Displaying 20 results from an estimated 900 matches similar to: "Quickie: Bitpacker endianness / OggPCM"
2005 Nov 09
2
Quickie: Bitpacker endianness / OggPCM
Michael Smith wrote:
> libogg has two bitpackers; a little endian one and a bigendian one.
ok, I didn't see it in the docs at 
http://www.xiph.org/ogg/doc/libogg/reference.html and didn't look in the 
header file first. My bad.
Is it correct to state that the oggpack_* functions use little endian 
order, and the oggpackB_* functions use big endian order? Is it safe to 
mix calls to
2005 Nov 10
5
OggPCM version / header finalization
I have OggPCM (as currently defined) support implemented in mencoder and 
mplayer. I'd like to request that we settle on modifications to this 
header by the middle of next week or freeze the current header as the 
official major version 1.0, so I can get the patches cleaned up and 
released. We will be shipping a separate product based on this work in 
the near-term future, and compatability
2005 Nov 13
3
OggPCM format description, rev 3
> Unfortunately the ALSA API defines a number of formats which are
> in practice extremely rare. In particular, any unsigned int format
> larger than 8 bits. For instance, the only unsigned int type that
> libsndfile supports is unsigned 8 bit.
I expected this, it just seemed like a good starting point to get more
than 7 formats on the table. Specifically I wanted to the logarithmic
2008 Feb 08
2
Ogg bitwise.c bit tracking
On 09/02/2008, Ralph Giles <giles@xiph.org> wrote:
> Yes, all that is reasonable. The original argument was that we need a
> library anyway, no one noticed the function call overhead, and using
> libogg simplified the embedding.
>
> Now, we'd like to remove libogg entirely as a dependency to avoid
> confusion when using other containers, but that's an api change...
2005 Nov 13
5
OggPCM format description, rev 3
Hi all,
I updated the wiki with another rev of this format. Updates include
support for 43 formats in 14 coding schemes, as derived from the ALSA API.
This seemed like a good way to get a list of what the formats in common
use out there are, so it should be fairly comprehensive.
Modifications to the "rev 2" format:
1. Expanded the 'id' field to support more than 7 formats.
2005 Nov 11
2
OggPCM proposal feedback
Arc wrote:
> Ok so we cap it to 64bit, since much more than that doesn't make sense (96bit 
> would be a "long double" C type)
On x86 CPUs, "long double" is 80 bits.
> I really don't like this idea, but I will entertain, formatting it as follows:
> 
> ID  Type  Bits  
> 0   Int   8
> 1   uInt  8
> 2   Int   16
> 3   Int   24
> 4   Int  
2005 Nov 09
3
OggPCM (uncompressed Ogg audio)
On Wed, Nov 09, 2005 at 05:33:37AM -0800, Arc wrote:
> > Data pages are identified to be part of a logical bitstream through their 
> > serial number, so don't need any additional identifiers. Thus, Arc, I don't 
> > quite understand why you would require another 32 bits at the beginning of 
> > each data packet, when ogg pages are already covering that
2002 Sep 14
4
Specific code questions
I haven't actually had many questions up to now.  Despite the
all-encompassing CP_INSTANCE monolith, things have been relatively
easy going.  Now we get into real grit:
First off, CBitman looks like it has endianness issues; it's packing
into host-order 32 bit arrays (the comments and symbol names seem to
indicate that this was originally byte-based packing code that got
upped to 32 bit. 
2006 Dec 07
4
oggPCM for general data
Greetings,
I am building a data collection system that will ultimately have 28 channels
and multi-rates up to 2 M/sec. I need some sort of lossless  format framing
and header system to transfer the data to a desktop PC over USB. Rather than
reinvent, I looked around to see what others are using and for existing
tools for testing. Surprisingly, I found few general purpose data formats
that can
2005 Nov 11
0
OggPCM proposal feedback
On Fri, Nov 11, 2005 at 07:17:53PM +1100, Erik de Castro Lopo wrote:
> We're talking about a file header here. Even if the header is a kilobyte in
> size, it will be completely **dwarfed** by the audio data following. So why 
> are you counting single bits like this?
