Android APIs
public final class

MediaCodec

extends Object
java.lang.Object
   ↳ android.media.MediaCodec

Class Overview

MediaCodec class can be used to access low-level media codecs, i.e. encoder/decoder components. It is part of the Android low-level multimedia support infrastructure (normally used together with MediaExtractor, MediaSync, MediaMuxer, MediaCrypto, MediaDrm, Image, Surface, and AudioTrack.)

MediaCodec buffer flow diagram

In broad terms, a codec processes input data to generate output data. It processes data asynchronously and uses a set of input and output buffers. At a simplistic level, you request (or receive) an empty input buffer, fill it up with data and send it to the codec for processing. The codec uses up the data and transforms it into one of its empty output buffers. Finally, you request (or receive) a filled output buffer, consume its contents and release it back to the codec.

Data Types

Codecs operate on three kinds of data: compressed data, raw audio data and raw video data. All three kinds of data can be processed using ByteBuffers, but you should use a Surface for raw video data to improve codec performance. Surface uses native video buffers without mapping or copying them to ByteBuffers; thus, it is much more efficient. You normally cannot access the raw video data when using a Surface, but you can use the ImageReader class to access unsecured decoded (raw) video frames. This may still be more efficient than using ByteBuffers, as some native buffers may be mapped into direct ByteBuffers. When using ByteBuffer mode, you can access raw video frames using the Image class and getInput/OutputImage(int).

Compressed Buffers

Input buffers (for decoders) and output buffers (for encoders) contain compressed data according to the format's type. For video types this is a single compressed video frame. For audio data this is normally a single access unit (an encoded audio segment typically containing a few milliseconds of audio as dictated by the format type), but this requirement is slightly relaxed in that a buffer may contain multiple encoded access units of audio. In either case, buffers do not start or end on arbitrary byte boundaries, but rather on frame/access unit boundaries.

Raw Audio Buffers

Raw audio buffers contain entire frames of PCM audio data, which is one sample for each channel in channel order. Each sample is a 16-bit signed integer in native byte order.

 short[] getSamplesForChannel(MediaCodec codec, int bufferId, int channelIx) {
   ByteBuffer outputBuffer = codec.getOutputBuffer(bufferId);
   MediaFormat format = codec.getOutputFormat(bufferId);
   ShortBuffer samples = outputBuffer.order(ByteOrder.nativeOrder()).asShortBuffer();
   int numChannels = formet.getInteger(MediaFormat.KEY_CHANNEL_COUNT);
   if (channelIx < 0 || channelIx >= numChannels) {
     return null;
   }
   short[] res = new short[samples.remaining() / numChannels];
   for (int i = 0; i < res.length; ++i) {
     res[i] = samples.get(i * numChannels + channelIx);
   }
   return res;
 }

Raw Video Buffers

In ByteBuffer mode video buffers are laid out according to their color format. You can get the supported color formats as an array from getCodecInfo().getCapabilitiesForType(…).colorFormats. Video codecs may support three kinds of color formats:

All video codecs support flexible YUV 4:2:0 buffers since LOLLIPOP_MR1.

States

During its life a codec conceptually exists in one of three states: Stopped, Executing or Released. The Stopped collective state is actually the conglomeration of three states: Uninitialized, Configured and Error, whereas the Executing state conceptually progresses through three sub-states: Flushed, Running and End-of-Stream.

MediaCodec state diagram

When you create a codec using one of the factory methods, the codec is in the Uninitialized state. First, you need to configure it via configure(…), which brings it to the Configured state, then call start() to move it to the Executing state. In this state you can process data through the buffer queue manipulation described above.

The Executing state has three sub-states: Flushed, Running and End-of-Stream. Immediately after start() the codec is in the Flushed sub-state, where it holds all the buffers. As soon as the first input buffer is dequeued, the codec moves to the Running sub-state, where it spends most of its life. When you queue an input buffer with the end-of-stream marker, the codec transitions to the End-of-Stream sub-state. In this state the codec no longer accepts further input buffers, but still generates output buffers until the end-of-stream is reached on the output. You can move back to the Flushed sub-state at any time while in the Executing state using flush().

Call stop() to return the codec to the Uninitialized state, whereupon it may be configured again. When you are done using a codec, you must release it by calling release().

On rare occasions the codec may encounter an error and move to the Error state. This is communicated using an invalid return value from a queuing operation, or sometimes via an exception. Call reset() to make the codec usable again. You can call it from any state to move the codec back to the Uninitialized state. Otherwise, call release() to move to the terminal Released state.

Creation

Use MediaCodecList to create a MediaCodec for a specific MediaFormat. When decoding a file or a stream, you can get the desired format from MediaExtractor.getTrackFormat. Inject any specific features that you want to add using MediaFormat.setFeatureEnabled, then call MediaCodecList.findDecoderForFormat to get the name of a codec that can handle that specific media format. Finally, create the codec using createByCodecName(String).

Note: On LOLLIPOP, the format to MediaCodecList.findDecoder/EncoderForFormat must not contain a frame rate. Use format.setString(MediaFormat.KEY_FRAME_RATE, null) to clear any existing frame rate setting in the format.

You can also create the preferred codec for a specific MIME type using createDecoder/EncoderByType(String). This, however, cannot be used to inject features, and may create a codec that cannot handle the specific desired media format.

Creating secure decoders

On versions KITKAT_WATCH and earlier, secure codecs might not be listed in MediaCodecList, but may still be available on the system. Secure codecs that exist can be instantiated by name only, by appending ".secure" to the name of a regular codec (the name of all secure codecs must end in ".secure".) createByCodecName(String) will throw an IOException if the codec is not present on the system.

From LOLLIPOP onwards, you should use the FEATURE_SecurePlayback feature in the media format to create a secure decoder.

Initialization

After creating the codec, you can set a callback using setCallback if you want to process data asynchronously. Then, configure the codec using the specific media format. This is when you can specify the output Surface for video producers – codecs that generate raw video data (e.g. video decoders). This is also when you can set the decryption parameters for secure codecs (see MediaCrypto). Finally, since some codecs can operate in multiple modes, you must specify whether you want it to work as a decoder or an encoder.

Since LOLLIPOP, you can query the resulting input and output format in the Configured state. You can use this to verify the resulting configuration, e.g. color formats, before starting the codec.

If you want to process raw input video buffers natively with a video consumer – a codec that processes raw video input, such as a video encoder – create a destination Surface for your input data using createInputSurface() after configuration. Alternately, set up the codec to use a previously created persistent input surface by calling setInputSurface(Surface).

Codec-specific Data

Some formats, notably AAC audio and MPEG4, H.264 and H.265 video formats require the actual data to be prefixed by a number of buffers containing setup data, or codec specific data. When processing such compressed formats, this data must be submitted to the codec after start() and before any frame data. Such data must be marked using the flag BUFFER_FLAG_CODEC_CONFIG in a call to queueInputBuffer.

Codec-specific data can also be included in the format passed to configure in ByteBuffer entries with keys "csd-0", "csd-1", etc. These keys are always included in the track MediaFormat obtained from the MediaExtractor. Codec-specific data in the format is automatically submitted to the codec upon start(); you MUST NOT submit this data explicitly. If the format did not contain codec specific data, you can choose to submit it using the specified number of buffers in the correct order, according to the format requirements. Alternately, you can concatenate all codec-specific data and submit it as a single codec-config buffer.

