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