MediaCas

public final class MediaCas
extends Object implements AutoCloseable

java.lang.Object
   ↳ android.media.MediaCas


MediaCas can be used to obtain keys for descrambling protected media streams, in conjunction with MediaDescrambler. The MediaCas APIs are designed to support conditional access such as those in the ISO/IEC13818-1. The CA system is identified by a 16-bit integer CA_system_id. The scrambling algorithms are usually proprietary and implemented by vendor-specific CA plugins installed on the device.

The app is responsible for constructing a MediaCas object for the CA system it intends to use. The app can query if a certain CA system is supported using static method isSystemIdSupported(int). It can also obtain the entire list of supported CA systems using static method enumeratePlugins().

Once the MediaCas object is constructed, the app should properly provision it by using method provision(String) and/or processEmm(byte). The EMMs (Entitlement management messages) can be distributed out-of-band, or in-band with the stream.

To descramble elementary streams, the app first calls openSession() to generate a Session object that will uniquely identify a session. A session provides a context for subsequent key updates and descrambling activities. The ECMs (Entitlement control messages) are sent to the session via method Session#processEcm.

The app next constructs a MediaDescrambler object, and initializes it with the session using MediaDescrambler#setMediaCasSession. This ties the descrambler to the session, and the descrambler can then be used to descramble content secured with the session's key, either during extraction, or during decoding with MediaCodec.

If the app handles sample extraction using its own extractor, it can use MediaDescrambler to descramble samples into clear buffers (if the session's license doesn't require secure decoders), or descramble a small amount of data to retrieve information necessary for the downstream pipeline to process the sample (if the session's license requires secure decoders).

If the session requires a secure decoder, a MediaDescrambler needs to be provided to MediaCodec to descramble samples queued by MediaCodec#queueSecureInputBuffer into protected buffers. The app should use MediaCodec#configure(MediaFormat, android.view.Surface, int, MediaDescrambler) instead of the normal MediaCodec.configure(android.media.MediaFormat, android.view.Surface, android.media.MediaCrypto, int) method to configure MediaCodec.

Using Android's MediaExtractor

If the app uses MediaExtractor, it can delegate the CAS session management to MediaExtractor by calling MediaExtractor#setMediaCas. MediaExtractor will take over and call openSession(), processEmm(byte) and/or Session#processEcm, etc.. if necessary.

When using MediaExtractor, the app would still need a MediaDescrambler to use with MediaCodec if the licensing requires a secure decoder. The session associated with the descrambler of a track can be retrieved by calling MediaExtractor#getCasInfo, and used to initialize a MediaDescrambler object for MediaCodec.

Listeners

The app may register a listener to receive events from the CA system using method setEventListener(EventListener, Handler). The exact format of the event is scheme-specific and is not specified by this API.

Summary

Nested classes

interface MediaCas.EventListener

An interface registered by the caller to MediaCas.setEventListener(EventListener, Handler) to receives scheme-specific notifications from a MediaCas instance. 

class MediaCas.PluginDescriptor

Describe a CAS plugin with its CA_system_ID and string name. 

class MediaCas.Session

Class for an open session with the CA system. 

Constants

int PLUGIN_STATUS_PHYSICAL_MODULE_CHANGED

The event to indicate that the status of CAS system is changed by the removal or insertion of physical CAS modules.

int PLUGIN_STATUS_SESSION_NUMBER_CHANGED

The event to indicate that the number of CAS system's session is changed.

int SCRAMBLING_MODE_AES128

Advanced Encryption System (AES) 128-bit Encryption mode.

int SCRAMBLING_MODE_AES_CBC

Advanced Encryption System (AES) Cipher Block Chaining (CBC) mode.

int SCRAMBLING_MODE_AES_ECB

Advanced Encryption System (AES) Electronic Code Book (ECB) mode.

int SCRAMBLING_MODE_AES_SCTE52

Advanced Encryption System (AES) Society of Cable Telecommunications Engineers (SCTE) 52 mode.

int SCRAMBLING_MODE_DVB_CISSA_V1

DVB Common IPTV Software-oriented Scrambling Algorithm (CISSA) Version 1.

int SCRAMBLING_MODE_DVB_CSA1

DVB (Digital Video Broadcasting) Common Scrambling Algorithm (CSA) 1.

