Fix the mime types for MPEG and MPEG-TS formats

As per the RFCs:
http://tools.ietf.org/html/rfc3555#page-38
http://tools.ietf.org/html/rfc3003
x86/dsputil: port ff_vector_clipf_sse to yasm

Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/movenc: Check that packet duration is valid in ff_mov_write_packet()

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/utils: Check end time in avpriv_new_chapter()

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/mov: Dont blindly trust the stream duration in seting chapter times

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