Codec

java.lang.Object
- ohos.media.codec.Codec

```
public class Codec
extends Object
```
Provides the audio/video encoding and decoding functions. It has two working modes: normal and pipeline.
In normal mode, applications must manually transfer source data to the codec continuously.
In pipeline mode, applications only need to set the data source using the Source class. The codec automatically reads source data from the data source and parses the data.
Applications are notified of the encoded or decoded data through the registered listener.
The following describes how to use the decoder.
To use the decoder in normal mode, perform the following steps:
1. Call createDecoder() to create a decoder instance.
2. Call setCodecFormat(ohos.media.common.Format) to set the data source format.
3. Call registerCodecListener(ohos.media.codec.Codec.ICodecListener) to register a listener.
4. Call start() to start decoding.
5. Call getAvailableBuffer(long) and writeBuffer(java.nio.ByteBuffer, ohos.media.common.BufferInfo) to transfer source data to the decoder instance.
6. Call stop() to stop decoding.
To use the decoder in pipeline mode, perform the following steps:
1. Call createDecoder() to create a decoder instance.
2. Call setSource(ohos.media.common.Source, ohos.media.codec.TrackInfo) to set the data source.
3. Call registerCodecListener(ohos.media.codec.Codec.ICodecListener) to register a listener.
4. Call start() to start decoding.
The following describes how to use the encoder.
To use the encoder in normal mode, perform the following steps:
1. Call createEncoder() to create an encoder instance.
2. Call setCodecFormat(ohos.media.common.Format) to set the output data format.
3. Call registerCodecListener(ohos.media.codec.Codec.ICodecListener) to register a listener.
4. Call start() to start encoding.
5. Call getAvailableBuffer(long) and writeBuffer(java.nio.ByteBuffer, ohos.media.common.BufferInfo) to transfer source data to the encoder instance.
6. Call stop() to stop encoding.
The encoder in pipeline mode applies only to videos. To use the encoder in pipeline mode, perform the following steps:
1. Call createEncoder() to create an encoder instance.
2. Call setSource(ohos.media.common.Source, ohos.media.codec.TrackInfo) to set the data source.
3. Call setSourceFormat(ohos.media.common.Format) to set the data source format and encoding parameters.
4. Call registerCodecListener(ohos.media.codec.Codec.ICodecListener) to register a listener.
5. Call start() to start encoding.
从以下版本开始:

1

SystemCapability

SystemCapability.Multimedia#MEDIA

嵌套类概要

嵌套类
限定符和类型类说明

static interface Codec.ICodecListener
Receives notifications during encoding or decoding, such as encoded or decoded data and error messages.

嵌套类
限定符和类型	类	说明
`static interface`	`Codec.ICodecListener`	Receives notifications during encoding or decoding, such as encoded or decoded data and error messages.

字段概要

字段
限定符和类型	字段	说明
`static int`	`VIDEO_SCALE_TYPE_CROP`	Indicates that the aspect ratio of the video remains unchanged.
`static int`	`VIDEO_SCALE_TYPE_FIT`	Indicates that the video is stretched in the rendering surface.

方法概要

所有方法静态方法实例方法具体方法
限定符和类型	方法	说明
`static Codec`	`createDecoder()`	Creates a decoder instance.
`static Codec`	`createEncoder()`	Creates an encoder instance.
`Surface`	`createLastingVideoSurface()`	Creates a lasting `Surface` object for this encoder.
`protected void`	`finalize()`	Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`boolean`	`flush()`	Flush all buffers.
`ByteBuffer`	`getAvailableBuffer(long timeout)`	Obtains a `ByteBuffer` in normal mode.
`Format`	`getBufferFormat(ByteBuffer buffer)`	Obtains the output data format.
`int`	`getInputBufferIndex(long timeout)`	Obtains a dequeued input buffer index.
`CodecDescription`	`obtainCodecDescription()`	Obtains the `CodecDescription` object.
`Map<Integer,String>`	`obtainCodecName()`	Obtains the codec name.
`PixelMap`	`obtainInputPixelMap(int index)`	Obtains a writable pixel map for a dequeued input buffer.
`Surface`	`obtainInputSurface()`	Obtains a `Surface` object created for this encoder.
`PixelMap`	`obtainOutputPixelMap(int index)`	Obtains a read-only pixel map for a dequeued output buffer.
`boolean`	`registerCodecListener(Codec.ICodecListener listener)`	Registers a listener to asynchronously receive encoded or decoded data.
`boolean`	`release()`	Releases all resources, including the memory applied by the native layer.
`boolean`	`setCodecFormat(Format format)`	Sets encoding or decoding parameters in normal mode.
`boolean`	`setLastingVideoSurface(Surface lastingSurface)`	Sets a lasting `Surface` object for this encoder.
`boolean`	`setProperty(Format format)`	Sets encoding or decoding properties.
`boolean`	`setSource(Source source, TrackInfo trackInfo)`	Sets the data source.
`boolean`	`setSourceFormat(Format format)`	Sets the data source format and encoding parameters.
`boolean`	`setVideoScaleType(int type)`	Sets the video scaling type.
`boolean`	`setVideoSurface(Surface surface)`	Sets the surface for the decoder to display decoded video data.
`boolean`	`start()`	Starts encoding or decoding after the preparation is complete.
`boolean`	`stop()`	Stops encoding or decoding.
`boolean`	`stopVideoSurface()`	Informs the encoder of the end of input and stops encoding.
`boolean`	`writeBuffer(ByteBuffer buffer, BufferInfo info)`	Pushes source data to the encoder or decoder.

