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

Extract AudioRecordReader

Browse Source 
Move the logic to read from an AudioRecord and handle all corner cases
for PTS. This simplifies AudioCapture.

PR #5102 <https://github.com/Genymobile/scrcpy/pull/5102>
This commit is contained in:
Romain Vimont 2024-07-14 23:28:13 +02:00
parent 414ce4c754
commit 053bf83f58
2 changed files with 71 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
server/src/main/java/com/genymobile/scrcpy/audio/AudioCapture.java
View File

@ -10,7 +10,6 @@ import android.annotation.TargetApi;
import android.content.ComponentName; import android.content.ComponentName;
import android.content.Intent; import android.content.Intent;
import android.media.AudioRecord; import android.media.AudioRecord;
import android.media.AudioTimestamp;
import android.media.MediaCodec; import android.media.MediaCodec;
import android.os.Build; import android.os.Build;
import android.os.SystemClock; import android.os.SystemClock;
@ -24,20 +23,11 @@ public final class AudioCapture {
private static final int CHANNELS = AudioConfig.CHANNELS; private static final int CHANNELS = AudioConfig.CHANNELS;
private static final int CHANNEL_MASK = AudioConfig.CHANNEL_MASK; private static final int CHANNEL_MASK = AudioConfig.CHANNEL_MASK;
private static final int ENCODING = AudioConfig.ENCODING; private static final int ENCODING = AudioConfig.ENCODING;
private static final int BYTES_PER_SAMPLE = AudioConfig.BYTES_PER_SAMPLE;
private static final int MAX_READ_SIZE = AudioConfig.MAX_READ_SIZE;
private static final long ONE_SAMPLE_US = (1000000 + SAMPLE_RATE - 1) / SAMPLE_RATE; // 1 sample in microseconds (used for fixing PTS)
private final int audioSource; private final int audioSource;
private AudioRecord recorder; private AudioRecord recorder;
private AudioRecordReader reader;
private final AudioTimestamp timestamp = new AudioTimestamp();
private long previousRecorderTimestamp = -1;
private long previousPts = 0;
private long nextPts = 0;
public AudioCapture(AudioSource audioSource) { public AudioCapture(AudioSource audioSource) {
this.audioSource = audioSource.value(); this.audioSource = audioSource.value();
@ -107,6 +97,7 @@ public final class AudioCapture {
recorder = Workarounds.createAudioRecord(audioSource, SAMPLE_RATE, CHANNEL_CONFIG, CHANNELS, CHANNEL_MASK, ENCODING); recorder = Workarounds.createAudioRecord(audioSource, SAMPLE_RATE, CHANNEL_CONFIG, CHANNELS, CHANNEL_MASK, ENCODING);
} }
recorder.startRecording(); recorder.startRecording();
reader = new AudioRecordReader(recorder);
} }
public void checkCompatibility() throws AudioCaptureException { public void checkCompatibility() throws AudioCaptureException {
@ -137,41 +128,7 @@ public final class AudioCapture {
} }
@TargetApi(Build.VERSION_CODES.N) @TargetApi(Build.VERSION_CODES.N)
public int read(ByteBuffer directBuffer, MediaCodec.BufferInfo outBufferInfo) { public int read(ByteBuffer outDirectBuffer, MediaCodec.BufferInfo outBufferInfo) {
int r = recorder.read(directBuffer, MAX_READ_SIZE); return reader.read(outDirectBuffer, outBufferInfo);
if (r <= 0) {
return r;
}
long pts;
int ret = recorder.getTimestamp(timestamp, AudioTimestamp.TIMEBASE_MONOTONIC);
if (ret == AudioRecord.SUCCESS && timestamp.nanoTime != previousRecorderTimestamp) {
pts = timestamp.nanoTime / 1000;
previousRecorderTimestamp = timestamp.nanoTime;
} else {
if (nextPts == 0) {
Ln.w("Could not get initial audio timestamp");
nextPts = System.nanoTime() / 1000;
}
// compute from previous timestamp and packet size
pts = nextPts;
}
long durationUs = r * 1000000L / (CHANNELS * BYTES_PER_SAMPLE * SAMPLE_RATE);
nextPts = pts + durationUs;
if (previousPts != 0 && pts < previousPts + ONE_SAMPLE_US) {
// Audio PTS may come from two sources:
// - recorder.getTimestamp() if the call works;
// - an estimation from the previous PTS and the packet size as a fallback.
//
// Therefore, the property that PTS are monotonically increasing is no guaranteed in corner cases, so enforce it.
pts = previousPts + ONE_SAMPLE_US;
}
previousPts = pts;
outBufferInfo.set(0, r, pts, 0);
return r;
} }
} }

67
server/src/main/java/com/genymobile/scrcpy/audio/AudioRecordReader.java Normal file
View File

@ -0,0 +1,67 @@
package com.genymobile.scrcpy.audio;
import com.genymobile.scrcpy.util.Ln;
import android.annotation.TargetApi;
import android.media.AudioRecord;
import android.media.AudioTimestamp;
import android.media.MediaCodec;
import android.os.Build;
import java.nio.ByteBuffer;
public class AudioRecordReader {
private static final long ONE_SAMPLE_US =
(1000000 + AudioConfig.SAMPLE_RATE - 1) / AudioConfig.SAMPLE_RATE; // 1 sample in microseconds (used for fixing PTS)
private final AudioRecord recorder;
private final AudioTimestamp timestamp = new AudioTimestamp();
private long previousRecorderTimestamp = -1;
private long previousPts = 0;
private long nextPts = 0;
public AudioRecordReader(AudioRecord recorder) {
this.recorder = recorder;
}
@TargetApi(Build.VERSION_CODES.N)
public int read(ByteBuffer outDirectBuffer, MediaCodec.BufferInfo outBufferInfo) {
int r = recorder.read(outDirectBuffer, AudioConfig.MAX_READ_SIZE);
if (r <= 0) {
return r;
}
long pts;
int ret = recorder.getTimestamp(timestamp, AudioTimestamp.TIMEBASE_MONOTONIC);
if (ret == AudioRecord.SUCCESS && timestamp.nanoTime != previousRecorderTimestamp) {
pts = timestamp.nanoTime / 1000;
previousRecorderTimestamp = timestamp.nanoTime;
} else {
if (nextPts == 0) {
Ln.w("Could not get initial audio timestamp");
nextPts = System.nanoTime() / 1000;
}
// compute from previous timestamp and packet size
pts = nextPts;
}
long durationUs = r * 1000000L / (AudioConfig.CHANNELS * AudioConfig.BYTES_PER_SAMPLE * AudioConfig.SAMPLE_RATE);
nextPts = pts + durationUs;
if (previousPts != 0 && pts < previousPts + ONE_SAMPLE_US) {
// Audio PTS may come from two sources:
// - recorder.getTimestamp() if the call works;
// - an estimation from the previous PTS and the packet size as a fallback.
//
// Therefore, the property that PTS are monotonically increasing is no guaranteed in corner cases, so enforce it.
pts = previousPts + ONE_SAMPLE_US;
}
previousPts = pts;
outBufferInfo.set(0, r, pts, 0);
return r;
}
}