vmnc: make code independent of sizeof(AVFrame)

Signed-off-by: Paul B Mahol <onemda@gmail.com>
vmnc: check return values of reallocation

Also avoid memory leaks.

Signed-off-by: Paul B Mahol <onemda@gmail.com>
yop: check return value of av_frame_alloc()

Signed-off-by: Paul B Mahol <onemda@gmail.com>
pcxenc: get rid of unused PCXContext

Signed-off-by: Paul B Mahol <onemda@gmail.com>
lavfi/gradfun: remove nv21/nv12 as they are not supported

Signed-off-by: Paul B Mahol <onemda@gmail.com>
avdevice/x11grab: use AV_OPT_TYPE_VIDEO_RATE

Signed-off-by: Paul B Mahol <onemda@gmail.com>
avdevice/fbdev: use AV_OPT_TYPE_VIDEO_RATE

Signed-off-by: Paul B Mahol <onemda@gmail.com>
lavfi/frei0r: use AV_OPT_TYPE_VIDEO_RATE

Signed-off-by: Paul B Mahol <onemda@gmail.com>
lavfi/frei0r: use AV_OPT_TYPE_IMAGE_SIZE

Signed-off-by: Paul B Mahol <onemda@gmail.com>
sgienc: remove unused SgiContext

Signed-off-by: Paul B Mahol <onemda@gmail.com>
qcelpdec: change asserts to av_asserts

Signed-off-by: Paul B Mahol <onemda@gmail.com>