+#[derive(Clone,Copy,Default)]
+struct FrameHeader {
+ blocksize: u32,
+ srate: u32,
+ channels: u8,
+ bits: u8,
+ time: u64,
+ blk_strat: bool,
+}
+
+#[derive(Default)]
+struct FLACPacketiser {
+ hdr: FrameHeader,
+ buf: Vec<u8>,
+ ref_crc: u16,
+ cur_crc: u16,
+ end: usize,
+ hdr_ok: bool,
+}
+
+fn read_utf8(br: &mut BitReader) -> DecoderResult<u64> {
+ let byte = br.read(8)? as u8;
+ let len = (!byte).leading_zeros();
+ if (len == 1) || (len > 5) {
+ return Err(DecoderError::InvalidData);
+ }
+ if len > 1 {
+ let mut val = u64::from(byte << len >> len);
+ for _ in 1..len {
+ let byte = br.read(8)?;
+ if (byte & 0xC0) != 0x80 {
+ return Err(DecoderError::InvalidData);
+ }
+ val = (val << 6) | u64::from(byte & 0x3F);
+ }
+ Ok(val)
+ } else {
+ Ok(u64::from(byte))
+ }
+}
+
+impl FLACPacketiser {
+ fn new() -> Self { Self::default() }
+ fn parse_header(&self) -> DecoderResult<FrameHeader> {
+ if self.buf.len() < 5 {
+ return Err(DecoderError::ShortData);
+ }
+ let mut br = BitReader::new(&self.buf, BitReaderMode::BE);
+ let sync_code = br.read(14)?;
+ if sync_code != 0x3FFE {
+ return Err(DecoderError::InvalidData);
+ }
+ let marker = br.read(1)?;
+ if marker != 0 {
+ return Err(DecoderError::InvalidData);
+ }
+ let blk_strat = br.read_bool()?;
+ let bsize = br.read(4)?;
+ let srate_idx = br.read(4)? as u8;
+ let chan_idx = br.read(4)? as u8;
+ let bits = match br.read(3)? {
+ 0 => 0,
+ 1 => 8,
+ 2 => 12,
+ 4 => 16,
+ 5 => 20,
+ 6 => 24,
+ _ => return Err(DecoderError::InvalidData),
+ };
+ let marker = br.read(1)?;
+ if marker != 0 {
+ return Err(DecoderError::InvalidData);
+ }
+
+ let time = read_utf8(&mut br)?;
+
+ let blocksize = match bsize {
+ 1 => 192,
+ 2..=5 => 576 << (bsize - 2),
+ 6 => br.read(8)? + 1,
+ 7 => br.read(16)? + 1,
+ 8..=15 => 256 << (bsize - 8),
+ _ => return Err(DecoderError::InvalidData),
+ };
+ let srate = match srate_idx {
+ 0 => 0,
+ 1 => 88200,
+ 2 => 176400,
+ 3 => 192000,
+ 4 => 8000,
+ 5 => 16000,
+ 6 => 22050,
+ 7 => 24000,
+ 8 => 32000,
+ 9 => 44100,
+ 10 => 48000,
+ 11 => 96000,
+ 12 => br.read(8)? * 1000,
+ 13 => br.read(16)?,
+ 14 => br.read(16)? * 10,
+ _ => return Err(DecoderError::InvalidData),
+ };
+ let channels = match chan_idx {
+ 0..=7 => chan_idx + 1,
+ 8 | 9 | 10 => 2,
+ _ => return Err(DecoderError::InvalidData),
+ };
+
+ let hdr_size = br.tell() / 8;
+ let ref_crc = br.read(8)? as u8;
+ let mut crc = 0;
+ for &b in self.buf[..hdr_size].iter() {
+ crc = update_crc8(crc, b);
+ }
+ if crc != ref_crc {
+ return Err(DecoderError::ChecksumError);
+ }
+
+ Ok(FrameHeader{ blk_strat, time, srate, channels, bits, blocksize })
+ }
+}
+
+impl NAPacketiser for FLACPacketiser {
+ fn add_data(&mut self, src: &[u8]) -> bool {
+ self.buf.extend_from_slice(src);
+ self.buf.len() < 4096
+ }
+ fn parse_stream(&mut self, id: u32) -> DecoderResult<NAStreamRef> {
+ let hdr = self.parse_header()?;
+ let ainfo = NAAudioInfo::new(hdr.srate, hdr.channels, if hdr.bits <= 16 { SND_S16P_FORMAT } else { SND_S32P_FORMAT }, hdr.blocksize as usize);
+ let info = NACodecInfo::new("flac", NACodecTypeInfo::Audio(ainfo), None);
+ Ok(NAStream::new(StreamType::Audio, id, info, 1, hdr.srate, 0).into_ref())
+ }
+ fn skip_junk(&mut self) -> DecoderResult<usize> {
+ Err(DecoderError::NotImplemented)
+ }
+ fn get_packet(&mut self, stream: NAStreamRef) -> DecoderResult<Option<NAPacket>> {
+ if self.end == self.buf.len() || self.buf.len() < 5 {
+ return Err(DecoderError::ShortData);
+ }
+ if !self.hdr_ok {
+ self.hdr = self.parse_header()?;
+ self.hdr_ok = true;
+ self.cur_crc = 0;
+ for i in 0..5 {
+ self.cur_crc = update_crc16(self.cur_crc, self.buf[i]);
+ }
+ self.end = 5;
+ }
+ while self.end < self.buf.len() {
+ let b = self.buf[self.end];
+ self.end += 1;
+ match self.end {
+ 0..=5 => unreachable!(),
+ 6 => self.ref_crc = u16::from(b),
+ 7 => self.ref_crc = (self.ref_crc << 8) | u16::from(b),
+ _ => {
+ let bbb = (self.ref_crc >> 8) as u8;
+ self.ref_crc = (self.ref_crc << 8) | u16::from(b);
+ self.cur_crc = update_crc16(self.cur_crc, bbb);
+ let mut found = self.ref_crc == self.cur_crc;
+ if self.end + 2 < self.buf.len() {
+ let b1 = self.buf[self.end];
+ let b2 = self.buf[self.end + 1];
+ if b1 != 0xFF || (b2 & 0xFC) != 0xF8 {
+ found = false;
+ }
+ }
+ if found {
+ let mut data = Vec::with_capacity(self.end);
+ data.extend_from_slice(&self.buf[..self.end]);
+ self.buf.drain(..self.end);
+ let mut ts = NATimeInfo::new(None, None, Some(u64::from(self.hdr.blocksize)), 1, self.hdr.srate);
+ ts.pts = if self.hdr.blk_strat {
+ Some(self.hdr.time)
+ } else {
+ Some(self.hdr.time * u64::from(self.hdr.blocksize))
+ };
+ self.end = 0;
+ self.hdr_ok = false;
+
+ return Ok(Some(NAPacket::new(stream, ts, true, data)));
+ }
+ },
+ }
+ }
+ Ok(None)
+ }
+ fn reset(&mut self) {
+ self.buf.clear();
+ self.end = 0;
+ self.hdr_ok = false;
+ }
+}
+
+pub fn get_packetiser() -> Box<dyn NAPacketiser + Send> {
+ Box::new(FLACPacketiser::new())
+}
+
projects / nihav.git / blobdiff