avfilter: add w/h parameters in timeline

Fixes Ticket #4008.
ffprobe: add -show_pixel_formats option

Adds option -show_pixel_formats to ffprobe which lists all
available pixel formats with some details.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
ffprobe: add pixel format flags output

Adds output of pixel format flags to ffprobe -show_pixel_formats option.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
ffprobe: add pixel format component bit depth output

Adds output of bit depth per pixel format component to
ffprobe -show_pixel_formats option.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
ffprobe: add pixel format chroma sub-sampling output

Adds output of chroma sub-sampling information to
ffprobe -show_pixel_formats option.

Note: This patch just prints the "raw" log2_charoma_w/h values instead
of the previously suggested mapping into a chroma sub-sampling pattern
string like "4:2:2".

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>