Cleanup and some minor restructuring. (#2)

* Cleanup and some minor restructuring.

* Update readme.

README.md

@@ -1,5 +1,10 @@
-# mp4.rs
-MP4 Reader in Rust
+# mp4rs
+> MP4 Reader in Rust
+
+ISO/IEC 14496-12 - ISO Base Media File Format (QuickTime, MPEG-4, etc)
+
+![Crates.io](https://img.shields.io/crates/v/mp4)
+![Crates.io](https://img.shields.io/crates/d/mp4)
 
 ## Development
 
@@ -16,3 +21,12 @@ cargo build
 ```
 cargo run --example mp4info <movie.mp4>
 ```
+
+## Resources
+Thanks to the following resources used when learning Rust:
+* https://github.com/mozilla/mp4parse-rust
+* https://github.com/pcwalton/rust-media
+* https://github.com/alfg/mp4
+
+## License
+MIT

src/atoms.rs

@@ -0,0 +1,822 @@
+use std::fmt;
+use std::io::{BufReader, SeekFrom, Seek, Read};
+use std::fs::File;
+use byteorder::{BigEndian, ReadBytesExt};
+use std::char::{decode_utf16, REPLACEMENT_CHARACTER};
+use crate::{Error, read_box_header, BoxHeader, HEADER_SIZE};
+
+pub type Result<T> = std::result::Result<T, Error>;
+
+#[derive(Clone, Copy, PartialEq)]
+pub enum BoxType {
+    FtypBox,
+    MvhdBox,
+    FreeBox,
+    MdatBox,
+    MoovBox,
+    MoofBox,
+    TkhdBox,
+    EdtsBox,
+    MdiaBox,
+    ElstBox,
+    MdhdBox,
+    HdlrBox,
+    MinfBox,
+    VmhdBox,
+    StblBox,
+    StsdBox,
+    SttsBox,
+    TrakBox,
+    UdtaBox,
+    DinfBox,
+    SmhdBox,
+    Avc1Box,
+    Mp4aBox,
+    UnknownBox(u32),
+}
+
+impl From<u32> for BoxType {
+    fn from(t: u32) -> BoxType {
+        use self::BoxType::*;
+        match t {
+            0x66747970 => FtypBox,
+            0x6d766864 => MvhdBox,
+            0x66726565 => FreeBox,
+            0x6d646174 => MdatBox,
+            0x6d6f6f76 => MoovBox,
+            0x6d6f6f66 => MoofBox ,
+            0x746b6864 => TkhdBox,
+            0x65647473 => EdtsBox,
+            0x6d646961 => MdiaBox,
+            0x656c7374 => ElstBox,
+            0x6d646864 => MdhdBox,
+            0x68646c72 => HdlrBox,
+            0x6d696e66 => MinfBox,
+            0x766d6864 => VmhdBox,
+            0x7374626c => StblBox,
+            0x73747364 => StsdBox,
+            0x73747473 => SttsBox,
+            0x7472616b => TrakBox,
+            0x75647461 => UdtaBox,
+            0x64696e66 => DinfBox,
+            0x736d6864 => SmhdBox,
+            0x61766331 => Avc1Box,
+            0x6d703461 => Mp4aBox,
+            _ => UnknownBox(t),
+        }
+    }
+}
+
+impl Into<u32> for BoxType {
+    fn into(self) -> u32 {
+        use self::BoxType::*;
+        match self {
+            FtypBox => 0x66747970,
+            MvhdBox => 0x6d766864,
+            FreeBox => 0x66726565,
+            MdatBox => 0x6d646174,
+            MoovBox => 0x6d6f6f76,
+            MoofBox => 0x6d6f6f66,
+            TkhdBox => 0x746b6864,
+            EdtsBox => 0x65647473,
+            MdiaBox => 0x6d646961,
+            ElstBox => 0x656c7374,
+            MdhdBox => 0x6d646864,
+            HdlrBox => 0x68646c72,
+            MinfBox => 0x6d696e66,
+            VmhdBox => 0x766d6864,
+            StblBox => 0x7374626c,
+            StsdBox => 0x73747364,
+            SttsBox => 0x73747473,
+            TrakBox => 0x7472616b,
+            UdtaBox => 0x75647461,
+            DinfBox => 0x64696e66,
+            SmhdBox => 0x736d6864,
+            Avc1Box => 0x61766331,
+            Mp4aBox => 0x6d703461,
+
+            UnknownBox(t) => t,
+        }
+    }
+}
+
+impl fmt::Debug for BoxType {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let fourcc: FourCC = From::from(self.clone());
+        write!(f, "{}", 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 From<BoxType> for FourCC {
+    fn from(t: BoxType) -> FourCC {
+        let box_num: u32 = Into::into(t);
+        From::from(box_num)
+    }
+}
+
+impl fmt::Debug for FourCC {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.value)
+    }
+}
+
+impl fmt::Display for FourCC {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.value)
+    }
+}
+
+#[derive(Debug, Default)]
+pub struct FtypBox {
+    pub major_brand: FourCC,
+    pub minor_version: u32,
+    pub compatible_brands: Vec<FourCC>,
+}
+
+#[derive(Debug, Default)]
+pub struct MoovBox {
+    pub mvhd: MvhdBox,
+    pub traks: Vec<TrakBox>,
+}
+
+impl MoovBox {
+    pub(crate) fn new() -> MoovBox {
+        Default::default()
+    }
+}
+
+#[derive(Debug, Default)]
+pub struct MvhdBox {
+    pub version: u8,
+    pub flags: u32,
+    pub creation_time: u32,
+    pub modification_time: u32,
+    pub timescale: u32,
+    pub duration: u32,
+    pub rate: u32,
+}
+
+#[derive(Debug, Default)]
+pub struct TrakBox {
+    pub tkhd: Option<TkhdBox>,
+    pub edts: Option<EdtsBox>,
+    pub mdia: Option<MdiaBox>,
+}
+
+impl TrakBox {
+    pub(crate) fn new() -> TrakBox {
+        Default::default()
+    }
+}
+
+#[derive(Debug, Default)]
+pub struct TkhdBox {
+    pub version: u8,
+    pub flags: u32,
+    pub creation_time: u32,
+    pub modification_time: u32,
+    pub track_id: u32,
+    pub duration: u64,
+    pub layer:  u16,
+    pub alternate_group: u16,
+    pub volume: u16,
+    pub matrix: Matrix,
+    pub width: u32,
+    pub height: u32,
+}
+
+#[derive(Debug, Default)]
+pub struct Matrix {
+    pub a: i32,
+    pub b: i32,
+    pub u: i32,
+    pub c: i32,
+    pub d: i32,
+    pub v: i32,
+    pub x: i32,
+    pub y: i32,
+    pub w: i32,
+}
+
+#[derive(Debug, Default)]
+pub struct EdtsBox {
+    pub elst: Option<ElstBox>,
+}
+
+impl EdtsBox {
+    pub(crate) fn new() -> EdtsBox {
+        Default::default()
+    }
+}
+
+#[derive(Debug, Default)]
+pub struct ElstBox {
+    pub version: u32,
+    pub entry_count: u32,
+    pub entries: Vec<ElstEntry>,
+}
+
+#[derive(Debug, Default)]
+pub struct ElstEntry {
+    pub segment_duration: u32,
+    pub media_time: u32,
+    pub media_rate: u16,
+    pub media_rate_fraction: u16,
+}
+
+#[derive(Debug, Default)]
+pub struct MdiaBox {
+    pub mdhd: Option<MdhdBox>,
+    pub hdlr: Option<HdlrBox>,
+    pub minf: Option<MinfBox>,
+}
+
+impl MdiaBox {
