1. Recap: Android Components
Application= Set of Android Components
Intent
Activity
UI Component typically corresponding to one screen.
BroadcastReceiver
Responds to notifications or status changes. Can wake up your process.
Service
Faceless task that runs in the background.
ContentProvider
Enable applications to share data.

2. Android Programming Lecture 10
Testing notes
Multimedia

4. Audio
Video
MP3
MIDI
PCM/WAVE
AAC LC
etc…
H.263
H.264 AVC
MPEG-4
etc…
The Android multimedia framework includes support for playing variety of common media types, so that you can easily integrate audio, video and images into your applications.

5. Media Playback
Android multimedia framework includes support for playing variety of common media types, so that you can easily integrate audio, video and images into your applications.
You can play audio or video from media files stored in your application’s resources (raw resources), from standalone files in the file system, or from a data stream arriving over a network connection, all using MediaPlayer class

6. Media Playback Guide
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7. Media Player
One of the most important components of the media framework is the MediaPlayer class. An object of this class can fetch, decode, and play both audio and video with minimal setup. It supports several different media sources such as:
Local resources
Internal URIs, such as one you might obtain from a Content Resolver
External URIs (streaming)
Supported Media Formats are:
RTSP (RTP, SDP)
HTTP/HTTPS progressive streaming
HTTP/HTTPS live streaming
3GPP
MPEG-4
MP3

8. Step 2: Configure the media player object to start the media playback
Step 1: Create the raw folder in the project and put the media file into the folder
Step 2: Configure the media player object to start the media playback
// Create an instance of MediaPlayer and load the music
MediaPlayer mediaPlayer = MediaPlayer.create(this,
R.raw.music);
// Start the media playback
mediaPlayer.start();
To replay the media, call reset() and prepare()
To pause, call pause()
To stop, call stop()
MediaPlayer class reference:

9. Media Player
Whit this example you can play an audio file as a local raw resource from res/raw/ directory:
You can also load a local content through an URI Object
You can also play a content from a remote URL via HTTP streaming.
MediaPlayer mediaPlayer = MediaPlayer.create(context, R.raw.sound_file_1); mediaPlayer.start(); // no need to call prepare(); create() does that for you
Uri myUri = ....; // initialize Uri here MediaPlayer mediaPlayer = new MediaPlayer(); mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); mediaPlayer.setDataSource(getApplicationContext(), myUri); mediaPlayer.prepare(); mediaPlayer.start();
String url = " // your URL here MediaPlayer mediaPlayer = new MediaPlayer(); mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); mediaPlayer.setDataSource(url); mediaPlayer.prepare(); // might take long! (for buffering, etc) mediaPlayer.start();

10. Read Media Information

11. Callback Functions
setOnBufferingUpdateListener
This method can be called in any state and calling it does not change the object state.
setOnCompletionListener
setOnErrorListener
setOnPreparedListener
setOnSeekCompleteListener

12. Task at home
Follow this tutorial to make a cool sound equalizer:

13. Audio Recording

14. Audio Capture
You can record audio using the MediaRecorder APIs if supported by the device hardware
Emulator does not have the capability to record audio and video
MediaRecorder class reference:

15. Media Recorder Create a new instance of android.media.MediaRecorder.
Set the audio source using MediaRecorder.setAudioSource(). You will probably want to use microphone with MediaRecorder.AudioSource.MIC
Set output file format using MediaRecorder.setOutputFormat().
Set output file name using MediaRecorder.setOutputFile().
Set the audio encoder using MediaRecorder.setAudioEncoder().
Call MediaRecorder.prepare() on the MediaRecorder instance.
To start audio capture, call MediaRecorder.start().
To stop audio capture, call MediaRecorder.stop().
When you are done with the MediaRecorder instance, call MediaRecorder.release() on it to release the resource.

16. private void startRecording() {
// 1. Create a new instance of android.media.MediaRecorder
MediaRecorder mRecorder = new MediaRecorder();
// 2. Set the audio source using MediaRecorder.setAudioSource()
// In this example, use microphone to get audio
mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
// 3. Set output file format using MediaRecorder.setOutputFormat().
mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
// 4. Set output file name using MediaRecorder.setOutputFile().
mRecorder.setOutputFile(“/sdcard/myaudio.3gp”);
// 5. Set the audio encoder using MediaRecorder.setAudioEncoder().
mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
// 6. Call MediaRecorder.prepare() on the MediaRecorder instance.
try {
mRecorder.prepare();
} catch (IOException e) {
Log.e(LOG_TAG, "prepare() failed"); }
// 7. To start audio capture, call MediaRecorder.start().
mRecorder.start();
private void stopRecording() {
// 8. To stop audio capture, call MediaRecorder.stop().
mRecorder.stop();
// 9. call MediaRecorder.release() on it to release the resource.
mRecorder.release();
mRecorder = null;

17. Things to Remember: Manifest
The application needs to have the permission to write to external storage if the output file is written to the external storage, and also the permission to record audio. These permissions must be set in the application's AndroidManifest.xml file, with something like:
<manifest >
. . .
<uses-permission android:name="android.permission.RECORD_AUDIO"/>
<uses-permission
android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
</manifest>

18. SoundPool Multiple sounds can be played from raw or compressed source
A SoundPool is a collection of samples that can be loaded into memory from a resource inside the APK or from a file in the file system
More efficient than media player in terms of CPU load, latency
Adjustable playback frequency
Each sound can be assigned a priority
Support for repeat mode
SoundPool class reference:

