This is a short compilation of ffmpeg/mplayer compilation pitfalls: libx264: If compilation fails with an error about the numbers of parameters in common/cpu.c you need to check which glibc version is used. Remove the second parameter to sched_getaffinity() if necessary and recompile. ffmpeg+x264 ffmpeg configure fails with: 
ERROR: libx264 not found
If you think configure made a mistake, make sure you are using the latest
version from SVN.  If the latest version fails, report the problem to the
[email protected] mailing list or IRC #ffmpeg on irc.freenode.net.
Include the log file "config.err" produced by configure as this will help
solving the problem.
This can be caused by two effects:
  • Unintended library is used for linking. Check wether you have different ones installed. Avoid this and uninstall them if possible. If necessary use LD_LIBRARY_PATH or --extra-ldflags to change the search order.
  • Incompatible combination of ffmpeg and libx264. Older libx264 provide a method x264_encoder_open which older ffmpeg versions do check for. More recent libx264 add a version number to the method name. Now when you compile a new libx264 against an older ffmpeg the libx264 detection that relies on the symbol name fails. As a workaround you could hack the configure script to check for "x264_encoder_open_78" instead of "x264_encoder_open" (given that 78 is the libx264 version you use).
ffmpeg+x264 ffmpeg compilation fails on AMD64 with: 
libavcodec/svq3.c: In function 'svq3_decode_slice_header':
libavcodec/svq3.c:721: warning: cast discards qualifiers from pointer target type
libavcodec/svq3.c:724: warning: cast discards qualifiers from pointer target type
libavcodec/svq3.c: In function 'svq3_decode_init':
libavcodec/svq3.c:870: warning: dereferencing type-punned pointer will break strict-aliasing rules
/tmp/ccSySbTo.s: Assembler messages:
/tmp/ccSySbTo.s:10644: Error: suffix or operands invalid for `add'
/tmp/ccSySbTo.s:10656: Error: suffix or operands invalid for `add'
/tmp/ccSySbTo.s:12294: Error: suffix or operands invalid for `add'
/tmp/ccSySbTo.s:12306: Error: suffix or operands invalid for `add'
make: *** [libavcodec/h264.o] Error 1
This post explains that this is related to a glibc issue and how to patch it. ffmpeg+x264 ffmpeg compilation fails with: 
libavcodec/libx264.c: In function 'encode_nals':
libavcodec/libx264.c:60: warning: implicit declaration of function 'x264_nal_encode'
libavcodec/libx264.c: In function 'X264_init':
libavcodec/libx264.c:169: error: 'x264_param_t' has no member named 'b_bframe_pyramid'
make: *** [libavcodec/libx264.o] Error 1
This means you are using incompatible ffmpeg and libx264 versions. Try to upgrade ffmpeg or to downgrade libx264. ffmpeg+video4linux 
/usr/include/linux/videodev.h:55: error: syntax error before "ulong"
/usr/include/linux/videodev.h:71: error: syntax error before '}' token
Workaround: 
--- configure.ac.080605 2005-06-08 21:56:04.000000000 +1200
+++ configure.ac        2005-06-08 21:56:42.000000000 +1200
@@ -1226,6 +1226,7 @@
 AC_CHECK_HEADERS(linux/videodev.h,,,
 [#ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
+#include <sys/types.h>
 #endif
 #ifdef HAVE_ASM_TYPES_H
 #include <asm/types.h>
http://www.winehq.org/pipermail/wine-devel/2005-June/037400.html oder Workaround: --disable-demuxer=v4l --disable-muxer=v4l --disable-demuxer=v4l2 --disable-muxer=v4l2 ffmpeg+old make 
make: *** No rule to make target `libavdevice/libavdevice.so', needed by `all'.  Stop.
Problem: GNU make is too old, you need at least v3.81 http://www.mail-archive.com/[email protected]/msg01284.html 
make: *** No rule to make target `install-libs', needed by `install'.  Stop.
Problem: GNU make is too old, you need at least v3.81 http://ffmpeg.arrozcru.org/forum/viewtopic.php?f=1&t=833 Mplayer+old make 
make: expand.c:489: allocated_variable_append: Assertion `current_variable_set_list->next != 0' failed.
Problem: GNU make is too old, you need at least v3.81 MPlayer 
i386/dsputil_mmx.o i386/dsputil_mmx.c
i386/dsputil_mmx.c: In function `transpose4x4':
i386/dsputil_mmx.c:621: error: can't find a register in class `GENERAL_REGS' while reloading `asm'
Workaround: Add the following to your configure call --extra-cflags="-O3 -fomit-frame-pointer" Note: if this somehow helped you and you know something to be added feel free to post a comment!