img2dec: seeking support

Signed-off-by: Paul B Mahol <onemda@gmail.com>
img2dec: do not change packet pts for image2pipe

Signed-off-by: Paul B Mahol <onemda@gmail.com>
fate: upate after 55d32eed8f

Signed-off-by: Paul B Mahol <onemda@gmail.com>
Fix compilation with --disable-everything --enable-decoder=dirac.
img2dec: fix -loop

This fixes a infinite loop with -loop and -vframes

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
swr: fix assertion failure if dither is used without the preout buffer differing from in

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
ffmpeg: fix dither to 24bit PCM output

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