Android uses the following codec-specific data buffers. These are also required to be set in the track format for proper MediaMuxer track configuration. Each parameter set and the codec-specific-data sections marked with (*) must start with a start code of "\x00\x00\x00\x01".

Format CSD buffer #0 CSD buffer #1 CSD buffer #2
AAC Decoder-specific information from ESDS* Not Used Not Used
VORBIS Identification header Setup header Not Used
OPUS Identification header Pre-skip in nanosecs
(unsigned 64-bit native-order integer.)
This overrides the pre-skip value in the identification header.
Seek Pre-roll in nanosecs
(unsigned 64-bit native-order integer.)
MPEG-4 Decoder-specific information from ESDS* Not Used Not Used
H.264 AVC SPS (Sequence Parameter Sets*) PPS (Picture Parameter Sets*) Not Used
H.265 HEVC VPS (Video Parameter Sets*) +
SPS (Sequence Parameter Sets*) +
PPS (Picture Parameter Sets*)
Not Used Not Used

Note: care must be taken if the codec is flushed immediately or shortly after start, before any output buffer or output format change has been returned, as the codec specific data may be lost during the flush. You must resubmit the data using buffers marked with BUFFER_FLAG_CODEC_CONFIG after such flush to ensure proper codec operation.

Encoders (or codecs that generate compressed data) will create and return the codec specific data before any valid output buffer in output buffers marked with the codec-config flag. Buffers containing codec-specific-data have no meaningful timestamps.

Data Processing

Each codec maintains a set of input and output buffers that are referred to by a buffer-ID in API calls. After a successful call to start() the client "owns" neither input nor output buffers. In synchronous mode, call dequeueInput/OutputBuffer(…) to obtain (get ownership of) an input or output buffer from the codec. In asynchronous mode, you will automatically receive available buffers via the MediaCodec.Callback.onInput/OutputBufferAvailable(…) callbacks.

Upon obtaining an input buffer, fill it with data and submit it to the codec using queueInputBuffer – or queueSecureInputBuffer if using decryption. Do not submit multiple input buffers with the same timestamp (unless it is codec-specific data marked as such).

The codec in turn will return a read-only output buffer via the onOutputBufferAvailable callback in asynchronous mode, or in response to a dequeuOutputBuffer call in synchronous mode. After the output buffer has been processed, call one of the releaseOutputBuffer methods to return the buffer to the codec.

While you are not required to resubmit/release buffers immediately to the codec, holding onto input and/or output buffers may stall the codec, and this behavior is device dependent. Specifically, it is possible that a codec may hold off on generating output buffers until all outstanding buffers have been released/resubmitted. Therefore, try to hold onto to available buffers as little as possible.

Depending on the API version, you can process data in three ways:

Processing Mode API version <= 20
Jelly Bean/KitKat
API version >= 21
Lollipop and later
Synchronous API using buffer arrays Supported Deprecated
Synchronous API using buffers Not Available Supported
Asynchronous API using buffers Not Available Supported

Asynchronous Processing using Buffers

Since LOLLIPOP, the preferred method is to process data asynchronously by setting a callback before calling configure. Asynchronous mode changes the state transitions slightly, because you must call start() after flush() to transition the codec to the Running sub-state and start receiving input buffers. Similarly, upon an initial call to start the codec will move directly to the Running sub-state and start passing available input buffers via the callback.

MediaCodec state diagram for asynchronous operation

MediaCodec is typically used like this in asynchronous mode:

 MediaCodec codec = MediaCodec.createByCodecName(name);
 MediaFormat mOutputFormat; // member variable
 codec.setCallback(new MediaCodec.Callback() {
   @Override
   void onInputBufferAvailable(MediaCodec mc, int inputBufferId) {
     ByteBuffer inputBuffer = codec.getInputBuffer(inputBufferId);
     // fill inputBuffer with valid data
     …
     codec.queueInputBuffer(inputBufferId, …);
   }

   @Override
   void onOutputBufferAvailable(MediaCodec mc, int outputBufferId, …) {
     ByteBuffer outputBuffer = codec.getOutputBuffer(outputBufferId);
     MediaFormat bufferFormat = codec.getOutputFormat(outputBufferId); // option A
     // bufferFormat is equivalent to mOutputFormat
     // outputBuffer is ready to be processed or rendered.
     …
     codec.releaseOutputBuffer(outputBufferId, …);
   }

   @Override
   void onOutputFormatChanged(MediaCodec mc, MediaFormat format) {
     // Subsequent data will conform to new format.
     // Can ignore if using getOutputFormat(outputBufferId)
     mOutputFormat = format; // option B
   }

   @Override
   void onError(…) {
     …
   }
 });
 codec.configure(format, …);
 mOutputFormat = codec.getOutputFormat(); // option B
 codec.start();
 // wait for processing to complete
 codec.stop();
 codec.release();

Synchronous Processing using Buffers

Since LOLLIPOP, you should retrieve input and output buffers using getInput/OutputBuffer(int) and/or getInput/OutputImage(int) even when using the codec in synchronous mode. This allows certain optimizations by the framework, e.g. when processing dynamic content. This optimization is disabled if you call getInput/OutputBuffers().

Note: do not mix the methods of using buffers and buffer arrays at the same time. Specifically, only call getInput/OutputBuffers directly after start() or after having dequeued an output buffer ID with the value of INFO_OUTPUT_FORMAT_CHANGED.

MediaCodec is typically used like this in synchronous mode:

 MediaCodec codec = MediaCodec.createByCodecName(name);
 codec.configure(format, …);
 MediaFormat outputFormat = codec.getOutputFormat(); // option B
 codec.start();
 for (;;) {
   int inputBufferId = codec.dequeueInputBuffer(timeoutUs);
   if (inputBufferId >= 0) {
     ByteBuffer inputBuffer = codec.getInputBuffer(…);
     // fill inputBuffer with valid data
     …
     codec.queueInputBuffer(inputBufferId, …);
   }
   int outputBufferId = codec.dequeueOutputBuffer(…);
   if (outputBufferId >= 0) {
     ByteBuffer outputBuffer = codec.getOutputBuffer(outputBufferId);
     MediaFormat bufferFormat = codec.getOutputFormat(outputBufferId); // option A
     // bufferFormat is identical to outputFormat
     // outputBuffer is ready to be processed or rendered.
     …
     codec.releaseOutputBuffer(outputBufferId, …);
   } else if (outputBufferId == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
     // Subsequent data will conform to new format.
     // Can ignore if using getOutputFormat(outputBufferId)
     outputFormat = codec.getOutputFormat(); // option B
   }
 }
 codec.stop();
 codec.release();

Synchronous Processing using Buffer Arrays (deprecated)

In versions KITKAT_WATCH and before, the set of input and output buffers are represented by the ByteBuffer[] arrays. After a successful call to start(), retrieve the buffer arrays using getInput/OutputBuffers(). Use the buffer ID-s as indices into these arrays (when non-negative), as demonstrated in the sample below. Note that there is no inherent correlation between the size of the arrays and the number of input and output buffers used by the system, although the array size provides an upper bound.

