BluetoothMidiService: Add support for sending SysEx messages that span multiple Bluetooth packets (8c26d843) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/midi/MidiConstants.java

+2 −2

Original line number	Diff line number	Diff line
		@@ -87,13 +87,13 @@ public final class MidiConstants {
		}

		// Returns true if this command can be used for running status
		public static boolean allowRunningStatus(int command) {
		public static boolean allowRunningStatus(byte command) {
		// only Channel Voice and Channel Mode commands can use running status
		return (command >= STATUS_NOTE_OFF && command < STATUS_SYSTEM_EXCLUSIVE);
		}

		// Returns true if this command cancels running status
		public static boolean cancelsRunningStatus(int command) {
		public static boolean cancelsRunningStatus(byte command) {
		// System Common messages cancel running status
		return (command >= STATUS_SYSTEM_EXCLUSIVE && command <= STATUS_END_SYSEX);
		}

media/packages/BluetoothMidiService/src/com/android/bluetoothmidiservice/BluetoothMidiDevice.java

+10 −12

Original line number	Diff line number	Diff line
		@@ -47,6 +47,7 @@ import java.util.UUID;
		public final class BluetoothMidiDevice {

		private static final String TAG = "BluetoothMidiDevice";
		private static final boolean DEBUG = false;

		private static final int MAX_PACKET_SIZE = 20;

		@@ -152,8 +153,10 @@ public final class BluetoothMidiDevice {
		@Override
		public void onCharacteristicChanged(BluetoothGatt gatt,
		BluetoothGattCharacteristic characteristic) {
		// logByteArray("Received ", characteristic.getValue(), 0,
		// characteristic.getValue().length);
		if (DEBUG) {
		logByteArray("Received ", characteristic.getValue(), 0,
		characteristic.getValue().length);
		}
		mPacketDecoder.decodePacket(characteristic.getValue(), mOutputReceiver);
		}
		};
		@@ -182,8 +185,10 @@ public final class BluetoothMidiDevice {
		byte[] writeBuffer = mWriteBuffers[count];
		System.arraycopy(buffer, 0, writeBuffer, 0, count);
		mCharacteristic.setValue(writeBuffer);
		// logByteArray("Sent ", mCharacteristic.getValue(), 0,
		// mCharacteristic.getValue().length);
		if (DEBUG) {
		logByteArray("Sent ", mCharacteristic.getValue(), 0,
		mCharacteristic.getValue().length);
		}
		mBluetoothGatt.writeCharacteristic(mCharacteristic);
		}
		}
		@@ -259,14 +264,7 @@ public final class BluetoothMidiDevice {
		private static void logByteArray(String prefix, byte[] value, int offset, int count) {
		StringBuilder builder = new StringBuilder(prefix);
		for (int i = offset; i < count; i++) {
		String hex = Integer.toHexString(value[i]);
		int length = hex.length();
		if (length == 1) {
		hex = "0x" + hex;
		} else {
		hex = hex.substring(length - 2, length);
		}
		builder.append(hex);
		builder.append(String.format("0x%02X", value[i]));
		if (i != value.length - 1) {
		builder.append(", ");
		}

media/packages/BluetoothMidiService/src/com/android/bluetoothmidiservice/BluetoothPacketEncoder.java

+84 −24

Original line number	Diff line number	Diff line
		@@ -44,7 +44,7 @@ public class BluetoothPacketEncoder extends PacketEncoder {
		// timestamp for first message in current packet
		private int mPacketTimestamp;
		// current running status, or zero if none
		private int mRunningStatus;
		private byte mRunningStatus;

		private boolean mWritePending;

		@@ -56,12 +56,28 @@ public class BluetoothPacketEncoder extends PacketEncoder {
		public void onReceive(byte[] msg, int offset, int count, long timestamp)
		throws IOException {

		synchronized (mLock) {
		int milliTimestamp = (int)(timestamp / MILLISECOND_NANOS) & MILLISECOND_MASK;
		int status = msg[0] & 0xFF;
		byte status = msg[offset];
		boolean isSysExStart = (status == MidiConstants.STATUS_SYSTEM_EXCLUSIVE);
		boolean isSysExContinuation = ((status & 0x80) == 0);

		int bytesNeeded;
		if (isSysExStart \|\| isSysExContinuation) {
		// SysEx messages can be split into multiple packets
		bytesNeeded = 1;
		} else {
		bytesNeeded = count;
		}

		synchronized (mLock) {
		boolean needsTimestamp = (milliTimestamp != mPacketTimestamp);
		int bytesNeeded = count;
		if (isSysExStart) {
		// SysEx start byte must be preceded by a timestamp
		needsTimestamp = true;
		} else if (isSysExContinuation) {
		// SysEx continuation packets must not have timestamp byte
		needsTimestamp = false;
		}
		if (needsTimestamp) bytesNeeded++; // add one for timestamp byte
		if (status == mRunningStatus) bytesNeeded--; // subtract one for status byte

