similar to: [?] About 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"

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)

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

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'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 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

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

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.

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

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

I posted a while back "complaining" about lack of a theora player on the iPhone. Porting the code for libtheora (and libogg/libvorbis) was (relatively) painless, and appears to be working. I'm up against a tougher challenge now... rendering the video! I tried using the brand-new SOC-funded SDL port to iphone to get the "player_example.c" code up and running, but ran into

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 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

I am attempting to migrate a Slackware server with Samba 4.12.3 from an NT style domain to AD. I have done this about 7-8 times on other servers in the past following the instructions on Samba's wiki. This time however, the upgrade process is failing completely to import any users or groups from the NT domain. I have enclosed below the output of the classicupgrade command - I can't

Hello. I'm trying to encode an Ogg Theora file from an unencrypted dvd using mplayer and encoder_example. I set up named pipes stream.wav and stream.yuv. I then run: mplayer -ao pcm -aofile stream.wav -vo null /dev/dvd & mplayer -vo yuv4mpeg -ao null -nosound /dev/dvd & encoder_example -v1 -a 1 stream.wav stream.yuv > lec1.ogg but I get the following error: File stream.wav is

> > FourCC is a codec identifier, nothing more. It's four letters which can > be > referenced against a table to see what codec it is, it's a standard used > by RIFF > (aka, wav and avi) and older Macintosh formats, and in my opinion, its > obsolete. > While it's true there are a bunch of FOURCC's that represent non-raw formats like DIVX etc, the ones

On Wed, Jan 15, 2025 at 02:34:26PM +0000, Daniel Stone wrote: > On Wed, 15 Jan 2025 at 14:20, Tomi Valkeinen wrote: > > No disagreement there, we need CREATE_DUMB2. > > > > My point is that we have the current UAPI, and we have userspace using > > it, but we don't have clear rules what the ioctl does with specific > > parameters, and we don't document how

Hi, I decided to try Theora and encoded a PAL DVD. I was very pleased with the result. It's better than "DiVX" for the same bitrate, I think, and the audio is clearly superior to MP3 audio. However, I'm having serious troubles encoding NTSC DVDs and getting the video and audio durations to match. I read some messages on this list about such problems and so what I am doing

On Thu, Jan 16, 2025 at 10:43:40AM +0200, Laurent Pinchart wrote: > On Wed, Jan 15, 2025 at 02:34:26PM +0000, Daniel Stone wrote: > > On Wed, 15 Jan 2025 at 14:20, Tomi Valkeinen wrote: > > > No disagreement there, we need CREATE_DUMB2. > > > > > > My point is that we have the current UAPI, and we have userspace using > > > it, but we don't have