Update public FFmpeg header files from r16647 to r18286.

third_party/ffmpeg/include/libavutil/fifo.h

Index: third_party/ffmpeg/include/libavutil/fifo.h
diff --git a/third_party/ffmpeg/include/libavutil/fifo.h b/third_party/ffmpeg/include/libavutil/fifo.h
index 93756e92c98e39d4c01a214bbf9a77a4e7fe4c21..d3538447159f03462e3a311481671f2a7b3531e0 100644
--- a/third_party/ffmpeg/include/libavutil/fifo.h
+++ b/third_party/ffmpeg/include/libavutil/fifo.h
@@ -17,8 +17,8 @@
  */
 
 /**
- * @file fifo.h
- * A very simple circular buffer FIFO implementation.
+ * @file libavutil/fifo.h
+ * a very simple circular buffer FIFO implementation
  */
 
 #ifndef AVUTIL_FIFO_H
@@ -31,15 +31,15 @@
 typedef struct AVFifoBuffer {
     uint8_t *buffer;
     uint8_t *rptr, *wptr, *end;
+    uint32_t rndx, wndx;
 } AVFifoBuffer;
 
 /**
  * Initializes an AVFifoBuffer.
- * @param *f AVFifoBuffer to initialize
  * @param size of FIFO
- * @return <0 for failure >=0 otherwise
+ * @return AVFifoBuffer or NULL if mem allocation failure
  */
-int av_fifo_init(AVFifoBuffer *f, unsigned int size);
+AVFifoBuffer *av_fifo_alloc(unsigned int size);
 
 /**
  * Frees an AVFifoBuffer.
@@ -48,6 +48,12 @@ int av_fifo_init(AVFifoBuffer *f, unsigned int size);
 void av_fifo_free(AVFifoBuffer *f);
 
 /**
+ * Resets the AVFifoBuffer to the state right after av_fifo_alloc, in particular it is emptied.
+ * @param *f AVFifoBuffer to reset
+ */
+void av_fifo_reset(AVFifoBuffer *f);
+
+/**
  * Returns the amount of data in bytes in the AVFifoBuffer, that is the
  * amount of data you can read from it.
  * @param *f AVFifoBuffer to read from
@@ -56,59 +62,33 @@ void av_fifo_free(AVFifoBuffer *f);
 int av_fifo_size(AVFifoBuffer *f);
 
 /**
- * Reads data from an AVFifoBuffer.
- * @param *f AVFifoBuffer to read from
- * @param *buf data destination
- * @param buf_size number of bytes to read
- */
-int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size);
-
-/**
- * Feeds data from an AVFifoBuffer to a user supplied callback.
+ * Feeds data from an AVFifoBuffer to a user-supplied callback.
  * @param *f AVFifoBuffer to read from
  * @param buf_size number of bytes to read
  * @param *func generic read function
  * @param *dest data destination
  */
-int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest);
-
-/**
- * Writes data into an AVFifoBuffer.
- * @param *f AVFifoBuffer to write to
- * @param *buf data source
- * @param size data size
- */
-attribute_deprecated void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size);
+int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size, void (*func)(void*, void*, int));
 
 /**
- * Feeds data from a user supplied callback to an AVFifoBuffer.
+ * Feeds data from a user-supplied callback to an AVFifoBuffer.
  * @param *f AVFifoBuffer to write to
  * @param *src data source
  * @param size number of bytes to write
- * @param *func generic write function. First parameter is src,
- * second is dest_buf, third is dest_buf_size.
+ * @param *func generic write function; the first parameter is src,
+ * the second is dest_buf, the third is dest_buf_size.
  * func must return the number of bytes written to dest_buf, or <= 0 to
  * indicate no more data available to write.
  * If func is NULL, src is interpreted as a simple byte array for source data.
- * @return the number of bytes written to the fifo.
+ * @return the number of bytes written to the FIFO
  */
 int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int));
 
-#if LIBAVUTIL_VERSION_MAJOR < 50
-/**
- * Resizes an AVFifoBuffer.
- * @param *f AVFifoBuffer to resize
- * @param size new AVFifoBuffer size in bytes
- * @see av_fifo_realloc2()
- */
-attribute_deprecated void av_fifo_realloc(AVFifoBuffer *f, unsigned int size);
-#endif
-
 /**
  * Resizes an AVFifoBuffer.
  * @param *f AVFifoBuffer to resize
  * @param size new AVFifoBuffer size in bytes
- * @return <0 for failure >=0 otherwise
+ * @return <0 for failure, >=0 otherwise
  */
 int av_fifo_realloc2(AVFifoBuffer *f, unsigned int size);