 MediaCodec codec = MediaCodec.createByCodecName(name);
 codec.configure(format, …);
 codec.start();
 ByteBuffer[] inputBuffers = codec.getInputBuffers();
 ByteBuffer[] outputBuffers = codec.getOutputBuffers();
 for (;;) {
   int inputBufferId = codec.dequeueInputBuffer(…);
   if (inputBufferId >= 0) {
     // fill inputBuffers[inputBufferId] with valid data
     …
     codec.queueInputBuffer(inputBufferId, …);
   }
   int outputBufferId = codec.dequeueOutputBuffer(…);
   if (outputBufferId >= 0) {
     // outputBuffers[outputBufferId] is ready to be processed or rendered.
     …
     codec.releaseOutputBuffer(outputBufferId, …);
   } else if (outputBufferId == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
     outputBuffers = codec.getOutputBuffers();
   } else if (outputBufferId == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
     // Subsequent data will conform to new format.
     MediaFormat format = codec.getOutputFormat();
   }
 }
 codec.stop();
 codec.release();

End-of-stream Handling

When you reach the end of the input data, you must signal it to the codec by specifying the BUFFER_FLAG_END_OF_STREAM flag in the call to queueInputBuffer. You can do this on the last valid input buffer, or by submitting an additional empty input buffer with the end-of-stream flag set. If using an empty buffer, the timestamp will be ignored.

The codec will continue to return output buffers until it eventually signals the end of the output stream by specifying the same end-of-stream flag in the MediaCodec.BufferInfo set in dequeueOutputBuffer or returned via onOutputBufferAvailable. This can be set on the last valid output buffer, or on an empty buffer after the last valid output buffer. The timestamp of such empty buffer should be ignored.

Do not submit additional input buffers after signaling the end of the input stream, unless the codec has been flushed, or stopped and restarted.

Using an Output Surface

The data processing is nearly identical to the ByteBuffer mode when using an output Surface; however, the output buffers will not be accessible, and are represented as null values. E.g. getOutputBuffer/Image(int) will return null and getOutputBuffers() will return an array containing only null-s.

When using an output Surface, you can select whether or not to render each output buffer on the surface. You have three choices:

Since M, the default timestamp is the presentation timestamp of the buffer (converted to nanoseconds). It was not defined prior to that.

Also since M, you can change the output Surface dynamically using setOutputSurface.

Using an Input Surface

When using an input Surface, there are no accessible input buffers, as buffers are automatically passed from the input surface to the codec. Calling dequeueInputBuffer will throw an IllegalStateException, and getInputBuffers() returns a bogus ByteBuffer[] array that MUST NOT be written into.

Call signalEndOfInputStream() to signal end-of-stream. The input surface will stop submitting data to the codec immediately after this call.

Seeking & Adaptive Playback Support

Video decoders (and in general codecs that consume compressed video data) behave differently regarding seek and format change whether or not they support and are configured for adaptive playback. You can check if a decoder supports adaptive playback via CodecCapabilities.isFeatureSupported(String). Adaptive playback support for video decoders is only activated if you configure the codec to decode onto a Surface.

Stream Boundary and Key Frames

It is important that the input data after start() or flush() starts at a suitable stream boundary: the first frame must a key frame. A key frame can be decoded completely on its own (for most codecs this means an I-frame), and no frames that are to be displayed after a key frame refer to frames before the key frame.

The following table summarizes suitable key frames for various video formats.

Format Suitable key frame
VP9/VP8 a suitable intraframe where no subsequent frames refer to frames prior to this frame.
(There is no specific name for such key frame.)
H.265 HEVC IDR or CRA
H.264 AVC IDR
MPEG-4
H.263
MPEG-2
a suitable I-frame where no subsequent frames refer to frames prior to this frame.
(There is no specific name for such key frame.)

For decoders that do not support adaptive playback (including when not decoding onto a Surface)

In order to start decoding data that is not adjacent to previously submitted data (i.e. after a seek) you MUST flush the decoder. Since all output buffers are immediately revoked at the point of the flush, you may want to first signal then wait for the end-of-stream before you call flush. It is important that the input data after a flush starts at a suitable stream boundary/key frame.

Note: the format of the data submitted after a flush must not change; flush() does not support format discontinuities; for that, a full stop() - configure(…) - start() cycle is necessary.

Also note: if you flush the codec too soon after start() – generally, before the first output buffer or output format change is received – you will need to resubmit the codec-specific-data to the codec. See the codec-specific-data section for more info.

For decoders that support and are configured for adaptive playback

In order to start decoding data that is not adjacent to previously submitted data (i.e. after a seek) it is not necessary to flush the decoder; however, input data after the discontinuity must start at a suitable stream boundary/key frame.

For some video formats - namely H.264, H.265, VP8 and VP9 - it is also possible to change the picture size or configuration mid-stream. To do this you must package the entire new codec-specific configuration data together with the key frame into a single buffer (including any start codes), and submit it as a regular input buffer.

You will receive an INFO_OUTPUT_FORMAT_CHANGED return value from dequeueOutputBuffer or a onOutputFormatChanged callback just after the picture-size change takes place and before any frames with the new size have been returned.

Note: just as the case for codec-specific data, be careful when calling flush() shortly after you have changed the picture size. If you have not received confirmation of the picture size change, you will need to repeat the request for the new picture size.

Error handling

The factory methods createByCodecName and createDecoder/EncoderByType throw IOException on failure which you must catch or declare to pass up. MediaCodec methods throw IllegalStateException when the method is called from a codec state that does not allow it; this is typically due to incorrect application API usage. Methods involving secure buffers may throw MediaCodec.CryptoException, which has further error information obtainable from getErrorCode().

Internal codec errors result in a MediaCodec.CodecException, which may be due to media content corruption, hardware failure, resource exhaustion, and so forth, even when the application is correctly using the API. The recommended action when receiving a CodecException can be determined by calling isRecoverable() and isTransient():

  • recoverable errors: If isRecoverable() returns true, then call stop(), configure(…), and start() to recover.
  • transient errors: If isTransient() returns true, then resources are temporarily unavailable and the method may be retried at a later time.
  • fatal errors: If both isRecoverable() and isTransient() return false, then the CodecException is fatal and the codec must be reset or released.

Both isRecoverable() and isTransient() do not return true at the same time.

Valid API Calls and API History

This sections summarizes the valid API calls in each state and the API history of the MediaCodec class. For API version numbers, see Build.VERSION_CODES.

