lavfi/mp: remove mp=dint

There are better and actually maintained filters that have similar
functionality.

Signed-off-by: Paul B Mahol <onemda@gmail.com>
lavfi/mp: remove mp=fil

The filter does not work correctly most of time.

Signed-off-by: Paul B Mahol <onemda@gmail.com>
avcodec/dsputil: add 12bit simple idct

Will be needed for jpeg

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/mjpegdec fix last_dc for bits != 8

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/mjpegdec: Fix normal jpeg with bits < 8

Untested due to lack of testcase

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/mjpegdec: 12bit Grayscale support

Fixes part of Ticket2812

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