<br><font size=2 face="sans-serif">Hi,</font>
<br>
<br><font size=2 face="sans-serif">Thanks for the reply.</font>
<br>
<br><font size=2 face="sans-serif">I have another important question wrt
24 bit platform implementation of OggVorbis</font>
<br>
<br><font size=2 face="sans-serif"><b>What can be the max code word length
in a code book?</b></font>
<br>
<br><font size=2 face="sans-serif">In some cases, I have seen it is max
21 bits. Can it go beyond 24 bits? If it can occur, Can you suggest how
to handle it in 24bit platform as we don't have any variable type representing
more than 24 bit.</font>
<br>
<br><font size=2 face="sans-serif">Please reply at your earliest.</font>
<br>
<br><font size=2 face="sans-serif">Thanks.</font>
<br><font size=2 face="sans-serif"><br>
Best Regards,<br>
------------------------------------------------------------------------------------------------------------------------<br>
Sanjay Kumar
Philips
Innovation Campus<br>
Technical Specialist
#1 Murphy Road<br>
Philips Applied Technologies
Ulsoor, Bangalore - 560 008<br>
Ph: +91 80 25579000 Extn. 5002<br>
Fax: +91 80 25561283<br>
Email: sanjaykumar.gupta@philips.com
<br>
------------------------------------------------------------------------------------------------------------------------<br>
<br>
</font>
<br>
<br>
<br>
<table width=100%>
<tr valign=top>
<td width=33%>
<br>
<br>
<br>
<br>
<br><font size=1 face="sans-serif"><b>Michael Smith</b> </font>
<p><font size=1 face="sans-serif">Sent by:</font>
<br><font size=1 face="sans-serif">mlrsmith@gmail.com</font>
<p><font size=1 face="sans-serif">2005-08-25 03:07 PM</font>
<td width=66%>
<table width=100%>
<tr>
<td>
<div align=right><font size=1 face="sans-serif">To</font></div>
<td valign=top><font size=1 face="sans-serif">Sanjaykumar Gupta/BTC/PDSL/PHILIPS@PHILIPS</font>
<tr>
<td>
<div align=right><font size=1 face="sans-serif">cc</font></div>
<td valign=top><font size=1 face="sans-serif">tremor@xiph.org<br>
tremor-bounces@xiph.org<br>
"Hibbs, Phil on [vorbis]" <vorbis@xiph.org><br>
vorbis-bounces@xiph.org</font>
<tr>
<td>
<div align=right><font size=1 face="sans-serif">Subject</font></div>
<td valign=top><font size=1 face="sans-serif">Re: [Tremor] what is max
and min bitrate supported in OggVorbis?</font>
<tr>
<td>
<div align=right><font size=1 face="sans-serif">Classification</font></div>
<td></table>
<br>
<table>
<tr valign=top>
<td>
<td></table>
<div align=right>
<br></div></table>
<br>
<br>
<br><font size=2><tt>On 8/25/05, Sanjaykumar Gupta <sanjaykumar.gupta@philips.com>
wrote:<br>
> <br>
> Hi All, <br>
> <br>
> I am planning to implement Ogg Vorbis Decoder on a 24 bit DSP. <br>
> <br>
> I have following doubts: <br>
> <br>
> 1) What is min and max bitrate? <br>
<br>
Minimum bitrate is extremely low. Much less than one kilobit per<br>
second. Maximum bitrate is not strictly bounded in the full vorbis<br>
specification (we still hope to create a 'portable friendly profile'<br>
in the future), but over 500 kbps is unusual.<br>
<br>
> <br>
> 2)What is max Audio Packet size ? <br>
<br>
Not strictly bounded. You can experiment with the reference encoder at<br>
very high bitrates to get an idea of what real streams are likely to<br>
top out at.<br>
<br>
> <br>
> 3)What is the max size of setup header? <br>
<br>
Can be large. Several kilobytes is common. Perhaps a limit of 8 kB<br>
might be reasonable for portable implementations?<br>
<br>
> <br>
> 4)Any idea how to start for making a 24Bit fixed point reference code?
Shall<br>
> I start with floating point or Tremor or Tremor Low Mem Version? <br>
<br>
I'd say tremor or tremor-lowmem, depending on whether you require<br>
particularly low memory usage or not (note that -lowmem requires<br>
somewhat more cpu).<br>
<br>
> <br>
> 5) What window sizes in Ogg Vorbis are normally supported for audio
portable<br>
> player? <br>
<br>
You should ideally support all window sizes (i.e. from 64 to 8096).<br>
The smaller ones (64 and 128) are pretty simple to deal with. 256,<br>
512, 2048, and 4096 are all used by the reference encoder for common<br>
cases, so are absolutely crucial. I think some encoders use 1024 as<br>
well. 8096 is something you could skip if you don't have the memory<br>
available, but if you can fit it in that would be preferable.<br>
<br>
> <br>
> 6) Floor0 is termed to be obsolete, Does this mean non of the commercially<br>
> available encoder supports Floor0? <br>
<br>
It's not obvious what you mean by "commercially available". Certainly<br>
there were releases of the reference encoder (which is by far the most<br>
commonly used one) which used floor0, and some people have floor0<br>
files. However, later releases (including 1.0 and later) do not use<br>
floor0, it's uncommon, and it's reasonable to remove support for it if<br>
you have limited cpu power (it's significantly more cpu-intensive than<br>
floor1).<br>
<br>
<br>
Mike<br>
</tt></font>
<br>