Displaying 20 results from an estimated 9000 matches similar to: "Encoding question"
2003 Jun 04
3
Vorbis packet sizes
As an optimisation to reading Ogg encapsulated files, I've been thinking
about a strategy of reading entire packets out of the stream, and sending
them to the decoder. This has the advantages that:
* The packet is just a linear array of bits in memory, with length known in
advance.
* The routine which gets bits out of the packet is then trivial and possibly
inlined.
* There is no possibility
2006 Apr 13
2
How to create a compact Speex library
Hi,
Sorry if this a repost but I want to create the
smallest Speex library possible to be put in TI's
TMS320 DSP. I'm only interested in one configuration:
5.97 Kbps narrowband. What part of source code can I
remove? Currently, when I compiled the version 1.1.12
libspeex.a library with the TI TMS320 and
Fixed-Integer options, I get around 522Kb. I would
like to reduce it to as small
2006 Apr 13
4
How to create a compact Speex library
--- Jean-Marc Valin <jean-marc.valin@usherbrooke.ca>
wrote:
> > Sorry if this a repost but I want to create the
> > smallest Speex library possible to be put in TI's
> > TMS320 DSP. I'm only interested in one
> configuration:
> > 5.97 Kbps narrowband. What part of source code
> can I
> > remove? Currently, when I compiled the version
>
2006 Feb 20
3
Huge VQ codebooks
Hi,
Does anybody know how codebooks are generated in OggVorbis encoder? We
are porting oggorbis encoder on embedded platform for which VQ codebook
memory is hugeeee to imagine. How can we reduce that? Can we do VQ with
less codebooks and if yes how? If any help available?
Parul
Embedded Engineer
Einfochips Ltd
2000 Nov 09
3
Vorbis packet #3, codebooks and their large size
Hi,
Am I correct in understanding that the codebooks are *not* adaptive during
compression? I see that Packet #3 is written to the stream in the beginning
of the encode process with no modification. If the codebooks are not
adaptive, then why are codebooks included in the stream at all? Why not
pass the mode type (A or B or C...) instead of all the mode info and let the
decoder load it's
2001 May 01
1
encoder observation
Hello!
First of all a question:
When you make the encoder tables (ie: mode_e.h)
do you use the mapping0_forward function?
Because you made the encoder tables, and after this
you did a minor correction in the final beta4 ...
(this correction was:
additional[0]=fabs(additional[0]*scale);
in the mapping0_forward function)
(I see this was a bug, and the modification
was correct, but this correction
2005 Aug 26
3
Reg. vorbis for real-time audio
Hi,
From the vorbis decoder specification, it is clear that the decoder
needs to have all the codebooks before decoding can actually begin.
I will appreciate if someone can clear the following questions:
1. I guess the codebooks are derived from the actual input data.
Probably the encoder may be making two passes through the input. The
first pass finds out the frequency of different symbols
2001 Feb 22
3
rtp payload format
http://www.xiph.org/ogg/vorbis/doc/draft-moffitt-vorbis-rtp-00.txt
This is the Internet-Draft I'll be submitting tomorrow and hopefully
presenting at the March IETF meeting.
If you see anything major, let me know right away, I'll be submitting
this in the morning.
jack.
--- >8 ----
List archives: http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To
2001 Oct 18
4
libvorbisrtp-0.1
alpha. (that about sums it up)
Will encode and play back via an sdp file and multicast on one
computer (over the net if you transfer the sdp file over by hand).
rc/rtenc3 and src/rtdec3 are in the style of encoder/decoder_example
...so this means you MUST edit it them to suit your system. For example,
I specify my rtenc3 to multicast just on eth1 (to avoid pissing off
my cable supplier on
2008 Sep 02
1
How can I minimize the memory use in Tremor?
Hi all,
I'm porting the Tremor code to an ARM platform. Unfortunately, we didn't use the low mem branch code for CPU performance consideration, and now I find the memory use in it is huge for the embedded system.