int SCRAMBLING_MODE_DVB_CSA2

DVB CSA 2.

int SCRAMBLING_MODE_DVB_CSA3_ENHANCE

DVB CSA 3 in fully enhanced mode.

int SCRAMBLING_MODE_DVB_CSA3_MINIMAL

DVB CSA 3 in minimally enhanced mode.

int SCRAMBLING_MODE_DVB_CSA3_STANDARD

DVB CSA 3 in standard mode.

int SCRAMBLING_MODE_DVB_IDSA

ATIS-0800006 IIF Default Scrambling Algorithm (IDSA).

int SCRAMBLING_MODE_MULTI2

A symmetric key algorithm.

int SCRAMBLING_MODE_RESERVED

DVB (Digital Video Broadcasting) reserved mode.

int SCRAMBLING_MODE_TDES_ECB

Triple Data Encryption Algorithm (TDES) Electronic Code Book (ECB) mode.

int SCRAMBLING_MODE_TDES_SCTE52

Triple Data Encryption Algorithm (TDES) Society of Cable Telecommunications Engineers (SCTE) 52 mode.

int SESSION_USAGE_LIVE

Cas session is used to descramble live streams.

int SESSION_USAGE_PLAYBACK

Cas session is used to descramble recoreded streams.

int SESSION_USAGE_RECORD

Cas session is used to descramble live streams and encrypt local recorded content

int SESSION_USAGE_TIMESHIFT

Cas session is used to descramble live streams , encrypt local recorded content and playback local encrypted content.

Public constructors

MediaCas(int casSystemId)

Instantiate a CA system of the specified system id.

MediaCas(Context context, int casSystemId, String tvInputServiceSessionId, int priorityHint)

Instantiate a CA system of the specified system id.

MediaCas(Context context, int casSystemId, String tvInputServiceSessionId, int priorityHint, Handler handler, MediaCas.EventListener listener)

Instantiate a CA system of the specified system id with EvenListener.

Public methods

void close()

Closes this resource, relinquishing any underlying resources.

static PluginDescriptor[] enumeratePlugins()

List all available CA plugins on the device.

static boolean isSystemIdSupported(int CA_system_id)

Query if a certain CA system is supported on this device.

MediaCas.Session openSession(int sessionUsage, int scramblingMode)

Open a session with usage and scrambling information, so that descrambler can be configured to descramble one or more streams scrambled by the conditional access system.

MediaCas.Session openSession()

Open a session to descramble one or more streams scrambled by the conditional access system.

void processEmm(byte[] data)

Send a received EMM packet to the CA system.

void processEmm(byte[] data, int offset, int length)

Send a received EMM packet to the CA system.

void provision(String provisionString)

Initiate a provisioning operation for a CA system.

void refreshEntitlements(int refreshType, byte[] refreshData)

Notify the CA system to refresh entitlement keys.

void sendEvent(int event, int arg, byte[] data)

Send an event to a CA system.

void setEventListener(MediaCas.EventListener listener, Handler handler)

Set an event listener to receive notifications from the MediaCas instance.

void setPrivateData(byte[] data)

Send the private data for the CA system.

Protected methods

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

Constants

PLUGIN_STATUS_PHYSICAL_MODULE_CHANGED

Added in API level 30
public static final int PLUGIN_STATUS_PHYSICAL_MODULE_CHANGED

The event to indicate that the status of CAS system is changed by the removal or insertion of physical CAS modules.

Constant Value: 0 (0x00000000)

PLUGIN_STATUS_SESSION_NUMBER_CHANGED

Added in API level 30
public static final int PLUGIN_STATUS_SESSION_NUMBER_CHANGED

The event to indicate that the number of CAS system's session is changed.

Constant Value: 1 (0x00000001)

SCRAMBLING_MODE_AES128

Added in API level 30
public static final int SCRAMBLING_MODE_AES128

Advanced Encryption System (AES) 128-bit Encryption mode.

Constant Value: 9 (0x00000009)

SCRAMBLING_MODE_AES_CBC

Added in API level 34
public static final int SCRAMBLING_MODE_AES_CBC

Advanced Encryption System (AES) Cipher Block Chaining (CBC) mode.

Constant Value: 14 (0x0000000e)

SCRAMBLING_MODE_AES_ECB

Added in API level 30
public static final int SCRAMBLING_MODE_AES_ECB

Advanced Encryption System (AES) Electronic Code Book (ECB) mode.

