Struct cros_codecs::decoders::h264::decoder::Decoder

pub struct Decoder<T>where
    T: DecodedHandle + DynDecodedHandle,{

    parser: Parser,
    blocking_mode: BlockingMode,
    backend: Box<dyn StatelessDecoderBackend<Handle = T>>,
    negotiation_status: NegotiationStatus,
    coded_resolution: Resolution,
    ready_queue: BinaryHeap<ReadyPicture<T>>,
    current_display_order: u64,
    dpb: Dpb<T>,
    max_num_reorder_frames: u32,
    cur_sps_id: u8,
    cur_pps_id: u8,
    prev_ref_pic_info: PrevReferencePicInfo,
    prev_pic_info: PrevPicInfo,
    curr_info: CurrentPicInfo,
    cur_pic: Option<PictureData>,
    last_field: Option<(Rc<RefCell<PictureData>>, T)>,
    ref_pic_list_p0: Vec<DpbEntry<T>>,
    ref_pic_list_b0: Vec<DpbEntry<T>>,
    ref_pic_list_b1: Vec<DpbEntry<T>>,
    ref_frame_list_0_short_term: Vec<DpbEntry<T>>,
    ref_frame_list_1_short_term: Vec<DpbEntry<T>>,
    ref_frame_list_long_term: Vec<DpbEntry<T>>,
    ref_pic_list0: Vec<DpbEntry<T>>,
    ref_pic_list1: Vec<DpbEntry<T>>,
}

Fields

parser: Parser

A parser to extract bitstream metadata

blocking_mode: BlockingMode

Whether the decoder should block on decode operations.

backend: Box<dyn StatelessDecoderBackend<Handle = T>>

The backend used for hardware acceleration.

negotiation_status: NegotiationStatus

Keeps track of whether the decoded format has been negotiated with the backend.

coded_resolution: Resolution

The current coded resolution

ready_queue: BinaryHeap<ReadyPicture<T>>

A queue with the handles of pictures that are ready to be sent to the DecoderSession, with the lowest order at the top.

current_display_order: u64

A monotonically increasing counter used to tag pictures in display order

dpb: Dpb<T>

The decoded picture buffer

max_num_reorder_frames: u32

Indicates an upper bound for the number of frames buffers, in the decoded picture buffer (DPB), that are required for storing frames, complementary field pairs, and non-paired fields before output. It is a requirement of bitstream conformance that the maximum number of frames, complementary field pairs, or non-paired fields that precede any frame, complementary field pair, or non-paired field in the coded video sequence in decoding order and follow it in output order shall be less than or equal to max_num_reorder_frames.

cur_sps_id: u8

The current active SPS id.

cur_pps_id: u8

The current active PPS id.

prev_ref_pic_info: PrevReferencePicInfo

Cached variables from the previous reference picture.

prev_pic_info: PrevPicInfo

Cached variables from the previous picture.

curr_info: CurrentPicInfo

Cached variables from the current picture.

cur_pic: Option<PictureData>

The current picture being worked on.

last_field: Option<(Rc<RefCell<PictureData>>, T)>

A cached, non-reference first field that did not make it into the DPB because it was full even after bumping the smaller POC. This field will be cached until the second field is processed so they can be output together.

We are not using DbpEntry<T> as the type because contrary to a DPB entry, the handle of this member is always valid.

ref_pic_list_p0: Vec<DpbEntry<T>>

Reference picture list for P slices. Retains the same meaning as in the specification. Points into the pictures stored in the DPB. Derived once per picture.

ref_pic_list_b0: Vec<DpbEntry<T>>

Reference picture list 0 for B slices. Retains the same meaning as in the specification. Points into the pictures stored in the DPB. Derived once per picture.

ref_pic_list_b1: Vec<DpbEntry<T>>

Reference picture list 1 for B slices. Retains the same meaning as in the specification. Points into the pictures stored in the DPB. Derived once per picture.

ref_frame_list_0_short_term: Vec<DpbEntry<T>>

Equivalent to refFrameList0ShortTerm in the spec. Used for building the references for P, SP and B slices in fields (8.2.4.2.2, 8.2.4.2.4). Derived once per field.

ref_frame_list_1_short_term: Vec<DpbEntry<T>>

Equivalent to refFrameList1ShortTerm in the spec. Used for building the references for B slices in fields (8.2.4.2.4). Derived once per field.

ref_frame_list_long_term: Vec<DpbEntry<T>>

Equivalent to refFrameList0LongTerm in the spec. Used for building the references for P, SP and B slices in fields (8.2.4.2.2, 8.2.4.2.4). Derived once per field.

ref_pic_list0: Vec<DpbEntry<T>>

Equivalent to RefPicList0 in the specification. Computed for every slice, points to the pictures in the DPB.

ref_pic_list1: Vec<DpbEntry<T>>

Equivalent to RefPicList1 in the specification. Computed for every slice, points to the pictures in the DPB.

