drgreen/scrcpy
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Read audio by blocks of 1024 samples

Browse Source 
In practice, the system captures audio samples by blocks of 1024
samples.

Remplace the hardcoded value of 5 milliseconds (240 samples), and let
AudioRecord fill the input buffer provided by MediaCodec (or by
AudioRawRecorder), with a maximum size of 1024 samples (just in case).
This commit is contained in:
Romain Vimont 2023-11-14 08:49:10 +01:00
parent 258eaaae2a
commit 3bb6b0cb9f
3 changed files with 10 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
server/src/main/java/com/genymobile/scrcpy/AudioCapture.java
View File

@ -24,6 +24,11 @@ public final class AudioCapture {
public static final int ENCODING = AudioFormat.ENCODING_PCM_16BIT;
public static final int BYTES_PER_SAMPLE = 2;
// Never read more than 1024 samples, even if the buffer is bigger (that would increase latency).
// A lower value is useless, since the system captures audio samples by blocks of 1024 (so for example if we read by blocks of 256 samples, we
// receive 4 successive blocks without waiting, then we wait for the 4 next ones).
public static final int MAX_READ_SIZE = 1024 * CHANNELS * BYTES_PER_SAMPLE;
private final int audioSource;
private AudioRecord recorder;
@ -36,10 +41,6 @@ public final class AudioCapture {
this.audioSource = audioSource.value();
}
public static int millisToBytes(int millis) {
return SAMPLE_RATE * CHANNELS * BYTES_PER_SAMPLE * millis / 1000;
}
private static AudioFormat createAudioFormat() {
AudioFormat.Builder builder = new AudioFormat.Builder();
builder.setEncoding(ENCODING);
@ -135,8 +136,8 @@ public final class AudioCapture {
}
@TargetApi(Build.VERSION_CODES.N)
public int read(ByteBuffer directBuffer, int size, MediaCodec.BufferInfo outBufferInfo) {
int r = recorder.read(directBuffer, size);
public int read(ByteBuffer directBuffer, MediaCodec.BufferInfo outBufferInfo) {
int r = recorder.read(directBuffer, MAX_READ_SIZE);
if (r <= 0) {
return r;
}

5
server/src/main/java/com/genymobile/scrcpy/AudioEncoder.java
View File

@ -37,9 +37,6 @@ public final class AudioEncoder implements AsyncProcessor {
private static final int SAMPLE_RATE = AudioCapture.SAMPLE_RATE;
private static final int CHANNELS = AudioCapture.CHANNELS;
private static final int READ_MS = 5; // milliseconds
private static final int READ_SIZE = AudioCapture.millisToBytes(READ_MS);
private final AudioCapture capture;
private final Streamer streamer;
private final int bitRate;
@ -93,7 +90,7 @@ public final class AudioEncoder implements AsyncProcessor {
while (!Thread.currentThread().isInterrupted()) {
InputTask task = inputTasks.take();
ByteBuffer buffer = mediaCodec.getInputBuffer(task.index);
int r = capture.read(buffer, READ_SIZE, bufferInfo);
int r = capture.read(buffer, bufferInfo);
if (r <= 0) {
throw new IOException("Could not read audio: " + r);
}

7
server/src/main/java/com/genymobile/scrcpy/AudioRawRecorder.java
View File

@ -13,9 +13,6 @@ public final class AudioRawRecorder implements AsyncProcessor {
private Thread thread;
private static final int READ_MS = 5; // milliseconds
private static final int READ_SIZE = AudioCapture.millisToBytes(READ_MS);
public AudioRawRecorder(AudioCapture capture, Streamer streamer) {
this.capture = capture;
this.streamer = streamer;
@ -28,7 +25,7 @@ public final class AudioRawRecorder implements AsyncProcessor {
return;
}
final ByteBuffer buffer = ByteBuffer.allocateDirect(READ_SIZE);
final ByteBuffer buffer = ByteBuffer.allocateDirect(AudioCapture.MAX_READ_SIZE);
final MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
try {
@ -43,7 +40,7 @@ public final class AudioRawRecorder implements AsyncProcessor {
streamer.writeAudioHeader();
while (!Thread.currentThread().isInterrupted()) {
buffer.position(0);
int r = capture.read(buffer, READ_SIZE, bufferInfo);
int r = capture.read(buffer, bufferInfo);
if (r < 0) {
throw new IOException("Could not read audio: " + r);
}