Fix FSF address in colormatrix and libzvbi license headers.

As reported by irc user aca.
The files in compat/avisynth are maintained elsewhere, no changes.
SDR2 demuxer

Signed-off-by: Paul B Mahol <onemda@gmail.com>
avformat/utils: factorize h264/hevc checks out in compute_pkt_fields()

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/utils: reset pts_buffer in estimate_timings_from_pts()

This fixes the first few dts after find_stream_info

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/utils: compute_pkt_fields: Fix DTS for the case where has_b_frames is too large but the correct one is constant

Fixes issue1.m2ts

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