search for: yuv

...ing--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" target for OpenGL. Basically, I have access to a buffer of RGBA data that I want to convert into YUV and pass to Theora to encode for me. There are lots of different ways to do the per-pixel conversion from RGB to YUV that I've found online; I think I have this part down fairly well. Eventually, what I end up with are three buffers, each one as large as the other and containing the from-RGB-t...

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.

...gainst 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 a major roadblock: The SDL port to iphone uses an opengl-es driver and opengl drivers for SDL don't support YUV overlay's! So the problem (at least for now) is how I can get the YUV encoded frames from a theora movie rendered on the iPhone? The options I've considered are: a) convert from YUV to RGB in code (this probably won't work for realtime decoding) b) convert from YUV to RGB using pixel...

...ultimedia player for Linux that I help develop: http://xine.sf.net) The plugin appeared to work all right in that it did not crash. The picture is a bit scrambled. It looks like too many pixels (or not enough pixels) are being copied from the source planes. I'm using the ThisFrameRecon YUV buffer pointer member of the PBI struct as the final display frame. I'm using the [Y|U|V]DataOffset members in order to index into the buffer. Is that the right thing to do? Thanks... -- -Mike Melanson <p><p><p>--- >8 ---- List archives: http://www.xiph.org/arc...

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 playi...

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 know anything about this format. I'd like to make a simple program to encode chosen f...

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...

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)

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...

..."; print "--help show this text\n"; print " this will only be possible if you are root\n"; print "--i Specify the Name of your Video file\n"; exit; } if ($divx eq "on") { system ("mkfifo stream.yuv && chmod 777 stream.yuv && mencoder $input -ovc lavc -oac copy -o tmp.avi -lavcopts vcodec=mpeg1video:vbitrate=1200 -vf harddup -of mpeg && mplayer -vc dummy -vo null -ao pcm:file=stream.wav tmp.avi && encoder_example stream.wav stream.yuv > theora.ogg | mplayer -...

...e instead of a png array. This is my base file: http://www.maefloresta.com/tmp/example.cpp The point where I am stuck starts at this comment: // LOOK HERE (line 313) And here is the issue: QImage supports RGB images, so my first task is to transform the content of the QImage variable from RGB to YUV. Here is the code I already use to do the trick with a ffmpeg API and it works: http://www.maefloresta.com/tmp/rgb2yuv.txt The function prototype is this: void RGBtoYUV420P(const uint8_t *bufferRGB, uint8_t *yuv, uint iRGBIncrement, bool bSwapRGB, int width, int height) Now, to write a theora fr...

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: http://lists.xiph.org/pipermail/theora/attachment...

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 16 bit 2 channel 48000 Hz RIFF WAV audio. File stream.yuv...

...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 which represent raw YUV types are pretty well defined. Yes you certainly still need the width, height, aspect ratio and frame rate. > > This is also interesting work in that, once we're done, we'll have a > standard to > use for a compressed lossless format.. a FLAC for video, for editing or >...

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! Al...

I have encoded successfully a YUV stream by using the encoder_example. Can We encode a row stream (get from a web cam) by using encoder_example. If we can not, is there any other way to encode a row stream by using theora codec. -- Nuwan Millawitiya -------------- next part -------------- An HTML attachment was scrubbed... URL: ht...

I have encoded successfully a YUV stream by using the encoder_example. Can We encode a row stream (get from a web cam) by using encoder_example. If we can not, is there any other way to encode a row stream by using theora codec. -- Nuwan Millawitiya -------------- next part -------------- An HTML attachment was scrubbed... URL: ht...

...= 0; int frame_x = 352; int frame_y = 288; int frame_x_offset = 0; int frame_y_offset = 0; int video_hzn = 25; int video_hzd = 1; int video_an = 1; int video_ad = 1; int video_r = 320000; int video_q = 16; int frame_counter = 250; signed char *yuvframe; int fetch_video_page( ogg_page *videopage, ogg_stream_state *to, theora_state *td ) { yuv_buffer yuv; ogg_packet op; yuv.y_width = video_x; yuv.y_height = video_y; yuv.y_stride = video_x; yuv.uv_width = video_x / 2; yuv.uv_height = video_y / 2; yuv.uv_s...

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,...

hi folks! i would like to know whether there will be some function to decode to some plain 24 bit RGB buffer in the future. i think this feature is sometimes important, especially when using different surface layers, or when modifying the buffer in realtime. if this feature will definitely not be, could someone tell me how i can convert to some RGB buffer in realtime? i already tried different