dashenc: degrade gracefully if a stream's bitrate is unavailable

If a stream's bitrate is not set, this attempts to use its rc_max_rate;
if neither is set, it avoids writing a bandwidth attribute at all.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/mpegtsenc: change the min value for mpegts_start_pid to allow ATSC PIDs

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
ffmpeg: fix variable type for end char

fixes warning

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
ffmpeg: better CFR frame duplication selection

This improves the handling of cases where the frame duration is not known

Fixes Ticket 4119
Fixes Ticket 1578

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