		@@ -71,15 +87,12 @@ public class BluetoothPacketEncoder extends PacketEncoder {
		flushLocked(true);
		}

		// write header if we are starting a new packet
		if (mAccumulatedBytes == 0) {
		// header byte with timestamp bits 7 - 12
		mAccumulationBuffer[mAccumulatedBytes++] = (byte)(0x80 \| (milliTimestamp >> 7));
		mPacketTimestamp = milliTimestamp;
		needsTimestamp = true;
		// write the header if necessary
		if (appendHeader(milliTimestamp)) {
		needsTimestamp = !isSysExContinuation;
		}

		// write new timestamp byte and status byte if necessary
		// write new timestamp byte if necessary
		if (needsTimestamp) {
		// timestamp byte with bits 0 - 6 of timestamp
		mAccumulationBuffer[mAccumulatedBytes++] =
		@@ -87,20 +100,55 @@ public class BluetoothPacketEncoder extends PacketEncoder {
		mPacketTimestamp = milliTimestamp;
		}

		if (isSysExStart \|\| isSysExContinuation) {
		// MidiFramer will end the packet with SysEx End if there is one in the buffer
		boolean hasSysExEnd =
		(msg[offset + count - 1] == MidiConstants.STATUS_END_SYSEX);
		int remaining = (hasSysExEnd ? count - 1 : count);

		while (remaining > 0) {
		if (mAccumulatedBytes == mAccumulationBuffer.length) {
		// write out our data if there is no more room
		// if necessary, block until previous packet is sent
		flushLocked(true);
		appendHeader(milliTimestamp);
		}

		int copy = mAccumulationBuffer.length - mAccumulatedBytes;
		if (copy > remaining) copy = remaining;
		System.arraycopy(msg, offset, mAccumulationBuffer, mAccumulatedBytes, copy);
		mAccumulatedBytes += copy;
		offset += copy;
		remaining -= copy;
		}

		if (hasSysExEnd) {
		// SysEx End command must be preceeded by a timestamp byte
		if (mAccumulatedBytes + 2 > mAccumulationBuffer.length) {
		// write out our data if there is no more room
		// if necessary, block until previous packet is sent
		flushLocked(true);
		appendHeader(milliTimestamp);
		}
		mAccumulationBuffer[mAccumulatedBytes++] = (byte)(0x80 \| (milliTimestamp & 0x7F));
		mAccumulationBuffer[mAccumulatedBytes++] = MidiConstants.STATUS_END_SYSEX;
		}
		} else {
		// Non-SysEx message
		if (status != mRunningStatus) {
		mAccumulationBuffer[mAccumulatedBytes++] = (byte)status;
		mAccumulationBuffer[mAccumulatedBytes++] = status;
		if (MidiConstants.allowRunningStatus(status)) {
		mRunningStatus = status;
		} else if (MidiConstants.allowRunningStatus(status)) {
		} else if (MidiConstants.cancelsRunningStatus(status)) {
		mRunningStatus = 0;
		}
		}

		// now copy data bytes
		int dataLength = count - 1;
		System.arraycopy(msg, 1, mAccumulationBuffer, mAccumulatedBytes, dataLength);
		// FIXME - handle long SysEx properly
		System.arraycopy(msg, offset + 1, mAccumulationBuffer, mAccumulatedBytes, dataLength);
		mAccumulatedBytes += dataLength;
		}

		// write the packet if possible, but do not block
		flushLocked(false);
		@@ -108,6 +156,18 @@ public class BluetoothPacketEncoder extends PacketEncoder {
		}
		};

		private boolean appendHeader(int milliTimestamp) {
		// write header if we are starting a new packet
		if (mAccumulatedBytes == 0) {
		// header byte with timestamp bits 7 - 12
		mAccumulationBuffer[mAccumulatedBytes++] = (byte)(0x80 \| ((milliTimestamp >> 7) & 0x3F));
		mPacketTimestamp = milliTimestamp;
		return true;
		} else {
		return false;
		}
		}

		// MidiFramer for normalizing incoming data
		private final MidiFramer mMidiFramer = new MidiFramer(mFramedDataReceiver);