diff --git a/doc/APIchanges b/doc/APIchanges index 8c7d279fec..be34c92d3f 100644 --- a/doc/APIchanges +++ b/doc/APIchanges @@ -13,6 +13,9 @@ libavutil: 2015-08-28 API changes, most recent first: +2017-02-xx - xxxxxxx - lavu 55.31.0 - cpu.h + Add av_cpu_max_align() for querying maximum required data alignment. + 2016-xx-xx - xxxxxxx - lavf 57.11.0 - avio.h Add avio_context_free(). From now on it must be used for freeing AVIOContext. diff --git a/libavutil/cpu.c b/libavutil/cpu.c index 0109c9e8d1..5aef6af217 100644 --- a/libavutil/cpu.c +++ b/libavutil/cpu.c @@ -16,6 +16,7 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ +#include #include #include @@ -180,3 +181,15 @@ int av_cpu_count(void) return nb_cpus; } + +size_t av_cpu_max_align(void) +{ + int flags = av_get_cpu_flags(); + + if (flags & AV_CPU_FLAG_AVX) + return 32; + if (flags & (AV_CPU_FLAG_ALTIVEC | AV_CPU_FLAG_SSE | AV_CPU_FLAG_NEON)) + return 16; + + return 8; +} diff --git a/libavutil/cpu.h b/libavutil/cpu.h index c205ee16f6..4dcde27dbe 100644 --- a/libavutil/cpu.h +++ b/libavutil/cpu.h @@ -21,6 +21,8 @@ #ifndef AVUTIL_CPU_H #define AVUTIL_CPU_H +#include + #include "version.h" #define AV_CPU_FLAG_FORCE 0x80000000 /* force usage of selected flags (OR) */ @@ -88,4 +90,15 @@ int av_parse_cpu_flags(const char *s); */ int av_cpu_count(void); +/** + * Get the maximum data alignment that may be required by Libav. + * + * Note that this is affected by the build configuration and the CPU flags mask, + * so e.g. if the CPU supports AVX, but libavutil has been built with + * --disable-avx or the AV_CPU_FLAG_AVX flag has been disabled through + * av_set_cpu_flags_mask(), then this function will behave as if AVX is not + * present. + */ +size_t av_cpu_max_align(void); + #endif /* AVUTIL_CPU_H */ diff --git a/libavutil/version.h b/libavutil/version.h index 7856a0acc3..0fcd19a1eb 100644 --- a/libavutil/version.h +++ b/libavutil/version.h @@ -54,7 +54,7 @@ */ #define LIBAVUTIL_VERSION_MAJOR 55 -#define LIBAVUTIL_VERSION_MINOR 30 +#define LIBAVUTIL_VERSION_MINOR 31 #define LIBAVUTIL_VERSION_MICRO 0 #define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \