Struct CodecFactoryProxy

pub struct CodecFactoryProxy { /* private fields */ }

Implementations

impl CodecFactoryProxy

pub fn new(channel: AsyncChannel) -> Self

Create a new Proxy for fuchsia.mediacodec/CodecFactory.

pub fn take_event_stream(&self) -> CodecFactoryEventStream

Get a Stream of events from the remote end of the protocol.

Panics

Panics if the event stream was already taken.

pub fn get_detailed_codec_descriptions( &self, ) -> QueryResponseFut<CodecFactoryGetDetailedCodecDescriptionsResponse, DefaultFuchsiaResourceDialect>

A client should call |GetDetailedCodecDescriptions()| to get a list of codecs supported either by software implementations or by underlying hardware.

pub fn create_decoder( &self, decoder_params: &CreateDecoderParams, decoder: ServerEnd<StreamProcessorMarker>, ) -> Result<(), Error>

CreateDecoder:

decoder_params - See CreateDecoder_Params comments for required and optional parameters for creating a decoder.

decoder - a Codec.NewRequest() which will hopefully be connected to a Codec server, or the Codec channel will get closed if no suitable codec can be found. We don’t return any additional Codec-specific status here because finding the Codec is allowed to be fully async, so we don’t necessarily yet know on return from this method which Codec will be selected, if any.

Rough sequence to create a decoder:

factory = ConnectToEnvironmentService(CodecFactory); CreateDecoder_Params params; [fill out params] CreateDecoder(params, decoder_request);

See use_media_decoder code for more detail.

pub fn create_encoder( &self, encoder_params: &CreateEncoderParams, encoder: ServerEnd<StreamProcessorMarker>, ) -> Result<(), Error>

CreateEncoder:

encoder_params - See CreateEncoder_Params comments for required and optional parameters for creating a decoder.

encoder - a Codec.NewRequest() which will hopefully be connected to a Codec server, or the Codec channel will get closed if no suitable codec can be found. We don’t return any additional Codec-specific status here because finding the Codec is allowed to be fully async, so we don’t necessarily yet know on return from this method which Codec will be selected, if any.

pub fn attach_lifetime_tracking( &self, codec_end: EventPair, ) -> Result<(), Error>

AttachLifetimeTracking:

Attach an eventpair endpoint to the next Create{X}(), so that the codec_end will be closed when the number of buffers allocated reaches ‘buffers_remaining’. Multiple eventpair endpoints can be attached per create, with an enforced limit of CODEC_FACTORY_LIFETIME_TRACKING_EVENTPAIR_PER_CREATE_MAX.

The lifetime signalled by this event is intended to track all resources used by the codec, including sysmem-allocated buffers created internally by the codec. The sysmem buffer collections visible to the client, for input and output buffers, are not included in the resources tracked here, because those can be tracked separately via fuchsia.sysmem.BufferCollection.AttachLifetimeTracking(). It is permitted to send a duplicate of codec_end to both this AttachLifetimeTracking() and also to fuchsia.sysmem.BufferCollection.AttachLifetimeTracking(). The ZX_EVENTPAIR_PEER_CLOSED will happen when both/all lifetimes are fully over. This conveniently avoids needing multiple separate async waits by the client.

In the case of server process crashes, or failure of a codec to plumb codec_end to sysmem, ZX_EVENTPAIR_PEER_CLOSED signalled on the peer of codec_end may occur shortly before all resources are freed.

A maximum of CODEC_FACTORY_LIFETIME_TRACKING_EVENTPAIR_PER_CREATE_MAX calls to AttachLifetimeTracking() are allowed before any Create{X}(). There is no way to cancel an attach short of closing the CodecFactory channel. Closing the client end of the eventpair doesn’t subtract from the number of pending attach(es). For this reason, it can be good to only send attach message(s) immediately before the relevant Create{X}(), when it’s known by the client that both the attach message(s) and the Create{X}() messages will be sent.

Closing the client’s end doesn’t result in any action by the server. If the server listens to events from the client end at all, it is for debug logging only.

The server intentionally doesn’t “trust” any bits signalled by the client. This mechanism intentionally uses only ZX_EVENTPAIR_PEER_CLOSED which can’t be triggered early, and is only triggered when all handles to codec_end are closed. No meaning is associated with any of the other signal bits, and clients should functionally ignore any other signal bits on either end of the eventpair or its peer.

The codec_end may lack ZX_RIGHT_SIGNAL or ZX_RIGHT_SIGNAL_PEER, but must have ZX_RIGHT_DUPLICATE (and must have ZX_RIGHT_TRANSFER to transfer without causing CodecFactory channel failure).

Trait Implementations

impl Clone for CodecFactoryProxy

fn clone(&self) -> CodecFactoryProxy

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl CodecFactoryProxyInterface for CodecFactoryProxy

type GetDetailedCodecDescriptionsResponseFut = QueryResponseFut<CodecFactoryGetDetailedCodecDescriptionsResponse>

fn get_detailed_codec_descriptions( &self, ) -> Self::GetDetailedCodecDescriptionsResponseFut

fn create_decoder( &self, decoder_params: &CreateDecoderParams, decoder: ServerEnd<StreamProcessorMarker>, ) -> Result<(), Error>

fn create_encoder( &self, encoder_params: &CreateEncoderParams, encoder: ServerEnd<StreamProcessorMarker>, ) -> Result<(), Error>

fn attach_lifetime_tracking(&self, codec_end: EventPair) -> Result<(), Error>

impl Debug for CodecFactoryProxy

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Proxy for CodecFactoryProxy

type Protocol = CodecFactoryMarker

The protocol which this Proxy controls.

fn from_channel(inner: AsyncChannel) -> Self

Create a proxy over the given channel.

fn into_channel(self) -> Result<AsyncChannel, Self>

Attempt to convert the proxy back into a channel.

fn as_channel(&self) -> &AsyncChannel

Get a reference to the proxy’s underlying channel.

fn into_client_end(self) -> Result<ClientEnd<Self::Protocol>, Self>

Attempt to convert the proxy back into a client end.

fn is_closed(&self) -> bool

Returns true if the proxy has received the PEER_CLOSED signal.

fn on_closed(&self) -> OnSignals<'_, Unowned<'_, Handle>>

Returns a future that completes when the proxy receives the PEER_CLOSED signal.