On Fri, Dec 16, 2011 at 08:22:20PM +0000, Mans Rullgard wrote: > The A32 bitstream reader variant is only used on ARMv5 and for > Prores due to the larger bit cache this decoder requires. > > In benchmarks on ARMv5 (Marvell Sheeva) with gcc 4.6, the only > statistically significant difference between ALT and A32 is > a 4% advantage for ALT in FLAC decoding. There is thus no (longer) > any reason to keep the A32 reader from this point of view. > > This patch adds an option to the ALT reader increasing the bit > cache to 32 bits as required by the Prores decoder. Benchmarking > shows no significant change in speed on Intel i7. Again, the > A32 reader fails to justify its existence. > > Signed-off-by: Mans Rullgard <[email protected]> > > --- a/libavcodec/get_bits.h > +++ b/libavcodec/get_bits.h > @@ -122,8 +102,11 @@ LAST_SKIP_BITS(name, gb, num) > > -#ifdef ALT_BITSTREAM_READER > +#ifdef LONG_BITSTREAM_READER > +# define MIN_CACHE_BITS 32 > +#else > # define MIN_CACHE_BITS 25 > +#endif
Some decoders have #define ALT_BITSTREAM_READER before header #includes, I assume these should be deleted now. Diego _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
