more utility code

[nihav.git] / src / codecs / mod.rs

#[cfg(feature="decoder_indeo2")]
pub mod indeo2;

use frame::*;
use std::rc::Rc;
use std::cell::RefCell;
use io::byteio::ByteIOError;
use io::bitreader::BitReaderError;
use io::codebook::CodebookError;

#[derive(Debug,Clone,Copy,PartialEq)]
#[allow(dead_code)]
pub enum DecoderError {
    InvalidData,
    ShortData,
    MissingReference,
    NotImplemented,
    Bug,
}

type DecoderResult<T> = Result<T, DecoderError>;

impl From<ByteIOError> for DecoderError {
    fn from(_: ByteIOError) -> Self { DecoderError::ShortData }
}

impl From<BitReaderError> for DecoderError {
    fn from(e: BitReaderError) -> Self {
        match e {
            BitReaderError::BitstreamEnd => DecoderError::ShortData,
            _ => DecoderError::InvalidData,
        }
    }
}

impl From<CodebookError> for DecoderError {
    fn from(_: CodebookError) -> Self { DecoderError::InvalidData }
}

#[allow(dead_code)]
struct HAMShuffler {
    lastframe: Option<NAFrameRef>,
}

impl HAMShuffler {
    #[allow(dead_code)]
    fn new() -> Self { HAMShuffler { lastframe: None } }
    #[allow(dead_code)]
    fn clear(&mut self) { self.lastframe = None; }
    #[allow(dead_code)]
    fn add_frame(&mut self, frm: NAFrame) {
        self.lastframe = Some(Rc::new(RefCell::new(frm)));
    }
    #[allow(dead_code)]
    fn clone_ref(&mut self) -> Option<NAFrameRef> {
        if let Some(ref mut frm) = self.lastframe {
            let newfrm = Rc::new(RefCell::new(NAFrame::from_copy(&frm.borrow())));
            *frm = newfrm.clone();
            Some(newfrm)
        } else {
            None
        }
    }
    #[allow(dead_code)]
    fn get_output_frame(&mut self) -> Option<NAFrameRef> {
        match self.lastframe {
            Some(ref frm) => Some(frm.clone()),
            None => None,
        }
    }
}

pub trait NADecoder {
    fn init(&mut self, info: Rc<NACodecInfo>) -> DecoderResult<()>;
    fn decode(&mut self, pkt: &NAPacket) -> DecoderResult<NAFrameRef>;
}

#[derive(Clone,Copy)]
pub struct DecoderInfo {
    name: &'static str,
    get_decoder: fn () -> Box<NADecoder>,
}

const DECODERS: &[DecoderInfo] = &[
#[cfg(feature="decoder_indeo2")]
    DecoderInfo { name: "indeo2", get_decoder: indeo2::get_decoder },
];

pub fn find_decoder(name: &str) -> Option<fn () -> Box<NADecoder>> {
    for &dec in DECODERS {
        if dec.name == name {
            return Some(dec.get_decoder);
        }
    }
    None
}