Constant Value: 10 (0x0000000a)

SCRAMBLING_MODE_AES_SCTE52

Added in API level 30
public static final int SCRAMBLING_MODE_AES_SCTE52

Advanced Encryption System (AES) Society of Cable Telecommunications Engineers (SCTE) 52 mode.

Constant Value: 11 (0x0000000b)

SCRAMBLING_MODE_DVB_CISSA_V1

Added in API level 30
public static final int SCRAMBLING_MODE_DVB_CISSA_V1

DVB Common IPTV Software-oriented Scrambling Algorithm (CISSA) Version 1.

Constant Value: 6 (0x00000006)

SCRAMBLING_MODE_DVB_CSA1

Added in API level 30
public static final int SCRAMBLING_MODE_DVB_CSA1

DVB (Digital Video Broadcasting) Common Scrambling Algorithm (CSA) 1.

Constant Value: 1 (0x00000001)

SCRAMBLING_MODE_DVB_CSA2

Added in API level 30
public static final int SCRAMBLING_MODE_DVB_CSA2

DVB CSA 2.

Constant Value: 2 (0x00000002)

SCRAMBLING_MODE_DVB_CSA3_ENHANCE

Added in API level 30
public static final int SCRAMBLING_MODE_DVB_CSA3_ENHANCE

DVB CSA 3 in fully enhanced mode.

Constant Value: 5 (0x00000005)

SCRAMBLING_MODE_DVB_CSA3_MINIMAL

Added in API level 30
public static final int SCRAMBLING_MODE_DVB_CSA3_MINIMAL

DVB CSA 3 in minimally enhanced mode.

Constant Value: 4 (0x00000004)

SCRAMBLING_MODE_DVB_CSA3_STANDARD

Added in API level 30
public static final int SCRAMBLING_MODE_DVB_CSA3_STANDARD

DVB CSA 3 in standard mode.

Constant Value: 3 (0x00000003)

SCRAMBLING_MODE_DVB_IDSA

Added in API level 30
public static final int SCRAMBLING_MODE_DVB_IDSA

ATIS-0800006 IIF Default Scrambling Algorithm (IDSA).

Constant Value: 7 (0x00000007)

SCRAMBLING_MODE_MULTI2

Added in API level 30
public static final int SCRAMBLING_MODE_MULTI2

A symmetric key algorithm.

Constant Value: 8 (0x00000008)

SCRAMBLING_MODE_RESERVED

Added in API level 30
public static final int SCRAMBLING_MODE_RESERVED

DVB (Digital Video Broadcasting) reserved mode.

Constant Value: 0 (0x00000000)

SCRAMBLING_MODE_TDES_ECB

Added in API level 30
public static final int SCRAMBLING_MODE_TDES_ECB

Triple Data Encryption Algorithm (TDES) Electronic Code Book (ECB) mode.

Constant Value: 12 (0x0000000c)

SCRAMBLING_MODE_TDES_SCTE52

Added in API level 30
public static final int SCRAMBLING_MODE_TDES_SCTE52

Triple Data Encryption Algorithm (TDES) Society of Cable Telecommunications Engineers (SCTE) 52 mode.

Constant Value: 13 (0x0000000d)

SESSION_USAGE_LIVE

Added in API level 30
public static final int SESSION_USAGE_LIVE

Cas session is used to descramble live streams.

Constant Value: 0 (0x00000000)

SESSION_USAGE_PLAYBACK

Added in API level 30
public static final int SESSION_USAGE_PLAYBACK

Cas session is used to descramble recoreded streams.

Constant Value: 1 (0x00000001)

SESSION_USAGE_RECORD

Added in API level 30
public static final int SESSION_USAGE_RECORD

Cas session is used to descramble live streams and encrypt local recorded content

Constant Value: 2 (0x00000002)

SESSION_USAGE_TIMESHIFT

Added in API level 30
public static final int SESSION_USAGE_TIMESHIFT

Cas session is used to descramble live streams , encrypt local recorded content and playback local encrypted content.

Constant Value: 3 (0x00000003)

Public constructors

MediaCas

Added in API level 26
public MediaCas (int casSystemId)

Instantiate a CA system of the specified system id.