+    pub(crate) fn new() -> MdiaBox {
+        Default::default()
+    }
+}
+
+#[derive(Debug, Default)]
+pub struct MdhdBox {
+    pub version: u8,
+    pub flags: u32,
+    pub creation_time: u32,
+    pub modification_time: u32,
+    pub timescale: u32,
+    pub duration: u32,
+    pub language: u16,
+    pub language_string: String,
+}
+
+#[derive(Debug, Default)]
+pub struct HdlrBox {
+    pub version: u8,
+    pub flags: u32,
+    pub handler_type: FourCC,
+    pub name: String,
+}
+
+#[derive(Debug, Default)]
+pub struct MinfBox {
+    pub vmhd: Option<VmhdBox>,
+    pub stbl: Option<StblBox>,
+}
+
+impl MinfBox {
+    pub(crate) fn new() -> MinfBox {
+        Default::default()
+    }
+}
+
+#[derive(Debug, Default)]
+pub struct VmhdBox {
+    pub version: u8,
+    pub flags: u32,
+    pub graphics_mode: u16,
+    pub op_color: u16,
+}
+
+#[derive(Debug, Default)]
+pub struct StblBox {
+    pub stts: Option<SttsBox>,
+    pub stsd: Option<StsdBox>,
+}
+
+impl StblBox {
+    pub(crate) fn new() -> StblBox {
+        Default::default()
+    }
+}
+
+#[derive(Debug, Default)]
+pub struct SttsBox {
+    pub version: u8,
+    pub flags: u32,
+    pub entry_count: u32,
+    pub sample_counts: Vec<u32>,
+    pub sample_deltas: Vec<u32>,
+}
+
+#[derive(Debug, Default)]
+pub struct StsdBox {
+    pub version: u8,
+    pub flags: u32,
+}
+
+pub fn parse_ftyp_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<FtypBox> {
+    let major = f.read_u32::<BigEndian>().unwrap();
+    let minor = f.read_u32::<BigEndian>().unwrap();
+    if size % 4 != 0 {
+        return Err(Error::InvalidData("invalid ftyp size"));
+    }
+    let brand_count = (size - 16) / 4; // header + major + minor
+
+    let mut brands = Vec::new();
+    for _ in 0..brand_count {
+        let b = f.read_u32::<BigEndian>().unwrap();
+        brands.push(From::from(b));
+    }
+
+    Ok(FtypBox {
+        major_brand: From::from(major),
+        minor_version: minor,
+        compatible_brands: brands,
+    })
+}
+
+pub(crate) fn parse_moov_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<MoovBox> {
+    let mut moov = MoovBox::new();
+
+    let mut start = 0u64;
+    while start < size as u64 {
+
+        // Get box header.
+        let header = read_box_header(f, start).unwrap();
+        let BoxHeader{ name, size: s, offset: _ } = header;
+
+        match name {
+            BoxType::MvhdBox => {
+                moov.mvhd = parse_mvhd_box(f, 0, s as u32).unwrap();
+            }
+            BoxType::TrakBox => {
+                let trak = parse_trak_box(f, 0, s as u32).unwrap();
+                moov.traks.push(trak);
+            }
+            BoxType::UdtaBox => {
+                start = (s as u32 - HEADER_SIZE) as u64;
+            }
+            _ => break
+        }
+    }
+    Ok(moov)
+}
+
+fn parse_mvhd_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<MvhdBox> {
+    let current =  f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
+
+    let version = f.read_u8().unwrap();
+    let flags_a = f.read_u8().unwrap();
+    let flags_b = f.read_u8().unwrap();
+    let flags_c = f.read_u8().unwrap();
+    let flags = u32::from(flags_a) << 16 | u32::from(flags_b) << 8 | u32::from(flags_c);
+    let creation_time = f.read_u32::<BigEndian>().unwrap();
+    let modification_time = f.read_u32::<BigEndian>().unwrap();
+    let timescale = f.read_u32::<BigEndian>().unwrap();
+    let duration = f.read_u32::<BigEndian>().unwrap();
+    let rate = f.read_u32::<BigEndian>().unwrap();
+
+    // Skip remaining bytes.
+    let after =  f.seek(SeekFrom::Current(0)).unwrap();
+    let remaining_bytes = (size as u64 - (after - current)) as i64;
+    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
+
+    Ok(MvhdBox{
+        version,
+        flags,
+        creation_time,
+        modification_time,
+        timescale,
+        duration,
+        rate,
+    })
+}
+
+fn parse_trak_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<TrakBox> {
+    let current =  f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
+    let mut trak = TrakBox::new();
+
+    let start = 0u64;
+    while start < size as u64 {
+        // Get box header.
+        let header = read_box_header(f, start).unwrap();
+        let BoxHeader{ name, size: s, offset: _ } = header;
+
+        match name {
+            BoxType::TkhdBox => {
+                let tkhd = parse_tkhd_box(f, 0, s as u32).unwrap();
+                trak.tkhd = Some(tkhd);
+            }
+            BoxType::EdtsBox => {
+                let edts = parse_edts_box(f, 0, s as u32).unwrap();
+                trak.edts = Some(edts);
+            }
+            BoxType::MdiaBox => {
+                let mdia = parse_mdia_box(f, 0, s as u32).unwrap();
+                trak.mdia = Some(mdia);
+            }
+            _ => break
+        }
+    }
+
+    // Skip remaining bytes.
+    let after =  f.seek(SeekFrom::Current(0)).unwrap();
+    let remaining_bytes = (size as u64 - (after - current)) as i64;
+    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
+    Ok(trak)
+}
+
+
+fn parse_tkhd_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<TkhdBox> {
+    let current =  f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
+
+    let version = f.read_u8().unwrap();
+    let flags_a = f.read_u8().unwrap();
+    let flags_b = f.read_u8().unwrap();
+    let flags_c = f.read_u8().unwrap();
+    let flags = u32::from(flags_a) << 16 | u32::from(flags_b) << 8 | u32::from(flags_c);
+    let creation_time = f.read_u32::<BigEndian>().unwrap();
+    let modification_time = f.read_u32::<BigEndian>().unwrap();
+    let track_id = f.read_u32::<BigEndian>().unwrap();
+    let duration = f.read_u64::<BigEndian>().unwrap();
+    f.read_u64::<BigEndian>().unwrap(); // skip.
+    let layer = f.read_u16::<BigEndian>().unwrap();
+    let alternate_group = f.read_u16::<BigEndian>().unwrap();
+    let volume = f.read_u16::<BigEndian>().unwrap() >> 8;
+
+    f.read_u8().unwrap(); // skip.
+    let matrix = Matrix{
