pcm.rs

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