--- /dev/null
+use nihav_core::codecs::*;
+use nihav_core::io::byteio::*;
+use nihav_codec_support::codecs::imaadpcm::*;
+use std::str::FromStr;
+
+struct IMAADPCMDecoder {
+ ainfo: NAAudioInfo,
+ chmap: NAChannelMap,
+ ch_state: [IMAState; 2],
+ block_len: usize,
+}
+
+impl IMAADPCMDecoder {
+ fn new() -> Self {
+ Self {
+ ainfo: NAAudioInfo::new(0, 1, SND_S16P_FORMAT, 0),
+ chmap: NAChannelMap::new(),
+ ch_state: [IMAState::new(), IMAState::new()],
+ block_len: 0,
+ }
+ }
+}
+
+impl NADecoder for IMAADPCMDecoder {
+ fn init(&mut self, _supp: &mut NADecoderSupport, info: NACodecInfoRef) -> DecoderResult<()> {
+ if let NACodecTypeInfo::Audio(ainfo) = info.get_properties() {
+ self.block_len = ainfo.get_block_len();
+ let channels = ainfo.get_channels() as usize;
+ validate!(channels == 2 || channels == 1);
+ validate!(self.block_len >= 8 * channels);
+ validate!((self.block_len & 3) == 0);
+ let len = (self.block_len / channels - 4) * 2 + 1;
+ self.ainfo = NAAudioInfo::new(ainfo.get_sample_rate(), channels as u8, SND_S16P_FORMAT, len);
+ self.chmap = NAChannelMap::from_str(if channels == 1 { "C" } else { "L,R" }).unwrap();
+ Ok(())
+ } else {
+ Err(DecoderError::InvalidData)
+ }
+ }
+ fn decode(&mut self, _supp: &mut NADecoderSupport, pkt: &NAPacket) -> DecoderResult<NAFrameRef> {
+ let info = pkt.get_stream().get_info();
+ if let NACodecTypeInfo::Audio(_) = info.get_properties() {
+ let pktbuf = pkt.get_buffer();
+ let channels = self.chmap.num_channels();
+ validate!(pktbuf.len() >= 8 * channels);
+ let nsamples = (pktbuf.len() / channels - 4) * 2 + 1;
+ let abuf = alloc_audio_buffer(self.ainfo, nsamples, self.chmap.clone())?;
+ let mut adata = abuf.get_abuf_i16().unwrap();
+ let mut off = [adata.get_offset(0), adata.get_offset(1)];
+ let dst = adata.get_data_mut().unwrap();
+
+ let mut mr = MemoryReader::new_read(pktbuf.as_slice());
+ let mut br = ByteReader::new(&mut mr);
+ for ch in 0..channels {
+ let pred = br.read_u16le()? as i16;
+ let step = br.read_byte()?;
+ br.read_skip(1)?;
+ validate!(step <= IMA_MAX_STEP);
+ self.ch_state[ch].reset(pred, step);
+ dst[off[ch]] = pred;
+ off[ch] += 1;
+ }
+ while br.left() > 0 {
+ for ch in 0..channels {
+ let mut cw = br.read_u32le()?;
+ for _ in 0..8 {
+ dst[off[ch]] = self.ch_state[ch].expand_sample((cw & 0xF) as u8);
+ off[ch] += 1;
+ cw >>= 4;
+ }
+ }
+ }
+ let mut frm = NAFrame::new_from_pkt(pkt, info.replace_info(NACodecTypeInfo::Audio(self.ainfo)), abuf);
+ frm.set_duration(Some(nsamples as u64));
+ frm.set_keyframe(false);
+ Ok(frm.into_ref())
+ } else {
+ Err(DecoderError::InvalidData)
+ }
+ }
+ fn flush(&mut self) {
+ }
+}
+
+pub fn get_decoder() -> Box<dyn NADecoder + Send> {
+ Box::new(IMAADPCMDecoder::new())
+}
+
+#[cfg(test)]
+mod test {
+ use nihav_core::codecs::RegisteredDecoders;
+ use nihav_core::demuxers::RegisteredDemuxers;
+ use nihav_codec_support::test::dec_video::*;
+ use crate::ms_register_all_codecs;
+ use nihav_commonfmt::generic_register_all_demuxers;
+ #[test]
+ fn test_ima_adpcm_ms() {
+ let mut dmx_reg = RegisteredDemuxers::new();
+ generic_register_all_demuxers(&mut dmx_reg);
+ let mut dec_reg = RegisteredDecoders::new();
+ ms_register_all_codecs(&mut dec_reg);
+
+ test_decoding("avi", "ima-adpcm-ms", "assets/MS/IMAG0006.AVI", None, &dmx_reg, &dec_reg,
+ ExpectedTestResult::MD5([0x0cdc640f, 0xb00df235, 0x1ec4a280, 0x065b5e9e]));
+ }
+}