SymbolMeaning
Supported
Semantics changed
Experimental support
[ ]Deprecated
Restricted to surface input mode
Restricted to surface output mode
Restricted to ByteBuffer input mode
Restricted to synchronous mode
Restricted to asynchronous mode
( )Can be called, but shouldn't
Uninitialized
Configured
Flushed
Running
End of Stream
Error
Released
SDK Version
State Method 16 17 18 19 20 21 22 23
createByCodecName
createDecoderByType
createEncoderByType
createPersistentInputSurface
16+ - - - - - - configure
- 18+ - - - - - createInputSurface
- - 16+ 16+ (16+) - - dequeueInputBuffer ⁕▧↩ ▧↩ ▧↩
- - 16+ 16+ 16+ - - dequeueOutputBuffer ⁕↩
- - 16+ 16+ 16+ - - flush
18+ 18+ 18+ 18+ 18+ 18+ - getCodecInfo
- - (21+) 21+ (21+) - - getInputBuffer
- - 16+ (16+) (16+) - - getInputBuffers [⁕↩] [↩] [↩]
- 21+ (21+) (21+) (21+) - - getInputFormat
- - (21+) 21+ (21+) - - getInputImage
18+ 18+ 18+ 18+ 18+ 18+ - getName
- - (21+) 21+ 21+ - - getOutputBuffer
- - 16+ 16+ 16+ - - getOutputBuffers [⁕↩] [↩] [↩]
- 21+ 16+ 16+ 16+ - - getOutputFormat()
- - (21+) 21+ 21+ - - getOutputFormat(int)
- - (21+) 21+ 21+ - - getOutputImage
- - - 16+ (16+) - - queueInputBuffer
- - - 16+ (16+) - - queueSecureInputBuffer
16+ 16+ 16+ 16+ 16+ 16+ 16+ release
- - - 16+ 16+ - - releaseOutputBuffer(int, boolean)
- - - 21+ 21+ - - releaseOutputBuffer(int, long)
21+ 21+ 21+ 21+ 21+ 21+ - reset
21+ - - - - - - setCallback
- 23+ - - - - - setInputSurface
23+ 23+ 23+ 23+ 23+ (23+) (23+) setOnFrameRenderedListener ○ ⎆
- 23+ 23+ 23+ 23+ - - setOutputSurface
19+ 19+ 19+ 19+ 19+ (19+) - setParameters
- 16+ 16+ 16+ 16+ (16+) - setVideoScalingMode
- - 18+ 18+ - - - signalEndOfInputStream
- 16+ 21+(⇄) - - - - start
- - 16+ 16+ 16+ - - stop

Summary

Nested Classes
class MediaCodec.BufferInfo Per buffer metadata includes an offset and size specifying the range of valid data in the associated codec (output) buffer. 
class MediaCodec.Callback MediaCodec callback interface. 
class MediaCodec.CodecException Thrown when an internal codec error occurs. 
class MediaCodec.CryptoException Thrown when a crypto error occurs while queueing a secure input buffer. 
class MediaCodec.CryptoInfo Metadata describing the structure of a (at least partially) encrypted input sample. 
interface MediaCodec.OnFrameRenderedListener Listener to be called when an output frame has rendered on the output surface 
Constants
int BUFFER_FLAG_CODEC_CONFIG This indicated that the buffer marked as such contains codec initialization / codec specific data instead of media data.
int BUFFER_FLAG_END_OF_STREAM This signals the end of stream, i.e.
int BUFFER_FLAG_KEY_FRAME This indicates that the (encoded) buffer marked as such contains the data for a key frame.
int BUFFER_FLAG_SYNC_FRAME This constant was deprecated in API level 21. Use BUFFER_FLAG_KEY_FRAME instead.
int CONFIGURE_FLAG_ENCODE If this codec is to be used as an encoder, pass this flag.
int CRYPTO_MODE_AES_CTR
int CRYPTO_MODE_UNENCRYPTED
int INFO_OUTPUT_BUFFERS_CHANGED This constant was deprecated in API level 21. This return value can be ignored as getOutputBuffers() has been deprecated. Client should request a current buffer using on of the get-buffer or get-image methods each time one has been dequeued.
int INFO_OUTPUT_FORMAT_CHANGED The output format has changed, subsequent data will follow the new format.
int INFO_TRY_AGAIN_LATER If a non-negative timeout had been specified in the call to dequeueOutputBuffer(MediaCodec.BufferInfo, long), indicates that the call timed out.
String PARAMETER_KEY_REQUEST_SYNC_FRAME Request that the encoder produce a sync frame "soon".
String PARAMETER_KEY_SUSPEND Temporarily suspend/resume encoding of input data.
String PARAMETER_KEY_VIDEO_BITRATE Change a video encoder's target bitrate on the fly.
int VIDEO_SCALING_MODE_SCALE_TO_FIT The content is scaled to the surface dimensions
int VIDEO_SCALING_MODE_SCALE_TO_FIT_WITH_CROPPING The content is scaled, maintaining its aspect ratio, the whole surface area is used, content may be cropped
Public Methods
void configure(MediaFormat format, Surface surface, MediaCrypto crypto, int flags)
Configures a component.
static MediaCodec createByCodecName(String name)
If you know the exact name of the component you want to instantiate use this method to instantiate it.
static MediaCodec createDecoderByType(String type)
Instantiate the preferred decoder supporting input data of the given mime type.
static MediaCodec createEncoderByType(String type)
Instantiate the preferred encoder supporting output data of the given mime type.
final Surface createInputSurface()
Requests a Surface to use as the input to an encoder, in place of input buffers.
static Surface createPersistentInputSurface()
Create a persistent input surface that can be used with codecs that normally have an input surface, such as video encoders.
final int dequeueInputBuffer(long timeoutUs)
Returns the index of an input buffer to be filled with valid data or -1 if no such buffer is currently available.
final int dequeueOutputBuffer(MediaCodec.BufferInfo info, long timeoutUs)
Dequeue an output buffer, block at most "timeoutUs" microseconds.
final void flush()
Flush both input and output ports of the component.
MediaCodecInfo getCodecInfo()
Get the codec info.
ByteBuffer getInputBuffer(int index)
Returns a cleared, writable ByteBuffer object for a dequeued input buffer index to contain the input data.
ByteBuffer[] getInputBuffers()
This method was deprecated in API level 21. Use the new getInputBuffer(int) method instead each time an input buffer is dequeued. Note: As of API 21, dequeued input buffers are automatically cleared. Do not use this method if using an input surface.
final MediaFormat getInputFormat()
Call this after configure(MediaFormat, Surface, MediaCrypto, int) returns successfully to get the input format accepted by the codec.
Image getInputImage(int index)
Returns a writable Image object for a dequeued input buffer index to contain the raw input video frame.
final String getName()
Get the component name.
ByteBuffer getOutputBuffer(int index)
Returns a read-only ByteBuffer for a dequeued output buffer index.
ByteBuffer[] getOutputBuffers()
This method was deprecated in API level 21. Use the new getOutputBuffer(int) method instead each time an output buffer is dequeued. This method is not supported if codec is configured in asynchronous mode. Note: As of API 21, the position and limit of output buffers that are dequeued will be set to the valid data range. Do not use this method if using an output surface.
final MediaFormat getOutputFormat()
Call this after dequeueOutputBuffer signals a format change by returning INFO_OUTPUT_FORMAT_CHANGED.
final MediaFormat getOutputFormat(int index)
Returns the output format for a specific output buffer.
Image getOutputImage(int index)
Returns a read-only Image object for a dequeued output buffer index that contains the raw video frame.
final void queueInputBuffer(int index, int offset, int size, long presentationTimeUs, int flags)
After filling a range of the input buffer at the specified index submit it to the component.
final void queueSecureInputBuffer(int index, int offset, MediaCodec.CryptoInfo info, long presentationTimeUs, int flags)
Similar to queueInputBuffer but submits a buffer that is potentially encrypted.
final void release()
Free up resources used by the codec instance.
final void releaseOutputBuffer(int index, boolean render)
If you are done with a buffer, use this call to return the buffer to the codec or to render it on the output surface.
final void releaseOutputBuffer(int index, long renderTimestampNs)
If you are done with a buffer, use this call to update its surface timestamp and return it to the codec to render it on the output surface.
final void reset()
Returns the codec to its initial (Uninitialized) state.
void setCallback(MediaCodec.Callback cb)
Sets an asynchronous callback for actionable MediaCodec events on the default looper.
void setCallback(MediaCodec.Callback cb, Handler handler)
Sets an asynchronous callback for actionable MediaCodec events.
void setInputSurface(Surface surface)
Configures the codec (e.g.
void setOnFrameRenderedListener(MediaCodec.OnFrameRenderedListener listener, Handler handler)
Registers a callback to be invoked when an output frame is rendered on the output surface.
void setOutputSurface(Surface surface)
Dynamically sets the output surface of a codec.
final void setParameters(Bundle params)
Communicate additional parameter changes to the component instance.
final void setVideoScalingMode(int mode)
If a surface has been specified in a previous call to configure(MediaFormat, Surface, MediaCrypto, int) specifies the scaling mode to use.
final void signalEndOfInputStream()
Signals end-of-stream on input.
final void start()
After successfully configuring the component, call start.
final void stop()
Finish the decode/encode session, note that the codec instance remains active and ready to be start()ed again.
Protected Methods
void finalize()
Invoked when the garbage collector has detected that this instance is no longer reachable.
[Expand]
Inherited Methods
From class java.lang.Object