+        a: f.read_i32::<byteorder::LittleEndian>().unwrap(),
+        b: f.read_i32::<BigEndian>().unwrap(),
+        u: f.read_i32::<BigEndian>().unwrap(),
+        c: f.read_i32::<BigEndian>().unwrap(),
+        d: f.read_i32::<BigEndian>().unwrap(),
+        v: f.read_i32::<BigEndian>().unwrap(),
+        x: f.read_i32::<BigEndian>().unwrap(),
+        y: f.read_i32::<BigEndian>().unwrap(),
+        w: f.read_i32::<BigEndian>().unwrap(),
+    };
+
+    let width = f.read_u32::<BigEndian>().unwrap() >> 8;
+    let height = f.read_u32::<BigEndian>().unwrap() >> 8;
+
+    // Skip remaining bytes.
+    let after =  f.seek(SeekFrom::Current(0)).unwrap();
+    let remaining_bytes = (size as u64 - (after - current)) as i64;
+    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
+
+    Ok(TkhdBox {
+        version,
+        flags,
+        creation_time,
+        modification_time,
+        track_id,
+        duration,
+        layer,
+        alternate_group,
+        volume,
+        matrix,
+        width,
+        height,
+    })
+}
+
+fn parse_edts_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<EdtsBox> {
+    let current =  f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
+    let mut edts = EdtsBox::new();
+
+    let start = 0u64;
+    while start < size as u64 {
+        // Get box header.
+        let header = read_box_header(f, start).unwrap();
+        let BoxHeader{ name, size: s, offset: _ } = header;
+
+        match name {
+            BoxType::ElstBox => {
+                let elst = parse_elst_box(f, 0, s as u32).unwrap();
+                edts.elst = Some(elst);
+            }
+            _ => break
+        }
+    }
+
+    // Skip remaining bytes.
+    let after =  f.seek(SeekFrom::Current(0)).unwrap();
+    let remaining_bytes = (size as u64 - (after - current)) as i64;
+    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
+    Ok(edts)
+}
+
+fn parse_elst_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<ElstBox> {
+    let current = f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
+
+    let version = f.read_u32::<BigEndian>().unwrap();
+    let entry_count = f.read_u32::<BigEndian>().unwrap();
+
+    let mut entries = Vec::new();
+
+    for _i in 0..entry_count {
+        let entry = ElstEntry{
+            segment_duration: f.read_u32::<BigEndian>().unwrap(),
+            media_time: f.read_u32::<BigEndian>().unwrap(),
+            media_rate: f.read_u16::<BigEndian>().unwrap(),
+            media_rate_fraction: f.read_u16::<BigEndian>().unwrap(),
+        };
+        entries.push(entry);
+    }
+
+    // Skip remaining bytes.
+    let after =  f.seek(SeekFrom::Current(0)).unwrap();
+    let remaining_bytes = (size as u64 - (after - current)) as i64;
+    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
+
+    Ok(ElstBox {
+        version,
+        entry_count,
+        entries,
+    })
+}
+
+fn parse_mdia_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<MdiaBox> {
+    let current =  f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
+    let mut mdia = MdiaBox::new();
+
+    let start = 0u64;
+    while start < size as u64 {
+        // Get box header.
+        let header = read_box_header(f, start).unwrap();
+        let BoxHeader{ name, size: s, offset: _ } = header;
+
+        match name {
+            BoxType::MdhdBox => {
+                let mdhd = parse_mdhd_box(f, 0, s as u32).unwrap();
+                mdia.mdhd = Some(mdhd);
+            }
+            BoxType::HdlrBox => {
+                let hdlr = parse_hdlr_box(f, 0, s as u32).unwrap();
+                mdia.hdlr = Some(hdlr);
+            }
+            BoxType::MinfBox => {
+                let minf = parse_minf_box(f, 0, s as u32).unwrap();
+                mdia.minf = Some(minf);
+            }
+            _ => break
+        }
+    }
+
+    // Skip remaining bytes.
+    let after =  f.seek(SeekFrom::Current(0)).unwrap();
+    let remaining_bytes = (size as u64 - (after - current)) as i64;
+    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
+    Ok(mdia)
+}
+
+fn parse_mdhd_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<MdhdBox> {
+    let current = f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
+
+    let version = f.read_u8().unwrap();
+    let flags_a = f.read_u8().unwrap();
+    let flags_b = f.read_u8().unwrap();
+    let flags_c = f.read_u8().unwrap();
+    let flags = u32::from(flags_a) << 16 | u32::from(flags_b) << 8 | u32::from(flags_c);
+    let creation_time = f.read_u32::<BigEndian>().unwrap();
+    let modification_time = f.read_u32::<BigEndian>().unwrap();
+    let timescale = f.read_u32::<BigEndian>().unwrap();
+    let duration = f.read_u32::<BigEndian>().unwrap();
+    let language = f.read_u16::<BigEndian>().unwrap();
+    let language_string = get_language_string(language);
+
+    // Skip remaining bytes.
+    let after =  f.seek(SeekFrom::Current(0)).unwrap();
+    let remaining_bytes = (size as u64 - (after - current)) as i64;
+    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
+
+    Ok(MdhdBox {
+        version,
+        flags,
+        creation_time,
+        modification_time,
+        timescale,
+        duration,
+        language,
+        language_string,
+    })
+}
+
+fn get_language_string(language: u16) -> String {
+    let mut lang: [u16; 3] = [0; 3];
+
+    lang[0] = ((language >> 10) & 0x1F) + 0x60;
+    lang[1] = ((language >> 5) & 0x1F) + 0x60;
+    lang[2] = ((language) & 0x1F) + 0x60;
+
+    // Decode utf-16 encoded bytes into a string.
+    let lang_str = decode_utf16(lang.iter().cloned())
+        .map(|r| r.unwrap_or(REPLACEMENT_CHARACTER))
+        .collect::<String>();
+
+    return lang_str;
+}
+
+fn parse_hdlr_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<HdlrBox> {
+    let current = f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
+
+    let version = f.read_u8().unwrap();
+    let flags_a = f.read_u8().unwrap();
+    let flags_b = f.read_u8().unwrap();
+    let flags_c = f.read_u8().unwrap();
