| 1 | use nihav_core::demuxers::*; |
| 2 | |
| 3 | struct GIFDemuxer<'a> { |
| 4 | src: &'a mut ByteReader<'a>, |
| 5 | frameno: u64, |
| 6 | is_87: bool, |
| 7 | pal: Arc<[u8; 1024]>, |
| 8 | } |
| 9 | |
| 10 | impl<'a> GIFDemuxer<'a> { |
| 11 | fn new(io: &'a mut ByteReader<'a>) -> Self { |
| 12 | Self { |
| 13 | src: io, |
| 14 | frameno: 0, |
| 15 | is_87: false, |
| 16 | pal: Arc::new([0; 1024]), |
| 17 | } |
| 18 | } |
| 19 | fn skip_blocks(&mut self) -> DemuxerResult<()> { |
| 20 | loop { |
| 21 | let size = self.src.read_byte()?; |
| 22 | if size == 0 { |
| 23 | break; |
| 24 | } |
| 25 | self.src.read_skip(usize::from(size))?; |
| 26 | } |
| 27 | Ok(()) |
| 28 | } |
| 29 | } |
| 30 | |
| 31 | impl<'a> DemuxCore<'a> for GIFDemuxer<'a> { |
| 32 | fn open(&mut self, strmgr: &mut StreamManager, _seek_index: &mut SeekIndex) -> DemuxerResult<()> { |
| 33 | let mut magic = [0; 6]; |
| 34 | self.src.read_buf(&mut magic)?; |
| 35 | validate!(&magic == b"GIF87a" || &magic == b"GIF89a"); |
| 36 | self.is_87 = &magic == b"GIF87a"; |
| 37 | |
| 38 | let width = usize::from(self.src.read_u16le()?); |
| 39 | let height = usize::from(self.src.read_u16le()?); |
| 40 | validate!(width > 0 && height > 0); |
| 41 | let flags = self.src.read_byte()?; |
| 42 | let edata_size = 1 + 2 + if (flags & 0x80) != 0 { 3 << ((flags & 7) + 1) } else { 0 }; |
| 43 | let mut edata = vec![0; edata_size]; |
| 44 | edata[0] = flags; |
| 45 | self.src.read_buf(&mut edata[1..])?; |
| 46 | if (flags & 0x80) != 0 { |
| 47 | let mut npal = [0; 1024]; |
| 48 | for (dpal, spal) in npal.chunks_exact_mut(4).zip(edata[3..].chunks_exact(3)) { |
| 49 | dpal[..3].copy_from_slice(spal); |
| 50 | } |
| 51 | self.pal = Arc::new(npal); |
| 52 | } |
| 53 | let mut delay = 0; |
| 54 | loop { |
| 55 | match self.src.peek_byte() { |
| 56 | Ok(0x2C) => break, |
| 57 | Ok(_) => {}, |
| 58 | Err(_err) => return Err(DemuxerError::IOError), |
| 59 | }; |
| 60 | let tag = self.src.read_byte()?; |
| 61 | match tag { |
| 62 | 0x21 => { |
| 63 | validate!(!self.is_87); |
| 64 | let subtype = self.src.read_byte()?; |
| 65 | match subtype { |
| 66 | 0xF9 => { |
| 67 | let bsize = self.src.read_byte()?; |
| 68 | validate!(bsize == 4); |
| 69 | let _flags = self.src.read_byte()?; |
| 70 | delay = self.src.read_u16le()?; |
| 71 | let _clr = self.src.read_byte()?; |
| 72 | self.skip_blocks()?; |
| 73 | }, |
| 74 | 0xFF => { |
| 75 | let bsize = self.src.read_byte()?; |
| 76 | validate!(bsize == 11); |
| 77 | let mut app_id = [0; 11]; |
| 78 | self.src.read_buf(&mut app_id)?; |
| 79 | if &app_id == b"NETSCAPE2.0" { |
| 80 | let bsize = self.src.read_byte()?; |
| 81 | validate!(bsize == 3); |
| 82 | let b = self.src.read_byte()?; |
| 83 | validate!(b == 1); |
| 84 | let _nloops = self.src.read_u16le()?; |
| 85 | } |
| 86 | self.skip_blocks()?; |
| 87 | }, |
| 88 | _ => { |
| 89 | self.skip_blocks()?; |
| 90 | }, |
| 91 | }; |
| 92 | }, |
| 93 | 0x2C => unreachable!(), |
| 94 | _ => return Err(DemuxerError::NotImplemented), |
| 95 | }; |
| 96 | } |
| 97 | |
| 98 | let vhdr = NAVideoInfo::new(width, height, false, PAL8_FORMAT); |
| 99 | let vci = NACodecTypeInfo::Video(vhdr); |
| 100 | let vinfo = NACodecInfo::new("gif", vci, Some(edata)); |
| 101 | if strmgr.add_stream(NAStream::new(StreamType::Video, 0, vinfo, u32::from(delay.max(1)), 100, 0)).is_none() { |
