[Libav-user] Saving frame to file

[Gonzalo Garramuno]

On 03/05/14 17:21, Jorge Lúcio wrote:

> The output could be BMP or PNG. I've tried to write my own function, 
> but so far the best I could do was to write a black and white version 
> of the frame. It's hard to figure out how the image data is stored on 
> the "data" field inside the AVFrame.

There isn't a function to do what you want, albeit you can use the 
ffmpeg utility to do the conversion for you.
The data is stored as specified in AVCodecContext->pix_fmt.  In 
principle this means some form of YUV (YUV422 or YUV444 usually). Your 
white image is probably the first luminance channel you extract from the 
file (Y).