+    let flags = u32::from(flags_a) << 16 | u32::from(flags_b) << 8 | u32::from(flags_c);
+    f.read_u32::<BigEndian>().unwrap(); // skip.
+    let handler = f.read_u32::<BigEndian>().unwrap();
+
+    let n = f.seek(SeekFrom::Current(12)).unwrap(); // 12 bytes reserved.
+    let buf_size = (size as u64 - (n - current)) - HEADER_SIZE as u64;
+    let mut buf = vec![0u8; buf_size as usize];
+    f.read_exact(&mut buf).unwrap();
+
+    let handler_string = match String::from_utf8(buf) {
+        Ok(t) => t,
+        _ => String::from("null"),
+    };
+
+    // Skip remaining bytes.
+    let after = f.seek(SeekFrom::Current(0)).unwrap();
+    let remaining_bytes = (size as u64 - (after - current)) as i64;
+    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
+
+    Ok(HdlrBox {
+        version,
+        flags,
+        handler_type: From::from(handler),
+        name: handler_string,
+    })
+}
+
+fn parse_minf_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<MinfBox> {
+    let current =  f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
+    let mut minf = MinfBox::new();
+
+    let mut start = 0u64;
+    while start < size as u64 {
+        // Get box header.
+        let header = read_box_header(f, start).unwrap();
+        let BoxHeader{ name, size: s, offset: _ } = header;
+
+        match name {
+            BoxType::VmhdBox => {
+                let vmhd = parse_vmhd_box(f, 0, s as u32).unwrap();
+                minf.vmhd = Some(vmhd);
+            }
+            BoxType::SmhdBox => {
+                start = (s as u32 - HEADER_SIZE) as u64;
+            }
+            BoxType::DinfBox => {
+                start = (s as u32 - HEADER_SIZE) as u64;
+            }
+            BoxType::StblBox => {
+                let stbl = parse_stbl_box(f, 0, s as u32).unwrap();
+                minf.stbl = Some(stbl);
+            }
+            _ => break
+        }
+    }
+
+    // Skip remaining bytes.
+    let after =  f.seek(SeekFrom::Current(0)).unwrap();
+    let remaining_bytes = (size as u64 - (after - current)) as i64;
+    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
+    Ok(minf)
+}
+
+fn parse_vmhd_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<VmhdBox> {
+    let current = f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
+
+    let version = f.read_u8().unwrap();
+    let flags_a = f.read_u8().unwrap();
+    let flags_b = f.read_u8().unwrap();
+    let flags_c = f.read_u8().unwrap();
+    let flags = u32::from(flags_a) << 16 | u32::from(flags_b) << 8 | u32::from(flags_c);
+    let graphics_mode = f.read_u16::<BigEndian>().unwrap();
+    let op_color = f.read_u16::<BigEndian>().unwrap();
+
+    // Skip remaining bytes.
+    let after = f.seek(SeekFrom::Current(0)).unwrap();
+    let remaining_bytes = (size as u64 - (after - current)) as i64;
+    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
+
+    Ok(VmhdBox {
+        version,
+        flags,
+        graphics_mode,
+        op_color,
+    })
+}
+
+fn parse_stbl_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<StblBox> {
+    let mut stbl = StblBox::new();
+
+    let start = 0u64;
+    while start < size as u64 {
+        // Get box header.
+        let header = read_box_header(f, start).unwrap();
+        let BoxHeader{ name, size: s, offset: _ } = header;
+
+        match name {
+            BoxType::StsdBox => {
+                let stsd = parse_stsd_box(f, 0, s as u32).unwrap();
+                stbl.stsd = Some(stsd);
+            }
+            BoxType::SttsBox => {
+                let stts = parse_stts_box(f, 0, s as u32).unwrap();
+                stbl.stts = Some(stts);
+            }
+            _ => break
+        }
+    }
+    Ok(stbl)
+}
+
+fn parse_stts_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<SttsBox> {
+    let current = f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
+
+    let version = f.read_u8().unwrap();
+    let flags_a = f.read_u8().unwrap();
+    let flags_b = f.read_u8().unwrap();
+    let flags_c = f.read_u8().unwrap();
+    let flags = u32::from(flags_a) << 16 | u32::from(flags_b) << 8 | u32::from(flags_c);
+    let entry_count = f.read_u32::<BigEndian>().unwrap();
+    let mut sample_counts = Vec::new();
+    let mut sample_deltas = Vec::new();
+
+    for _i in 0..entry_count {
+        let sc = f.read_u32::<BigEndian>().unwrap();
+        let sd = f.read_u32::<BigEndian>().unwrap();
+        sample_counts.push(sc);
+        sample_deltas.push(sd);
+    }
+
+    // Skip remaining bytes.
+    let after = f.seek(SeekFrom::Current(0)).unwrap();
+    let remaining_bytes = (size as u64 - (after - current)) as i64;
+    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
+
+    Ok(SttsBox {
+        version,
+        flags,
+        entry_count,
+        sample_counts,
+        sample_deltas,
+    })
+}
+
+fn parse_stsd_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<StsdBox> {
+    let current = f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
+
+    let version = f.read_u8().unwrap();
+    let flags_a = f.read_u8().unwrap();
+    let flags_b = f.read_u8().unwrap();
+    let flags_c = f.read_u8().unwrap();
+    let flags = u32::from(flags_a) << 16 | u32::from(flags_b) << 8 | u32::from(flags_c);
+    f.read_u32::<BigEndian>().unwrap(); // skip.
+
+    let mut start = 0u64;
+    while start < size as u64 {
+        // Get box header.
+        let header = read_box_header(f, start).unwrap();
+        let BoxHeader{ name, size: s, offset: _ } = header;
+
+        match name {
+            BoxType::Avc1Box => {
+                start = (s as u32 - HEADER_SIZE) as u64;
+            }
+            BoxType::Mp4aBox => {
+                start = (s as u32 - HEADER_SIZE) as u64;
+            }
+            _ => break
+        }
+    }
+
+    // Skip remaining bytes.
+    let after = f.seek(SeekFrom::Current(0)).unwrap();
+    let remaining_bytes = (size as u64 - (after - current)) as i64;
+    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
+    Ok(StsdBox {
+        version,
+        flags,
+    })
+}

