avformat/wavdec: Dont trust the fact chunk for PCM

Fixes Ticket3033

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 83fc6c822b06688e572333299927d93eb3c6c426)

Conflicts:
	libavformat/wav.c
(cherry picked from commit 89b5f5f494a2387541de8960839c2539a73a31fa)
avcodec/h264_refs: modify key frame detection heuristic to detect more cases

Fixes Ticket2968

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 5ac6b6028f17b64723884c9fa72cfcbd369a1ba2)

Conflicts:
	libavcodec/h264_refs.c
(cherry picked from commit 6636dd551fda4fac77f2caa25d24d81abcadcd71)
avformat/mov: force parsing of headers if stts is absent

Fixes Ticket2991

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit e41ea866fc26f38d770bbc1ad67703e7f4400ae1)
avcodec/h264: reduce noisiness of "mmco: unref short failure"

Do not consider it an error if we have no frames and should discard one.
This condition can easily happen when decoding is started from an I frame

Fixes Ticket2811

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 08a89761964bdd0a023eff6d37a1131fb7e1d7a0)

Conflicts:
	libavcodec/h264_refs.c