Struct devices::virtio::video::decoder::backend::vda::VdaDecoderSession

pub struct VdaDecoderSession {
    vda_session: Session,
    format: Option<PixelFormat>,
    timestamp_to_resource_id: BTreeMap<u32, u32>,
}

Fields

vda_session: Session

format: Option<PixelFormat>

timestamp_to_resource_id: BTreeMap<u32, u32>

libvda can only handle 32-bit timestamps, so we will give it the buffer ID as a timestamp and map it back to the actual timestamp using this table when a decoded frame is produced.

Trait Implementations

impl DecoderSession for VdaDecoderSession

fn set_output_parameters( &mut self, buffer_count: usize, format: Format ) -> Result<(), VideoError>

Tell how many output buffers will be used for this session and which format they will carry. This method must be called after a ProvidePictureBuffers event is emitted, and before the first call to use_output_buffer().

fn decode( &mut self, resource_id: u32, timestamp: u64, resource: GuestResourceHandle, offset: u32, bytes_used: u32 ) -> Result<(), VideoError>

Decode the compressed stream contained in [offset..offset+bytes_used] of the shared memory in the input resource.

fn flush(&mut self) -> Result<(), VideoError>

Flush the decoder device, i.e. finish processing all queued decode requests and emit frames for them.

fn reset(&mut self) -> Result<(), VideoError>

Reset the decoder device, i.e. cancel all pending decoding requests.

fn clear_output_buffers(&mut self) -> Result<(), VideoError>

Immediately release all buffers passed using use_output_buffer() and reuse_output_buffer().

fn event_pipe(&self) -> &dyn AsRawDescriptor

Returns the event pipe on which the availability of events will be signaled. Note that the returned value is borrowed and only valid as long as the session is alive.

fn use_output_buffer( &mut self, picture_buffer_id: i32, resource: GuestResource ) -> Result<(), VideoError>

Ask the device to use resource to store decoded frames according to its layout. picture_buffer_id is the ID of the picture that will be reproduced in PictureReady events using this buffer.

fn reuse_output_buffer( &mut self, picture_buffer_id: i32 ) -> Result<(), VideoError>

Ask the device to reuse an output buffer previously passed to use_output_buffer and that has previously been returned to the decoder in a PictureReady event.

fn read_event(&mut self) -> Result<DecoderEvent, VideoError>

Blocking call to read a single event from the event pipe.