Update FFmpeg code to n3.2-65-gee56777

media/ffvpx/libavutil/avutil.h

@@ -23,7 +23,8 @@
 
 /**
  * @file
- * external API header
+ * @ingroup lavu
+ * Convenience header that includes @ref lavu "libavutil"'s core.
  */
 
 /**
@@ -78,14 +79,15 @@
  */
 
 /**
- * @defgroup lavu Common utility functions
+ * @defgroup lavu libavutil
+ * Common code shared across all FFmpeg libraries.
  *
- * @brief
- * libavutil contains the code shared across all the other FFmpeg
- * libraries
- *
- * @note In order to use the functions provided by avutil you must include
- * the specific header.
+ * @note
+ * libavutil is designed to be modular. In most cases, in order to use the
+ * functions provided by one component of libavutil you must explicitly include
+ * the specific header containing that feature. If you are only using
+ * media-related components, you could simply include libavutil/avutil.h, which
+ * brings in most of the "core" components.
  *
  * @{
  *
@@ -94,7 +96,7 @@
  * @{
  * @}
  *
- * @defgroup lavu_math Maths
+ * @defgroup lavu_math Mathematics
  * @{
  *
  * @}