Add support for building shared libraries with MSVC

This requires the makedef perl script by Derek, from the
c89-to-c99 repo. That scripts produces a .def file, listing
the symbols to be exported, based on the gcc version scripts
and the built object files.

To properly load non-function symbols from DLL files, the
data symbol declarations need to have the attribute
__declspec(dllimport) when building the calling code. (On mingw,
the linker can fix this up automatically, which is why it has not
been an issue so far. If this attribute is omitted, linking
actually succeeds, but reads from the table will not produce the
desired results at runtime.)

MSVC seems to manage to link DLLs (and run properly) even if
this attribute is present while building the library itself
(which normally isn't recommended) - other object files in the
same library manage to link to the symbol (with a small warning
at link time, like "warning LNK4049: locally defined symbol
_avpriv_mpa_bitrate_tab imported" - it doesn't seem to be possible
to squelch this warning), and the definition of the tables
themselves produce a warning that can be squelched ("warning C4273:
'avpriv_mpa_bitrate_tab' : inconsistent dll linkage, see previous
definition of 'avpriv_mpa_bitrate_tab').

In this setup, mingw isn't able to link object files that refer to
data symbols with __declspec(dllimport) without those symbols
actually being linked via a DLL (linking avcodec.dll ends up with
errors like "undefined reference to `__imp__avpriv_mpa_freq_tab'").
The dllimport declspec isn't needed at all in mingw, so we simply
choose not to declare it for other compilers than MSVC that requires
it. (If ICL support later requires it, the condition can be extended
later to include both of them.)

This also implies that code that is built to link to a certain
library as a DLL can't link to the same library as a static library.
Therefore, we only allow building either static or shared but not
both at the same time. (That is, static libraries as such can be,
and actually are, built - this is used for linking the test tools to
internal symbols in the libraries - but e.g. libavformat built to
link to libavcodec as a DLL cannot link statically to libavcodec.)

Also, linking to DLLs is slightly different from linking to shared
libraries on other platforms. DLLs use a thing called import
libraries, which is basically a stub library allowing the linker
to know which symbols exist in the DLL and what name the DLL will
have at runtime.

In mingw/gcc, the import library is usually named libfoo.dll.a,
which goes next to a static library named libfoo.a. This allows
gcc to pick the dynamic one, if available, from the normal -lfoo
switches, just as it does for libfoo.a vs libfoo.so on Unix. On
MSVC however, you need to literally specify the name of the import
library instead of the static library.

Signed-off-by: Martin Storsjö <martin@martin.st>
fate: add a dependency helper macro

Signed-off-by: Mans Rullgard <mans@mansr.com>
fate: dependencies for demux tests

Signed-off-by: Mans Rullgard <mans@mansr.com>
fate-als: add dependencies

Signed-off-by: Mans Rullgard <mans@mansr.com>
fate-indeo: add dependencies

Signed-off-by: Mans Rullgard <mans@mansr.com>
fate-mpc: add dependencies

Signed-off-by: Mans Rullgard <mans@mansr.com>
fate-twinvq: add dependencies

Signed-off-by: Mans Rullgard <mans@mansr.com>
fate: add dependencies for misc microsoft codecs

Signed-off-by: Mans Rullgard <mans@mansr.com>
changelog: Mention the MSVC DLL support

Also retroactively add a changelog entry to the 9beta1 list
for general MSVC support, which was present there already.

Signed-off-by: Martin Storsjö <martin@martin.st>
avformat: Fix references to the removed function av_write_header in comments

Signed-off-by: Martin Storsjö <martin@martin.st>
riff: Move functions around to be covered by appropriate #ifdefs

This fixes compilation with --disable-muxers.
fate: dependencies for screen codec tests
aac: fix build with hardcoded tables

aac_tablegen.h includes aac.h for the POW_SF2_ZERO definition, but
this also pulls in a raft of other headers, some of which are not
safe to use in code built with the host compiler.

Moving POW_SF2_ZERO to aac_tablegen_decl.h, where the declaration
of the array it relates to already resides, fixes the problems.

Signed-off-by: Mans Rullgard <mans@mansr.com>
rtp: Update the check for distinguishing between RTP and RTCP

Also add enums for more RTCP packet types, according to the IANA
list of registered types.

Signed-off-by: Martin Storsjö <martin@martin.st>
rtsp: Vertically align a constant definition

Signed-off-by: Martin Storsjö <martin@martin.st>
rtsp: Allow setting the reordering buffer size via an AVOption

Signed-off-by: Martin Storsjö <martin@martin.st>
configure: fix libcdio check

The compiler/linker flags passed to check_lib2 should not be quoted.

Signed-off-by: Mans Rullgard <mans@mansr.com>
bmv: get a new frame on every decode_frame(), so we can use direct rendering
indeo3: do not try to output more lines than we can fit

Internally chroma planes have multiple of four height while allocated image
planes might be smaller if CODEC_FLAG_EMU_EDGE is set. Thus we should not
output more lines of chroma than frame can accept.

Also the decoder can be safely switched to direct rendering now.
fate: Add proper dependencies in lossless-video.mak

The output of make fate-list is identical to before.

Signed-off-by: Martin Storsjö <martin@martin.st>