Audio record improvement

Signed-off-by: Leo Ma <begeekmyfriend@gmail.com>

library/src/main/java/net/ossrs/yasea/SrsEncoder.java

@@ -31,12 +31,12 @@ public class SrsEncoder {
     public static int vLandscapeHeight = 720;
     public static int vOutWidth = 720;   // Note: the stride of resolution must be set as 16x for hard encoding with some chip like MTK
     public static int vOutHeight = 1280;  // Since Y component is quadruple size as U and V component, the stride must be set as 32x
-    public static int vBitrate = 1200 * 1000;  // 1200kbps
+    public static int vBitrate = 1200 * 1024;  // 1200 kbps
     public static final int VFPS = 24;
     public static final int VGOP = 48;
     public static final int ASAMPLERATE = 44100;
     public static int aChannelConfig = AudioFormat.CHANNEL_IN_STEREO;
-    public static final int ABITRATE = 32 * 1000;  // 32kbps
+    public static final int ABITRATE = 128 * 1024;  // 128 kbps
 
     private SrsEncodeHandler mHandler;
 
@@ -231,12 +231,12 @@ public class SrsEncoder {
     }
 
     public void setVideoHDMode() {
-        vBitrate = 1200 * 1000;  // 1200 kbps
+        vBitrate = 1200 * 1024;  // 1200 kbps
         x264Preset = "veryfast";
     }
 
     public void setVideoSmoothMode() {
-        vBitrate = 500 * 1000;  // 500 kbps
+        vBitrate = 500 * 1024;  // 500 kbps
         x264Preset = "superfast";
     }
 
@@ -391,10 +391,11 @@ public class SrsEncoder {
     }
 
     public AudioRecord chooseAudioRecord() {
-        int minBufferSize = AudioRecord.getMinBufferSize(SrsEncoder.ASAMPLERATE, AudioFormat.CHANNEL_IN_STEREO, AudioFormat.ENCODING_PCM_16BIT);
-        AudioRecord mic = new AudioRecord(MediaRecorder.AudioSource.DEFAULT, SrsEncoder.ASAMPLERATE, AudioFormat.CHANNEL_IN_STEREO, AudioFormat.ENCODING_PCM_16BIT, minBufferSize);
+        AudioRecord mic = new AudioRecord(MediaRecorder.AudioSource.DEFAULT, SrsEncoder.ASAMPLERATE,
+            AudioFormat.CHANNEL_IN_STEREO, AudioFormat.ENCODING_PCM_16BIT, getPcmBufferSize() * 4);
         if (mic.getState() != AudioRecord.STATE_INITIALIZED) {
-            mic = new AudioRecord(MediaRecorder.AudioSource.DEFAULT, SrsEncoder.ASAMPLERATE, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, minBufferSize);
+            mic = new AudioRecord(MediaRecorder.AudioSource.DEFAULT, SrsEncoder.ASAMPLERATE,
+                AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, getPcmBufferSize() * 4);
             if (mic.getState() != AudioRecord.STATE_INITIALIZED) {
                 mic = null;
             } else {
@@ -407,6 +408,12 @@ public class SrsEncoder {
         return mic;
     }
 
+    private int getPcmBufferSize() {
+        int pcmBufSize = AudioRecord.getMinBufferSize(ASAMPLERATE, AudioFormat.CHANNEL_IN_STEREO,
+            AudioFormat.ENCODING_PCM_16BIT) + 8191;
+        return pcmBufSize - (pcmBufSize % 8192);
+    }
+
     // choose the video encoder by name.
     private MediaCodecInfo chooseVideoEncoder(String name) {
         int nbCodecs = MediaCodecList.getCodecCount();

library/src/main/java/net/ossrs/yasea/SrsPublisher.java

@@ -19,6 +19,7 @@ public class SrsPublisher {
     private static AudioRecord mic;
     private static AcousticEchoCanceler aec;
     private static AutomaticGainControl agc;
+    private byte[] mPcmBuffer = new byte[4096];
     private boolean aloop = false;
     private Thread aworker;
 
@@ -219,14 +220,12 @@ public class SrsPublisher {
     private void startAudio() {
         if (mic != null) {
             mic.startRecording();
-
-            byte pcmBuffer[] = new byte[4096];
             while (aloop && !Thread.interrupted()) {
-                int size = mic.read(pcmBuffer, 0, pcmBuffer.length);
+                int size = mic.read(mPcmBuffer, 0, mPcmBuffer.length);
                 if (size <= 0) {
                     break;
                 }
-                mEncoder.onGetPcmFrame(pcmBuffer, size);
+                mEncoder.onGetPcmFrame(mPcmBuffer, size);
             }
         }
     }