diff options
Diffstat (limited to 'media/java')
| -rw-r--r-- | media/java/android/media/MediaCodecInfo.java | 15 | ||||
| -rw-r--r-- | media/java/android/media/midi/MidiDevice.java | 12 | ||||
| -rw-r--r-- | media/java/android/media/midi/package.html | 63 |
3 files changed, 82 insertions, 8 deletions
diff --git a/media/java/android/media/MediaCodecInfo.java b/media/java/android/media/MediaCodecInfo.java index 65d0450..8243d40 100644 --- a/media/java/android/media/MediaCodecInfo.java +++ b/media/java/android/media/MediaCodecInfo.java @@ -1198,15 +1198,20 @@ public final class MediaCodecInfo { (double) mFrameRateRange.getUpper())); } + private int getBlockCount(int width, int height) { + return Utils.divUp(width, mBlockWidth) * Utils.divUp(height, mBlockHeight); + } + @NonNull private Size findClosestSize(int width, int height) { - int targetPixels = width * height; + int targetBlockCount = getBlockCount(width, height); Size closestSize = null; - int mimPixelsDiff = Integer.MAX_VALUE; + int minDiff = Integer.MAX_VALUE; for (Size size : mMeasuredFrameRates.keySet()) { - int pixelsDiff = Math.abs(targetPixels - size.getWidth() * size.getHeight()); - if (pixelsDiff < mimPixelsDiff) { - mimPixelsDiff = pixelsDiff; + int diff = Math.abs(targetBlockCount - + getBlockCount(size.getWidth(), size.getHeight())); + if (diff < minDiff) { + minDiff = diff; closestSize = size; } } diff --git a/media/java/android/media/midi/MidiDevice.java b/media/java/android/media/midi/MidiDevice.java index 93fb6d2..e1990cd 100644 --- a/media/java/android/media/midi/MidiDevice.java +++ b/media/java/android/media/midi/MidiDevice.java @@ -113,8 +113,13 @@ public final class MidiDevice implements Closeable { /** * Called to open a {@link MidiInputPort} for the specified port number. * + * An input port can only be used by one sender at a time. + * Opening an input port will fail if another application has already opened it for use. + * A {@link MidiDeviceStatus} can be used to determine if an input port is already open. + * * @param portNumber the number of the input port to open - * @return the {@link MidiInputPort} + * @return the {@link MidiInputPort} if the open is successful, + * or null in case of failure. */ public MidiInputPort openInputPort(int portNumber) { try { @@ -133,8 +138,11 @@ public final class MidiDevice implements Closeable { /** * Called to open a {@link MidiOutputPort} for the specified port number. * + * An output port may be opened by multiple applications. + * * @param portNumber the number of the output port to open - * @return the {@link MidiOutputPort} + * @return the {@link MidiOutputPort} if the open is successful, + * or null in case of failure. */ public MidiOutputPort openOutputPort(int portNumber) { try { diff --git a/media/java/android/media/midi/package.html b/media/java/android/media/midi/package.html index 673c4ba..7baa5bc 100644 --- a/media/java/android/media/midi/package.html +++ b/media/java/android/media/midi/package.html @@ -31,7 +31,7 @@ capabilities, etc.</li> <li> Timestamps to avoid jitter.</li> <li> Support creation of <em>virtual MIDI devices</em> that can be connected to other devices. An example might be a synthesizer app that can be controlled by a composing app.</li> - <li> Support direction connection or “patching” of devices for lower latency.</li> + <li> Support direct connection or “patching” of devices for lower latency.</li> </ul> <h2 id=transports_supported>Transports Supported</h2> @@ -75,6 +75,18 @@ Then the app will not appear in the Play Store for old devices that do not suppo <uses-feature android:name="android.software.midi" android:required="true"/> </pre> +<h2 id=check_feature>Check for Feature Support</h2> + +<p>An app can also check at run-time whether the MIDI feature is supported on a platform. +This is particularly useful during development when you install apps directly on a device. +</p> + +<pre class=prettyprint> +if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_MIDI)) { + // do MIDI stuff +} +</pre> + <h2 id=the_midimanager>The MidiManager</h2> @@ -338,5 +350,54 @@ public class MidiSynthDeviceService extends MidiDeviceService { } } </pre> + +<h1 id=using_midi_btle>Using MIDI Over Bluetooth LE</h1> + +<p>MIDI devices can be connected to Android using Bluetooth LE.</p> + +<p>Before using the device, the app must scan for available BTLE devices and then allow +the user to connect. An example program +will be provided so look for it on the Android developer website.</p> + +<h2 id=btle_location_permissions>Request Location Permission for BTLE</h2> + +<p>Applications that scan for Bluetooth devices must request permission in the +manifest file. This LOCATION permission is required because it may be possible to +guess the location of an Android device by seeing which BTLE devices are nearby.</p> + +<pre class=prettyprint> +<uses-permission android:name="android.permission.BLUETOOTH"/> +<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/> +<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/> +</pre> + +<p>Apps must also request location permission from the user at run-time. +See the documentation for <code>Activity.requestPermissions()</code> for details and an example. +</p> + +<h2 id=btle_scan_devices>Scan for MIDI Devices</h2> + +<p>The app will only want to see MIDI devices and not mice or other non-MIDI devices. +So construct a ScanFilter using the UUID for standard MIDI over BTLE.</p> + +<pre class=prettyprint> +MIDI over BTLE UUID = "03B80E5A-EDE8-4B33-A751-6CE34EC4C700" +</pre> + +<h2 id=btle_open_device>Open a MIDI Bluetooth Device</h2> + +<p>See the documentation for <code>android.bluetooth.le.BluetoothLeScanner.startScan()</code> +method for details. When the user selects a MIDI/BTLE device then you can open it +using the MidiManager.</p> + +<pre class=prettyprint> +m.openBluetoothDevice(bluetoothDevice, callback, handler); +</pre> + +<p>Once the MIDI/BTLE device has been opened by one app then it will also become available to other +apps using the +<a href="#get_list_of_already_plugged_in_entities">MIDI device discovery calls described above</a>. +</p> + </body> </html> |