Displaying 20 results from an estimated 9000 matches similar to: "resolution issues"
2007 Jan 06
7
FFmpeg Theora encoding patch
Hi,
Attached is my patch to add theora encoding to ffmpeg's libavcodec (by
using libtheora). I am requesting help to fix the bug I mention below
and am seeking general comments before I submit the patch properly.
Files encoded using this encoder have a problem playing in VLC. The
files will not play unless "Drop late frames" has been unticked in the
advanced video settings.
2003 Mar 05
5
VP3 IDCT
Hi,
Is there anything special I need to know about VP3's IDCT? I mean
besides the fact that there are separate IDCTs to handle sparse
coefficient matrices. Are the IDCT functions mathematically equivalent to
any textbook IDCT functions?
Thanks...
--
-Mike Melanson
--- >8 ----
List archives: http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To
2003 Dec 06
5
What sort of math i required?
Hi,
Keep up the good work! The file sizes of Theora's output is amazing!
I have just joined the list, and would like to contribute to the
2003 Mar 09
4
Proof of Concept
Hi,
So it took a little while to get here but VP3 through ffmpeg is
finally starting to achieve viewable results. It partially works right
now. Keyframes only. And monochrome. Oh, and the picture is upside down
(something I did not realize about VP3 until I let it fly just now).
Anyway, here is a picture of ffmpeg's VP3 decoder in action using xine:
2011 Mar 31
1
DCT-coefficients in
Why for white-pixel image, oc_enc_fdct8x8_c() returns
the matrix with non-zero AC-coefficients?
_x[64]:
* 107 107 107 107 107 107 107 107
* 107 107 107 107 107 107 107 107
* 107 107 107 107 107 107 107 107
* 107 107 107 107 107 107 107 107
* 107 107 107 107 107 107 107 107
* 107 107 107 107 107 107 107 107
* 107 107 107 107 107 107 107 107
* 107 107 107 107 107 107 107 107
_y[64]:
* 3426
2005 Feb 11
1
Changing the IDCT spec
So, in preparation for some decoder optimization work planned by Rudolf
Marek, the subject of the size of the registers needed in the IDCT
came up.
The current spec language ensures that the result is exactly compatible
with the C code for VP3. This language requires that some of the
arguments to the multiplies be 17 or 18 bits, because they need to hold
the sum or difference of two 16-bit
2004 Mar 02
1
VP3 Format Doc, v0.4
Hi,
Check it out-- another update in the space of a week:
http://home.pcisys.net/~melanson/codecs/vp3-format.txt
v0.4: March 2, 2004
- renamed and expanded section "Initializing The Quantization Matrices"
- outlined section "Reconstructing The Frame"
- moved Theora Differences Appendix to its own section entitled "Theora
Specification"
- added Appendix:
2002 Nov 11
3
Theora vs. Nullsoft NSV
How does the Theora project differ from Nullsofts NSV project?
Other than the obvious fact they use mp3....
<p><p>--- >8 ----
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2003 Feb 26
7
[OT] Just saying hi!
I hope this list is small enough for not beeing banned when
introducing oneself. So...
Hi,
I just subscribed to the theora-lists. I'm from the XVID project,
so I know a deal about video and MPEG-4 in particular, but nothing about
Vorbis/Theora etc., That's why I'm here, because I'm interested in
patent-free alternatives.
I guess there is no documentation of the current status
2010 May 04
2
Why Our Civilization's Video Art and Culture is Threatened by the MPEG-LA
http://www.osnews. com/story/ 23236/Why_ Our_Civilization _s_Video_ Art_and_Culture_ is_Threatened_ by_the_MPEG- LA
it looking more and more like GIF/LZW/Unisys, but it called Microsoft/apple/ MPEG-LA/etc
and I cant wait until there is a video camera that is not using codec from MPEG-LA
2002 Aug 28
5
Analogue artifact estimation
Hi List,
Just batting a few ideas around here, but would it be possible to include in to the codec, estimation for common video artifacts that occur in the analogue world?