After looking into the code, I found the header parse, especially, the codebook unpack part takes a lot of memory. Tremor decodes the codebooks to a cache to store
2009 Jun 18
3
Fixing ogg vorbis corruption caused by bad metadata
2009/6/18 Adam Rosi-Kessel <adam at rosi-kessel.org>:
> Ivo Emanuel Gon?alves wrote, on 6/18/2009 6:14 AM:
>>
>> On 6/18/09, Conrad Parker<conrad at metadecks.org> ?wrote:
>>>
>>> This sounds like it needs a new tool specifically for fixing broken
>>> Ogg files.
>>
>> I see two solutions:
>>
>> 1) the new vcut which I
2003 Jun 30
2
Problem with decoding number of codebooks
Hello,
I'm trying to write a Vorbis decoder (just as a hobby) but I've got a
problem with reading the setup header. According to the Vorbis
documentation the first data that should be read after the initial
'vorbis' string is an eight bit integer which when incremented by one,
contains the number of codebooks in the header. My problem is that
whenever I read this number it seems
2006 May 10
2
frame size
Hi,
Can someone please tell me how should I go about changing the frame size which is hardcoded to 160 for NB and WB and 320 for UWB.
For NB speech(8KHz) the framesize of 160 is 20ms frame but for WB and UWB its 10ms.
What are the parameters being affected by simply changing the framesize and sub-frame size in "modes.c"
How to change the buffer size and how its affected.
can we have a
1995 Nov 14
1
Vorbis Codebooks
Hello,
Vorbis uses codebooks, for example to do vectorquantization and huffman-encoding.
My question is - are all these codebook dynamicly generated ("trained")
or are there also static codebooks used ?
If yes, what specific tasks are these 2 types used for, during encoding ?
Thanks
Stoffke
<p>--- >8 ----
List archives: http://www.xiph.org/archives/
Ogg project
2005 Mar 13
1
Traffic Shaping for DVB gateway
Hello all,
I am providing broadband service through DVB circuit.
I have 4KB uplink and 32KB downlink. I want to share
32KB downlink bandwidth among 192.168.0.0/24 (20 users
in this subnet i.e 192.168.0.2-192.168.0.22)subnet
where each user will get 2KB to 6KB bandwidth. And
from 4KB uplink bandwidth each users will get only 1KB
to 2KB bandwidth.
2004 May 24
6
RFC draft for Vorbis over RTP
Hi!
What happened to this document? Was it just left dying in the IETF system?
Tor
--- >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-dev-request@xiph.org'
containing only the word 'unsubscribe' in the body. No subject is needed.
Unsubscribe messages sent to the
2009 Jul 14
2
Fixing ogg vorbis corruption caused by bad metadata
Monty Montgomery wrote:
> Yes. Without the first three packets (which hold all the codec
> settings and all the instruction how to handle the subsequent packets)
> the rest of the stream is gibberish. Vorbis can't even unpack the
> bits without the codebooks packed into the third header.
Curiosity man here.
Is there a finite set of predetermined codebooks or is the codebook
2004 Sep 16
3
speex on TI C5x fixed-point DSP
Greetings,
I've just started porting speex to a TI C5509 DSP. It doesn't look like
it's going to be too painful, but there are a couple of quirks about the
C5x.
1) chars are 16 bits because memory addresses are for 16bit words
2) ints and short are also 16 bits (so sizeof(char) = sizeof(short) =
sizeof(int) = 1)
3) the c5x is essentially big endian
My plan is to change int and
2004 Feb 05
1
Psychoacoustic model
We've implemented a vorbis decoder based on Tremor and as part of the
documentation we're also writing about psycho acoustic models and
encoding.
We're quite up to date with the decoding process and psycho acoustics
in general but unfortunately not on the psycho acoustic encoding used
in Vorbis.
We have a few questions that would we would be very thankful to have
answer to:
Which
2003 Mar 12
2
encoder block diagram
I've made a block diagram of the encoder because I tried to find out, how it works
http://stoffke.freeshell.65535.net/ogg/block.html
Although there are specifiation docs, that give very
detailed information about single aspects of the encoding (or decoding) ,
I'm missing documenations that give a more general overview,
about how the encoder works.
(Vorbis Illuminated seems a bit