Constants

public static final int BUFFER_FLAG_CODEC_CONFIG

Added in API level 16

This indicated that the buffer marked as such contains codec initialization / codec specific data instead of media data.

Constant Value: 2 (0x00000002)

public static final int BUFFER_FLAG_END_OF_STREAM

Added in API level 16

This signals the end of stream, i.e. no buffers will be available after this, unless of course, flush() follows.

Constant Value: 4 (0x00000004)

public static final int BUFFER_FLAG_KEY_FRAME

Added in API level 21

This indicates that the (encoded) buffer marked as such contains the data for a key frame.

Constant Value: 1 (0x00000001)

public static final int BUFFER_FLAG_SYNC_FRAME

Added in API level 16

This constant was deprecated in API level 21.
Use BUFFER_FLAG_KEY_FRAME instead.

This indicates that the (encoded) buffer marked as such contains the data for a key frame.

Constant Value: 1 (0x00000001)

public static final int CONFIGURE_FLAG_ENCODE

Added in API level 16

If this codec is to be used as an encoder, pass this flag.

Constant Value: 1 (0x00000001)

public static final int CRYPTO_MODE_AES_CTR

Added in API level 16

Constant Value: 1 (0x00000001)

public static final int CRYPTO_MODE_UNENCRYPTED

Added in API level 16

Constant Value: 0 (0x00000000)

public static final int INFO_OUTPUT_BUFFERS_CHANGED

Added in API level 16

This constant was deprecated in API level 21.
This return value can be ignored as getOutputBuffers() has been deprecated. Client should request a current buffer using on of the get-buffer or get-image methods each time one has been dequeued.

The output buffers have changed, the client must refer to the new set of output buffers returned by getOutputBuffers() from this point on.

Constant Value: -3 (0xfffffffd)

public static final int INFO_OUTPUT_FORMAT_CHANGED

Added in API level 16

The output format has changed, subsequent data will follow the new format. getOutputFormat() returns the new format. Note, that you can also use the new getOutputFormat(int) method to get the format for a specific output buffer. This frees you from having to track output format changes.

Constant Value: -2 (0xfffffffe)

public static final int INFO_TRY_AGAIN_LATER

Added in API level 16

If a non-negative timeout had been specified in the call to dequeueOutputBuffer(MediaCodec.BufferInfo, long), indicates that the call timed out.

Constant Value: -1 (0xffffffff)

public static final String PARAMETER_KEY_REQUEST_SYNC_FRAME

Added in API level 19

Request that the encoder produce a sync frame "soon". Provide an Integer with the value 0.

Constant Value: "request-sync"

public static final String PARAMETER_KEY_SUSPEND

Added in API level 19

Temporarily suspend/resume encoding of input data. While suspended input data is effectively discarded instead of being fed into the encoder. This parameter really only makes sense to use with an encoder in "surface-input" mode, as the client code has no control over the input-side of the encoder in that case. The value is an Integer object containing the value 1 to suspend or the value 0 to resume.

Constant Value: "drop-input-frames"

public static final String PARAMETER_KEY_VIDEO_BITRATE

Added in API level 19

Change a video encoder's target bitrate on the fly. The value is an Integer object containing the new bitrate in bps.

Constant Value: "video-bitrate"

public static final int VIDEO_SCALING_MODE_SCALE_TO_FIT

Added in API level 16

The content is scaled to the surface dimensions

Constant Value: 1 (0x00000001)

public static final int VIDEO_SCALING_MODE_SCALE_TO_FIT_WITH_CROPPING

Added in API level 16

The content is scaled, maintaining its aspect ratio, the whole surface area is used, content may be cropped

Constant Value: 2 (0x00000002)

Public Methods

public void configure (MediaFormat format, Surface surface, MediaCrypto crypto, int flags)

Added in API level 16

Configures a component.

Parameters
format MediaFormat: The format of the input data (decoder) or the desired format of the output data (encoder). Passing null as format is equivalent to passing an an empty mediaformat.
surface Surface: Specify a surface on which to render the output of this decoder. Pass null as surface if the codec does not generate raw video output (e.g. not a video decoder) and/or if you want to configure the codec for ByteBuffer output.
crypto MediaCrypto: Specify a crypto object to facilitate secure decryption of the media data. Pass null as crypto for non-secure codecs.
flags int: Specify CONFIGURE_FLAG_ENCODE to configure the component as an encoder.
Throws
IllegalArgumentException if the surface has been released (or is invalid), or the format is unacceptable (e.g. missing a mandatory key), or the flags are not set properly (e.g. missing CONFIGURE_FLAG_ENCODE for an encoder).
IllegalStateException if not in the Uninitialized state.
MediaCodec.CryptoException upon DRM error.
MediaCodec.CodecException upon codec error.

public static MediaCodec createByCodecName (String name)

Added in API level 16

If you know the exact name of the component you want to instantiate use this method to instantiate it. Use with caution. Likely to be used with information obtained from MediaCodecList

Parameters
name String: The name of the codec to be instantiated.
Returns
MediaCodec
Throws
IOException if the codec cannot be created.
IllegalArgumentException if name is not valid.
NullPointerException if name is null.

public static MediaCodec createDecoderByType (String type)

Added in API level 16

Instantiate the preferred decoder supporting input data of the given mime type. The following is a partial list of defined mime types and their semantics:

  • "video/x-vnd.on2.vp8" - VP8 video (i.e. video in .webm)
  • "video/x-vnd.on2.vp9" - VP9 video (i.e. video in .webm)
  • "video/avc" - H.264/AVC video
  • "video/hevc" - H.265/HEVC video
  • "video/mp4v-es" - MPEG4 video
  • "video/3gpp" - H.263 video
  • "audio/3gpp" - AMR narrowband audio
  • "audio/amr-wb" - AMR wideband audio
  • "audio/mpeg" - MPEG1/2 audio layer III
  • "audio/mp4a-latm" - AAC audio (note, this is raw AAC packets, not packaged in LATM!)
  • "audio/vorbis" - vorbis audio
  • "audio/g711-alaw" - G.711 alaw audio
  • "audio/g711-mlaw" - G.711 ulaw audio
Note: It is preferred to use findDecoderForFormat(MediaFormat) and createByCodecName(String) to ensure that the resulting codec can handle a given format.

