Displaying 20 results from an estimated 259 matches for "yuv".
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2006 Aug 20
1
Simple RGB->YUV Stuff...
...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...
2007 May 25
2
Cleaning app
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.
2008 Oct 07
3
Theora on iPhone
...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...
2002 Aug 05
3
Cross-Compiling VP3 lib on Linux
...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...
2008 Jan 15
0
Re: YUV to RGB
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...
2008 Feb 25
3
More examples?
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...
2004 Jun 04
4
YUV question
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...
2005 Feb 09
2
Converting RGB YUV and back
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)
2008 Feb 16
3
Gray scale video output from theora
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...
2005 Nov 03
0
all2theora script
...";
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 -...
2012 Apr 18
2
png2theora.c + QImage
...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...
2008 Nov 26
1
[?] About YUV format
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
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2004 Dec 03
3
trying to encode from dvd using mplayer
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...
2005 Nov 08
3
OggYUV
...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
>...
2010 Mar 17
3
encoding raw file (.yuv) using ffmpeg2theora
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...
2008 Jan 15
2
Encoding with encoder_example
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
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2008 Jan 15
2
Encoding with encoder_example
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
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2005 Oct 05
1
Simple encodig sample...
...= 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...
2007 Nov 20
5
yuv - rgb conversion without contrast decrease.
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,...
2005 Jun 30
5
will there be theora_decode_RGBout() ?
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