public
final
class
MediaMuxer
extends Object
java.lang.Object | |
↳ | android.media.MediaMuxer |
MediaMuxer facilitates muxing elementary streams. Currently supports mp4 or webm file as the output and at most one audio and/or one video elementary stream. MediaMuxer does not support muxing B-frames.
It is generally used like this:
MediaMuxer muxer = new MediaMuxer("temp.mp4", OutputFormat.MUXER_OUTPUT_MPEG_4); // More often, the MediaFormat will be retrieved from MediaCodec.getOutputFormat() // or MediaExtractor.getTrackFormat(). MediaFormat audioFormat = new MediaFormat(...); MediaFormat videoFormat = new MediaFormat(...); int audioTrackIndex = muxer.addTrack(audioFormat); int videoTrackIndex = muxer.addTrack(videoFormat); ByteBuffer inputBuffer = ByteBuffer.allocate(bufferSize); boolean finished = false; BufferInfo bufferInfo = new BufferInfo(); muxer.start(); while(!finished) { // getInputBuffer() will fill the inputBuffer with one frame of encoded // sample from either MediaCodec or MediaExtractor, set isAudioSample to // true when the sample is audio data, set up all the fields of bufferInfo, // and return true if there are no more samples. finished = getInputBuffer(inputBuffer, isAudioSample, bufferInfo); if (!finished) { int currentTrackIndex = isAudioSample ? audioTrackIndex : videoTrackIndex; muxer.writeSampleData(currentTrackIndex, inputBuffer, bufferInfo); } }; muxer.stop(); muxer.release();
Nested classes | |||
---|---|---|---|
class |
MediaMuxer.OutputFormat
Defines the output format. |
Public constructors | |
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MediaMuxer(String path, int format)
Constructor. |
Public methods | |
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int
|
addTrack(MediaFormat format)
Adds a track with the specified format. |
void
|
release()
Make sure you call this when you're done to free up any resources instead of relying on the garbage collector to do this for you at some point in the future. |
void
|
setLocation(float latitude, float longitude)
Set and store the geodata (latitude and longitude) in the output file. |
void
|
setOrientationHint(int degrees)
Sets the orientation hint for output video playback. |
void
|
start()
Starts the muxer. |
void
|
stop()
Stops the muxer. |
void
|
writeSampleData(int trackIndex, ByteBuffer byteBuf, MediaCodec.BufferInfo bufferInfo)
Writes an encoded sample into the muxer. |
Protected methods | |
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void
|
finalize()
Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. |
Inherited methods | |
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From
class
java.lang.Object
|
MediaMuxer (String path, int format)
Constructor. Creates a media muxer that writes to the specified path.
Parameters | |
---|---|
path |
String :
The path of the output media file. |
format |
int :
The format of the output media file. |
Throws | |
---|---|
IllegalArgumentException |
if path is invalid or format is not supported. |
IOException |
if failed to open the file for write. |
See also:
int addTrack (MediaFormat format)
Adds a track with the specified format.
The following table summarizes support for specific format keys across android releases. Keys marked with '+:' are required.
OS Version(s) | MediaFormat keys used for
| ||
---|---|---|---|
All Tracks | Audio Tracks | Video Tracks | |
JELLY_BEAN_MR2 |
+: KEY_MIME |
+: KEY_SAMPLE_RATE ,+: KEY_CHANNEL_COUNT ,+: codec-specific dataAAC |
+: KEY_WIDTH ,+: KEY_HEIGHT ,no KEY_ROTATION ,
use setOrientationHint() .mp4,+: codec-specific dataAVC, MPEG4 |
KITKAT |
|||
KITKAT_WATCH |
|||
LOLLIPOP |
as above, plus +: codec-specific dataVorbis & .webm |
||
LOLLIPOP_MR1 |
|||
M |
as above, plusKEY_BIT_RATE AAC |
||
N |
as above, plusKEY_BIT_RATE MPEG4,KEY_HDR_STATIC_INFO #, .webm,KEY_COLOR_STANDARD #,KEY_COLOR_TRANSFER #,KEY_COLOR_RANGE #,+: codec-specific dataHEVC, codec-specific dataVP9 |
||
Notes: |
|||
Note that the codec-specific data for the track must be specified using
this method. Furthermore, codec-specific data must not be passed/specified via the
|
The following table summarizes codec support for containers across android releases:
OS Version(s) | Codec support | ||
---|---|---|---|
MP4 | WEBM | ||
JELLY_BEAN_MR2 |
AAC ,NB-AMR ,WB-AMR ,H.263 ,MPEG-4 ,AVC (H.264) |
Not supported | |
KITKAT |
|||
KITKAT_WATCH |
|||
LOLLIPOP |
Vorbis ,VP8 |
||
LOLLIPOP_MR1 |
|||
M |
|||
N |
as above, plusHEVC (H.265) |
as above, plusVP9 |
Parameters | |
---|---|
format |
MediaFormat :
The media format for the track. This must not be an empty
MediaFormat. |
Returns | |
---|---|
int |
The track index for this newly added track, and it should be used
in the writeSampleData(int, ByteBuffer, MediaCodec.BufferInfo) . |
Throws | |
---|---|
IllegalArgumentException |
if format is invalid. |
IllegalStateException |
if muxer is in the wrong state. |
void release ()
Make sure you call this when you're done to free up any resources instead of relying on the garbage collector to do this for you at some point in the future.
void setLocation (float latitude, float longitude)
Set and store the geodata (latitude and longitude) in the output file.
