From: Kostya Shishkov Date: Sat, 10 Jun 2023 10:28:31 +0000 (+0200) Subject: introduce the interface for multi-threaded decoders X-Git-Url: https://git.nihav.org/?a=commitdiff_plain;ds=sidebyside;h=22da9ca81a57646f1453a97301d6bedb9973dea7;p=nihav.git introduce the interface for multi-threaded decoders --- diff --git a/nihav-core/src/codecs/mod.rs b/nihav-core/src/codecs/mod.rs index 1482a61..04d480a 100644 --- a/nihav-core/src/codecs/mod.rs +++ b/nihav-core/src/codecs/mod.rs @@ -134,6 +134,74 @@ impl RegisteredDecoders { } } +/// Multithreaded decoder trait. +pub trait NADecoderMT: NAOptionHandler { + /// Initialises the decoder. + /// + /// It takes [`NADecoderSupport`] allocated by the caller and `NACodecInfoRef` provided by demuxer. + /// + /// [`NADecoderSupport`]: ./struct.NADecoderSupport.html + fn init(&mut self, supp: &mut NADecoderSupport, info: NACodecInfoRef, nthreads: usize) -> DecoderResult<()>; + /// Checks if a new frame can be queued for encoding. + fn can_take_input(&mut self) -> bool; + /// Queues a frame for decoding. + /// + /// Returns flag signalling whether the frame was queued or an error if it occured during the preparation stage. + /// + /// Parameter `id` is used to distinguish pictures as the output may be an error code with no timestamp available. + fn queue_pkt(&mut self, supp: &mut NADecoderSupport, pkt: &NAPacket, id: u32) -> DecoderResult; + /// Checks if some frames are already decoded and waiting to be retrieved. + fn has_output(&mut self) -> bool; + /// Waits for a frame to be decoded. + /// + /// In case there are no decoded frames yet, `None` is returned. + /// Otherwise, a decoding result and the input picture ID are returned. + fn get_frame(&mut self) -> (DecoderResult, u32); + /// Tells decoder to clear internal state (e.g. after error or seeking). + fn flush(&mut self); +} + +/// Decoder information used during creating a multi-threaded decoder for requested codec. +#[derive(Clone,Copy)] +pub struct MTDecoderInfo { + /// Short decoder name. + pub name: &'static str, + /// The function that creates a multi-threaded decoder instance. + pub get_decoder: fn () -> Box, +} + +/// Structure for registering known multi-threaded decoders. +/// +/// It is supposed to be filled using `register_all_mt_decoders()` from some decoders crate and then it can be used to create multi-threaded decoders for the requested codecs. +#[derive(Default)] +pub struct RegisteredMTDecoders { + decs: Vec, +} + +impl RegisteredMTDecoders { + /// Constructs a new instance of `RegisteredMTDecoders`. + pub fn new() -> Self { + Self { decs: Vec::new() } + } + /// Adds another decoder to the registry. + pub fn add_decoder(&mut self, dec: MTDecoderInfo) { + self.decs.push(dec); + } + /// Searches for the decoder for the provided name and returns a function for creating it on success. + pub fn find_decoder(&self, name: &str) -> Option Box> { + for &dec in self.decs.iter() { + if dec.name == name { + return Some(dec.get_decoder); + } + } + None + } + /// Provides an iterator over currently registered decoders. + pub fn iter(&self) -> std::slice::Iter { + self.decs.iter() + } +} + /// Frame skipping mode for decoders. #[derive(Clone,Copy,PartialEq,Debug)] pub enum FrameSkipMode {