Crash encoding mpeg2 with the number of consecutive b-frames set to zero

[eumagga0x2a]

At the very end of an encoding process using the Mpeg2 (ff) encoder, probably at postEncode, Avidemux crashes hard if B-frames were disabled. The saved video is playable and seems to be complete.

[eumagga0x2a]

Crash fixed by [ffEncoder] make sure we have something to pop out before popping it out, thanks! Will later look into apparently each mpeg2 encoding ending with

Code Select Expand

Application provided invalid, non monotonically increasing dts to muxer in stream

error from libavformat/mux.c:642 at least when using the Mpeg PS container.

[eumagga0x2a]

The remaining issue was fixed by Mean while I was still sleeping 

[lav/encoder] bail if the encoded frame queue is empty

Thanks!