diff --git a/examples/mp4dump.rs b/examples/mp4dump.rs
index 4e4a7dd..48537d2 100644
--- a/examples/mp4dump.rs
+++ b/examples/mp4dump.rs
@@ -107,6 +107,17 @@ fn get_boxes(file: File) -> Result<Vec<Box>> {
             boxes.push(build_box(co64));
         }
     }
+
+    // If fragmented, add moof boxes.
+    for moof in mp4.moofs.iter() {
+        boxes.push(build_box(moof));
+        boxes.push(build_box(&moof.mfhd));
+        for traf in moof.trafs.iter() {
+            boxes.push(build_box(traf));
+            boxes.push(build_box(&traf.tfhd));
+        }
+    }
+
     Ok(boxes)
 }
 
diff --git a/examples/mp4info.rs b/examples/mp4info.rs
index 234548a..1d98c19 100644
--- a/examples/mp4info.rs
+++ b/examples/mp4info.rs
@@ -40,6 +40,7 @@ fn info<P: AsRef<Path>>(filename: &P) -> Result<()> {
     println!("  version:        {}", mp4.moov.mvhd.version);
     println!("  creation time:  {}", creation_time(mp4.moov.mvhd.creation_time));
     println!("  duration:       {:?}", mp4.duration());
+    println!("  fragments:      {:?}", mp4.is_fragmented());
     println!("  timescale:      {:?}\n", mp4.timescale());
 
     println!("Found {} Tracks", mp4.tracks().len());
@@ -56,7 +57,6 @@ fn info<P: AsRef<Path>>(filename: &P) -> Result<()> {
             media_info
         );
     }
-
     Ok(())
 }
 
@@ -70,7 +70,7 @@ fn video_info(track: &Mp4Track) -> Result<String> {
             track.width(),
             track.height(),
             track.bitrate() / 1000,
-            track.frame_rate_f64()
+            track.frame_rate()
         ))
     } else {
         Ok(format!(
@@ -80,7 +80,7 @@ fn video_info(track: &Mp4Track) -> Result<String> {
             track.width(),
             track.height(),
             track.bitrate() / 1000,
-            track.frame_rate_f64()
+            track.frame_rate()
         ))
     }
 }
diff --git a/src/mp4box/mfhd.rs b/src/mp4box/mfhd.rs
new file mode 100644
index 0000000..cbb4abc
--- /dev/null
+++ b/src/mp4box/mfhd.rs
@@ -0,0 +1,97 @@
+use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
+use std::io::{Read, Seek, Write};
+
+use crate::mp4box::*;
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct MfhdBox {
+    pub version: u8,
+    pub flags: u32,
+    pub sequence_number: u32,
+}
+
+impl Default for MfhdBox {
+    fn default() -> Self {
+        MfhdBox {
+            version: 0,
+            flags: 0,
+            sequence_number: 1,
+        }
+    }
+}
+
+impl MfhdBox {
+    pub fn get_type(&self) -> BoxType {
+        BoxType::MfhdBox
+    }
+
+    pub fn get_size(&self) -> u64 {
+        HEADER_SIZE + HEADER_EXT_SIZE + 4 
+    }
+}
+
+impl Mp4Box for MfhdBox {
+    fn box_type(&self) -> BoxType {
+        return self.get_type();
+    }
+
+    fn box_size(&self) -> u64 {
+        return self.get_size();
+    }
+}
+
+impl<R: Read + Seek> ReadBox<&mut R> for MfhdBox {
+    fn read_box(reader: &mut R, size: u64) -> Result<Self> {
+        let start = box_start(reader)?;
+
+        let (version, flags) = read_box_header_ext(reader)?;
+        let sequence_number = reader.read_u32::<BigEndian>()?;
+
+        skip_bytes_to(reader, start + size)?;
+
+        Ok(MfhdBox {
+            version,
+            flags,
+            sequence_number,
+        })
+    }
+}
+
+impl<W: Write> WriteBox<&mut W> for MfhdBox {
+    fn write_box(&self, writer: &mut W) -> Result<u64> {
+        let size = self.box_size();
+        BoxHeader::new(self.box_type(), size).write(writer)?;
+
+        write_box_header_ext(writer, self.version, self.flags)?;
+        writer.write_u32::<BigEndian>(self.sequence_number)?;
+
+        Ok(size)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::mp4box::BoxHeader;
+    use std::io::Cursor;
+
+    #[test]
+    fn test_mfhd() {
+        let src_box = MfhdBox {
+            version: 0,
+            flags: 0,
+            sequence_number: 1,
+        };
+        let mut buf = Vec::new();
+        src_box.write_box(&mut buf).unwrap();
+        assert_eq!(buf.len(), src_box.box_size() as usize);
+
+        let mut reader = Cursor::new(&buf);
+        let header = BoxHeader::read(&mut reader).unwrap();
+        assert_eq!(header.name, BoxType::MfhdBox);
+        assert_eq!(src_box.box_size(), header.size);
+
+        let dst_box = MfhdBox::read_box(&mut reader, header.size).unwrap();
+        assert_eq!(src_box, dst_box);
+    }
+}
diff --git a/src/mp4box/mod.rs b/src/mp4box/mod.rs
index a82aa5f..b0053cf 100644
--- a/src/mp4box/mod.rs
+++ b/src/mp4box/mod.rs
@@ -16,8 +16,10 @@ pub(crate) mod mdhd;
 pub(crate) mod mdia;
 pub(crate) mod minf;
 pub(crate) mod moov;
+pub(crate) mod moof;
 pub(crate) mod mp4a;
 pub(crate) mod mvhd;
+pub(crate) mod mfhd;
 pub(crate) mod smhd;
 pub(crate) mod stbl;
 pub(crate) mod stco;
@@ -27,11 +29,14 @@ pub(crate) mod stss;
 pub(crate) mod stsz;
 pub(crate) mod stts;
 pub(crate) mod tkhd;
+pub(crate) mod tfhd;
 pub(crate) mod trak;
+pub(crate) mod traf;
 pub(crate) mod vmhd;
 