从类继承的方法 java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 字段详细资料
  - VIDEO_SCALE_TYPE_CROP
```
public static final int VIDEO_SCALE_TYPE_CROP
```
    Indicates that the aspect ratio of the video remains unchanged.
    If the aspect ratio of the video differs from that of the surface, the video will be cropped to fit the surface.
    
    从以下版本开始:
    
    3
    
    另请参阅:
    
    常量字段值
  - VIDEO_SCALE_TYPE_FIT
```
public static final int VIDEO_SCALE_TYPE_FIT
```
    Indicates that the video is stretched in the rendering surface.
    If the aspect ratio of the video differs from that of the surface, the original aspect ratio will not be retained during video rendering.
    
    从以下版本开始:
    
    3
    
    另请参阅:
    
    常量字段值
- 方法详细资料
  - createDecoder
```
public static Codec createDecoder()
```
    Creates a decoder instance.
    
    返回:
    
    Returns a decoder instance.
    
    从以下版本开始:
    
    1
  - createEncoder
```
public static Codec createEncoder()
```
    Creates an encoder instance.
    
    返回:
    
    Returns an encoder instance.
    
    从以下版本开始:
    
    1
  - registerCodecListener
```
public boolean registerCodecListener(Codec.ICodecListener listener)
```
    Registers a listener to asynchronously receive encoded or decoded data.
    To use the Codec class for encoding or decoding, a listener must be registered. If registerCodecListener is called multiple times, the codec records only the last registered listener.
    If null is transferred, the codec clears the previous listener.
    The current method must be called prior to start().
    
    参数:
    
    listener - Indicates a codec listener instance. For details, see ICodecListener.
    
    返回:
    
    Returns true if the listener is registered; returns false otherwise.
    
    从以下版本开始:
    
    1
  - setSource
```
public boolean setSource(Source source,
                         TrackInfo trackInfo)
```
    Sets the data source.
    If you set the data source by calling this method, the pipeline mode is used. The codec automatically parses source data in the background and notifies your application of the parsed data through the listener.
    For an encoder, you must also call setSourceFormat(ohos.media.common.Format) to set the data source format and encoding parameters.
    The current method must be called prior to start().
    
    参数:
    
    source - Indicates the data source. For details, see Source.
    
    trackInfo - Indicates the source track information for a decoder. This parameter is invalid for an encoder. The value null indicates that no track information is available.
    
    返回:
    
    Returns true if the setting is successful; returns false otherwise.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if a parameter is invalid.
    
    从以下版本开始:
    
    1
  - setSourceFormat
```
public boolean setSourceFormat(Format format)
```
    Sets the data source format and encoding parameters.
    After the data source is set for an encoder, you must call this method to set the data source format and encoding parameters.
    
    参数:
    
    format - Indicates the data source format and encoding parameters.
    
    返回:
    
    Returns true if the setting is successful; returns false otherwise.
    
    从以下版本开始:
    
    1
  - setCodecFormat
```
public boolean setCodecFormat(Format format)
```
    Sets encoding or decoding parameters in normal mode.
    If the normal mode is used, you must call this method to set the source data format and encoding or decoding parameters.
    For an encoder, this method is used to set the source data format and encoding parameters.
    For a decoder, this method is used to set the source data format.
    The current method must be called prior to start().
    If setSource(ohos.media.common.Source, ohos.media.codec.TrackInfo) is called for the decoder, the decoder automatically analyzes the source data format. You do not need to call the current method.
    