Parameters
casSystemId int: The system id of the CA system.

Throws
MediaCasException.UnsupportedCasException if the device does not support the specified CA system.

MediaCas

Added in API level 26
public MediaCas (Context context, 
                int casSystemId, 
                String tvInputServiceSessionId, 
                int priorityHint)

Instantiate a CA system of the specified system id.

Parameters
context Context: the context of the caller. This value cannot be null.

casSystemId int: The system id of the CA system.

tvInputServiceSessionId String: The Id of the session opened in TV Input Service (TIS) TvInputService.onCreateSession(String, String) This value may be null.

priorityHint int: priority hint from the use case type for new created CAS system. Value is TvInputService.PRIORITY_HINT_USE_CASE_TYPE_BACKGROUND, TvInputService.PRIORITY_HINT_USE_CASE_TYPE_SCAN, TvInputService.PRIORITY_HINT_USE_CASE_TYPE_PLAYBACK, TvInputService.PRIORITY_HINT_USE_CASE_TYPE_LIVE, or TvInputService.PRIORITY_HINT_USE_CASE_TYPE_RECORD

Throws
MediaCasException.UnsupportedCasException if the device does not support the specified CA system.

MediaCas

Added in API level 26
public MediaCas (Context context, 
                int casSystemId, 
                String tvInputServiceSessionId, 
                int priorityHint, 
                Handler handler, 
                MediaCas.EventListener listener)

Instantiate a CA system of the specified system id with EvenListener.

Parameters
context Context: the context of the caller. This value cannot be null.

casSystemId int: The system id of the CA system.

tvInputServiceSessionId String: The Id of the session opened in TV Input Service (TIS) TvInputService.onCreateSession(String, String) This value may be null.

priorityHint int: priority hint from the use case type for new created CAS system. Value is TvInputService.PRIORITY_HINT_USE_CASE_TYPE_BACKGROUND, TvInputService.PRIORITY_HINT_USE_CASE_TYPE_SCAN, TvInputService.PRIORITY_HINT_USE_CASE_TYPE_PLAYBACK, TvInputService.PRIORITY_HINT_USE_CASE_TYPE_LIVE, or TvInputService.PRIORITY_HINT_USE_CASE_TYPE_RECORD

handler Handler: the handler whose looper the event listener will be called on. If handler is null, we'll try to use current thread's looper, or the main looper. If neither are available, an internal thread will be created instead.

listener MediaCas.EventListener: the event listener to be set. This value may be null.

Throws
MediaCasException.UnsupportedCasException if the device does not support the specified CA system.

Public methods

close

Added in API level 26
public void close ()

Closes this resource, relinquishing any underlying resources. This method is invoked automatically on objects managed by the try-with-resources statement.

enumeratePlugins

Added in API level 26
public static PluginDescriptor[] enumeratePlugins ()

List all available CA plugins on the device.

Returns
PluginDescriptor[] an array of descriptors for the available CA plugins.

isSystemIdSupported

Added in API level 26
public static boolean isSystemIdSupported (int CA_system_id)

Query if a certain CA system is supported on this device.

Parameters
CA_system_id int: the id of the CA system.

Returns
boolean Whether the specified CA system is supported on this device.

openSession

Added in API level 30
public MediaCas.Session openSession (int sessionUsage, 
                int scramblingMode)

Open a session with usage and scrambling information, so that descrambler can be configured to descramble one or more streams scrambled by the conditional access system.

Tuner resource manager (TRM) uses the client priority value to decide whether it is able to get cas session resource if cas session resources is limited. If the client can't get the resource, this call returns MediaCasException.InsufficientResourceException.

Parameters
sessionUsage int: used for the created session. Value is SESSION_USAGE_LIVE, SESSION_USAGE_PLAYBACK, SESSION_USAGE_RECORD, or SESSION_USAGE_TIMESHIFT

scramblingMode int: used for the created session. Value is SCRAMBLING_MODE_RESERVED, SCRAMBLING_MODE_DVB_CSA1, SCRAMBLING_MODE_DVB_CSA2, SCRAMBLING_MODE_DVB_CSA3_STANDARD, SCRAMBLING_MODE_DVB_CSA3_MINIMAL, SCRAMBLING_MODE_DVB_CSA3_ENHANCE, SCRAMBLING_MODE_DVB_CISSA_V1, SCRAMBLING_MODE_DVB_IDSA, SCRAMBLING_MODE_MULTI2, SCRAMBLING_MODE_AES128, SCRAMBLING_MODE_AES_CBC, SCRAMBLING_MODE_AES_ECB, SCRAMBLING_MODE_AES_SCTE52, SCRAMBLING_MODE_TDES_ECB, or SCRAMBLING_MODE_TDES_SCTE52

Returns
MediaCas.Session session the newly opened session. This value may be null.

