[FFmpeg-user] which filter is used to produce fake yuv image

[qw]

Hi

http://ffmpeg.org/ffmpeg-filters.html

I want to use some filter to produce one specified yuv/rgb image, and render text on that image via drawtext filter later in filter graph. Then run the filter graph, and get text_h and text_w from 'ff_vf_drawtext'. which filter is used to produce fake yuv/rgb image in ffmpeg?

Is there some efficient way to get the values of text_h and text_w?

Thanks!

B.R.

Andrew