similar to: YUV question

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"

grDevices::convertColor has arguments 'from' and 'to' which can take on value 'XYZ'. Can someone confirm that 'XYZ' is the same as the CIE chromaticity coordinates that are also sometimes refered to as 'xyY' in the literature? Or are these the CIE tristimulus values? It looks to me like the first case is true, but I would appreciate hearing from one of

Hello, I want to make a program to extract frame from a theora movie as images. I tried with the decoding example located at theora web site (dump_video.c. I use it to extract a frame as yuv image but when I try to convert it to ppm with yuvtoppm program i obtain a strange image ( see http://poux.be/tmp/file.ppm ). I think it's a problem with the byte order for yuv, but don't I don't

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.

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. 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:

Dear r-helpers, I wonder whether, given the "#rrggbb" representation of a colour, there is a simple way to select the complementary colour, also expressed as a "#rrggbb" string. Any suggestions would be appreciated. John -------------------------------- John Fox, Professor Department of Sociology McMaster University Hamilton, Ontario Canada L8S 4M4 905-525-9140x23604

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

Hi, I guess this is a good time to start putting together a wish list for a video codec. I see that for audio the compression is around 10X for reasonable quality. I am sure this will start its own thread of conversation. For video you can do 40X fairly easily and the big task is to go to 80X or 100X with reasonable picture quality, say, a peak luma SNR of more than 30 dB. Uncompressed

Hello, I've got strange problem with centos (as well as rhel btw) chrooted environment. First of all I created simple directory with only the libs for 'bash' and 'id' tools: ---- # chroot testcase/ bash-3.1# id uid=0 gid=0 groups=0,1,2,3,4,6,10 ---- Yes, I even do not have /etc/ directory inside testcase/ , but id shows groups from the _host_ root account. I tried to

This is sort of working -- but I can't get it to do a 4k output. Not sure how the monitor resolution is detected - This monitor is supposed to do 3480x1200 60hz 4:4:4 But the info I get from hwinfo is different. How does nouveau get this information? If it is from an ID - with a list - the list is probably is wrong. # hwinfo --monitor 95: None 00.1: 10002 LCD Monitor [Created at

Has anyone plotted or is it possible to plot CIE *xy* chromaticity diagram http://en.wikipedia.org/wiki/File:CIE1931xy_blank.svg I need this plot in color. ishida [[alternative HTML version deleted]]

Hey, So I have a scatter plot and I am trying to plot a curve to fit the data based on a Holling Type III functional response. My function is this: nll2<-function(a,b) { conefun<-(a*DBH^2)/(b^2+DBH^2) nlls2<-dnbinom(x=cones ,size=DBH, mu=conefun,log=TRUE) -sum(nlls) } and my plot is this: plot (DBH,cones) DBH is on the x-axis and cones is on the y-axis. How do I get the curve

hello, all. i am trying something new and am stuck. i typically go with whatever colors the pie function pops out, but i would like to customize it. please find below a sample dataset. ##TVs per household. TVs <- factor(c(rep("0", 1), rep("1", 16), rep("2", 14), rep("3", 12), rep("4", 3), rep("5", 2), rep("6", 2)))

A rather distressing timestamp issue (to multiple users here). Anyone seen similar behavior or have a suggestion/solution? Problem: Opening and closing an excel file (no changes/keystrokes to file) on the Samba server causes the file to be saved with time stamp of closing. (There is no autosave set on Excel - also see other info below) MS Excel 97 SR-2 NT 4.0 SP5 Solaris 2.6 or 2.7 (2

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

Dear R-users: The following code produces two cones in two panels. What I would like to have is to have them in one, and to meet in the origin. Does anyone have any good ideas how to do this? Thanks for your help Jaakko library(lattice) A<-matrix(ncol=2, nrow=64) for(i in 0:63) { A[i+1,1]<-sin(i/10) A[i+1,2]<-cos(i/10) }

Hi all, I'm trying to generate barplots from simple but long (~100000-row) data files, in which each bar will comprise two stacked 'sub-bars'. All the upper sub-bars will have the same hue, and all the lower bars will, likewise, have another uniform hue. However, I wish to specify the luminance (aka brightness) of each bar (i.e., each whole bar comprising two sub-bars) separately,

I'm working with the following code below to generate a how do I set the h,c, and l values such that the significant, positive residuals appear different on a grayscale printer from significant grayscale residuals. The challenge as I see it is that one can only distinguish the positive and negative residuals with the hue/. Varying the chroma and the luminance only affect the