| 1 | use std::io::SeekFrom; |
| 2 | use io::byteio::ByteReader; |
| 3 | |
| 4 | #[derive(Debug,Clone,Copy,PartialEq)] |
| 5 | pub enum DetectionScore { |
| 6 | No, |
| 7 | ExtensionMatches, |
| 8 | MagicMatches, |
| 9 | } |
| 10 | |
| 11 | impl DetectionScore { |
| 12 | pub fn less(&self, other: DetectionScore) -> bool { |
| 13 | (*self as i32) < (other as i32) |
| 14 | } |
| 15 | } |
| 16 | |
| 17 | #[allow(dead_code)] |
| 18 | enum Arg { |
| 19 | Byte(u8), |
| 20 | U16BE(u16), |
| 21 | U16LE(u16), |
| 22 | U24BE(u32), |
| 23 | U24LE(u32), |
| 24 | U32BE(u32), |
| 25 | U32LE(u32), |
| 26 | U64BE(u64), |
| 27 | U64LE(u64), |
| 28 | } |
| 29 | |
| 30 | impl Arg { |
| 31 | fn val(&self) -> u64 { |
| 32 | match *self { |
| 33 | Arg::Byte(b) => { b as u64 } |
| 34 | Arg::U16BE(v) => { v as u64 } |
| 35 | Arg::U16LE(v) => { v as u64 } |
| 36 | Arg::U24BE(v) => { v as u64 } |
| 37 | Arg::U24LE(v) => { v as u64 } |
| 38 | Arg::U32BE(v) => { v as u64 } |
| 39 | Arg::U32LE(v) => { v as u64 } |
| 40 | Arg::U64BE(v) => { v } |
| 41 | Arg::U64LE(v) => { v } |
| 42 | } |
| 43 | } |
| 44 | fn read_val(&self, src: &mut ByteReader) -> Option<u64> { |
| 45 | match *self { |
| 46 | Arg::Byte(_) => { |
| 47 | let res = src.peek_byte(); |
| 48 | if let Err(_) = res { return None; } |
| 49 | Some(res.unwrap() as u64) |
| 50 | } |
| 51 | Arg::U16BE(_) => { |
| 52 | let res = src.peek_u16be(); |
| 53 | if let Err(_) = res { return None; } |
| 54 | Some(res.unwrap() as u64) |
| 55 | } |
| 56 | Arg::U16LE(_) => { |
| 57 | let res = src.peek_u16le(); |
| 58 | if let Err(_) = res { return None; } |
| 59 | Some(res.unwrap() as u64) |
| 60 | } |
| 61 | Arg::U24BE(_) => { |
| 62 | let res = src.peek_u24be(); |
| 63 | if let Err(_) = res { return None; } |
| 64 | Some(res.unwrap() as u64) |
| 65 | } |
| 66 | Arg::U24LE(_) => { |
| 67 | let res = src.peek_u24le(); |
| 68 | if let Err(_) = res { return None; } |
| 69 | Some(res.unwrap() as u64) |
| 70 | } |
| 71 | Arg::U32BE(_) => { |
| 72 | let res = src.peek_u32be(); |
| 73 | if let Err(_) = res { return None; } |
| 74 | Some(res.unwrap() as u64) |
| 75 | } |
| 76 | Arg::U32LE(_) => { |
| 77 | let res = src.peek_u32le(); |
| 78 | if let Err(_) = res { return None; } |
| 79 | Some(res.unwrap() as u64) |
| 80 | } |
| 81 | Arg::U64BE(_) => { |
| 82 | let res = src.peek_u64be(); |
| 83 | if let Err(_) = res { return None; } |
| 84 | Some(res.unwrap()) |
| 85 | } |
| 86 | Arg::U64LE(_) => { |
| 87 | let res = src.peek_u64le(); |
| 88 | if let Err(_) = res { return None; } |
| 89 | Some(res.unwrap()) |
| 90 | } |
| 91 | } |
| 92 | } |
| 93 | fn eq(&self, src: &mut ByteReader) -> bool { |
| 94 | let val = self.read_val(src); |
| 95 | if let None = val { false } |
| 96 | else { val.unwrap() == self.val() } |
| 97 | } |
| 98 | fn ge(&self, src: &mut ByteReader) -> bool { |
| 99 | let val = self.read_val(src); |
| 100 | if let None = val { false } |
| 101 | else { val.unwrap() >= self.val() } |
| 102 | } |
| 103 | fn gt(&self, src: &mut ByteReader) -> bool { |
| 104 | let val = self.read_val(src); |
| 105 | if let None = val { false } |
| 106 | else { val.unwrap() > self.val() } |
| 107 | } |
| 108 | fn le(&self, src: &mut ByteReader) -> bool { |
| 109 | let val = self.read_val(src); |
| 110 | if let None = val { false } |
| 111 | else { val.unwrap() <= self.val() } |
| 112 | } |
| 113 | fn lt(&self, src: &mut ByteReader) -> bool { |
| 114 | let val = self.read_val(src); |
| 115 | if let None = val { false } |
| 116 | else { val.unwrap() < self.val() } |
| 117 | } |
| 118 | } |
| 119 | |
| 120 | #[allow(dead_code)] |
| 121 | enum CC<'a> { |
| 122 | Or(&'a CC<'a>, &'a CC<'a>), |
| 123 | Eq(Arg), |
| 124 | Str(&'static [u8]), |
| 125 | In(Arg, Arg), |
| 126 | Lt(Arg), |
| 127 | Le(Arg), |
| 128 | Gt(Arg), |
| 129 | Ge(Arg), |
| 130 | } |
| 131 | |
| 132 | impl<'a> CC<'a> { |
| 133 | fn eval(&self, src: &mut ByteReader) -> bool { |
| 134 | match *self { |