    参数:
    
    format - Indicates the data format.
    
    返回:
    
    Returns true if the setting is successful; returns false otherwise.
    
    从以下版本开始:
    
    1
  - setProperty
```
public boolean setProperty(Format format)
```
    Sets encoding or decoding properties.
    In normal mode, this method must be called after setCodecFormat(ohos.media.common.Format).
    In pipeline mode, this method can only used for encoding and must be called after setSource(ohos.media.common.Source, ohos.media.codec.TrackInfo).
    
    参数:
    
    format - Indicates the data format.
    
    返回:
    
    Returns true if the setting is successful; returns false otherwise.
    
    从以下版本开始:
    
    1
  - obtainInputSurface
```
public Surface obtainInputSurface()
```
    Obtains a Surface object created for this encoder.
    The Surface object is used for the input of the encoder.
    This method must be called after #SetCodecFormat(ohos.media.common.Format) or setSourceFormat(ohos.media.common.Format) and before start().
    
    返回:
    
    Returns the created Surface object.
    
    从以下版本开始:
    
    4
  - setVideoSurface
```
public boolean setVideoSurface(Surface surface)
```
    Sets the surface for the decoder to display decoded video data.
    
    参数:
    
    surface - Indicates a surface instance.
    
    返回:
    
    Returns true if the setting is successful; returns false otherwise.
    
    从以下版本开始:
    
    1
  - setVideoScaleType
```
public boolean setVideoScaleType(int type)
```
    Sets the video scaling type.
    参数:
    type - Indicates the way the video will be scaled. The value must be one of the following:
    
    VIDEO_SCALE_TYPE_FIT
    VIDEO_SCALE_TYPE_CROP
    返回:
    
    Returns true if the operation is successful; returns false otherwise.
    
    从以下版本开始:
    
    3
  - getAvailableBuffer
```
public ByteBuffer getAvailableBuffer(long timeout)
```
    Obtains a ByteBuffer in normal mode.
    This method applies only to the normal mode and is invalid in the pipeline mode. In normal mode, you must manually transfer source data to the codec. Specifically, call getAvailableBuffer to obtain a ByteBuffer, then fill the source data in the ByteBuffer, and finally call writeBuffer(java.nio.ByteBuffer, ohos.media.common.BufferInfo) to pass the source data from the ByteBuffer to the codec.
    The current method must be called after start().
    
    参数:
    
    timeout - Indicates the duration that the codec can wait for a ByteBuffer, in milliseconds. If there is no available ByteBuffer after the specified duration is reached, the value null is returned. If this parameter is set to -1, the method is blocked until it obtains a byte buffer or an error occurs.
    
    返回:
    
    Returns a ByteBuffer; returns null if a timeout or error occurs.
    
    从以下版本开始:
    
    1
  - writeBuffer
```
public boolean writeBuffer(ByteBuffer buffer,
                           BufferInfo info)
```
    Pushes source data to the encoder or decoder.
    This method applies only to the normal mode and is invalid in the pipeline mode. The ByteBuffer parameter must be set to that obtained by calling getAvailableBuffer(long).
    The current method must be called after start().
    
    参数:
    
    buffer - Indicates the ByteBuffer returned by getAvailableBuffer(long).
    
    info - Indicates the BufferInfo type. For details, see BufferInfo.
    
    返回:
    
    Returns true if the source data is pushed to the encoder or decoder; returns false otherwise.
    
    从以下版本开始:
    
    1
  - getBufferFormat
```
public Format getBufferFormat(ByteBuffer buffer)
```
    Obtains the output data format.
    This function is used to obtain the format of output data after encoding or decoding. The output data is carried in the ByteBuffer parameter in ICodecListener#onReadBuffer.
    
    参数:
    
    buffer - Indicates the ByteBuffer returned by ICodecListener#onReadBuffer.
    
    返回:
    
    Returns the output data format if obtained; returns null otherwise.
    
    从以下版本开始:
    
    1
  - start
```
public boolean start()
```
    Starts encoding or decoding after the preparation is complete.
    
    返回:
    
    Returns true if the task is started; returns false otherwise.
    
    从以下版本开始:
    
    1
  - stop
```
public boolean stop()
```
    Stops encoding or decoding.
    