src/lib.rs

@@ -3,10 +3,10 @@ extern crate byteorder;
 use std::io::prelude::*;
 use std::io::{BufReader, Read, SeekFrom};
 use std::fs::File;
-use std::fmt;
 use std::convert::TryInto;
-use std::char::{decode_utf16, REPLACEMENT_CHARACTER};
-use byteorder::{ReadBytesExt, BigEndian};
+
+mod atoms;
+use crate::atoms::*;
 
 const HEADER_SIZE: u32 = 8;
 
@@ -14,7 +14,6 @@ const HEADER_SIZE: u32 = 8;
 pub enum Error {
     InvalidData(&'static str),
 }
-pub type Result<T> = std::result::Result<T, Error>;
 
 #[derive(Debug, PartialEq)]
 pub enum TrackType {
@@ -37,233 +36,13 @@ impl BMFF {
     }
 }
 
-#[derive(Debug, Default)]
-struct BMFFBox {
-    head: BoxHeader,
-}
-
-impl BMFFBox {
-    fn new() -> BMFFBox {
-        Default::default()
-    }
-}
-
-#[derive(Debug, Default)]
+#[derive(Debug, Clone, Copy)]
 struct BoxHeader {
-    name: String,
+    name: BoxType,
     size: u64,
     offset: u64,
 }
 
-#[derive(Debug, Default)]
-pub struct FtypBox {
-    pub major_brand: FourCC,
-    pub minor_version: u32,
-    pub compatible_brands: Vec<FourCC>,
-}
-
-#[derive(Debug, Default)]
-pub struct MoovBox {
-    pub mvhd: MvhdBox,
-    pub traks: Vec<TrakBox>,
-}
-
-impl MoovBox {
-    fn new() -> MoovBox {
-        Default::default()
-    }
-}
-
-#[derive(Debug, Default)]
-pub struct MvhdBox {
-    pub version: u8,
-    pub flags: u32,
-    pub creation_time: u32,
-    pub modification_time: u32,
-    pub timescale: u32,
-    pub duration: u32,
-    pub rate: u32,
-}
-
-#[derive(Debug, Default)]
-pub struct TrakBox {
-    pub tkhd: Option<TkhdBox>,
-    pub edts: Option<EdtsBox>,
-    pub mdia: Option<MdiaBox>,
-}
-
-impl TrakBox {
-    fn new() -> TrakBox {
-        Default::default()
-    }
-}
-
-#[derive(Debug, Default)]
-pub struct TkhdBox {
-    pub version: u8,
-    pub flags: u32,
-    pub creation_time: u32,
-    pub modification_time: u32,
-    pub track_id: u32,
-    pub duration: u64,
-    pub layer:  u16,
-    pub alternate_group: u16,
-    pub volume: u16,
-    pub matrix: Matrix,
-    pub width: u32,
-    pub height: u32,
-}
-
-#[derive(Debug, Default)]
-pub struct Matrix {
-    a: i32,
-    b: i32,
-    u: i32,
-    c: i32,
-    d: i32,
-    v: i32,
-    x: i32,
-    y: i32,
-    w: i32,
-}
-
-#[derive(Debug, Default)]
-pub struct EdtsBox {
-    pub elst: Option<ElstBox>,
-}
-
-impl EdtsBox {
-    fn new() -> EdtsBox {
-        Default::default()
-    }
-}
-
-#[derive(Debug, Default)]
-pub struct ElstBox {
-    pub version: u32,
-    pub entry_count: u32,
-    pub entries: Vec<ElstEntry>,
-}
-
-#[derive(Debug, Default)]
-pub struct ElstEntry {
-    pub segment_duration: u32,
-    pub media_time: u32,
-    pub media_rate: u16,
-    pub media_rate_fraction: u16,
-}
-
-#[derive(Debug, Default)]
-pub struct MdiaBox {
-    pub mdhd: Option<MdhdBox>,
-    pub hdlr: Option<HdlrBox>,
-    pub minf: Option<MinfBox>,
-}
-
-impl MdiaBox {
-    fn new() -> MdiaBox {
-        Default::default()
-    }
-}
-
-#[derive(Debug, Default)]
-pub struct MdhdBox {
-    pub version: u8,
-    pub flags: u32,
-    pub creation_time: u32,
-    pub modification_time: u32,
-    pub timescale: u32,
-    pub duration: u32,
-    pub language: u16,
-    pub language_string: String,
-}
-
-#[derive(Debug, Default)]
-pub struct HdlrBox {
-    pub version: u8,
-    pub flags: u32,
-    pub handler_type: FourCC,
-    pub name: String,
-}
-
-#[derive(Debug, Default)]
-pub struct MinfBox {
-    pub vmhd: Option<VmhdBox>,
-    pub stbl: Option<StblBox>,
-}
-
-impl MinfBox {
-    fn new() -> MinfBox {
-        Default::default()
-    }
-}
-
-#[derive(Debug, Default)]
-pub struct VmhdBox {
-    pub version: u8,
-    pub flags: u32,
-    pub graphics_mode: u16,
-    pub op_color: u16,
-}
-
-#[derive(Debug, Default)]
-pub struct StblBox {
-    pub stts: Option<SttsBox>,
-    pub stsd: Option<StsdBox>,
-}
-
-impl StblBox {
-    fn new() -> StblBox {
-        Default::default()
-    }
-}
-
-#[derive(Debug, Default)]
-pub struct SttsBox {
-    pub version: u8,
-    pub flags: u32,
-    pub entry_count: u32,
-    pub sample_counts: Vec<u32>,
-    pub sample_deltas: Vec<u32>,
-}
-
-#[derive(Debug, Default)]
-pub struct StsdBox {
-    pub version: u8,
-    pub flags: u32,
-}
-
-#[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)
-    }
-}
-
 pub fn read_mp4(f: File) -> Result<BMFF> {
 
     // Open file and read boxes.
@@ -283,32 +62,25 @@ fn read_boxes(f: File) -> Result<BMFF> {
 
         // Get box header.
         let header = read_box_header(&mut reader, start).unwrap();
-        let BoxHeader{ name, size, offset } = header;
+        let BoxHeader{ name, size, offset: _ } = header;
 
-        let mut b = BMFFBox::new();
-        b.head = BoxHeader{
-            name: name.try_into().unwrap(),
-            size: size as u64,
-            offset: offset as u64,
-        };
-
-        // Match and parse the filetype.
-        match b.head.name.as_ref() {
-            "ftyp" => {
+        // Match and parse the atom boxes.
+        match name {
+            BoxType::FtypBox => {
                 let ftyp = parse_ftyp_box(&mut reader, 0, size as u32).unwrap();
                 bmff.ftyp = ftyp;
             }
-            "free" => {
+            BoxType::FreeBox => {
                 start = 0;
             }
-            "mdat" => {
+            BoxType::MdatBox => {
                 start = (size as u32 - HEADER_SIZE) as u64;
             }
-            "moov" => {
+            BoxType::MoovBox => {
                 let moov = parse_moov_box(&mut reader, 0, size as u32).unwrap();
                 bmff.moov = Some(moov);
             }
-            "moof" => {
+            BoxType::MoofBox => {
                 start = (size as u32 - HEADER_SIZE) as u64;
             }
             _ => break
@@ -323,7 +95,7 @@ fn read_box_header(reader: &mut BufReader<File>, start: u64) -> Result<BoxHeader
 
     // Create and read to buf.
     let mut buf = [0u8;8]; // 8 bytes for box header.
-    let _n = reader.read(&mut buf);
+    reader.read(&mut buf).unwrap();
 
     // Get size.
     let s = buf[0..4].try_into().unwrap();
@@ -334,563 +106,18 @@ fn read_box_header(reader: &mut BufReader<File>, start: u64) -> Result<BoxHeader
     
     // Get box type string.
     let t = buf[4..8].try_into().unwrap();
-    let typ = match std::str::from_utf8(t) {
-        Ok(v) => v,
-        Err(e) => panic!("Invalid UTF-8 sequence: {}", e),
-    };
+    let typ = u32::from_be_bytes(t);
 
     let offset = match size {
         1 => 4 + 4 + 8,
         _ => 4 + 4,
     };
+
     Ok(BoxHeader {
-        name: typ.try_into().unwrap(),
+        name: BoxType::from(typ),
         size: size as u64,
         offset: offset as u64,
     })
 }
 
-fn parse_ftyp_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<FtypBox> {
-    let major = f.read_u32::<BigEndian>().unwrap();
-    let minor = f.read_u32::<BigEndian>().unwrap();
-    if size % 4 != 0 {
-        return Err(Error::InvalidData("invalid ftyp size"));
-    }
-    let brand_count = (size - 16) / 4; // header + major + minor
 
-    let mut brands = Vec::new();
-    for _ in 0..brand_count {
-        let b = f.read_u32::<BigEndian>().unwrap();
-        brands.push(From::from(b));
-    }
-
-    Ok(FtypBox {
-        major_brand: From::from(major),
-        minor_version: minor,
-        compatible_brands: brands,
-    })
-}
-
-fn parse_moov_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<MoovBox> {
-    let mut moov = MoovBox::new();
-
-    let mut start = 0u64;
-    while start < size as u64 {
-
-        // Get box header.
-        let header = read_box_header(f, start).unwrap();
-        let BoxHeader{ name, size: s, offset } = header;
-
-        let mut b = BMFFBox::new();
-        b.head = BoxHeader{
-            name: name.try_into().unwrap(),
-            size: s as u64,
-            offset: offset as u64,
-        };
-
-
-        match b.head.name.as_ref() {
-            "mvhd" => {
-                moov.mvhd = parse_mvhd_box(f, 0, s as u32).unwrap();
-            }
-            "trak" => {
-                let trak = parse_trak_box(f, 0, s as u32).unwrap();
-                moov.traks.push(trak);
-            }
-            "udta" => {
-                start = (s as u32 - HEADER_SIZE) as u64;
-            }
-            _ => break
-        }
-    }
-    Ok(moov)
-}
-
-fn parse_mvhd_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<MvhdBox> {
-    let current =  f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
-
-    let version = f.read_u8().unwrap();
-    let flags_a = f.read_u8().unwrap();
-    let flags_b = f.read_u8().unwrap();
-    let flags_c = f.read_u8().unwrap();
-    let flags = u32::from(flags_a) << 16 | u32::from(flags_b) << 8 | u32::from(flags_c);
-    let creation_time = f.read_u32::<BigEndian>().unwrap();
-    let modification_time = f.read_u32::<BigEndian>().unwrap();
-    let timescale = f.read_u32::<BigEndian>().unwrap();
-    let duration = f.read_u32::<BigEndian>().unwrap();
-    let rate = f.read_u32::<BigEndian>().unwrap();
-
-    // Skip remaining bytes.
-    let after =  f.seek(SeekFrom::Current(0)).unwrap();
-    let remaining_bytes = (size as u64 - (after - current)) as i64;
-    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
-
-    Ok(MvhdBox{
-        version,
-        flags,
-        creation_time,
-        modification_time,
-        timescale,
-        duration,
-        rate,
-    })
-}
-
-fn parse_trak_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<TrakBox> {
-    let current =  f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
-    let mut trak = TrakBox::new();
-
-    let start = 0u64;
-    while start < size as u64 {
-        // Get box header.
-         let header = read_box_header(f, start).unwrap();
-         let BoxHeader{ name, size: s, offset } = header;
-
-         let mut b = BMFFBox::new();
-         b.head = BoxHeader{
-             name: name.try_into().unwrap(),
-             size: s as u64,
-             offset: offset as u64,
-         };
-
-         match b.head.name.as_ref() {
-             "tkhd" => {
-                 let tkhd = parse_tkhd_box(f, 0, s as u32).unwrap();
-                 trak.tkhd = Some(tkhd);
-             }
-             "edts" => {
-                 let edts = parse_edts_box(f, 0, s as u32).unwrap();
-                 trak.edts = Some(edts);
-             }
-             "mdia" => {
-                 let mdia = parse_mdia_box(f, 0, s as u32).unwrap();
-                 trak.mdia = Some(mdia);
-             }
-             _ => break
-         }
-    }
-
-    // Skip remaining bytes.
-    let after =  f.seek(SeekFrom::Current(0)).unwrap();
-    let remaining_bytes = (size as u64 - (after - current)) as i64;
-    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
-    Ok(trak)
-}
-
-
-fn parse_tkhd_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<TkhdBox> {
-    let current =  f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
-
-    let version = f.read_u8().unwrap();
-    let flags_a = f.read_u8().unwrap();
-    let flags_b = f.read_u8().unwrap();
-    let flags_c = f.read_u8().unwrap();
-    let flags = u32::from(flags_a) << 16 | u32::from(flags_b) << 8 | u32::from(flags_c);
-    let creation_time = f.read_u32::<BigEndian>().unwrap();
-    let modification_time = f.read_u32::<BigEndian>().unwrap();
-    let track_id = f.read_u32::<BigEndian>().unwrap();
-    let duration = f.read_u64::<BigEndian>().unwrap();
-    f.read_u64::<BigEndian>().unwrap(); // skip.
-    let layer = f.read_u16::<BigEndian>().unwrap();
-    let alternate_group = f.read_u16::<BigEndian>().unwrap();
-    let volume = f.read_u16::<BigEndian>().unwrap() >> 8;
-
-    f.read_u8().unwrap(); // skip.
-    let matrix = Matrix{
-        a: f.read_i32::<byteorder::LittleEndian>().unwrap(),
-        b: f.read_i32::<BigEndian>().unwrap(),
-        u: f.read_i32::<BigEndian>().unwrap(),
-        c: f.read_i32::<BigEndian>().unwrap(),
-        d: f.read_i32::<BigEndian>().unwrap(),
-        v: f.read_i32::<BigEndian>().unwrap(),
-        x: f.read_i32::<BigEndian>().unwrap(),
-        y: f.read_i32::<BigEndian>().unwrap(),
-        w: f.read_i32::<BigEndian>().unwrap(),
-    };
-
-    let width = f.read_u32::<BigEndian>().unwrap() >> 8;
-    let height = f.read_u32::<BigEndian>().unwrap() >> 8;
-
-    // Skip remaining bytes.
-    let after =  f.seek(SeekFrom::Current(0)).unwrap();
-    let remaining_bytes = (size as u64 - (after - current)) as i64;
-    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
-
-    Ok(TkhdBox {
-        version,
-        flags,
-        creation_time,
-        modification_time,
-        track_id,
-        duration,
-        layer,
-        alternate_group,
-        volume,
-        matrix,
-        width,
-        height,
-    })
-}
-
-fn parse_edts_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<EdtsBox> {
-    let current =  f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
-    let mut edts = EdtsBox::new();
-
-    let start = 0u64;
-    while start < size as u64 {
-        // Get box header.
-        let header = read_box_header(f, start).unwrap();
-        let BoxHeader{ name, size: s, offset } = header;
-
-        let mut b = BMFFBox::new();
-        b.head = BoxHeader{
-            name: name.try_into().unwrap(),
-            size: s as u64,
-            offset: offset as u64,
-        };
-
-        match b.head.name.as_ref() {
-            "elst" => {
-                let elst = parse_elst_box(f, 0, s as u32).unwrap();
-                edts.elst = Some(elst);
-            }
-            _ => break
-        }
-    }
-
-    // Skip remaining bytes.
-    let after =  f.seek(SeekFrom::Current(0)).unwrap();
-    let remaining_bytes = (size as u64 - (after - current)) as i64;
-    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
-    Ok(edts)
-}
-
-fn parse_elst_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<ElstBox> {
-    let current = f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
-
-    let version = f.read_u32::<BigEndian>().unwrap();
-    let entry_count = f.read_u32::<BigEndian>().unwrap();
-
-    let mut entries = Vec::new();
-
-    for _i in 0..entry_count {
-        let entry = ElstEntry{
-            segment_duration: f.read_u32::<BigEndian>().unwrap(),
-            media_time: f.read_u32::<BigEndian>().unwrap(),
-            media_rate: f.read_u16::<BigEndian>().unwrap(),
-            media_rate_fraction: f.read_u16::<BigEndian>().unwrap(),
-        };
-        entries.push(entry);
-    }
-
-    // Skip remaining bytes.
-    let after =  f.seek(SeekFrom::Current(0)).unwrap();
-    let remaining_bytes = (size as u64 - (after - current)) as i64;
-    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
-
-    Ok(ElstBox {
-        version,
-        entry_count,
-        entries,
-    })
-}
-
-fn parse_mdia_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<MdiaBox> {
-    let current =  f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
-    let mut mdia = MdiaBox::new();
-
-    let start = 0u64;
-    while start < size as u64 {
-        // Get box header.
-        let header = read_box_header(f, start).unwrap();
-        let BoxHeader{ name, size: s, offset } = header;
-
-        let mut b = BMFFBox::new();
-        b.head = BoxHeader{
-            name: name.try_into().unwrap(),
-            size: s as u64,
-            offset: offset as u64,
-        };
-
-        match b.head.name.as_ref() {
-            "mdhd" => {
-                let mdhd = parse_mdhd_box(f, 0, s as u32).unwrap();
-                mdia.mdhd = Some(mdhd);
-            }
-            "hdlr" => {
-                let hdlr = parse_hdlr_box(f, 0, s as u32).unwrap();
-                mdia.hdlr = Some(hdlr);
-            }
-            "minf" => {
-                let minf = parse_minf_box(f, 0, s as u32).unwrap();
-                mdia.minf = Some(minf);
-            }
-            _ => break
-        }
-    }
-
-    // Skip remaining bytes.
-    let after =  f.seek(SeekFrom::Current(0)).unwrap();
-    let remaining_bytes = (size as u64 - (after - current)) as i64;
-    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
-    Ok(mdia)
-}
-
-fn parse_mdhd_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<MdhdBox> {
-    let current = f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
-
-    let version = f.read_u8().unwrap();
-    let flags_a = f.read_u8().unwrap();
-    let flags_b = f.read_u8().unwrap();
-    let flags_c = f.read_u8().unwrap();
-    let flags = u32::from(flags_a) << 16 | u32::from(flags_b) << 8 | u32::from(flags_c);
-    let creation_time = f.read_u32::<BigEndian>().unwrap();
-    let modification_time = f.read_u32::<BigEndian>().unwrap();
-    let timescale = f.read_u32::<BigEndian>().unwrap();
-    let duration = f.read_u32::<BigEndian>().unwrap();
-    let language = f.read_u16::<BigEndian>().unwrap();
-    let language_string = get_language_string(language);
-
-    // Skip remaining bytes.
-    let after =  f.seek(SeekFrom::Current(0)).unwrap();
-    let remaining_bytes = (size as u64 - (after - current)) as i64;
-    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
-
-    Ok(MdhdBox {
-        version,
-        flags,
-        creation_time,
-        modification_time,
-        timescale,
-        duration,
-        language,
-        language_string,
-    })
-}
-
-fn get_language_string(language: u16) -> String {
-    let mut lang: [u16; 3] = [0; 3];
-
-    lang[0] = ((language >> 10) & 0x1F) + 0x60;
-    lang[1] = ((language >> 5) & 0x1F) + 0x60;
-    lang[2] = ((language) & 0x1F) + 0x60;
-
-    // Decode utf-16 encoded bytes into a string.
-    let lang_str = decode_utf16(lang.iter().cloned())
-        .map(|r| r.unwrap_or(REPLACEMENT_CHARACTER))
-        .collect::<String>();
-
-    return lang_str;
-}
-
-fn parse_hdlr_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<HdlrBox> {
-    let current = f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
-
-    let version = f.read_u8().unwrap();
-    let flags_a = f.read_u8().unwrap();
-    let flags_b = f.read_u8().unwrap();
-    let flags_c = f.read_u8().unwrap();
-    let flags = u32::from(flags_a) << 16 | u32::from(flags_b) << 8 | u32::from(flags_c);
-    f.read_u32::<BigEndian>().unwrap(); // skip.
-    let handler = f.read_u32::<BigEndian>().unwrap();
-
-    let n = f.seek(SeekFrom::Current(12)).unwrap(); // 12 bytes reserved.
-    let buf_size = (size as u64 - (n - current)) - HEADER_SIZE as u64;
-    let mut buf = vec![0u8; buf_size as usize];
-    f.read_exact(&mut buf).unwrap();
-
-    let handler_string = match String::from_utf8(buf) {
-        Ok(t) => t,
-        _ => String::from("null"),
-    };
-
-    // Skip remaining bytes.
-    let after = f.seek(SeekFrom::Current(0)).unwrap();
-    let remaining_bytes = (size as u64 - (after - current)) as i64;
-    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
-
-    Ok(HdlrBox {
-        version,
-        flags,
-        handler_type: From::from(handler),
-        name: handler_string,
-    })
-}
-
-fn parse_minf_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<MinfBox> {
-    let current =  f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
-    let mut minf = MinfBox::new();
-
-    let mut start = 0u64;
-    while start < size as u64 {
-        // Get box header.
-        let header = read_box_header(f, start).unwrap();
-        let BoxHeader{ name, size: s, offset } = header;
-
-        let mut b = BMFFBox::new();
-        b.head = BoxHeader{
-            name: name.try_into().unwrap(),
-            size: s as u64,
-            offset: offset as u64,
-        };
-
-        match b.head.name.as_ref() {
-            "vmhd" => {
-                let vmhd = parse_vmhd_box(f, 0, s as u32).unwrap();
-                minf.vmhd = Some(vmhd);
-            }
-            "smhd" => {
-                start = (s as u32 - HEADER_SIZE) as u64;
-            }
-            "dinf" => {
-                start = (s as u32 - HEADER_SIZE) as u64;
-            }
-            "stbl" => {
-                let stbl = parse_stbl_box(f, 0, s as u32).unwrap();
-                minf.stbl = Some(stbl);
-            }
-            _ => break
-        }
-    }
-
-    // Skip remaining bytes.
-    let after =  f.seek(SeekFrom::Current(0)).unwrap();
-    let remaining_bytes = (size as u64 - (after - current)) as i64;
-    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
-    Ok(minf)
-}
-
-fn parse_vmhd_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<VmhdBox> {
-    let current = f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
-
-    let version = f.read_u8().unwrap();
-    let flags_a = f.read_u8().unwrap();
-    let flags_b = f.read_u8().unwrap();
-    let flags_c = f.read_u8().unwrap();
-    let flags = u32::from(flags_a) << 16 | u32::from(flags_b) << 8 | u32::from(flags_c);
-//    let flags = f.read_u32::<BigEndian>().unwrap();
-    let graphics_mode = f.read_u16::<BigEndian>().unwrap();
-    let op_color = f.read_u16::<BigEndian>().unwrap();
-
-    // Skip remaining bytes.
-    let after = f.seek(SeekFrom::Current(0)).unwrap();
-    let remaining_bytes = (size as u64 - (after - current)) as i64;
-    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
-
-    Ok(VmhdBox {
-        version,
-        flags,
-        graphics_mode,
-        op_color,
-    })
-}
-
-fn parse_stbl_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<StblBox> {
-    let mut stbl = StblBox::new();
-
-    let start = 0u64;
-    while start < size as u64 {
-        // Get box header.
-        let header = read_box_header(f, start).unwrap();
-        let BoxHeader{ name, size: s, offset } = header;
-
-        let mut b = BMFFBox::new();
-        b.head = BoxHeader{
-            name: name.try_into().unwrap(),
-            size: s as u64,
-            offset: offset as u64,
-        };
-
-        match b.head.name.as_ref() {
-            "stsd" => {
-                let stsd = parse_stsd_box(f, 0, s as u32).unwrap();
-                stbl.stsd = Some(stsd);
-            }
-            "stts" => {
-                let stts = parse_stts_box(f, 0, s as u32).unwrap();
-                stbl.stts = Some(stts);
-            }
-            _ => break
-        }
-    }
-    Ok(stbl)
-}
-
-fn parse_stts_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<SttsBox> {
-    let current = f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
-
-    let version = f.read_u8().unwrap();
-    let flags_a = f.read_u8().unwrap();
-    let flags_b = f.read_u8().unwrap();
-    let flags_c = f.read_u8().unwrap();
-    let flags = u32::from(flags_a) << 16 | u32::from(flags_b) << 8 | u32::from(flags_c);
-    let entry_count = f.read_u32::<BigEndian>().unwrap();
-    let mut sample_counts = Vec::new();
-    let mut sample_deltas = Vec::new();
-
-    for _i in 0..entry_count {
-        let sc = f.read_u32::<BigEndian>().unwrap();
-        let sd = f.read_u32::<BigEndian>().unwrap();
-        sample_counts.push(sc);
-        sample_deltas.push(sd);
-    }
-
-    // Skip remaining bytes.
-    let after = f.seek(SeekFrom::Current(0)).unwrap();
-    let remaining_bytes = (size as u64 - (after - current)) as i64;
-    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
-
-    Ok(SttsBox {
-        version,
-        flags,
-        entry_count,
-        sample_counts,
-        sample_deltas,
-    })
-}
-
-fn parse_stsd_box(f: &mut BufReader<File>, _offset: u64, size: u32) -> Result<StsdBox> {
-    let current = f.seek(SeekFrom::Current(0)).unwrap(); // Current cursor position.
-
-    let version = f.read_u8().unwrap();
-    let flags_a = f.read_u8().unwrap();
-    let flags_b = f.read_u8().unwrap();
-    let flags_c = f.read_u8().unwrap();
-    let flags = u32::from(flags_a) << 16 | u32::from(flags_b) << 8 | u32::from(flags_c);
-    f.read_u32::<BigEndian>().unwrap(); // skip.
-
-    let mut start = 0u64;
-    while start < size as u64 {
-        // Get box header.
-        let header = read_box_header(f, start).unwrap();
-        let BoxHeader{ name, size: s, offset } = header;
-
-        let mut b = BMFFBox::new();
-        b.head = BoxHeader{
-            name: name.try_into().unwrap(),
-            size: s as u64,
-            offset: offset as u64,
-        };
-
-        match b.head.name.as_ref() {
-            "avc1" => {
-//                println!("found avc1");
-                start = (s as u32 - HEADER_SIZE) as u64;
-            }
-            "mp4a" => {
-//                println!("found mp4a");
-                start = (s as u32 - HEADER_SIZE) as u64;
-            }
-            _ => break
-        }
-    }
-
-    // Skip remaining bytes.
-    let after = f.seek(SeekFrom::Current(0)).unwrap();
-    let remaining_bytes = (size as u64 - (after - current)) as i64;
-    f.seek(SeekFrom::Current(remaining_bytes - HEADER_SIZE as i64)).unwrap();
-    Ok(StsdBox {
-        version,
-        flags,
-    })
-}