Parameters
type String: The mime type of the input data.
Returns
MediaCodec
Throws
IOException if the codec cannot be created.
IllegalArgumentException if type is not a valid mime type.
NullPointerException if type is null.

public static MediaCodec createEncoderByType (String type)

Added in API level 16

Instantiate the preferred encoder supporting output data of the given mime type. Note: It is preferred to use findEncoderForFormat(MediaFormat) and createByCodecName(String) to ensure that the resulting codec can handle a given format.

Parameters
type String: The desired mime type of the output data.
Returns
MediaCodec
Throws
IOException if the codec cannot be created.
IllegalArgumentException if type is not a valid mime type.
NullPointerException if type is null.

public final Surface createInputSurface ()

Added in API level 18

Requests a Surface to use as the input to an encoder, in place of input buffers. This may only be called after configure(MediaFormat, Surface, MediaCrypto, int) and before start().

The application is responsible for calling release() on the Surface when done.

The Surface must be rendered with a hardware-accelerated API, such as OpenGL ES. lockCanvas(android.graphics.Rect) may fail or produce unexpected results.

Returns
Surface
Throws
IllegalStateException if not in the Configured state.

public static Surface createPersistentInputSurface ()

Added in API level 23

Create a persistent input surface that can be used with codecs that normally have an input surface, such as video encoders. A persistent input can be reused by subsequent MediaCodec or MediaRecorder instances, but can only be used by at most one codec or recorder instance concurrently.

The application is responsible for calling release() on the Surface when done.

Returns
Surface an input surface that can be used with setInputSurface(Surface).

public final int dequeueInputBuffer (long timeoutUs)

Added in API level 16

Returns the index of an input buffer to be filled with valid data or -1 if no such buffer is currently available. This method will return immediately if timeoutUs == 0, wait indefinitely for the availability of an input buffer if timeoutUs < 0 or wait up to "timeoutUs" microseconds if timeoutUs > 0.

Parameters
timeoutUs long: The timeout in microseconds, a negative timeout indicates "infinite".
Returns
int
Throws
IllegalStateException if not in the Executing state, or codec is configured in asynchronous mode.
MediaCodec.CodecException upon codec error.

public final int dequeueOutputBuffer (MediaCodec.BufferInfo info, long timeoutUs)

Added in API level 16

Dequeue an output buffer, block at most "timeoutUs" microseconds. Returns the index of an output buffer that has been successfully decoded or one of the INFO_* constants.

Parameters
info MediaCodec.BufferInfo: Will be filled with buffer meta data.
timeoutUs long: The timeout in microseconds, a negative timeout indicates "infinite".
Returns
int
Throws
IllegalStateException if not in the Executing state, or codec is configured in asynchronous mode.
MediaCodec.CodecException upon codec error.

public final void flush ()

Added in API level 16

Flush both input and output ports of the component.

Upon return, all indices previously returned in calls to dequeueInputBuffer and dequeueOutputBuffer — or obtained via onInputBufferAvailable or onOutputBufferAvailable callbacks — become invalid, and all buffers are owned by the codec.

If the codec is configured in asynchronous mode, call start() after flush has returned to resume codec operations. The codec will not request input buffers until this has happened. Note, however, that there may still be outstanding onOutputBufferAvailable callbacks that were not handled prior to calling flush. The indices returned via these callbacks also become invalid upon calling flush and should be discarded.

If the codec is configured in synchronous mode, codec will resume automatically if it is configured with an input surface. Otherwise, it will resume when dequeueInputBuffer is called.

Throws
IllegalStateException if not in the Executing state.
MediaCodec.CodecException upon codec error.

public MediaCodecInfo getCodecInfo ()

Added in API level 18

Get the codec info. If the codec was created by createDecoderByType or createEncoderByType, what component is chosen is not known beforehand, and thus the caller does not have the MediaCodecInfo.

Returns
MediaCodecInfo
Throws
IllegalStateException if in the Released state.

public ByteBuffer getInputBuffer (int index)

Added in API level 21

Returns a cleared, writable ByteBuffer object for a dequeued input buffer index to contain the input data. After calling this method any ByteBuffer or Image object previously returned for the same input index MUST no longer be used.

Parameters
index int: The index of a client-owned input buffer previously returned from a call to dequeueInputBuffer(long), or received via an onInputBufferAvailable callback.
Returns
ByteBuffer the input buffer, or null if the index is not a dequeued input buffer, or if the codec is configured for surface input.
Throws
IllegalStateException if not in the Executing state.
MediaCodec.CodecException upon codec error.

public ByteBuffer[] getInputBuffers ()

Added in API level 16

This method was deprecated in API level 21.
Use the new getInputBuffer(int) method instead each time an input buffer is dequeued. Note: As of API 21, dequeued input buffers are automatically cleared. Do not use this method if using an input surface.

Retrieve the set of input buffers. Call this after start() returns. After calling this method, any ByteBuffers previously returned by an earlier call to this method MUST no longer be used.

Returns
ByteBuffer[]
Throws
IllegalStateException if not in the Executing state, or codec is configured in asynchronous mode.
MediaCodec.CodecException upon codec error.

public final MediaFormat getInputFormat ()

Added in API level 21

Call this after configure(MediaFormat, Surface, MediaCrypto, int) returns successfully to get the input format accepted by the codec. Do this to determine what optional configuration parameters were supported by the codec.

Returns
MediaFormat
Throws
IllegalStateException if not in the Executing or Configured state.
MediaCodec.CodecException upon codec error.

public Image getInputImage (int index)

Added in API level 21

Returns a writable Image object for a dequeued input buffer index to contain the raw input video frame. After calling this method any ByteBuffer or Image object previously returned for the same input index MUST no longer be used.

Parameters
index int: The index of a client-owned input buffer previously returned from a call to dequeueInputBuffer(long), or received via an onInputBufferAvailable callback.
Returns
Image the input image, or null if the index is not a dequeued input buffer, or not a ByteBuffer that contains a raw image.
Throws
IllegalStateException if not in the Executing state.
MediaCodec.CodecException upon codec error.

public final String getName ()

Added in API level 18

Get the component name. If the codec was created by createDecoderByType or createEncoderByType, what component is chosen is not known beforehand.

Returns
String
Throws
IllegalStateException if in the Released state.

public ByteBuffer getOutputBuffer (int index)

Added in API level 21

Returns a read-only ByteBuffer for a dequeued output buffer index. The position and limit of the returned buffer are set to the valid output data. After calling this method, any ByteBuffer or Image object previously returned for the same output index MUST no longer be used.

Parameters
index int: The index of a client-owned output buffer previously returned from a call to dequeueOutputBuffer(MediaCodec.BufferInfo, long), or received via an onOutputBufferAvailable callback.
Returns
ByteBuffer the output buffer, or null if the index is not a dequeued output buffer, or the codec is configured with an output surface.
Throws
IllegalStateException if not in the Executing state.
MediaCodec.CodecException upon codec error.

public ByteBuffer[] getOutputBuffers ()

Added in API level 16

This method was deprecated in API level 21.
Use the new getOutputBuffer(int) method instead each time an output buffer is dequeued. This method is not supported if codec is configured in asynchronous mode. Note: As of API 21, the position and limit of output buffers that are dequeued will be set to the valid data range. Do not use this method if using an output surface.

