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 |
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(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. |
|
MediaCas(int casSystemId)
Instantiate a CA system of the specified system id. |
|
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
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
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
public static final int SCRAMBLING_MODE_AES128
Advanced Encryption System (AES) 128-bit Encryption mode.
Constant Value: 9 (0x00000009)
SCRAMBLING_MODE_AES_CBC
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
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
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
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
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
public static final int SCRAMBLING_MODE_DVB_CSA2
DVB CSA 2.
Constant Value: 2 (0x00000002)
SCRAMBLING_MODE_DVB_CSA3_ENHANCE
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
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
public static final int SCRAMBLING_MODE_DVB_CSA3_STANDARD
DVB CSA 3 in standard mode.
Constant Value: 3 (0x00000003)
SCRAMBLING_MODE_DVB_IDSA
public static final int SCRAMBLING_MODE_DVB_IDSA
ATIS-0800006 IIF Default Scrambling Algorithm (IDSA).
Constant Value: 7 (0x00000007)
SCRAMBLING_MODE_MULTI2
public static final int SCRAMBLING_MODE_MULTI2
A symmetric key algorithm.
Constant Value: 8 (0x00000008)
SCRAMBLING_MODE_RESERVED
public static final int SCRAMBLING_MODE_RESERVED
DVB (Digital Video Broadcasting) reserved mode.
Constant Value: 0 (0x00000000)
SCRAMBLING_MODE_TDES_ECB
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
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
public static final int SESSION_USAGE_LIVE
Cas session is used to descramble live streams.
Constant Value: 0 (0x00000000)
SESSION_USAGE_PLAYBACK
public static final int SESSION_USAGE_PLAYBACK
Cas session is used to descramble recoreded streams.
Constant Value: 1 (0x00000001)
SESSION_USAGE_RECORD
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
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
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
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. |
MediaCas
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. |
Public methods
close
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
public static PluginDescriptor[] enumeratePlugins ()
List all available CA plugins on the device.
| Returns | |
|---|---|
PluginDescriptor[] |
an array of descriptors for the available CA plugins. |
isSystemIdSupported
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
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
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
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
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
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
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
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
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
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
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.
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Last updated 2025-02-10 UTC.