Implement av_fifo_space().

Patch by Olivier Guilyardi list et samalyse DOT c0m.

Originally committed as revision 18321 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavutil/avutil.h

@@ -35,7 +35,7 @@
 #define AV_VERSION(a, b, c) AV_VERSION_DOT(a, b, c)
 
 #define LIBAVUTIL_VERSION_MAJOR 50
-#define LIBAVUTIL_VERSION_MINOR  2
+#define LIBAVUTIL_VERSION_MINOR  3
 #define LIBAVUTIL_VERSION_MICRO  0
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \

libavutil/fifo.c

@@ -54,6 +54,11 @@ int av_fifo_size(AVFifoBuffer *f)
     return (uint32_t)(f->wndx - f->rndx);
 }
 
+int av_fifo_space(AVFifoBuffer *f)
+{
+    return f->end - f->buffer - av_fifo_size(f);
+}
+
 int av_fifo_realloc2(AVFifoBuffer *f, unsigned int new_size) {
     unsigned int old_size= f->end - f->buffer;
 

libavutil/fifo.h

@@ -61,6 +61,14 @@ void av_fifo_reset(AVFifoBuffer *f);
  */
 int av_fifo_size(AVFifoBuffer *f);
 
+/**
+ * Returns the amount of space in bytes in the AVFifoBuffer, that is the
+ * amount of data you can write into it.
+ * @param *f AVFifoBuffer to write into
+ * @return size
+ */
+int av_fifo_space(AVFifoBuffer *f);
+
 /**
  * Feeds data from an AVFifoBuffer to a user-supplied callback.
  * @param *f AVFifoBuffer to read from