+//! Container format detection.
+//!
+//! Usually user does not know the container format of the opened file.
+//! That is why format detection functionality is needed.
+//! This module contains the set of rules to detect container not merely by file extension but also by its content if possible.
+//!
+//! # Examples
+//!
+//! ```no_run
+//! use nihav_core::detect::detect_format;
+//! use std::fs::File;
+//! use nihav_core::io::byteio::*;
+//!
+//! let name = "mediafile.ogv";
+//! let mut file = File::open(name).unwrap();
+//! let mut filereader = FileReader::new_read(&mut file);
+//! let mut br = ByteReader::new(&mut filereader);
+//! let result = detect_format(name, &mut br);
+//! if let Some((name, score)) = result {
+//! println!("detected format {} with score {:?}", name, score);
+//! }
+//! ```
use std::io::SeekFrom;
use crate::io::byteio::ByteReader;
+/// Format detection score.
#[derive(Debug,Clone,Copy,PartialEq)]
pub enum DetectionScore {
+ /// Format is not detected.
No,
+ /// Format matched by file extension.
ExtensionMatches,
+ /// Format matches by markers inside the file.
MagicMatches,
}
impl DetectionScore {
- pub fn less(&self, other: DetectionScore) -> bool {
- (*self as i32) < (other as i32)
+ /// Checks whether current detection score is less than a value it is compared against.
+ pub fn less(self, other: DetectionScore) -> bool {
+ (self as i32) < (other as i32)
}
}
impl Arg {
fn val(&self) -> u64 {
match *self {
- Arg::Byte(b) => { b as u64 }
- Arg::U16BE(v) => { v as u64 }
- Arg::U16LE(v) => { v as u64 }
- Arg::U24BE(v) => { v as u64 }
- Arg::U24LE(v) => { v as u64 }
- Arg::U32BE(v) => { v as u64 }
- Arg::U32LE(v) => { v as u64 }
+ Arg::Byte(b) => { u64::from(b) }
+ Arg::U16BE(v) => { u64::from(v) }
+ Arg::U16LE(v) => { u64::from(v) }
+ Arg::U24BE(v) => { u64::from(v) }
+ Arg::U24LE(v) => { u64::from(v) }
+ Arg::U32BE(v) => { u64::from(v) }
+ Arg::U32LE(v) => { u64::from(v) }
Arg::U64BE(v) => { v }
Arg::U64LE(v) => { v }
}
match *self {
Arg::Byte(_) => {
let res = src.peek_byte();
- if let Err(_) = res { return None; }
- Some(res.unwrap() as u64)
+ if res.is_err() { return None; }
+ Some(u64::from(res.unwrap()))
}
Arg::U16BE(_) => {
let res = src.peek_u16be();
- if let Err(_) = res { return None; }
- Some(res.unwrap() as u64)
+ if res.is_err() { return None; }
+ Some(u64::from(res.unwrap()))
}
Arg::U16LE(_) => {
let res = src.peek_u16le();
- if let Err(_) = res { return None; }
- Some(res.unwrap() as u64)
+ if res.is_err() { return None; }
+ Some(u64::from(res.unwrap()))
}
Arg::U24BE(_) => {
let res = src.peek_u24be();
- if let Err(_) = res { return None; }
- Some(res.unwrap() as u64)
+ if res.is_err() { return None; }
+ Some(u64::from(res.unwrap()))
}
Arg::U24LE(_) => {
let res = src.peek_u24le();
- if let Err(_) = res { return None; }
- Some(res.unwrap() as u64)
+ if res.is_err() { return None; }
+ Some(u64::from(res.unwrap()))
}
Arg::U32BE(_) => {
let res = src.peek_u32be();
- if let Err(_) = res { return None; }
- Some(res.unwrap() as u64)
+ if res.is_err() { return None; }
+ Some(u64::from(res.unwrap()))
}
Arg::U32LE(_) => {
let res = src.peek_u32le();
- if let Err(_) = res { return None; }
- Some(res.unwrap() as u64)
+ if res.is_err() { return None; }
+ Some(u64::from(res.unwrap()))
}
Arg::U64BE(_) => {
let res = src.peek_u64be();
- if let Err(_) = res { return None; }
+ if res.is_err() { return None; }
Some(res.unwrap())
}
Arg::U64LE(_) => {
let res = src.peek_u64le();
- if let Err(_) = res { return None; }
+ if res.is_err() { return None; }
Some(res.unwrap())
}
}
}
fn eq(&self, src: &mut ByteReader) -> bool {
let val = self.read_val(src);
- if let None = val { false }
+ if val.is_none() { false }
else { val.unwrap() == self.val() }
}
fn ge(&self, src: &mut ByteReader) -> bool {
let val = self.read_val(src);
- if let None = val { false }
+ if val.is_none() { false }
else { val.unwrap() >= self.val() }
}
fn gt(&self, src: &mut ByteReader) -> bool {
let val = self.read_val(src);
- if let None = val { false }
+ if val.is_none() { false }
else { val.unwrap() > self.val() }
}
fn le(&self, src: &mut ByteReader) -> bool {
let val = self.read_val(src);
- if let None = val { false }
+ if val.is_none() { false }
else { val.unwrap() <= self.val() }
}
fn lt(&self, src: &mut ByteReader) -> bool {
let val = self.read_val(src);
- if let None = val { false }
+ if val.is_none() { false }
else { val.unwrap() < self.val() }
}
}
CC::Gt(ref arg) => { arg.gt(src) },
CC::Ge(ref arg) => { arg.ge(src) },
CC::Str(str) => {
- let mut val: Vec<u8> = Vec::with_capacity(str.len());
- val.resize(str.len(), 0);
+ let mut val: Vec<u8> = vec![0; str.len()];
let res = src.peek_buf(val.as_mut_slice());
- if let Err(_) = res { return false; }
+ if res.is_err() { return false; }
val == str
}
}
},
];
+/// Tries to detect container format.
+///
+/// This function tries to determine container format using both file extension and checking against container specific markers inside.
+/// In case of success the function returns short container name and the detection score.
+/// Result should have the highest detection score among tested.
pub fn detect_format(name: &str, src: &mut ByteReader) -> Option<(&'static str, DetectionScore)> {
let mut result = None;
let lname = name.to_lowercase();
for detector in DETECTORS {
let mut score = DetectionScore::No;
- if name.len() > 0 {
+ if !name.is_empty() {
for ext in detector.extensions.split(',') {
if lname.ends_with(ext) {
score = DetectionScore::ExtensionMatches;
}
}
}
- let mut passed = detector.conditions.len() > 0;
+ let mut passed = !detector.conditions.is_empty();
for ck in detector.conditions {
- let ret = src.seek(SeekFrom::Start(ck.offs as u64));
- if let Err(_) = ret {
+ let ret = src.seek(SeekFrom::Start(u64::from(ck.offs)));
+ if ret.is_err() {
passed = false;
break;
}
projects / nihav.git / blobdiff