parse ftyp box

Cargo.lock

@@ -1,6 +1,16 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "byteorder"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "mp4"
 version = "0.1.0"
+dependencies = [
+ "byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
 
+[metadata]
+"checksum byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a7c3dd8985a7111efc5c80b44e23ecdd8c007de8ade3b96595387e812b957cf5"

Cargo.toml

@@ -7,3 +7,4 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+byteorder = "1"

src/main.rs

@@ -1,7 +1,9 @@
 use std::io::prelude::*;
 use std::io::{BufReader, Read, SeekFrom};
 use std::fs::File;
+use std::fmt;
 use std::convert::TryInto;
+use byteorder::{BigEndian, ReadBytesExt};
 
 #[derive(Debug)]
 struct Box {
@@ -10,13 +12,51 @@ struct Box {
     offset: u32,
 }
 
+#[derive(Debug)]
+struct FtypBox {
+    major_brand: FourCC,
+    minor_version: u32,
+    compatible_brands: Vec<FourCC>,
+}
+
+#[derive(Default, PartialEq, Clone)]
+pub struct FourCC {
+    pub value: String
+}
+
+impl From<u32> for FourCC {
+    fn from(number: u32) -> FourCC {
+        let mut box_chars = Vec::new();
+        for x in 0..4 {
+            let c = (number >> (x * 8) & 0x0000_00FF) as u8;
+            box_chars.push(c);
+        }
+        box_chars.reverse();
+
+        let box_string = match String::from_utf8(box_chars) {
+            Ok(t) => t,
+            _ => String::from("null"), // error to retrieve fourcc
+        };
+
+        FourCC {
+            value: box_string
+        }
+    }
+}
+
+impl fmt::Debug for FourCC {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.value)
+    }
+}
+
 fn main() -> std::io::Result<()> {
 
     // Using BufReader.
     let f = File::open("tears-of-steel-2s.mp4")?;
     let filesize = f.metadata().unwrap().len();
     let mut reader = BufReader::new(f);
-    let mut v = Vec::new();
+    let mut boxes = Vec::new();
 
     let mut offset = 0u64;
     while offset < filesize {
@@ -42,13 +82,19 @@ fn main() -> std::io::Result<()> {
             Err(e) => panic!("Invalid UTF-8 sequence: {}", e),
         };
 
+        match typ.as_ref() {
+            "ftyp" =>  parse_ftyp_box(&mut reader, 0, size),
+            _ => (),
+        };
+
+
         // Make Box struct and add to vector.
         let b = Box{
-            name: typ.try_into().expect("asdf"),
+            name: typ.try_into().unwrap(),
             size: size,
             offset: offset as u32,
         };
-        v.push(b);
+        boxes.push(b);
 
         // This will find all boxes, including nested boxes.
         // let mut offset = match size {
@@ -62,11 +108,41 @@ fn main() -> std::io::Result<()> {
     }
 
     // Print results.
-    for a in v {
-        println!("{:?}", a);
+    for b in boxes {
+        println!("{:?}", b);
+
     }
 
     // Done.
     println!("done");
     Ok(())
-}
+}
+
+fn parse_ftyp_box(f: &mut BufReader<File>, offset: u64, size: u32) {
+    println!("found ftyp");
+
+    let major = f.read_u32::<byteorder::BigEndian>().unwrap();
+    let minor = f.read_u32::<byteorder::BigEndian>().unwrap();
+    let brand_count = (size - 16) / 4; // header + major + minor
+
+    println!("{}", brand_count);
+
+    let mut brands = Vec::new();
+    for _ in 0..brand_count {
+        let b = f.read_u32::<byteorder::BigEndian>().unwrap();
+        brands.push(From::from(b));
+    }
+
+    let ftyp = FtypBox {
+        major_brand: From::from(major),
+        minor_version: minor,
+        compatible_brands: brands,
+    };
+    println!("{:?}", ftyp);
+
+    println!("end ftyp");
+    // Ok(FtypBox {
+    //     major_brand: major,
+    //     minor_version: minor,
+    // })
+}