nihav-commonfmt/src/codecs/pcm.rs

   1 use std::rc::Rc;
   2 use std::cell::RefCell;
   3 use nihav_core::formats::*;
   4 use nihav_core::codecs::*;
   5 use nihav_core::frame::*;
   6
   7 struct PCMDecoder { chmap: NAChannelMap }
   8
   9 impl PCMDecoder {
  10     fn new() -> Self {
  11         PCMDecoder { chmap: NAChannelMap::new() }
  12     }
  13 }
  14
  15 const CHMAP_MONO: [NAChannelType; 1] = [NAChannelType::C];
  16 const CHMAP_STEREO: [NAChannelType; 2] = [NAChannelType::L, NAChannelType::R];
  17
  18 fn get_default_chmap(nch: u8) -> NAChannelMap {
  19     let mut chmap = NAChannelMap::new();
  20     match nch {
  21         1 => chmap.add_channels(&CHMAP_MONO),
  22         2 => chmap.add_channels(&CHMAP_STEREO),
  23         _ => (),
  24     }
  25     chmap
  26 }
  27
  28 fn get_duration(ainfo: &NAAudioInfo, duration: Option<u64>, data_size: usize) -> u64 {
  29     if duration == None {
  30         let size_bits = (data_size as u64) * 8;
  31         let blk_size = (ainfo.get_channels() as u64) * (ainfo.get_format().get_bits() as u64);
  32         size_bits / blk_size
  33     } else {
  34         duration.unwrap() as u64
  35     }
  36 }
  37
  38 impl NADecoder for PCMDecoder {
  39     fn init(&mut self, info: Rc<NACodecInfo>) -> DecoderResult<()> {
  40         if let NACodecTypeInfo::Audio(ainfo) = info.get_properties() {
  41             self.chmap = get_default_chmap(ainfo.get_channels());
  42             if self.chmap.num_channels() == 0 { return Err(DecoderError::InvalidData); }
  43             Ok(())
  44         } else {
  45             Err(DecoderError::InvalidData)
  46         }
  47     }
  48     fn decode(&mut self, pkt: &NAPacket) -> DecoderResult<NAFrameRef> {
  49         let info = pkt.get_stream().get_info();
  50         if let NACodecTypeInfo::Audio(ainfo) = info.get_properties() {
  51             let duration = get_duration(&ainfo, pkt.get_duration(), pkt.get_buffer().len());
  52             let pktbuf = pkt.get_buffer();
  53             let mut buf: Vec<u8> = Vec::with_capacity(pktbuf.len());
  54             buf.clone_from(&pktbuf);
  55             let abuf = NAAudioBuffer::new_from_buf(ainfo, Rc::new(RefCell::new(buf)), self.chmap.clone());
  56             let mut frm = NAFrame::new_from_pkt(pkt, info, NABufferType::AudioPacked(abuf));
  57             frm.set_duration(Some(duration));
  58             frm.set_keyframe(true);
  59             Ok(Rc::new(RefCell::new(frm)))
  60         } else {
  61             Err(DecoderError::InvalidData)
  62         }
  63     }
  64 }
  65
  66 pub fn get_decoder() -> Box<NADecoder> {
  67     Box::new(PCMDecoder::new())
  68 }