Android supports playing and capturing a variety of common audio and video formats. The MediaPlayer class is used for playback and MediaRecorder for capture. MediaPlayer can play resources, files, and streams, while MediaRecorder requires setting permissions, audio/video sources, and format/encoder before starting recording. The VideoView widget simplifies playing video by wrapping MediaPlayer and a SurfaceView.

1. Android
Audio
and
Video
Jussi
Pohjolainen

2. Audio
and
Video
• Supports
variety
of
common
media
types
– See
Media
Formats
– http://developer.android.com/guide/appendix/
media-formats.html
• Can
play
raw
resources,
standalone
files
and
streams
• MediaPlayer
for
playing
and
MediaCapture
for
capturing
• Emulator
does
not
have
the
capability
to
record
audio
or
video

3. MediaPlayer

4. Audio
and
Video
Playback
• From
raw
(res/raw
folder)
– MediaPlayer mp = MediaPlayer.create(context,
R.raw.sound_file_1);
– mp.start();
• To
replay
the
media,
call
reset()
and
prepare()
• To
pause,
use
pause()
and
to
stop
use
stop()

5. Playing
from
File
or
Stream
• Use
setDataSource()
–
method
– MediaPlayer mp = new MediaPlayer();
– mp.setDataSource(PATH_TO_FILE OR URL);
– mp.prepare();
– mp.start();

6. Playing
Videos:
VideoView
Widget
• If
using
MediaPlayer
for
videos,
you
must
set
the
SurfaceView
for
the
video
• Easier
way:
use
VideoView
Widget
• VideoView
wraps
MediaPlayer
and
SurfaceView
• How?
– VideoView videoview = (VideoView) findById..
– videoview.setVideoPath(…);
– videoview.setMediaController(new MediaController(this));
– videoview.requestFocus();

7. MediaRecorder:
Record
Audio
and
Video

8. Audio
Capture
• Create
instance
of
MediaRecorder
• Create
a
file
path
for
the
data
to
go
• Set
audio
source
to
MediaRecorder.AudioSource.MIC
• Set
output
format
• Set
audio
encoder
• Call
prepare,
start
and
stop
• App
must
have
permission
to
make
audio
captures!

9. Example
of
Audio
Capture
MediaRecorder recorder = new MediaRecorder();
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
// 3GPP
recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
// AMR (Narrowband) audio codec
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
recorder.setOutputFile(PATH_NAME);
recorder.prepare();
recorder.start(); // Recording is now started
...
recorder.stop();

10. Couple
Things
to
Remember
• Remember
to
set
permissions:
– android.permission.RECORD_AUDIO
– android.permission.WRITE_EXTERNAL_STORAGE
• To
get
the
full
path
to
external
storage,
use:
–
String
path =
Environment.getExternalStorageDirectory().getAbsolutePath
();

11. Video
Capture
• MediaRecorder
is
used
also
to
capture
Video
• You
can
preview
the
the
captured
video
on
any
SurfaceView
(for
example
VideoWidget):
–
recordMyVideo.setPreviewDisplay(
videoView.get
Holder().getSurface()
);

12. Example
of
Video
Capture
MediaRecorder recordMyVideo = new MediaRecorder();
recordMyVideo.setAudioSource(MediaRecorder.AudioSource.MIC);
recordMyVideo.setVideoSource(MediaRecorder.VideoSource.CAMERA);
recordMyVideo.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
recordMyVideo.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
recordMyVideo.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);
recordMyVideo.setMaxDuration(5000);
recordMyVideo.setVideoSize(320, 240);
recordMyVideo.setVideoFrameRate(15);
// get full path to sd-card
recordMyVideo.setOutputFile( getMyVideoSourcePath() );
// use videoWidget as preview
recordMyVideo.setPreviewDisplay( videoView.getHolder().getSurface() );