| 135 | CC::Or (ref a, ref b) => { a.eval(src) || b.eval(src) }, |
| 136 | CC::Eq(ref arg) => { arg.eq(src) }, |
| 137 | CC::In(ref a, ref b) => { a.le(src) && b.ge(src) }, |
| 138 | CC::Lt(ref arg) => { arg.lt(src) }, |
| 139 | CC::Le(ref arg) => { arg.le(src) }, |
| 140 | CC::Gt(ref arg) => { arg.gt(src) }, |
| 141 | CC::Ge(ref arg) => { arg.ge(src) }, |
| 142 | CC::Str(str) => { |
| 143 | let mut val: Vec<u8> = Vec::with_capacity(str.len()); |
| 144 | val.resize(str.len(), 0); |
| 145 | let res = src.peek_buf(val.as_mut_slice()); |
| 146 | if let Err(_) = res { return false; } |
| 147 | val == str |
| 148 | } |
| 149 | } |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | struct CheckItem<'a> { |
| 154 | offs: u32, |
| 155 | cond: &'a CC<'a>, |
| 156 | } |
| 157 | |
| 158 | #[allow(dead_code)] |
| 159 | struct DetectConditions<'a> { |
| 160 | demux_name: &'static str, |
| 161 | extensions: &'static str, |
| 162 | conditions: &'a [CheckItem<'a>], |
| 163 | } |
| 164 | |
| 165 | const DETECTORS: &[DetectConditions] = &[ |
| 166 | DetectConditions { |
| 167 | demux_name: "avi", |
| 168 | extensions: ".avi", |
| 169 | conditions: &[CheckItem{offs: 0, cond: &CC::Or(&CC::Str(b"RIFF"), &CC::Str(b"ON2 ")) }, |
| 170 | CheckItem{offs: 8, cond: &CC::Or(&CC::Or(&CC::Str(b"AVI LIST"), |
| 171 | &CC::Str(b"AVIXLIST")), |
| 172 | &CC::Str(b"ON2fLIST")) }, |
| 173 | ] |
| 174 | }, |
| 175 | DetectConditions { |
| 176 | demux_name: "gdv", |
| 177 | extensions: ".gdv", |
| 178 | conditions: &[CheckItem{offs: 0, cond: &CC::Eq(Arg::U32LE(0x29111994))}], |
| 179 | }, |
| 180 | ]; |
| 181 | |
| 182 | pub fn detect_format(name: &str, src: &mut ByteReader) -> Option<(&'static str, DetectionScore)> { |
| 183 | let mut result = None; |
| 184 | let lname = name.to_lowercase(); |
| 185 | for detector in DETECTORS { |
| 186 | let mut score = DetectionScore::No; |
| 187 | if name.len() > 0 { |
| 188 | for ext in detector.extensions.split(',') { |
| 189 | if lname.ends_with(ext) { |
| 190 | score = DetectionScore::ExtensionMatches; |
| 191 | break; |
| 192 | } |
| 193 | } |
| 194 | } |
| 195 | let mut passed = detector.conditions.len() > 0; |
| 196 | for ck in detector.conditions { |
| 197 | let ret = src.seek(SeekFrom::Start(ck.offs as u64)); |
| 198 | if let Err(_) = ret { |
| 199 | passed = false; |
| 200 | break; |
| 201 | } |
| 202 | if !ck.cond.eval(src) { |
| 203 | passed = false; |
| 204 | break; |
| 205 | } |
| 206 | } |
| 207 | if passed { |
| 208 | score = DetectionScore::MagicMatches; |
| 209 | } |
| 210 | if score == DetectionScore::MagicMatches { |
| 211 | return Some((detector.demux_name, score)); |
| 212 | } |
| 213 | if let None = result { |
| 214 | result = Some((detector.demux_name, score)); |
| 215 | } else { |
| 216 | let (_, oldsc) = result.unwrap(); |
| 217 | if oldsc.less(score) { |
| 218 | result = Some((detector.demux_name, score)); |
| 219 | } |
| 220 | } |
| 221 | } |
| 222 | result |
| 223 | } |
| 224 | |
| 225 | #[cfg(test)] |
| 226 | mod test { |
| 227 | use super::*; |
| 228 | use std::fs::File; |
| 229 | use io::byteio::*; |
| 230 | |
| 231 | #[test] |
| 232 | fn test_avi_detect() { |
| 233 | let name = "assets/laser05.avi"; |
| 234 | let mut file = File::open(name).unwrap(); |
| 235 | let mut fr = FileReader::new_read(&mut file); |
| 236 | let mut br = ByteReader::new(&mut fr); |
| 237 | let (name, score) = detect_format(name, &mut br).unwrap(); |
| 238 | assert_eq!(name, "avi"); |
| 239 | assert_eq!(score, DetectionScore::MagicMatches); |
| 240 | } |
| 241 | |
| 242 | #[test] |
| 243 | fn test_gdv_detect() { |
| 244 | let name = "assets/intro1.gdv"; |
| 245 | let mut file = File::open(name).unwrap(); |
| 246 | let mut fr = FileReader::new_read(&mut file); |
| 247 | let mut br = ByteReader::new(&mut fr); |
| 248 | let (name, score) = detect_format(name, &mut br).unwrap(); |
| 249 | assert_eq!(name, "gdv"); |
| 250 | assert_eq!(score, DetectionScore::MagicMatches); |
| 251 | } |
| 252 | } |