dsputil: remove deprecated dsp_mask usage

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
lavu/frame: copy all frame properties in av_frame_copy_props

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
lavu/frame: av_frame_make_writable: set the channels on the new frame.

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