From be914dbf8f715ca7ee35b76ad94ae01d3b3886b2 Mon Sep 17 00:00:00 2001
From: Lyubomir Marinov <lyubomir.marinov@jitsi.org>
Date: Tue, 9 Jul 2013 16:47:49 +0300
Subject: [PATCH] Works on improving the acoustic echo cancellation (AEC) of
Windows Audio Session API (WASAPI).
---
.../protocol/wasapi/AudioCaptureClient.java | 65 +++++++++++++++----
.../media/protocol/wasapi/WASAPIStream.java | 14 ++--
2 files changed, 63 insertions(+), 16 deletions(-)
diff --git a/src/org/jitsi/impl/neomedia/jmfext/media/protocol/wasapi/AudioCaptureClient.java b/src/org/jitsi/impl/neomedia/jmfext/media/protocol/wasapi/AudioCaptureClient.java
index 06722ef2..1778a82d 100644
--- a/src/org/jitsi/impl/neomedia/jmfext/media/protocol/wasapi/AudioCaptureClient.java
+++ b/src/org/jitsi/impl/neomedia/jmfext/media/protocol/wasapi/AudioCaptureClient.java
@@ -40,6 +40,24 @@ public class AudioCaptureClient
private static final Logger logger
= Logger.getLogger(AudioCaptureClient.class);
+ private static int maybeIAudioCaptureClientGetNextPacketSize(
+ long iAudioCaptureClient)
+ {
+ int numFramesInNextPacket;
+
+ try
+ {
+ numFramesInNextPacket
+ = IAudioCaptureClient_GetNextPacketSize(iAudioCaptureClient);
+ }
+ catch (HResultException hre)
+ {
+ numFramesInNextPacket = 0; // Silence the compiler.
+ logger.error("IAudioCaptureClient_GetNextPacketSize", hre);
+ }
+ return numFramesInNextPacket;
+ }
+
/**
* The internal buffer of this instance in which audio data is read from the
* associated <tt>IAudioCaptureClient</tt> by the instance and awaits to be
@@ -142,6 +160,17 @@ public class AudioCaptureClient
*/
final AudioFormat outFormat;
+ /**
+ * The indicator which reports whether audio samples have been read out of
+ * this instance since the indicator has been set to <tt>false</tt>. For
+ * example, determines whether audio samples have been read out of this
+ * instance since this instance has given control to its associated
+ * <tt>BufferTransferHandler</tt> (if any) and thus resolves a condition
+ * similar to a busy wait which arises if the associated
+ * <tt>BufferTransferHandler</tt> does not read any data.
+ */
+ private boolean read;
+
/**
* The number of channels with which {@link #iAudioClient} has been
* initialized.
@@ -505,6 +534,8 @@ else if (!started)
{
read = doRead(iMediaBuffer, buffer, offset, length);
cause = null;
+ if (read > 0)
+ this.read = true;
}
catch (Throwable t)
{
@@ -556,18 +587,9 @@ private BufferTransferHandler readInEventHandleCmd()
* Determine the size in bytes of the next data packet in the capture
* endpoint buffer.
*/
- int numFramesInNextPacket;
+ int numFramesInNextPacket
+ = maybeIAudioCaptureClientGetNextPacketSize(iAudioCaptureClient);
- try
- {
- numFramesInNextPacket
- = IAudioCaptureClient_GetNextPacketSize(iAudioCaptureClient);
- }
- catch (HResultException hre)
- {
- numFramesInNextPacket = 0; // Silence the compiler.
- logger.error("IAudioCaptureClient_GetNextPacketSize", hre);
- }
if (numFramesInNextPacket != 0)
{
int toRead = numFramesInNextPacket * dstFrameSize;
@@ -619,6 +641,7 @@ private void runInEventHandleCmd(Runnable eventHandleCmd)
{
long eventHandle;
BufferTransferHandler transferHandler;
+ int numFramesInNextPacket;
synchronized (this)
{
@@ -648,6 +671,17 @@ private void runInEventHandleCmd(Runnable eventHandleCmd)
try
{
transferHandler = readInEventHandleCmd();
+ if (transferHandler != null)
+ read = false;
+ /*
+ * If the audio engine has more samples to deliver to the
+ * application, deliver them as soon as the transferHandler,
+ * if any, has been given a chance to read (from) the
+ * available samples.
+ */
+ numFramesInNextPacket
+ = maybeIAudioCaptureClientGetNextPacketSize(
+ iAudioCaptureClient);
}
finally
{
@@ -668,7 +702,8 @@ private void runInEventHandleCmd(Runnable eventHandleCmd)
* exception, we will WaitForSingleObject in order to
* give the application time to recover.
*/
- continue;
+ if (read)
+ continue;
}
catch (Throwable t)
{
@@ -682,6 +717,12 @@ private void runInEventHandleCmd(Runnable eventHandleCmd)
}
}
}
+ /*
+ * The audio engine may already have more samples to deliver to
+ * the application.
+ */
+ if (numFramesInNextPacket != 0)
+ continue;
int wfso;
diff --git a/src/org/jitsi/impl/neomedia/jmfext/media/protocol/wasapi/WASAPIStream.java b/src/org/jitsi/impl/neomedia/jmfext/media/protocol/wasapi/WASAPIStream.java
index 51b50143..bdbb3d85 100644
--- a/src/org/jitsi/impl/neomedia/jmfext/media/protocol/wasapi/WASAPIStream.java
+++ b/src/org/jitsi/impl/neomedia/jmfext/media/protocol/wasapi/WASAPIStream.java
@@ -1014,7 +1014,14 @@ private void initializeRender(final MediaLocator locator, AudioFormat format)
* at this time. If the transferHandler (which will normally invoke
* transferRenderData) was non-null, it would cause excessive CPU use.
*/
- BufferTransferHandler transferHandler = null;
+ BufferTransferHandler transferHandler
+ = new BufferTransferHandler()
+ {
+ public void transferData(PushBufferStream stream)
+ {
+ transferRenderData();
+ }
+ };
render
= new AudioCaptureClient(
@@ -1022,7 +1029,7 @@ private void initializeRender(final MediaLocator locator, AudioFormat format)
locator,
AudioSystem.DataFlow.PLAYBACK,
WASAPI.AUDCLNT_STREAMFLAGS_LOOPBACK,
- /* hnsBufferDuration */ Format.NOT_SPECIFIED,
+ WASAPISystem.DEFAULT_BUFFER_DURATION,
format,
transferHandler);
replenishRender = true;
@@ -1115,7 +1122,7 @@ private void processInput(int dwInputStreamIndex, int maxLength)
if ((dwInputStreamIndex == RENDER_INPUT_STREAM_INDEX)
&& replenishRender)
{
- int replenishThreshold = renderBufferMaxLength;
+ int replenishThreshold = (3 * renderBufferMaxLength / 2);
if (audioCaptureClient.getAvailableLength()
< replenishThreshold)
@@ -1698,7 +1705,6 @@ private void transferCaptureData()
* Notifies this instance that audio data has been made available in
* {@link #render}.
*/
- @SuppressWarnings("unused")
private void transferRenderData()
{
/*
--
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