the decoder to know how the bit where packed, to know what
> are the lenght of the different entries stored in the bitstream?
> i see that the codebook_entries is made to store the number of entries,
> but
> where is the size of the different entries stored in?
>
>
> ----- Original Message -----
> From: "Graham Mitchell" <graham at grahammitchell.com>
> To: <vorbis at xiph.org>
> Sent: Monday, September 22, 2003 12:27 PM
> Subject: Re: [vorbis] bit rate
>
>
>> > could someone give me the defintion of bitrate, and explain me why the
>> > bitrate is variable in vorbis?
>>
>> Beni gave an excellent explanation, but I should also plug my own Vorbis
>> introduction, which spends a fair amount of time discussing bitrates.
>> http://grahammitchell.com/writings/vorbis_intro.html
>>
>> As to why it is variable in Ogg Vorbis, the short and sweet version is
>> "because some passages are harder to encode than others, and it's
>> foolish
>> not to 'save' bits on easier sections so you can use them on tougher
>> sections instead."
>>
>> --
>> Graham Mitchell - computer science teacher, Leander High School
>> "Christians and their opponents again and again expect that some new
>> discovery will either turn matters of faith into matters of knowledge or
>> else reduce them to patent absurdities. But it has never happened. What
>> we
>> believe always remains intellectually possible; it never becomes
>> intellectually compulsive. I have an idea that when this ceases to be
>> so,
>> the world will be ending."
>> -- C.S. Lewis, from "Religion and Rocketry"
>> --- >8 ----
>> List archives:  http://www.xiph.org/archives/
>> Ogg project homepage: http://www.xiph.org/ogg/
>> To unsubscribe from this list, send a message to
>> 'vorbis-request at xiph.org'
>> containing only the word 'unsubscribe' in the body.  No subject is
>> needed.
>> Unsubscribe messages sent to the list will be ignored/filtered.
>>
>
>
> ******** F'SATIE disclaimer ********
> This message may contain privileged and confidential information intended
> only for the use of the addressee named above.
> If you are not the intended recipient of this message, you are hereby
> notified that you must not disseminate, copy or take any action in
> reliance on it.
> If you have received this message in error, please notify F'SATIE at
> administrator at fsatie.ac.za.
>
> Any views expressed in this message are those of the individual sender,
> except when the sender specifically states them to be the view of F'SATIE.
>
>
> --- >8 ----
> List archives:  http://www.xiph.org/archives/
> Ogg project homepage: http://www.xiph.org/ogg/
> To unsubscribe from this list, send a message to 'vorbis-request at xiph.org'
> containing only the word 'unsubscribe' in the body.  No subject is needed.
> Unsubscribe messages sent to the list will be ignored/filtered.
>

<p><p>-------------------------------------------
Karthik M
System Administrator - Infrastructure Team

SIP Technologies & Exports Limited,
G4, Elnet Software City, CPT Road,
Taramani, Chennai 600 113,
INDIA.

Phone: +91-44-22541401
       +91-44-22541031
Fax:   +91-44-22541475

Website: http://www.siptech.com
-------------------------------------------

<p>. 

--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to 'vorbis-request at xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is needed.
Unsubscribe messages sent to the list will be ignored/filtered.



More information about the Vorbis mailing list