Displaying 20 results from an estimated 1000 matches similar to: "Simple RGB->YUV Stuff..."
2005 Mar 14
1
question from beginner (YCbCr to RGB)
Hello, i'm sorry for my English is not good.
I need help with convert yuv_buffer data (YCbCr) to RGB without SDL.
I write:
BYTE *frame=new BYTE[YUV_BUFFER.y_height*YUV_BUFFER.y_width*4];
for(int cc=0; cc<YUV_BUFFER.y_height*YUV_BUFFER.y_width; cc++)
{
frame[cc*4+0]=YUV_BUFFER.y[cc]+1.371*(YUV_BUFFER.v[cc]-128);
2004 Dec 08
3
yuv2rgb
hi all,
i'm trying to code a tool to get some images from a ogg/theora file ....
so basically i need to get a frame and convert to rgb ... and here is my
question (sorry, i'm newbe here) ...
how to convert a yuv_buffer to a rgb matrix ?
i tryied diferent ways but my mistakes are bassically cause i don't
understant how yuv_buffer structure works ...
anybody can help? thanks a lot.
2004 Apr 01
1
YUV Format
I posted this the other day... but it didn't get delivered...
-------------------------------------------------------------------
I'm getting stuck into a theora decoder for directshow... i was just wondering if someone could give me some info.
What output format does theora use ?
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwmt/html/YUVFormats.asp
2005 Oct 05
1
Simple encodig sample...
Hi all.
I'm Mat & I'm new :)
I'm testing libtheora + libogg perhaps for a commercial product.
I started watching encoder_example.c ... I simplified it for testing
it easier.
It seems ok to me but I have no experience with theora so I would like
to know if my code is correct.
I tried to debug it with Valgrind and I found 4 possible memory leaks...
but I think they can be
2004 Aug 02
1
Theroa Guess Confirmation
Hi there, is there any document giving a high-level overview of how to
use "libtheora"? As it stands, I'm scrounging through headers and
example code, and doing a whole lot of guessing. In the meantime,
could you either confirm or deny the following guesses?
1) Before compressing with Theora, I must unpack my YUY2 data into
three separate arrays (Y, U, and V respectively), and
2007 May 03
1
converting YUV to RGB
Hello all,
I'd like to convert the theora yuv_buffer to RGB that I can render onto a
texture.
Googling around, there are a tone of different formulae to do so.
There is this (with lots of corrections and amendments further down the
page):
http://www.fourcc.org/fccyvrgb.php <http://www.fourcc.org/fccyvrgb.php>
and there is the MSDN stuff that says you need to convert 4:2:0 and
2005 Feb 09
1
Trying to do windows encoding dll
Hi everybody, me again.
I'm trying to write my own VFW-like dll... It doesn't need to do much.
1.) compress a single frame and give it back to the host application
2.) host applications sends the frame
3.) client application receives frame
4.) client application tells the dll to decompress the data
So if I try to do this, something is going wrong...
Perhaps someone could have a look at my
2007 May 25
2
Cleaning app
Hello all,
When I'm doing something like:
yuv_buffer yuv;
theora_decode_YUVout(&td,&yuv);
I'm guessing a bunch of stuff gets newed/malloced for yuv.y, yuv.u, and
yuv.u.
Who is responsible for deleting/freeing that stuff?
Cheers,
Kos.
2004 Jun 29
6
Encoding theora...
Just trying to debug my theora encoder... just wondering if someone could
give me some insight on a few thigns...
In the yuv_buffer i'm sending in... i am just setting
y_stride = y_width = videoWidth
uv_stride = videoWidth/2
y_height = videoHeight
uv_height = videoHeight/2
Making the y buffer (width*height) and each of u and v (width*height/4)
Am i correct in doing this ? I knwo stride
2008 Jan 15
0
Re: YUV to RGB
Mike Melanson: I want to store RGB values instead of YUV. I don't understand the theoretical and practical implications of this and that's why I'm asking about it. I would like to know whether it cannot work and why.
I'm targeting a minimum Pentium 4 Celeron, 256MB RAM. Video resolution are about 200 X 200 pixels with a maximum of 2 playing simultaneously as the game is playing
2004 Dec 20
2
frame_height, height, y_height etc...
I'd previously been working on the assumption that the frame_height was the
height of the inner picture region... and height was the height of the outer
frame.
Then upon readnig the spec... where it calls the outer part the frame and
the inner part the picture region... i assumed i'd made a mistake and that
frame_width is actually >= width in the theorainfo structure... ie
2008 Feb 16
3
Gray scale video output from theora
hi all
I guess that *Theora* will convert the input color space (RGB or CMYK or
any) into YUV before it process and encode. (that means theora can operate
on several color space, but it get convert into YUV before process)
Is that true...?
I want to get a gray scale, encoded video output from the *Theora* encoder
while the input video is getting from a web cam (color input and gray scale
2005 Sep 27
4
problems understanding yuv_buffer format
hi folks!
once again i am trying to decode a yuv_buffer to a 24 bit RGB buffer.
last time nobody seemed willing to tell me how to do this, so i am
trying again.
i try to make my questions more simple. what i need to know is:
how many bytes are in each y, u, v array?
what for are these strides?
what exactly is a "plane" in a frame, and what does it do?
what i want to achieve is
2007 Aug 31
1
yuv_buffer strides
Hi,
is there any place where the possible values for the strides in the
yuv_buffer structure is specified? or just in the source code? ;)
I could compress a video with, lets say, yuvbuf.y_stride =
yuvbuf.y_width, so the yuvbuf.y[0] really started in the start of the
y channel data. I watched the video in several players, and
everythings' ok. But, when programming the decompress process, the
2006 Oct 06
0
V4L + Theora small app...
Hi all.
I post a small app I made that create 2 clips using a V4L device.
I would like to get every tips you think it's useful...
Some notes:
- I make 2 clips because in our project we create series of clips and
it's important to check that the all the resources ( memory,
descriptors, etc. ) are freed correctly and to reuse all the resources
that can be reused
- the clips are not well
2005 Feb 09
2
Converting RGB YUV and back
Hi all,
how can I convert a RGB (24 or 32) image I'm getting from a webcam for
example to YUV to compress it with theora, decompress it and convert it back
to RGB to draw it?
Any suggestions?
Best regards,
Florian
(Stuttgart, GERMANY)
2007 Nov 20
5
yuv - rgb conversion without contrast decrease.
Hello list,
When I convert an yuv pixel into rgb using the recipies in
http://www.fourcc.org/fccyvrgb.php I get an accurate color conversion
but the contrast seems to be decreased. If i write, e.g., the pixel
directly into an sdl yuv_overlay, I get a well-contrasted frame,
however, if I convert the pixel to rgb and call SDL_MapRGB, I get a
contrast-decreased frame.
Thanks,
Ribamar
2009 Feb 09
1
liboggplay: yuv to rgb patch
Hey,
::: I'm sending a patch for liboggplay for comments. It adds
- runtime cpu extension detection
- fixed mmx implementation
- added sse2 yuv to rgb conversion
- added a faster vanilla implementation
::: currently it works fine on unix systems, the MSVC implementation needs
a bit of a hacking, but basically you get the concept of the refactoring.
If you have any
2004 Jun 04
4
YUV question
On Fri, 4 Jun 2004, Makc wrote:
> Here's what you can find in the net on YUV scheme:
Hmm? What prompted this?
> The statement I care to make here, is simply that there ain't neither
> such thing as "luminance", which details "the eye is more sensitive to",
"ain't neither"? Double negative, so I take your statement to mean
that there *is* such
2008 Nov 26
1
[?] About YUV format
Hello. I read documentation, but I didn't found anything about encoder
supported YUV format. Is Y in [0-255] or in [16,235]? And U,V are in
[16,239]?
I'm trying to write a fast (with lookup) conversion from RGB -> YUV...
Thanks in advance,
Andrea
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