    返回:
    
    Returns true if the task is stopped; returns false otherwise.
    
    从以下版本开始:
    
    1
  - release
```
public boolean release()
```
    Releases all resources, including the memory applied by the native layer. After this method is called, the Codec instance will not have the encoding or decoding capability.
    
    返回:
    
    Returns true if the resources are released; returns false otherwise.
    
    从以下版本开始:
    
    1
  - flush
```
public boolean flush()
```
    Flush all buffers.
    
    返回:
    
    Returns true if flush succeed; returns false otherwise.
    
    从以下版本开始:
    
    5
  - stopVideoSurface
```
public boolean stopVideoSurface()
```
    Informs the encoder of the end of input and stops encoding.
    
    返回:
    
    Returns true if the encoder input ends normally; returns false otherwise.
    
    从以下版本开始:
    
    6
  - obtainCodecName
```
public Map<Integer,String> obtainCodecName()
```
    Obtains the codec name.
    
    返回:
    
    Returns the codec name.
    
    从以下版本开始:
    
    6
  - obtainCodecDescription
```
public CodecDescription obtainCodecDescription()
```
    Obtains the CodecDescription object.
    
    返回:
    
    Returns the CodecDescription object.
    
    从以下版本开始:
    
    6
  - obtainOutputPixelMap
```
public PixelMap obtainOutputPixelMap(int index)
```
    Obtains a read-only pixel map for a dequeued output buffer.
    
    参数:
    
    index - Indicates the index of a dequeued output buffer returned by ICodecListener#onReadBuffer.
    
    返回:
    
    Returns the output pixel map if obtained; returns null otherwise.
    
    从以下版本开始:
    
    6
  - obtainInputPixelMap
```
public PixelMap obtainInputPixelMap(int index)
```
    Obtains a writable pixel map for a dequeued input buffer.
    
    参数:
    
    index - Indicates the index of a dequeued input buffer returned by getInputBufferIndex(long).
    
    返回:
    
    Returns the input pixel map if obtained; returns null otherwise.
    
    从以下版本开始:
    
    6
  - createLastingVideoSurface
```
public Surface createLastingVideoSurface()
```
    Creates a lasting Surface object for this encoder.
    The lasting Surface object is used for the input of the encoder.
    This method must be called after #SetCodecFormat(ohos.media.common.Format) or setSourceFormat(ohos.media.common.Format) and before start().
    
    返回:
    
    Returns the created lasting Surface object.
    
    从以下版本开始:
    
    6
  - setLastingVideoSurface
```
public boolean setLastingVideoSurface(Surface lastingSurface)
```
    Sets a lasting Surface object for this encoder.
    The lasting Surface object is used for the input of the encoder.
    This method must be called after #SetCodecFormat(ohos.media.common.Format) or setSourceFormat(ohos.media.common.Format) and before start().
    
    参数:
    
    lastingSurface - Indicates the lasting surface used for input.
    
    返回:
    
    Returns true if the setting is successful; returns false otherwise.
    
    从以下版本开始:
    
    6
  - getInputBufferIndex
```
public int getInputBufferIndex(long timeout)
```
    Obtains a dequeued input buffer index.
    
    参数:
    
    timeout - Indicates the duration that the codec can wait for a dequeued input buffer index, in milliseconds.
    
    返回:
    
    Returns the index if obtained; returns -1 otherwise.
    
    从以下版本开始:
    
    6
  - finalize
```
protected void finalize()
                 throws Throwable
```
    从类复制的说明: Object
    
    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 Java™ 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.
    
    覆盖:
    
    finalize 在类中 Object
    
    抛出:
    
    Throwable - the Exception raised by this method
    
    另请参阅:
    
    WeakReference, PhantomReference

类 Codec

嵌套类概要

字段概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

VIDEO_SCALE_TYPE_CROP

VIDEO_SCALE_TYPE_FIT

方法详细资料

createDecoder

createEncoder

registerCodecListener

setSource

setSourceFormat

setCodecFormat

setProperty

obtainInputSurface

setVideoSurface

setVideoScaleType

getAvailableBuffer

writeBuffer

getBufferFormat

start

stop

release

flush

stopVideoSurface

obtainCodecName

obtainCodecDescription

obtainOutputPixelMap

obtainInputPixelMap

createLastingVideoSurface

setLastingVideoSurface

getInputBufferIndex

finalize