| 102 | return Err(DemuxerError::MemoryError); |
| 103 | } |
| 104 | |
| 105 | Ok(()) |
| 106 | } |
| 107 | |
| 108 | fn get_frame(&mut self, strmgr: &mut StreamManager) -> DemuxerResult<NAPacket> { |
| 109 | loop { |
| 110 | match self.src.read_byte()? { |
| 111 | 0x2C => { |
| 112 | let mut data = vec![0; 10]; |
| 113 | data[0] = 0x2C; |
| 114 | self.src.read_buf(&mut data[1..])?; |
| 115 | if (data[9] & 0x80) != 0 { |
| 116 | let cmap_size = 3 << ((data[9] & 7) + 1); |
| 117 | data.resize(10 + cmap_size, 0); |
| 118 | self.src.read_buf(&mut data[10..])?; |
| 119 | } |
| 120 | let lzw_bits = self.src.read_byte()?; |
| 121 | data.push(lzw_bits); |
| 122 | let mut tbuf = [0; 255]; |
| 123 | loop { |
| 124 | let bsize = usize::from(self.src.read_byte()?); |
| 125 | data.push(bsize as u8); |
| 126 | if bsize == 0 { |
| 127 | break; |
| 128 | } |
| 129 | self.src.read_buf(&mut tbuf[..bsize])?; |
| 130 | data.extend_from_slice(&tbuf[..bsize]); |
| 131 | } |
| 132 | |
| 133 | let stream = strmgr.get_stream(0).unwrap(); |
| 134 | let ts = stream.make_ts(Some(self.frameno), None, None); |
| 135 | let mut pkt = NAPacket::new(stream, ts, self.frameno == 0, data); |
| 136 | pkt.add_side_data(NASideData::Palette(false, self.pal.clone())); |
| 137 | self.frameno += 1; |
| 138 | return Ok(pkt); |
| 139 | }, |
| 140 | 0x21 => { |
| 141 | self.src.read_byte()?; |
| 142 | self.skip_blocks()?; |
| 143 | }, |
| 144 | 0x3B => return Err(DemuxerError::EOF), |
| 145 | _ => unimplemented!(), |
| 146 | }; |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | fn seek(&mut self, _time: NATimePoint, _seek_index: &SeekIndex) -> DemuxerResult<()> { |
| 151 | Err(DemuxerError::NotPossible) |
| 152 | } |
| 153 | fn get_duration(&self) -> u64 { 0 } |
| 154 | } |
| 155 | |
| 156 | impl<'a> NAOptionHandler for GIFDemuxer<'a> { |
| 157 | fn get_supported_options(&self) -> &[NAOptionDefinition] { &[] } |
| 158 | fn set_options(&mut self, _options: &[NAOption]) { } |
| 159 | fn query_option_value(&self, _name: &str) -> Option<NAValue> { None } |
| 160 | } |
| 161 | |
| 162 | pub struct GIFDemuxerCreator { } |
| 163 | |
| 164 | impl DemuxerCreator for GIFDemuxerCreator { |
| 165 | fn new_demuxer<'a>(&self, br: &'a mut ByteReader<'a>) -> Box<dyn DemuxCore<'a> + 'a> { |
| 166 | Box::new(GIFDemuxer::new(br)) |
| 167 | } |
| 168 | fn get_name(&self) -> &'static str { "gif" } |
| 169 | } |
| 170 | |
| 171 | #[cfg(test)] |
| 172 | mod test { |
| 173 | use super::*; |
| 174 | use std::fs::File; |
| 175 | |
| 176 | #[test] |
| 177 | fn test_gif_demux() { |
| 178 | // sample: https://samples.mplayerhq.hu/image-samples/GIF/3D.gif |
| 179 | let mut file = File::open("assets/Misc/3D.gif").unwrap(); |
| 180 | let mut fr = FileReader::new_read(&mut file); |
| 181 | let mut br = ByteReader::new(&mut fr); |
| 182 | let mut dmx = GIFDemuxer::new(&mut br); |
| 183 | let mut sm = StreamManager::new(); |
| 184 | let mut si = SeekIndex::new(); |
| 185 | dmx.open(&mut sm, &mut si).unwrap(); |
| 186 | |
| 187 | loop { |
| 188 | let pktres = dmx.get_frame(&mut sm); |
| 189 | if let Err(e) = pktres { |
| 190 | if e == DemuxerError::EOF { break; } |
| 191 | panic!("error"); |
| 192 | } |
| 193 | let pkt = pktres.unwrap(); |
| 194 | println!("Got {}", pkt); |
| 195 | } |
| 196 | } |
| 197 | } |