19. Creating Sound Effects
SoundPool is designed for short files which can be kept in memory decompressed for quick access, this is best suited for sound effects in apps and games
Media Player is designed for longer sound files or streams, this is best suited for music files or larger files. The files will be loaded disk each time created is called, this will save on memory space but introduce a small delay (not really noticeable)
SoundPool
MediaPlayer
Refer to the video for a comparison between the two classes

20. SoundPool soundPool = new SoundPool(4, AudioManager.STREAM_MUSIC, 0);
Constructs a SoundPool with the maximum number of simultaneous streams and Audio stream type.
SoundPool soundPool = new SoundPool(4, AudioManager.STREAM_MUSIC, 0);
int soundId = mSoundPool.load(this, R.raw.b1, 1);
soundPool.play(soundId, 1f, 1f, 1, 0, 1f);
Load the sound from the specified resource.
Play the music clip
• soundID – Sound ID returned by the load() function
• leftVolume – Left volume value (0.0 ~ 1.0)
• rightVolume – right volume value (0.0 ~ 1.0)
• priority – stream priority (0 = lowest priority)
• loop – loop mode (0 = no loop, -1 = loop forever)
• rate – playback rate (0.5 ~ 2.0, 1.0 = normal playback)
SoundPool class reference:

21. Task at home
In assignment 1 game, ask the player to record the short sound, and use the sound in the game, like when the ball hits the paddle and bounces

22. Video

23. VideoView
VideoView is a View that has video playback capabilities and can be used directly in a layout
It is a View working with media player
The VideoView class can load images from various sources (such as resources or content providers), takes care of computing its measurement from the video so that it can be used in any layout manager, and provides various display options such as scaling and tinting
We can then add controls (play, pause, forward, back, etc) with the MediaController class.

24. Video View main_layout.xml MainActivity.java
Uri.parse(Environment.getExternalStorageDirectory().getPath() + "/example.mp4");
Add VideoView component on layout file
Set content on VideoView
setVideoURI(...)
setVideoPath(...)
Use start(), stop(), etc. to control video.

25. Callback Functions setOnPreparedListener -> onPrepared()
Called when VideoView is prepared for play.
Use when waiting contents on online to be prepared.
setOnCompletionListener -> onCompletion()
Called when VideoView playback is completed

26. Using Native App Invoke the video playback by using the common intent
Remember, your app is now in the background.
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(srcPath)); intent.setDataAndType(Uri.parse(srcPath), "video/mp4"); startActivity(intent);

27. Camera

28. Camera
The Android framework includes support for various cameras and camera features available on devices, allowing you to capture pictures and videos in your applications.
The Android framework supports capturing images and video through the Camera API or camera Intent.

29. Camera Camera MediaRecorder Intent
This class is the primary API for controlling device cameras. This class is used to take pictures or videos when you are building a camera application.
MediaRecorder
This class is used to record video from the camera.
Intent
An intent action type of MediaStore.ACTION_IMAGE_CAPTURE or MediaStore.ACTION_VIDEO_CAPTURE can be used to capture images or videos without directly using the Camera object.

30. Image Capture Intent
private static final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 100; private Uri fileUri; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // create Intent to take a picture and return control to the calling application Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE); // create a file to save the image intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri); // set the image file name // start the image capture Intent startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE); }
Capturing images using a camera intent is quick way to enable your application to take pictures with minimal coding. An image capture intent can include the following extra information

31. Image Capture Intent
private static final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 100; private Uri fileUri; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // create Intent to take a picture and return control to the calling application Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE); // create a file to save the image intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri); // set the image file name // start the image capture Intent startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE); }
MediaStore.EXTRA_OUTPUT- This setting requires a Uri object specifying a path and file name where you'd like to save the picture. This setting is optional but strongly recommended. If you do not specify this value, the camera application saves the requested picture in the default location with a default name, specified in the returned intent's Intent.getData() field.

32. Retrieve Results
@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE) { if (resultCode == RESULT_OK) { // Image captured and saved to fileUri specified in the Intent
Bitmap thumbnail = data.getParcelableExtra("data"); Toast.makeText(this, "Image saved to:\n" data.getData(), Toast.LENGTH_LONG).show(); } else if (resultCode == RESULT_CANCELED) { // User cancelled the image capture } else { // Image capture failed, advise user } } if (requestCode == CAPTURE_VIDEO_ACTIVITY_REQUEST_CODE) { if (resultCode == RESULT_OK) { // Video captured and saved to fileUri specified in the Intent Toast.makeText(this, "Video saved to:\n" data.getData(), Toast.LENGTH_LONG).show(); } else if (resultCode == RESULT_CANCELED) { // User cancelled the video capture } else { // Video capture failed, advise user } } }
Receive the result with the file system location of the new Image
Receive the result
with the file
system location of
the new Video.

34. Media Router
As users connect their televisions, home theatre systems and music players with wireless technologies, they want to be able to play content from Android apps on these larger, louder devices. Enabling this kind of playback can turn your one-device, one-user app into a shared experience that delights and inspires multiple users.

35. Media Router

36. Recommended Reading Android Developer Site: Media and Camera
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Vogella Tutorial: Handling Media with Android
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