For example, anything that's gone through a composite stage will likely have dot-crawl and false colour - if we can recognise this effect in the encoder, we can treat it as a special case.
Other artifacts that come to
2011 Mar 22
5
FPGA encode stages flow diagram
Good day!
I create diagram of encoder process. Using it i create implementation of
encoder in FPGA (Xilinx/Altera). Please critique it. Is there missing
stages?
Here is blog http://developer-fpga.blogspot.com/
Here is picture of encoding stage 1
https://lh4.googleusercontent.com/-NV8o9DG3jvE/TYjYXr-dYGI/AAAAAAAAAos/U06O-YvhSI0/s1600/stage1.jpg
Here is picture of encoding stage 2
2003 May 28
2
autoconf problem
./configure: line 524: syntax error near unexpected token `AM_INIT_AUTOMAKE(libtheora,0.0)'
./configure: line 524: `AM_INIT_AUTOMAKE(libtheora,0.0)'
I'm sure I'm doing something pro-stupid, but ---
my setup works fine for ogg & vorbis.
autoconf ver 2.13
automake (GNU automake) 1.4-p4 if that matters
hey let's put tool version numbers into the README
-dan
2011 Mar 18
3
alghorithm of working encoder in libtheora
Hi,
Is somewhere alghorithm description of encoder process implemented in
libtheora? May be some drafts? May be frame dataflow throw encoder stages?
PLEASE
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2002 Aug 05
3
Cross-Compiling VP3 lib on Linux
Hi,
I have been working with VP3 for some time now. Dan Miller from
On2 just told me about this list.
A few months ago, I managed to get On2's VP3 source snapshot to
compile under Linux, a feat that many have apparently attempted and
quickly abandoned. I compiled a small console app and the results of the
experiment are explained here:
2004 Jul 02
4
Encoding paramaters...
I've got my encoder working now... and i put a proeprty page interface to
allow the user to set a few encoding paramters to start off with... but
changing the paramters doesn't seem to make barely any difference...
These are the defaults i'm using...
mTheoraInfo.target_bitrate=400000;
mTheoraInfo.quality=30;
mTheoraInfo.dropframes_p=0;
mTheoraInfo.quick_p=1;
2002 Oct 29
3
Simple player and encoder binaries for Windows
--- Stephane wrote:
VP3 codec uses a lot of CPU for decoding. We will need some optimization
because now this codec is way too slow for home uses.
--- end of quote ---
Actually, the Windows VP3 QuickTime codec runs just fine on a 400MHz Pentium II box, with only occasional glitches on some dodgy Celeron systems. At work, we routinely test 320x240 full-color, full-motion video on low-end boxes.
2002 Sep 04
4
Limiting bandwidth to around max. 8k per second - possible? UPDATE
Ok, we got it working with 176x144 resolution.
The following string produced an image that was not falling behind too
much for too long - basically a little when it was getting TONS of
movement, and then catching up fast.
"65 58 110 0 1 1 90 8 120 1 1 "
Now, we need to get this working on a 320x240 resolution, too (as sadly
VP3 does not support 160x120. Seems to be a little senseless,
2002 Jul 17
3
More introductions
--- "Tabuleiro" wrote:
Hi, guys. I was working with the VP3 code, planning to integrate it with Ogg
for a self-contained solution for video playback, platform independant, no
installation required, no QT, no AVI runtimes. My main interest is CD-based
work using local files and portability/performance, not really into
streaming or anything fancy (network error correction, prediction,
2011 Mar 01
1
theora encoder reordering, order of puting data from DCT 8x8 blocks to huffman compressor, and puting result of huffman compressor to buffer bitstream memory
Good day!
I'm creating HDL IP CORE (for using in FPGA) for theora encoder (now only
I-frames).
I don't undestand one moment. Now i develop such stages:
1. From RBG(byer) to YCbCr converter
2. DCT processing (8x8 pixels blocks)
3. Quantizator of DCT coeff.
4. Zig-Zag of quantized DCT coeff.
and now i have uresolved last stage of compression - how i must send 8x8
blocks to huffman