Retrieve the set of output buffers. Call this after start() returns and whenever dequeueOutputBuffer signals an output buffer change by returning INFO_OUTPUT_BUFFERS_CHANGED. After calling this method, any ByteBuffers previously returned by an earlier call to this method MUST no longer be used.

Returns
ByteBuffer[]
Throws
IllegalStateException if not in the Executing state, or codec is configured in asynchronous mode.
MediaCodec.CodecException upon codec error.

public final MediaFormat getOutputFormat ()

Added in API level 16

Call this after dequeueOutputBuffer signals a format change by returning INFO_OUTPUT_FORMAT_CHANGED. You can also call this after configure(MediaFormat, Surface, MediaCrypto, int) returns successfully to get the output format initially configured for the codec. Do this to determine what optional configuration parameters were supported by the codec.

Returns
MediaFormat
Throws
IllegalStateException if not in the Executing or Configured state.
MediaCodec.CodecException upon codec error.

public final MediaFormat getOutputFormat (int index)

Added in API level 21

Returns the output format for a specific output buffer.

Parameters
index int: The index of a client-owned input buffer previously returned from a call to dequeueInputBuffer(long).
Returns
MediaFormat the format for the output buffer, or null if the index is not a dequeued output buffer.

public Image getOutputImage (int index)

Added in API level 21

Returns a read-only Image object for a dequeued output buffer index that contains the raw video frame. After calling this method, any ByteBuffer or Image object previously returned for the same output index MUST no longer be used.

Parameters
index int: The index of a client-owned output buffer previously returned from a call to dequeueOutputBuffer(MediaCodec.BufferInfo, long), or received via an onOutputBufferAvailable callback.
Returns
Image the output image, or null if the index is not a dequeued output buffer, not a raw video frame, or if the codec was configured with an output surface.
Throws
IllegalStateException if not in the Executing state.
MediaCodec.CodecException upon codec error.

public final void queueInputBuffer (int index, int offset, int size, long presentationTimeUs, int flags)

Added in API level 16

After filling a range of the input buffer at the specified index submit it to the component. Once an input buffer is queued to the codec, it MUST NOT be used until it is later retrieved by getInputBuffer(int) in response to a dequeueInputBuffer(long) return value or a onInputBufferAvailable(MediaCodec, int) callback.

Many decoders require the actual compressed data stream to be preceded by "codec specific data", i.e. setup data used to initialize the codec such as PPS/SPS in the case of AVC video or code tables in the case of vorbis audio. The class MediaExtractor provides codec specific data as part of the returned track format in entries named "csd-0", "csd-1" ...

These buffers can be submitted directly after start() or flush() by specifying the flag BUFFER_FLAG_CODEC_CONFIG. However, if you configure the codec with a MediaFormat containing these keys, they will be automatically submitted by MediaCodec directly after start. Therefore, the use of BUFFER_FLAG_CODEC_CONFIG flag is discouraged and is recommended only for advanced users.

To indicate that this is the final piece of input data (or rather that no more input data follows unless the decoder is subsequently flushed) specify the flag BUFFER_FLAG_END_OF_STREAM.

Note: Prior to M, presentationTimeUs was not propagated to the frame timestamp of (rendered) Surface output buffers, and the resulting frame timestamp was undefined. Use releaseOutputBuffer(int, long) to ensure a specific frame timestamp is set. Similarly, since frame timestamps can be used by the destination surface for rendering synchronization, care must be taken to normalize presentationTimeUs so as to not be mistaken for a system time. (See SurfaceView specifics).

Parameters
index int: The index of a client-owned input buffer previously returned in a call to dequeueInputBuffer(long).
offset int: The byte offset into the input buffer at which the data starts.
size int: The number of bytes of valid input data.
presentationTimeUs long: The presentation timestamp in microseconds for this buffer. This is normally the media time at which this buffer should be presented (rendered). When using an output surface, this will be propagated as the timestamp for the frame (after conversion to nanoseconds).
flags int: A bitmask of flags BUFFER_FLAG_CODEC_CONFIG and BUFFER_FLAG_END_OF_STREAM. While not prohibited, most codecs do not use the BUFFER_FLAG_KEY_FRAME flag for input buffers.
Throws
IllegalStateException if not in the Executing state.
MediaCodec.CodecException upon codec error.
MediaCodec.CryptoException if a crypto object has been specified in configure(MediaFormat, Surface, MediaCrypto, int)

public final void queueSecureInputBuffer (int index, int offset, MediaCodec.CryptoInfo info, long presentationTimeUs, int flags)

Added in API level 16

Similar to queueInputBuffer but submits a buffer that is potentially encrypted. Check out further notes at queueInputBuffer.

Parameters
index int: The index of a client-owned input buffer previously returned in a call to dequeueInputBuffer(long).
offset int: The byte offset into the input buffer at which the data starts.
info MediaCodec.CryptoInfo: Metadata required to facilitate decryption, the object can be reused immediately after this call returns.
presentationTimeUs long: The presentation timestamp in microseconds for this buffer. This is normally the media time at which this buffer should be presented (rendered).
flags int: A bitmask of flags BUFFER_FLAG_CODEC_CONFIG and BUFFER_FLAG_END_OF_STREAM. While not prohibited, most codecs do not use the BUFFER_FLAG_KEY_FRAME flag for input buffers.
Throws
IllegalStateException if not in the Executing state.
MediaCodec.CodecException upon codec error.
MediaCodec.CryptoException if an error occurs while attempting to decrypt the buffer. An error code associated with the exception helps identify the reason for the failure.

public final void release ()

Added in API level 16

Free up resources used by the codec instance. Make sure you call this when you're done to free up any opened component instance instead of relying on the garbage collector to do this for you at some point in the future.

public final void releaseOutputBuffer (int index, boolean render)

Added in API level 16

If you are done with a buffer, use this call to return the buffer to the codec or to render it on the output surface. If you configured the codec with an output surface, setting render to true will first send the buffer to that output surface. The surface will release the buffer back to the codec once it is no longer used/displayed. Once an output buffer is released to the codec, it MUST NOT be used until it is later retrieved by getOutputBuffer(int) in response to a dequeueOutputBuffer(MediaCodec.BufferInfo, long) return value or a onOutputBufferAvailable(MediaCodec, int, MediaCodec.BufferInfo) callback.

Parameters
index int: The index of a client-owned output buffer previously returned from a call to dequeueOutputBuffer(MediaCodec.BufferInfo, long).
render boolean: If a valid surface was specified when configuring the codec, passing true renders this output buffer to the surface.
Throws
IllegalStateException if not in the Executing state.
MediaCodec.CodecException upon codec error.

public final void releaseOutputBuffer (int index, long renderTimestampNs)

Added in API level 21

If you are done with a buffer, use this call to update its surface timestamp and return it to the codec to render it on the output surface. If you have not specified an output surface when configuring this video codec, this call will simply return the buffer to the codec.

The timestamp may have special meaning depending on the destination surface.

