similar to: problems understanding yuv_buffer format

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.

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

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 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

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.

Here's a shot at a list of fields: // High level data Displayed Width&Height Stored Width&Height Aspect Ratio (Fractional) Frame Rate (Fractional) FourCC (Optional, set to zero to use values below) Colorspace (enum, R'G'B', Y'CbCr, JPEG (not sure proper name), etc) // Subsampling data U Channel X Sample Rate (Fractional) U Channel Y Sample Rate (Fractional) U Channel

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

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

> > 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

Hello all. I've been playing around with theora since it first entered CVS, and I like what I'm seeing. Today I've been fixing xine's theoraplugin to understand theora_info.frame_{width,height} and theora_info.offset_{x,y}. I only got it working after some experimenting and basically copying the code from player_example. A few questions related to this: 1. What are the legal

Hi, I'd like to add user-allocated frame memory to theora via a theora_user_yuv_out callback. An additional helper function (theora_user_buffer_is_freeable) would also be required. With these two functions, user applications could submit memory buffers directly to libtheora, which would reduce the number of frame copies in a typical application from two per frame to one per frame. I've

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

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

I've got my encoder working now... and i put a proeprty page interface to allow the user to set a few encoding paramters to start off with... but changing the paramters doesn't seem to make barely any difference... These are the defaults i'm using... mTheoraInfo.target_bitrate=400000; mTheoraInfo.quality=30; mTheoraInfo.dropframes_p=0; mTheoraInfo.quick_p=1;

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);

On Tue, 17 Dec 2019 at 10:45, James Jones <jajones at nvidia.com> wrote: > > Make sure framebuffer dimensions and tiling > parameters will not result in accesses beyond the > end of the GEM buffer they are bound to. > > Signed-off-by: James Jones <jajones at nvidia.com> > --- > drivers/gpu/drm/nouveau/nouveau_display.c | 93 +++++++++++++++++++++++ > 1 file

Updated version of video preview covering frame writing every 3 keyframe and a xsl typo. Best regards :) kysucix -- Make things as simple as possible, but no simpler. - Albert Einstein

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

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

Hi. Here it is my patch to put a video preview of a theora stream in status.xsl. I just added a: <video-preview>1</video-preview> parameters in icecast.xml.in that control the previewing function. It encodes a png in $webroot/$mountname.tmp and then move it to $webroot/$mountname.png As for now it saves a frame every theora keyframe, which is probably too heavy for the server but