This method should be called before start()
. The geodata is stored
in udta box if the output format is
MUXER_OUTPUT_MPEG_4
, and is ignored for other output
formats. The geodata is stored according to ISO-6709 standard.
Parameters | |
---|---|
latitude |
float :
Latitude in degrees. Its value must be in the range [-90,
90]. |
longitude |
float :
Longitude in degrees. Its value must be in the range
[-180, 180]. |
Throws | |
---|---|
IllegalArgumentException |
If the given latitude or longitude is out of range. |
IllegalStateException |
If this method is called after start() .
|
void setOrientationHint (int degrees)
Sets the orientation hint for output video playback.
This method should be called before start()
. Calling this
method will not rotate the video frame when muxer is generating the file,
but add a composition matrix containing the rotation angle in the output
video if the output format is
MUXER_OUTPUT_MPEG_4
so that a video player can
choose the proper orientation for playback. Note that some video players
may choose to ignore the composition matrix in a video during playback.
By default, the rotation degree is 0.
Parameters | |
---|---|
degrees |
int :
the angle to be rotated clockwise in degrees.
The supported angles are 0, 90, 180, and 270 degrees. |
Throws | |
---|---|
IllegalArgumentException |
if degree is not supported. |
IllegalStateException |
If this method is called after start() .
|
void start ()
Starts the muxer.
Make sure this is called after addTrack(MediaFormat)
and before
writeSampleData(int, ByteBuffer, MediaCodec.BufferInfo)
.
Throws | |
---|---|
IllegalStateException |
If this method is called after start()
or Muxer is released
|
void stop ()
Stops the muxer.
Once the muxer stops, it can not be restarted.
Throws | |
---|---|
IllegalStateException |
if muxer is in the wrong state. |
void writeSampleData (int trackIndex, ByteBuffer byteBuf, MediaCodec.BufferInfo bufferInfo)
Writes an encoded sample into the muxer.
The application needs to make sure that the samples are written into the right tracks. Also, it needs to make sure the samples for each track are written in chronological order (e.g. in the order they are provided by the encoder.)
Parameters | |
---|---|
trackIndex |
int :
The track index for this sample. |
byteBuf |
ByteBuffer :
The encoded sample. |
bufferInfo |
MediaCodec.BufferInfo :
The buffer information related to this sample. |
Throws | |
---|---|
IllegalArgumentException |
if trackIndex, byteBuf or bufferInfo is invalid. |
IllegalStateException |
if muxer is in wrong state.
MediaMuxer uses the flags provided in MediaCodec.BufferInfo ,
to signal sync frames.
|
void finalize ()
Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.
A subclass overrides the finalize
method to dispose of
system resources or to perform other cleanup.
The general contract of finalize
is that it is invoked
if and when the JavaTM virtual
machine has determined that there is no longer any
means by which this object can be accessed by any thread that has
not yet died, except as a result of an action taken by the
finalization of some other object or class which is ready to be
finalized. The finalize
method may take any action, including
making this object available again to other threads; the usual purpose
of finalize
, however, is to perform cleanup actions before
the object is irrevocably discarded. For example, the finalize method
for an object that represents an input/output connection might perform
explicit I/O transactions to break the connection before the object is
permanently discarded.
The finalize
method of class Object
performs no
special action; it simply returns normally. Subclasses of
Object
may override this definition.
The Java programming language does not guarantee which thread will
invoke the finalize
method for any given object. It is
guaranteed, however, that the thread that invokes finalize will not
be holding any user-visible synchronization locks when finalize is
invoked. If an uncaught exception is thrown by the finalize method,
the exception is ignored and finalization of that object terminates.
After the finalize
method has been invoked for an object, no
further action is taken until the Java virtual machine has again
determined that there is no longer any means by which this object can
be accessed by any thread that has not yet died, including possible
actions by other objects or classes which are ready to be finalized,
at which point the object may be discarded.
The finalize
method is never invoked more than once by a Java
virtual machine for any given object.
Any exception thrown by the finalize
method causes
the finalization of this object to be halted, but is otherwise
ignored.
Throws | |
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Throwable |