SurfaceView specifics
If you render your buffer on a SurfaceView, you can use the timestamp to render the buffer at a specific time (at the VSYNC at or after the buffer timestamp). For this to work, the timestamp needs to be reasonably close to the current nanoTime(). Currently, this is set as within one (1) second. A few notes:
  • the buffer will not be returned to the codec until the timestamp has passed and the buffer is no longer used by the Surface.
  • buffers are processed sequentially, so you may block subsequent buffers to be displayed on the Surface. This is important if you want to react to user action, e.g. stop the video or seek.
  • if multiple buffers are sent to the Surface to be rendered at the same VSYNC, the last one will be shown, and the other ones will be dropped.
  • if the timestamp is not "reasonably close" to the current system time, the Surface will ignore the timestamp, and display the buffer at the earliest feasible time. In this mode it will not drop frames.
  • for best performance and quality, call this method when you are about two VSYNCs' time before the desired render time. For 60Hz displays, this is about 33 msec.
Once an output buffer is released to the codec, it MUST NOT be used until it is later retrieved by getOutputBuffer(int) in response to a dequeueOutputBuffer(MediaCodec.BufferInfo, long) return value or a onOutputBufferAvailable(MediaCodec, int, MediaCodec.BufferInfo) callback.

Parameters
index int: The index of a client-owned output buffer previously returned from a call to dequeueOutputBuffer(MediaCodec.BufferInfo, long).
renderTimestampNs long: The timestamp to associate with this buffer when it is sent to the Surface.
Throws
IllegalStateException if not in the Executing state.
MediaCodec.CodecException upon codec error.

public final void reset ()

Added in API level 21

Returns the codec to its initial (Uninitialized) state. Call this if an unrecoverable error has occured to reset the codec to its initial state after creation.

Throws
MediaCodec.CodecException if an unrecoverable error has occured and the codec could not be reset.
IllegalStateException if in the Released state.

public void setCallback (MediaCodec.Callback cb)

Added in API level 21

Sets an asynchronous callback for actionable MediaCodec events on the default looper.

Same as setCallback(Callback, Handler) with handler set to null.

Parameters
cb MediaCodec.Callback: The callback that will run. Use null to clear a previously set callback (before configure is called and run in synchronous mode).

public void setCallback (MediaCodec.Callback cb, Handler handler)

Added in API level 23

Sets an asynchronous callback for actionable MediaCodec events. If the client intends to use the component in asynchronous mode, a valid callback should be provided before configure(MediaFormat, Surface, MediaCrypto, int) is called. When asynchronous callback is enabled, the client should not call getInputBuffers(), getOutputBuffers(), dequeueInputBuffer(long) or dequeueOutputBuffer(BufferInfo, long).

Also, flush() behaves differently in asynchronous mode. After calling flush, you must call start() to "resume" receiving input buffers, even if an input surface was created.

Parameters
cb MediaCodec.Callback: The callback that will run. Use null to clear a previously set callback (before configure is called and run in synchronous mode).
handler Handler: Callbacks will happen on the handler's thread. If null, callbacks are done on the default thread (the caller's thread or the main thread.)

public void setInputSurface (Surface surface)

Added in API level 23

Configures the codec (e.g. encoder) to use a persistent input surface in place of input buffers. This may only be called after configure(MediaFormat, Surface, MediaCrypto, int) and before start(), in lieu of createInputSurface().

Parameters
surface Surface: a persistent input surface created by createPersistentInputSurface()
Throws
IllegalStateException if not in the Configured state or does not require an input surface.
IllegalArgumentException if the surface was not created by createPersistentInputSurface().

public void setOnFrameRenderedListener (MediaCodec.OnFrameRenderedListener listener, Handler handler)

Added in API level 23

Registers a callback to be invoked when an output frame is rendered on the output surface.

This method can be called in any codec state, but will only have an effect in the Executing state for codecs that render buffers to the output surface.

Note: This callback is for informational purposes only: to get precise render timing samples, and can be significantly delayed and batched. Some frames may have been rendered even if there was no callback generated.

Parameters
listener MediaCodec.OnFrameRenderedListener: the callback that will be run
handler Handler: the callback will be run on the handler's thread. If null, the callback will be run on the default thread, which is the looper from which the codec was created, or a new thread if there was none.

public void setOutputSurface (Surface surface)

Added in API level 23

Dynamically sets the output surface of a codec.

This can only be used if the codec was configured with an output surface. The new output surface should have a compatible usage type to the original output surface. E.g. codecs may not support switching from a SurfaceTexture (GPU readable) output to ImageReader (software readable) output.

Parameters
surface Surface: the output surface to use. It must not be null.
Throws
IllegalStateException if the codec does not support setting the output surface in the current state.
IllegalArgumentException if the new surface is not of a suitable type for the codec.

public final void setParameters (Bundle params)

Added in API level 19

Communicate additional parameter changes to the component instance. Note: Some of these parameter changes may silently fail to apply.

Parameters
params Bundle: The bundle of parameters to set.
Throws
IllegalStateException if in the Released state.

public final void setVideoScalingMode (int mode)

Added in API level 16

If a surface has been specified in a previous call to configure(MediaFormat, Surface, MediaCrypto, int) specifies the scaling mode to use. The default is "scale to fit".

Parameters
mode int
Throws
IllegalArgumentException if mode is not recognized.
IllegalStateException if in the Released state.

public final void signalEndOfInputStream ()

Added in API level 18

Signals end-of-stream on input. Equivalent to submitting an empty buffer with BUFFER_FLAG_END_OF_STREAM set. This may only be used with encoders receiving input from a Surface created by createInputSurface().

Throws
IllegalStateException if not in the Executing state.
MediaCodec.CodecException upon codec error.

public final void start ()

Added in API level 16

After successfully configuring the component, call start.

Call start also if the codec is configured in asynchronous mode, and it has just been flushed, to resume requesting input buffers.

Throws
IllegalStateException if not in the Configured state or just after flush() for a codec that is configured in asynchronous mode.
MediaCodec.CodecException upon codec error. Note that some codec errors for start may be attributed to future method calls.

public final void stop ()

Added in API level 16

Finish the decode/encode session, note that the codec instance remains active and ready to be start()ed again. To ensure that it is available to other client call release() and don't just rely on garbage collection to eventually do this for you.

Throws
IllegalStateException if in the Released state.

Protected Methods

protected void finalize ()

Added in API level 16

Invoked when the garbage collector has detected that this instance is no longer reachable. The default implementation does nothing, but this method can be overridden to free resources.

Note that objects that override finalize are significantly more expensive than objects that don't. Finalizers may be run a long time after the object is no longer reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup. Note also that finalizers are run on a single VM-wide finalizer thread, so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary for a class that has a native peer and needs to call a native method to destroy that peer. Even then, it's better to provide an explicit close method (and implement Closeable), and insist that callers manually dispose of instances. This works well for something like files, but less well for something like a BigInteger where typical calling code would have to deal with lots of temporaries. Unfortunately, code that creates lots of temporaries is the worst kind of code from the point of view of the single finalizer thread.

If you must use finalizers, consider at least providing your own ReferenceQueue and having your own thread process that queue.

Unlike constructors, finalizers are not automatically chained. You are responsible for calling super.finalize() yourself.

Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.