--- /dev/null
+use nihav_core::demuxers::*;
+
+struct GIFDemuxer<'a> {
+ src: &'a mut ByteReader<'a>,
+ frameno: u64,
+ is_87: bool,
+ pal: Arc<[u8; 1024]>,
+}
+
+impl<'a> GIFDemuxer<'a> {
+ fn new(io: &'a mut ByteReader<'a>) -> Self {
+ Self {
+ src: io,
+ frameno: 0,
+ is_87: false,
+ pal: Arc::new([0; 1024]),
+ }
+ }
+ fn skip_blocks(&mut self) -> DemuxerResult<()> {
+ loop {
+ let size = self.src.read_byte()?;
+ if size == 0 {
+ break;
+ }
+ self.src.read_skip(usize::from(size))?;
+ }
+ Ok(())
+ }
+}
+
+impl<'a> DemuxCore<'a> for GIFDemuxer<'a> {
+ fn open(&mut self, strmgr: &mut StreamManager, _seek_index: &mut SeekIndex) -> DemuxerResult<()> {
+ let mut magic = [0; 6];
+ self.src.read_buf(&mut magic)?;
+ validate!(&magic == b"GIF87a" || &magic == b"GIF89a");
+ self.is_87 = &magic == b"GIF87a";
+
+ let width = usize::from(self.src.read_u16le()?);
+ let height = usize::from(self.src.read_u16le()?);
+ validate!(width > 0 && height > 0);
+ let flags = self.src.read_byte()?;
+ let edata_size = 1 + 2 + if (flags & 0x80) != 0 { 3 << ((flags & 7) + 1) } else { 0 };
+ let mut edata = vec![0; edata_size];
+ edata[0] = flags;
+ self.src.read_buf(&mut edata[1..])?;
+ if (flags & 0x80) != 0 {
+ let mut npal = [0; 1024];
+ for (dpal, spal) in npal.chunks_exact_mut(4).zip(edata[3..].chunks_exact(3)) {
+ dpal[..3].copy_from_slice(spal);
+ }
+ self.pal = Arc::new(npal);
+ }
+ let mut delay = 0;
+ loop {
+ match self.src.peek_byte() {
+ Ok(0x2C) => break,
+ Ok(_) => {},
+ Err(_err) => return Err(DemuxerError::IOError),
+ };
+ let tag = self.src.read_byte()?;
+ match tag {
+ 0x21 => {
+ validate!(!self.is_87);
+ let subtype = self.src.read_byte()?;
+ match subtype {
+ 0xF9 => {
+ let bsize = self.src.read_byte()?;
+ validate!(bsize == 4);
+ let _flags = self.src.read_byte()?;
+ delay = self.src.read_u16le()?;
+ let _clr = self.src.read_byte()?;
+ self.skip_blocks()?;
+ },
+ 0xFF => {
+ let bsize = self.src.read_byte()?;
+ validate!(bsize == 11);
+ let mut app_id = [0; 11];
+ self.src.read_buf(&mut app_id)?;
+ if &app_id == b"NETSCAPE2.0" {
+ let bsize = self.src.read_byte()?;
+ validate!(bsize == 3);
+ let b = self.src.read_byte()?;
+ validate!(b == 1);
+ let _nloops = self.src.read_u16le()?;
+ }
+ self.skip_blocks()?;
+ },
+ _ => {
+ self.skip_blocks()?;
+ },
+ };
+ },
+ 0x2C => unreachable!(),
+ _ => return Err(DemuxerError::NotImplemented),
+ };
+ }
+
+ let vhdr = NAVideoInfo::new(width, height, false, PAL8_FORMAT);
+ let vci = NACodecTypeInfo::Video(vhdr);
+ let vinfo = NACodecInfo::new("gif", vci, Some(edata));
+ if strmgr.add_stream(NAStream::new(StreamType::Video, 0, vinfo, u32::from(delay.max(1)), 100, 0)).is_none() {
+ return Err(DemuxerError::MemoryError);
+ }
+
+ Ok(())
+ }
+
+ fn get_frame(&mut self, strmgr: &mut StreamManager) -> DemuxerResult<NAPacket> {
+ loop {
+ match self.src.read_byte()? {
+ 0x2C => {
+ let mut data = vec![0; 10];
+ data[0] = 0x2C;
+ self.src.read_buf(&mut data[1..])?;
+ if (data[9] & 0x80) != 0 {
+ let cmap_size = 3 << ((data[9] & 7) + 1);
+ data.resize(10 + cmap_size, 0);
+ self.src.read_buf(&mut data[10..])?;
+ }
+ let lzw_bits = self.src.read_byte()?;
+ data.push(lzw_bits);
+ let mut tbuf = [0; 255];
+ loop {
+ let bsize = usize::from(self.src.read_byte()?);
+ data.push(bsize as u8);
+ if bsize == 0 {
+ break;
+ }
+ self.src.read_buf(&mut tbuf[..bsize])?;
+ data.extend_from_slice(&tbuf[..bsize]);
+ }
+
+ let stream = strmgr.get_stream(0).unwrap();
+ let ts = stream.make_ts(Some(self.frameno), None, None);
+ let mut pkt = NAPacket::new(stream, ts, self.frameno == 0, data);
+ pkt.add_side_data(NASideData::Palette(false, self.pal.clone()));
+ self.frameno += 1;
+ return Ok(pkt);
+ },
+ 0x21 => {
+ self.src.read_byte()?;
+ self.skip_blocks()?;
+ },
+ 0x3B => return Err(DemuxerError::EOF),
+ _ => unimplemented!(),
+ };
+ }
+ }
+
+ fn seek(&mut self, _time: NATimePoint, _seek_index: &SeekIndex) -> DemuxerResult<()> {
+ Err(DemuxerError::NotPossible)
+ }
+ fn get_duration(&self) -> u64 { 0 }
+}
+
+impl<'a> NAOptionHandler for GIFDemuxer<'a> {
+ fn get_supported_options(&self) -> &[NAOptionDefinition] { &[] }
+ fn set_options(&mut self, _options: &[NAOption]) { }
+ fn query_option_value(&self, _name: &str) -> Option<NAValue> { None }
+}
+
+pub struct GIFDemuxerCreator { }
+
+impl DemuxerCreator for GIFDemuxerCreator {
+ fn new_demuxer<'a>(&self, br: &'a mut ByteReader<'a>) -> Box<dyn DemuxCore<'a> + 'a> {
+ Box::new(GIFDemuxer::new(br))
+ }
+ fn get_name(&self) -> &'static str { "gif" }
+}
+
+#[cfg(test)]
+mod test {
+ use super::*;
+ use std::fs::File;
+
+ #[test]
+ fn test_gif_demux() {
+ // sample: https://samples.mplayerhq.hu/image-samples/GIF/3D.gif
+ let mut file = File::open("assets/Misc/3D.gif").unwrap();
+ let mut fr = FileReader::new_read(&mut file);
+ let mut br = ByteReader::new(&mut fr);
+ let mut dmx = GIFDemuxer::new(&mut br);
+ let mut sm = StreamManager::new();
+ let mut si = SeekIndex::new();
+ dmx.open(&mut sm, &mut si).unwrap();
+
+ loop {
+ let pktres = dmx.get_frame(&mut sm);
+ if let Err(e) = pktres {
+ if e == DemuxerError::EOF { break; }
+ panic!("error");
+ }
+ let pkt = pktres.unwrap();
+ println!("Got {}", pkt);
+ }
+ }
+}
projects / nihav.git / blobdiff