Implementations

impl Decoder<VADecodedHandle>

pub fn new_vaapi(
    display: Rc<Display>,
    blocking_mode: BlockingMode
) -> Result<Self>

impl<T> Decoder<T>where
    T: DecodedHandle + DynDecodedHandle + 'static,

pub(crate) fn new(
    backend: Box<dyn StatelessDecoderBackend<Handle = T>>,
    blocking_mode: BlockingMode
) -> Result<Self>

fn negotiation_possible(
    sps: &Sps,
    dpb: &Dpb<T>,
    current_resolution: Resolution
) -> Result<bool>

fn get_max_num_order_frames(sps: &Sps, max_dpb_frames: usize) -> u32

fn process_sps(&mut self, nalu: &Nalu<impl AsRef<[u8]>>) -> Result<()>

fn compute_pic_order_count(&mut self, pic: &mut PictureData) -> Result<()>

fn update_pic_nums(
    &mut self,
    frame_num: i32,
    gap_picture: Option<&PictureData>
) -> Result<()>

fn sort_pic_num_descending(pics: &mut [DpbEntry<T>])

fn sort_long_term_pic_num_ascending(pics: &mut [DpbEntry<T>])

fn sort_frame_num_wrap_descending(pics: &mut [DpbEntry<T>])

fn sort_long_term_frame_idx_ascending(pics: &mut [DpbEntry<T>])

fn debug_ref_list_p(ref_pic_list: &[DpbEntry<T>], field_pic: bool)

fn debug_ref_list_b(ref_pic_list: &[DpbEntry<T>], ref_pic_list_name: &str)

fn init_ref_pic_list_p(&mut self)

8.2.4.2.1 Initialization process for the reference picture list for P and SP slices in frames

fn init_ref_field_pic_list_p(&mut self)

8.2.4.2.2 Initialization process for the reference picture list for P and SP slices in fields

fn sort_poc_descending(pics: &mut [DpbEntry<T>])

fn sort_poc_ascending(pics: &mut [DpbEntry<T>])

fn swap_b1_if_needed(&mut self)

fn init_ref_pic_list_b(&mut self)

fn init_ref_field_pic_list_b(&mut self)

8.2.4.2.4 Initialization process for reference picture lists for B slices in fields

fn init_ref_field_pic_list(
    &mut self,
    ref_frame_list_name: RefFrameListName,
    ref_pic_list_name: RefPicListName
)

Copies from refFrameListXShortTerm and refFrameListLongTerm into RefPicListX as per 8.2.4.2.5. Used when building the reference list for fields in interlaced decoding.

fn init_ref_pic_lists(&mut self)

fn sliding_window_marking(&mut self, pic: &mut PictureData) -> Result<()>

fn mmco_op_1(&self, pic: &PictureData, marking: usize) -> Result<()>

fn mmco_op_2(&self, pic: &PictureData, marking: usize) -> Result<()>

fn mmco_op_3(&self, pic: &PictureData, marking: usize) -> Result<()>

fn mmco_op_4(&mut self, pic: &PictureData, marking: usize) -> Result<()>

fn mmco_op_5(&mut self, pic: &mut PictureData) -> Result<()>

fn mmco_op_6(&mut self, pic: &mut PictureData, marking: usize) -> Result<()>

fn handle_memory_management_ops(&mut self, pic: &mut PictureData) -> Result<()>

fn fill_prev_ref_info(&mut self, pic: &PictureData)

Store some variables related to the previous reference picture. These will be used in the decoding of future pictures.

fn fill_prev_info(&mut self, pic: &PictureData)

Store some variables related to the previous picture. These will be used in the decoding of future pictures.

fn reference_pic_marking(&mut self, pic: &mut PictureData) -> Result<()>

fn add_to_dpb(
    &mut self,
    pic: Rc<RefCell<PictureData>>,
    handle: Option<T>
) -> Result<()>

fn add_to_ready_queue(&mut self, pic_rc: Rc<RefCell<PictureData>>, handle: T)

Adds picture to the ready queue if it could not be added to the DPB.

fn finish_picture(&mut self, pic: PictureData, handle: T) -> Result<()>

fn handle_frame_num_gap(&mut self, frame_num: i32, timestamp: u64) -> Result<()>

fn init_current_pic(
    &mut self,
    slice: &Slice<&[u8]>,
    first_field: Option<Rc<RefCell<PictureData>>>,
    timestamp: u64
) -> Result<()>

