Update public FFmpeg header files from r16647 to r18286.

third_party/ffmpeg/include/libavutil/mem.h

Index: third_party/ffmpeg/include/libavutil/mem.h
diff --git a/third_party/ffmpeg/include/libavutil/mem.h b/third_party/ffmpeg/include/libavutil/mem.h
index ec6e3b745694a0f56b8991fb06f64081ebaa5c71..e50553aefee85bfdd3f7c382fb4200924206bb6a 100644
--- a/third_party/ffmpeg/include/libavutil/mem.h
+++ b/third_party/ffmpeg/include/libavutil/mem.h
@@ -19,8 +19,8 @@
  */
 
 /**
- * @file mem.h
- * Memory handling functions.
+ * @file libavutil/mem.h
+ * memory handling functions
  */
 
 #ifndef AVUTIL_MEM_H
@@ -28,22 +28,6 @@
 
 #include "common.h"
 
-#if defined(__ICC) || defined(__SUNPRO_C)
-    #define DECLARE_ALIGNED(n,t,v)      t v __attribute__ ((aligned (n)))
-    #define DECLARE_ASM_CONST(n,t,v)    const t __attribute__ ((aligned (n))) v
-#elif defined(__GNUC__)
-    #define DECLARE_ALIGNED(n,t,v)      t v __attribute__ ((aligned (n)))
-    #define DECLARE_ASM_CONST(n,t,v)    static const t v attribute_used __attribute__ ((aligned (n)))
-#elif defined(_MSC_VER)
-    #define DECLARE_ALIGNED(n,t,v)      __declspec(align(n)) t v
-    #define DECLARE_ASM_CONST(n,t,v)    __declspec(align(n)) static const t v
-#elif HAVE_INLINE_ASM
-    #error The asm code needs alignment, but we do not know how to do it for this compiler.
-#else
-    #define DECLARE_ALIGNED(n,t,v)      t v
-    #define DECLARE_ASM_CONST(n,t,v)    static const t v
-#endif
-
 #if AV_GCC_VERSION_AT_LEAST(3,1)
     #define av_malloc_attrib __attribute__((__malloc__))
 #else
@@ -57,31 +41,31 @@
 #endif
 
 /**
- * Allocate a block of \p size bytes with alignment suitable for all
+ * Allocates a block of \p size bytes with alignment suitable for all
  * memory accesses (including vectors if available on the CPU).
  * @param size Size in bytes for the memory block to be allocated.
- * @return Pointer to the allocated block, NULL if it cannot allocate
- * it.
+ * @return Pointer to the allocated block, NULL if the block cannot
+ * be allocated.
  * @see av_mallocz()
  */
 void *av_malloc(unsigned int size) av_malloc_attrib av_alloc_size(1);
 
 /**
- * Allocate or reallocate a block of memory.
- * If \p ptr is NULL and \p size > 0, allocate a new block. If \p
- * size is zero, free the memory block pointed by \p ptr.
+ * Allocates or reallocates a block of memory.
+ * If \p ptr is NULL and \p size > 0, allocates a new block. If \p
+ * size is zero, frees the memory block pointed to by \p ptr.
  * @param size Size in bytes for the memory block to be allocated or
  * reallocated.
  * @param ptr Pointer to a memory block already allocated with
  * av_malloc(z)() or av_realloc() or NULL.
- * @return Pointer to a newly reallocated block or NULL if it cannot
- * reallocate or the function is used to free the memory block.
+ * @return Pointer to a newly reallocated block or NULL if the block
+ * cannot be reallocated or the function is used to free the memory block.
  * @see av_fast_realloc()
  */
 void *av_realloc(void *ptr, unsigned int size) av_alloc_size(2);
 
 /**
- * Free a memory block which has been allocated with av_malloc(z)() or
+ * Frees a memory block which has been allocated with av_malloc(z)() or
  * av_realloc().
  * @param ptr Pointer to the memory block which should be freed.
  * @note ptr = NULL is explicitly allowed.
@@ -91,27 +75,26 @@ void *av_realloc(void *ptr, unsigned int size) av_alloc_size(2);
 void av_free(void *ptr);
 
 /**
- * Allocate a block of \p size bytes with alignment suitable for all
+ * Allocates a block of \p size bytes with alignment suitable for all
  * memory accesses (including vectors if available on the CPU) and
- * set to zeroes all the bytes of the block.
+ * zeroes all the bytes of the block.
  * @param size Size in bytes for the memory block to be allocated.
- * @return Pointer to the allocated block, NULL if it cannot allocate
- * it.
+ * @return Pointer to the allocated block, NULL if it cannot be allocated.
  * @see av_malloc()
  */
 void *av_mallocz(unsigned int size) av_malloc_attrib av_alloc_size(1);
 
 /**
- * Duplicate the string \p s.
- * @param s String to be duplicated.
+ * Duplicates the string \p s.
+ * @param s string to be duplicated
  * @return Pointer to a newly allocated string containing a
- * copy of \p s or NULL if it cannot be allocated.
+ * copy of \p s or NULL if the string cannot be allocated.
  */
 char *av_strdup(const char *s) av_malloc_attrib;
 
 /**
- * Free a memory block which has been allocated with av_malloc(z)() or
- * av_realloc() and set to NULL the pointer to it.
+ * Frees a memory block which has been allocated with av_malloc(z)() or
+ * av_realloc() and set the pointer pointing to it to NULL.
  * @param ptr Pointer to the pointer to the memory block which should
  * be freed.
  * @see av_free()