Throws
IllegalStateException if the MediaCas instance is not valid.
MediaCasException for CAS-specific errors.
MediaCasStateException for CAS-specific state exceptions.

openSession

Added in API level 26
public MediaCas.Session openSession ()

Open a session to descramble one or more streams scrambled by the conditional access system.

Tuner resource manager (TRM) uses the client priority value to decide whether it is able to get cas session resource if cas session resources is limited. If the client can't get the resource, this call returns MediaCasException.InsufficientResourceException.

Returns
MediaCas.Session session the newly opened session.

Throws
IllegalStateException if the MediaCas instance is not valid.
MediaCasException for CAS-specific errors.
MediaCasStateException for CAS-specific state exceptions.

processEmm

Added in API level 26
public void processEmm (byte[] data)

Send a received EMM packet to the CA system. This is similar to processEmm(byte[], int, int) except that the entire byte array is sent.

Parameters
data byte: byte array of the EMM data. This value cannot be null.

Throws
IllegalStateException if the MediaCas instance is not valid.
MediaCasException for CAS-specific errors.
MediaCasStateException for CAS-specific state exceptions.

processEmm

Added in API level 26
public void processEmm (byte[] data, 
                int offset, 
                int length)

Send a received EMM packet to the CA system.

Parameters
data byte: byte array of the EMM data. This value cannot be null.

offset int: position within data where the EMM data begins.

length int: length of the data (starting from offset).

Throws
IllegalStateException if the MediaCas instance is not valid.
MediaCasException for CAS-specific errors.
MediaCasStateException for CAS-specific state exceptions.

provision

Added in API level 26
public void provision (String provisionString)

Initiate a provisioning operation for a CA system.

Parameters
provisionString String: string containing information needed for the provisioning operation, the format of which is scheme and implementation specific. This value cannot be null.

Throws
IllegalStateException if the MediaCas instance is not valid.
MediaCasException for CAS-specific errors.
MediaCasStateException for CAS-specific state exceptions.

refreshEntitlements

Added in API level 26
public void refreshEntitlements (int refreshType, 
                byte[] refreshData)

Notify the CA system to refresh entitlement keys.

Parameters
refreshType int: the type of the refreshment.

refreshData byte: private data associated with the refreshment. This value may be null.

Throws
IllegalStateException if the MediaCas instance is not valid.
MediaCasException for CAS-specific errors.
MediaCasStateException for CAS-specific state exceptions.

sendEvent

Added in API level 26
public void sendEvent (int event, 
                int arg, 
                byte[] data)

Send an event to a CA system. The format of the event is scheme-specific and is opaque to the framework.

Parameters
event int: an integer denoting a scheme-specific event to be sent.

arg int: a scheme-specific integer argument for the event.

data byte: a byte array containing scheme-specific data for the event. This value may be null.

Throws
IllegalStateException if the MediaCas instance is not valid.
MediaCasException for CAS-specific errors.
MediaCasStateException for CAS-specific state exceptions.

setEventListener

Added in API level 26
public void setEventListener (MediaCas.EventListener listener, 
                Handler handler)

Set an event listener to receive notifications from the MediaCas instance.

Parameters
listener MediaCas.EventListener: the event listener to be set. This value may be null.

handler Handler: the handler whose looper the event listener will be called on. If handler is null, we'll try to use current thread's looper, or the main looper. If neither are available, an internal thread will be created instead.

setPrivateData

Added in API level 26
public void setPrivateData (byte[] data)

Send the private data for the CA system.

Parameters
data byte: byte array of the private data. This value cannot be null.

Throws
IllegalStateException if the MediaCas instance is not valid.
MediaCasException for CAS-specific errors.
MediaCasStateException for CAS-specific state exceptions.

Protected methods

finalize

Added in API level 26
protected 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 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.