It does not make much sense to me, but GCC somehow optimises the
inline assembler even though the output is very obviously used and
having observable side effects.
This reverts commit 09731fbfc3.
So far, AV_READ_TIME would return the cycle counter. This posed two
problems:
1) On recent systems, it would just raise an illegal instruction
exception. Indeed RDCYCLE is blocked in user space to ward off some
side channel attacks. In particular, this would cause the random
number generator to crash.
2) It does not match the x86 behaviour and the apparent original intent
of AV_READ_TIME in the functional code base (outside test cases).
So this replaces the cycle counter with the time counter. The unit is
a platform-dependent constant fraction of time, and the value should be
stable across harts (RISC-V lingo for physical CPU thread).
This uses the architected RISC-V 64-bit cycle counter from the
RISC-V unprivileged instruction set.
In 64-bit and 128-bit, this is a straightforward CSR read.
In 32-bit mode, the 64-bit value is exposed as two CSRs, which
cannot be read atomically, so a loop is necessary to detect and fix up
the race condition where the bottom half wraps exactly between the two
reads.
This reduces the number of false dependencies on header files and
speeds up compilation.
Originally committed as revision 22407 to svn://svn.ffmpeg.org/ffmpeg/trunk
Otherwise doxygen complains about ambiguous filenames when files exist
under the same name in different subdirectories.
Originally committed as revision 16912 to svn://svn.ffmpeg.org/ffmpeg/trunk
Consistently apply this rule: the guard name is obtained from the
filename by stripping the leading "lib", converting '/' and '.' to
'_' and uppercasing the resulting name. Guard names in the root
directory have to be prefixed by "FFMPEG_".
Originally committed as revision 15120 to svn://svn.ffmpeg.org/ffmpeg/trunk
while playing with some new hardware, I found it's running a forked mplayer
-- and it looks like they're following the GPL.
The maintainer's page is here: http://atty.jp/?Zaurus/mplayer
Unfortunately it's mostly in Japanese, so it's hard to figure out any
details.
Their code looks quite interesting (at least to those of us w/ ARM CPUs).
The patches I've attached are the patches from atty.jp with a couple of
modifications by myself:
- ported to current CVS
- reverted their change of removing SNOW support from ffmpeg
- cleaned up their bswap mess
- removed DOS-style linebreaks from various files
patch by (Bernhard Rosenkraenzer: bero, arklinux org)
Originally committed as revision 4311 to svn://svn.ffmpeg.org/ffmpeg/trunk
Rémi Denis-Courmont
Mans Rullgard
Diego Biurrun
Stefano Sabatini
Aurelien Jacobs
Luca Barbato
Michael Niedermayer
Bernhard Rosenkränzer
Zdenek Kabelac
Fabrice Bellard