Extracting frames from *.YUV

[ahmeddrira]

HI
Im newbies here sorry for my bad english
i am preparing a projet about acceleration of the vidéo codec of H264 , I need some help
I have to know how the YUV vidéo file is structured and how can i extract frame from this file
I must read a header and extract some information then brows the file frame by frame .
so how can i do that ?
what information i find in the header ?
what carater i found when browsing the file represent a start of frame and the end ?
...
please help me .
i use C++ for developping
THANKS.

[LoRd_MuldeR]

It's raw YUV data. There's no header.

That's why you must pass the resolution, the framerate and the framecount manually to x264 when working with *.yuv files...

[ahmeddrira]

sorry i don't anderstand you
my codec source have as input a *.yuv file

[LoRd_MuldeR]

sorry i don't anderstand you
my codec source have as input a *.yuv file

And, as I already told you, these files contain raw YUV data. There's no "header" in such files!

[neuron2]

Also, there is no delimiter character or string between frames. You know the frame boundaries only by knowing how many samples are there for each frame.

[Dust Signs]

Hi,

all the images in the byte stream are followed by one another with no delimiter in between.
Maybe the following image helps you understanding the structure of one picture (planar YUV 4:2:0): http://upload.wikimedia.org/wikipedia/en/0/0d/Yuv420.svg

Dust Signs

[ahmeddrira]

thanks a lot i andrestand many think but can is their a document or a thread to read it and andrestand more .

[LoRd_MuldeR]

thanks a lot i andrestand many think but can is their a document or a thread to read it and andrestand more .

You won't find many doc's about *.yuv files, as it's simply "raw" data dumped to a binary file.

There's no file format specifications for that. If at all, you should try to understand how "YUV 4:2:0" (aka "YV12") data is organized.

The image posted by Dust Signs may be helpful...

[roozhou]

The only thing you need to know is the resolution (assuming AxB, both must be even).
The size of each frame is A*B*1.5 Bytes. The nth frame locates at n*A*B*1.5 bytes.

[Sagekilla]

I think that applies when you're using a zeroed index. Otherwise, that would mean your 1st frame (for say, 320x240) starts at 115200 bytes. More accurately, that would be the first byte of the 2nd frame.

[ahmeddrira]

thanks a lot for your help . :)

[Sagekilla]

Just play around a bit and check before hand. I'm fairly certain from bytes [0, (width*height*1.5) - 1] is your "first frame," since there is nothing but video data in yuv.