Why waste?  You only have to read the header once for a stream, and libogg2 
provides a convient bitpacker which can
2005 Nov 09
0
OggPCM (uncompressed Ogg audio)
On Wed, Nov 09, 2005 at 09:31:29AM -0800, Ralph Giles wrote:
> > 
> > I am open to eliminating it, if it can be shown that the act of reading or 
> > skipping this data complicates implementation or makes it less efficient, 
> > however, the decidion to do so should include several people (Monty, Ralph, etc) 
> > who haven't joined this discussion yet.
> 
>
2006 Dec 08
0
oggPCM for general data
On Fri, Dec 08, 2006 at 01:37:15AM -0500, Bill Johnson wrote:
>   Has anyone built libogg and/or liboggz using a cross compiler such as the
> arm-elf GNU port?
Conrad didn't mention is explicitly, but libogg also works find on 
arm. For a small embedded app, I'd just compile the two source files 
into a static library manually. If you're not using a smart linker,
you may also
2005 Nov 15
2
OggPCM2 : chunked vs interleaved data
Michael Smith wrote:
>Whilst I accept that there are many good uses for chunked data, I
>think the transformation is trivial, particularly given certain
>characteristics of the Ogg container. Remember, the data, if you read
>an ogg stream into memory, is _already_ likely to be non-contiguous,
>due to ogg's structure. It's trivial, and has insignificant additional
2008 Feb 12
1
Ogg bitwise.c bit tracking
Ivo Emanuel Gon?alves wrote:
> And IF that kind of performance can be gained in libvorbis too, the
> question is, what are we waiting for?
I doubt the performance gain would be that large. Theora had the fun  
little situation where it was thunking into the big endian version of  
some bitpacker functions which were one-line calls to the little  
endian version. Because gcc seemed to be
2008 Feb 08
2
Ogg bitwise.c bit tracking
It's very small, maybe it could be made a separate statically linked lib ?
Or some of it inlined.
That said, libogg is small too, and some of the routines in there are quite
small as well.
2005 Nov 10
2
OggPCM proposal feedback
I threw a rough draft of an alternative format incorporating the 
comments received so far in this discussion on the wiki:
http://wiki.xiph.org/index.php/OggPCM#Format
Oliver,
This seems to me like it would support the ambisonic requirements you 
mention, though it doesn't (and I imagine won't) describe the mic 
locations. Somebody who actually uses that info could probably define 
extra
2005 Nov 09
0
OggPCM proposal feedback
On Thu, Nov 10, 2005 at 10:13:19AM +1100, Erik de Castro Lopo wrote:
> 
>   a) There is no marker to distinguish little endian data
>      from big endian data.
The original reason for this is because Ogg makes such a matter moot, 
since the bitpacker in libogg2 handles endian.. however, if a "chunk" 
packer is made available (similar to memcpy), this becomes important 
since
2005 Nov 09
8
OggPCM proposal feedback
Hi all,
Siliva contacted me about this OggPCM proposal and asked me
to join in. For those who don't know me, I am the main author
and maintainer of libsndfile and therefore know quite a bit
about how uncompressed audio is stored in sound files. However
even I would not consider myself an expert; there are areas
to do with channel assignments that I know I am ignorant of.
I am also quite
2004 Feb 17
2
ldap, quickie...
Hi,
I'm a bit confused over the whole "dn" concept .... various 
documentation states that I should create new samba-entries with
dn: uid=user,ou=<user-org>,dc=<domain>
and other states that i should do it with
dn: cn=user,ou=<user-org>,dc=<domain>
Right now i have a few entries, created both ways... and since i'm not 
quite home in ldap, I haven't
2007 Oct 19
2
OggPCM family
Hi,
The Xiph Wiki contains the four pages:
    OggPCM
    OggPCM Draft1 (with Talk page)
    OggPCM Draft2
    OggPCM Draft3
Can I suggest that this be reduced to just one
(or maybe two) pages.  I suggest this because
somebody has started making changes to
OggPCM Draft2.  My guess is that this is not
desirable.
Regards,
Martin
-- 
Martin J Leese
E-mail: martin.leese@stanfordalumni.org
Web: