similar to: YUV Format

I've spent the weekend or so trying to get my head around Theora and I'm just not having any luck. First of all, I really don't have any interest in immersing myself in video encoding--I just have one simple thing I'd like to do--so I haven't spent any time reading about the theory or specs or anything like that. I'm attempting to write a "render-to-theora"

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);

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

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

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

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

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

On Wed, Nov 09, 2005 at 10:52:53AM +0800, illiminable wrote: > > "fourcc" 's of rgb types > http://www.fourcc.org/rgb.php I'm prowd to say that http://wiki.xiph.org/OggRGB supports all of these losslessly as well as PNG for non-indexed bitmaps. These are video formats, correct? Not just single frames? > raw yuv formats only > http://www.fourcc.org/yuv.php

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 -------------- next part -------------- An HTML attachment was scrubbed... URL:

> If you want to limit the allowable values for the FourCC field, I don't have > an issue with that, but I think it's useful for decoders to be able to tell > easily whether or not they support the format (since most decoders will > operate on the well defined formats) and useful for encoders, since most data > sources are described by a fourcc (the exception being

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.

This also includes, other non raw formats... http://www.fourcc.org/codecs.php "fourcc" 's of rgb types http://www.fourcc.org/rgb.php raw yuv formats only http://www.fourcc.org/yuv.php Registered fourcc codecs http://www.microsoft.com/whdc/archive/fourcc.mspx Enumeration of actual types that are used in directshow (bottom of page)

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)

Hello! I'm trying to use ffmpeg2theora to encode raw (.yuv) files in I420 format (just frames, no headers at all), but failed to find corresponding input format. Is there any documentation of supported formats for ffmpeg2theora? Or maybe there is another command-line tool for Windows to encode raw video using Theora algorithm? Thank you for help! Alexander.

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

Hello. I'm a theora newbie... I see it accept video frames in some differents YUV formats. How theora manage them internally? I mean: if i encode the same video twice, first time encoding it with YUV444 packets and then with YUV420, will second video be smaller than first (due to subsampling...)? Or theora compress them in the same way? Thanks in advance, A. F.

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

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

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The attached patch splits Theora decode and YUV2RGB into separate threads. These are by far the two most computationally demanding components of Cortado, so by splitting them we can substantially improve performance on multiprocessor machines. I have verified that the patch does split these into two threads, and performance does appear to improve.

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