oboe: add waitForAvailableFrames()

This can avoid glitches if the input buffer is too empty
and the MMAP timing is unreliable.

1 files changed, 17 insertions, 0 deletions

diff --git a/include/oboe/AudioStream.h b/include/oboe/AudioStream.h
index 1f7954ed..d9b2046a 100644
--- a/include/oboe/AudioStream.h
+++ b/include/oboe/AudioStream.h
@@ -401,6 +401,23 @@ public:
         return previousCallback;
     }
 
+    /**
+     * @return number of frames of data currently in the buffer
+     */
+    ResultWithValue<int32_t> getAvailableFrames();
+
+    /**
+     * Wait until the stream has a minimum amount of data available in its buffer.
+     * This can be used with an EXCLUSIVE MMAP input stream to avoid reading data too close to
+     * the DSP write position, which may cause glitches.
+     *
+     * @param numFrames minimum frames available
+     * @param timeoutNanoseconds
+     * @return number of frames available, ErrorTimeout
+     */
+    ResultWithValue<int32_t> waitForAvailableFrames(int32_t numFrames,
+                                                    int64_t timeoutNanoseconds);
+
 protected:
 
     /**