Init the current picture being decoded.

fn bump_as_needed(&mut self, current_pic: &PictureData) -> Vec<DpbEntry<T>>

Bumps the DPB if needed. DPB bumping is described on C.4.5.3.

fn clear_ref_pic_lists(&mut self)

fn get_ready_frames(&mut self) -> Vec<T>

Get the DecodedFrameHandles for the pictures in the ready queue, in display order.

fn drain(&mut self) -> Result<()>

Drain the decoder, processing all pending frames.

fn find_first_field(
    &mut self,
    slice: &Slice<impl AsRef<[u8]>>
) -> Result<Option<(Rc<RefCell<PictureData>>, T)>>

Find the first field for the picture started by slice, if any.

fn handle_picture(&mut self, timestamp: u64, slice: &Slice<&[u8]>) -> Result<()>

Handle a picture. Called only once. Uses an heuristic to determine when a new picture starts in the slice NALUs.

fn pic_num_f(pic: &PictureData, max_pic_num: i32) -> i32

fn long_term_pic_num_f(pic: &PictureData, max_long_term_frame_idx: i32) -> i32

fn copy_into_ref_pic_list(
    &mut self,
    ref_pic_list: RefPicList,
    ref_pic_list_name: RefPicListName
)

fn short_term_pic_list_modification(
    &mut self,
    current_slice: &Slice<impl AsRef<[u8]>>,
    ref_pic_list: RefPicList,
    rplm: &RefPicListModification,
    pic_num_lx_pred: &mut i32,
    ref_idx_lx: &mut usize
) -> Result<()>

fn long_term_pic_list_modification(
    &mut self,
    current_slice: &Slice<impl AsRef<[u8]>>,
    ref_pic_list: RefPicList,
    rplm: &RefPicListModification,
    ref_idx_lx: &mut usize
) -> Result<()>

fn modify_ref_pic_list(
    &mut self,
    current_slice: &Slice<impl AsRef<[u8]>>,
    ref_pic_list: RefPicList
) -> Result<()>

fn modify_ref_pic_lists(
    &mut self,
    current_slice: &Slice<impl AsRef<[u8]>>
) -> Result<()>

fn handle_slice(&mut self, timestamp: u64, slice: &Slice<&[u8]>) -> Result<()>

Handle a slice. Called once per slice NALU.

fn submit_picture(&mut self) -> VideoDecoderResult<(PictureData, T)>

Submits the picture to the accelerator.

pub fn get_raster_from_zigzag_8x8(src: [u8; 64], dst: &mut [u8; 64])

pub fn get_raster_from_zigzag_4x4(src: [u8; 16], dst: &mut [u8; 16])

fn peek_sps(parser: &mut Parser, bitstream: &[u8]) -> Option<Sps>

fn decode_access_unit(
    &mut self,
    timestamp: u64,
    bitstream: &[u8]
) -> VideoDecoderResult<()>

fn block_on_one(&mut self) -> VideoDecoderResult<()>

Trait Implementations

impl<T> VideoDecoder for Decoder<T>where
    T: DecodedHandle + DynDecodedHandle + 'static,

fn decode(
    &mut self,
    timestamp: u64,
    bitstream: &[u8]
) -> VideoDecoderResult<Vec<Box<dyn DynDecodedHandle>>>

Decode the bitstream represented by timestamp. Returns zero or more decoded handles representing the decoded data.

fn flush(&mut self) -> VideoDecoderResult<Vec<Box<dyn DynDecodedHandle>>>

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

fn negotiation_possible(&self) -> bool

Whether negotiation of the decoded format is possible. In particular, a decoder will indicate that negotiation is possible after enough metadata is collected from parsing the bitstream through calls to the decode() method.

fn num_resources_left(&self) -> Option<usize>

Gets the number of output resources left in the backend after accounting for any buffers that might be queued in the decoder.

fn num_resources_total(&self) -> usize

Gets the number of output resources allocated by the backend.

fn coded_resolution(&self) -> Option<Resolution>

Returns the current coded resolution of the bitstream being processed. This may be None if we have not read the stream parameters yet.

fn poll(
    &mut self,
    blocking_mode: BlockingMode
) -> VideoDecoderResult<Vec<Box<dyn DynDecodedHandle>>>

Polls the decoder, emitting frames for all queued decode requests. This is similar to flush, but it does not change the state of the decoded picture buffer nor does it reset any internal state.