From: Anton Khirnov <an...@khirnov.net>
(cherry picked from commit e6bff23f1e11aefb16a2b5d6ee72bf7469c5a66e)
Signed-off-by: James Almer <jamr...@gmail.com>
---
This is (afaics) the last API introduced to libav before the major bump.
doc/APIchanges | 3 +++
libavutil/cpu.c | 22 ++++++++++++++++++++++
libavutil/cpu.h | 13 +++++++++++++
libavutil/version.h | 2 +-
4 files changed, 39 insertions(+), 1 deletion(-)
diff --git a/doc/APIchanges b/doc/APIchanges
index 4effbf9364..6a57c210a9 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -15,6 +15,9 @@ libavutil: 2015-08-28
API changes, most recent first:
+2017-09-xx - xxxxxxx - lavu 55.75.100 / lavu 55.31.0 - cpu.h
+ Add av_cpu_max_align() for querying maximum required data alignment.
+
2017-09-01 - xxxxxxx - lavf 57.81.100 - avio.h
Add avio_read_partial().
diff --git a/libavutil/cpu.c b/libavutil/cpu.c
index a22da0fa8c..c89f4e0b5f 100644
--- a/libavutil/cpu.c
+++ b/libavutil/cpu.c
@@ -16,9 +16,11 @@
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#include <stddef.h>
#include <stdint.h>
#include <stdatomic.h>
+#include "attributes.h"
#include "cpu.h"
#include "cpu_internal.h"
#include "config.h"
@@ -299,3 +301,23 @@ int av_cpu_count(void)
return nb_cpus;
}
+
+size_t av_cpu_max_align(void)
+{
+ int av_unused flags = av_get_cpu_flags();
+
+#if ARCH_ARM || ARCH_AARCH64
+ if (flags & AV_CPU_FLAG_NEON)
+ return 16;
+#elif ARCH_PPC
+ if (flags & AV_CPU_FLAG_ALTIVEC)
+ return 16;
+#elif ARCH_X86
+ if (flags & AV_CPU_FLAG_AVX)
+ return 32;
+ if (flags & AV_CPU_FLAG_SSE)
+ return 16;
+#endif
+
+ return 8;
+}
diff --git a/libavutil/cpu.h b/libavutil/cpu.h
index de05593446..9e5d40affe 100644
--- a/libavutil/cpu.h
+++ b/libavutil/cpu.h
@@ -21,6 +21,8 @@
#ifndef AVUTIL_CPU_H
#define AVUTIL_CPU_H
+#include <stddef.h>
+
#include "attributes.h"
#define AV_CPU_FLAG_FORCE 0x80000000 /* force usage of selected flags (OR)
*/
@@ -113,4 +115,15 @@ int av_parse_cpu_caps(unsigned *flags, const char *s);
*/
int av_cpu_count(void);
+/**
+ * Get the maximum data alignment that may be required by FFmpeg.
+ *
+ * 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 6e25b4690c..d99eff5d15 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -80,7 +80,7 @@
#define LIBAVUTIL_VERSION_MAJOR 55
-#define LIBAVUTIL_VERSION_MINOR 74
+#define LIBAVUTIL_VERSION_MINOR 75
#define LIBAVUTIL_VERSION_MICRO 100
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
--
2.13.3
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