libavformat: Check mkdir return error codes

Previously, the returned error codes were intentionally ignored
(see fadd3a68213), to avoid aborting if the directory already
existed. If the mkdir actually failed, this was caught when
opening files within the directory fails anyway.

By handling the error code here (but explicitly ignoring EEXIST),
the error messages and return codes in these cases are more
appropriate and less confusing.

Signed-off-by: Martin Storsjö <martin@martin.st>
ismindex: Avoid writing ismf files if no base name has been specified

Previously, this could create files named "(null).ismf", if the -ismf
parameter is specified (before an input file name), but without
specifying any base name.

Signed-off-by: Martin Storsjö <martin@martin.st>
Split off floating point AAN (I)DCT into separate components
Merge commit '803e82276b3716bf6012ec69e8854dae14a4fd2b'

* commit '803e82276b3716bf6012ec69e8854dae14a4fd2b':
  libavformat: Check mkdir return error codes

Conflicts:
	libavformat/hdsenc.c
	libavformat/smoothstreamingenc.c

See: c89f8f80cc83622471eaf99e451e78df68475e19
See: a3886ea3c5947ca05bfe01b053d9ce2f9725d9eb
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'fcf597625c7a991ca389f3a9b8ff4f5e383301c0'

* commit 'fcf597625c7a991ca389f3a9b8ff4f5e383301c0':
  ismindex: Avoid writing ismf files if no base name has been specified

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '1274ea8dbaec44355bde07f6bb31fec0c4e6fd2d'

* commit '1274ea8dbaec44355bde07f6bb31fec0c4e6fd2d':
  Split off floating point AAN (I)DCT into separate components

Conflicts:
	configure
	libavcodec/Makefile
	libavcodec/dct-test.c
	libavcodec/idctdsp.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
avformat/utils: Exclude the header size when computing duration from bit_rate

This improves the estimate for MP3s with cover art tags.

Fixes Ticket2931

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