 pub use ftyp::FtypBox;
 pub use moov::MoovBox;
+pub use moof::MoofBox;
 
 pub const HEADER_SIZE: u64 = 8;
 // const HEADER_LARGE_SIZE: u64 = 16;
@@ -68,11 +73,13 @@ macro_rules! boxtype {
 boxtype! {
     FtypBox => 0x66747970,
     MvhdBox => 0x6d766864,
+    MfhdBox => 0x6d666864,
     FreeBox => 0x66726565,
     MdatBox => 0x6d646174,
     MoovBox => 0x6d6f6f76,
     MoofBox => 0x6d6f6f66,
     TkhdBox => 0x746b6864,
+    TfhdBox => 0x74666864,
     EdtsBox => 0x65647473,
     MdiaBox => 0x6d646961,
     ElstBox => 0x656c7374,
@@ -90,6 +97,7 @@ boxtype! {
     StcoBox => 0x7374636F,
     Co64Box => 0x636F3634,
     TrakBox => 0x7472616b,
+    TrafBox => 0x74726166,
     UdtaBox => 0x75647461,
     DinfBox => 0x64696e66,
     SmhdBox => 0x736d6864,
diff --git a/src/mp4box/moof.rs b/src/mp4box/moof.rs
new file mode 100644
index 0000000..f9d9201
--- /dev/null
+++ b/src/mp4box/moof.rs
@@ -0,0 +1,90 @@
+use std::io::{Read, Seek, SeekFrom, Write};
+
+use crate::mp4box::*;
+use crate::mp4box::{mfhd::MfhdBox, traf::TrafBox};
+
+#[derive(Debug, Clone, PartialEq, Default)]
+pub struct MoofBox {
+    pub mfhd: MfhdBox,
+    pub trafs: Vec<TrafBox>,
+}
+
+impl MoofBox {
+    pub fn get_type(&self) -> BoxType {
+        BoxType::MoofBox
+    }
+
+    pub fn get_size(&self) -> u64 {
+        let mut size = HEADER_SIZE + self.mfhd.box_size();
+        for traf in self.trafs.iter() {
+            size += traf.box_size();
+        }
+        size
+    }
+}
+
+impl Mp4Box for MoofBox {
+    fn box_type(&self) -> BoxType {
+        return self.get_type();
+    }
+
+    fn box_size(&self) -> u64 {
+        return self.get_size();
+    }
+}
+
+impl<R: Read + Seek> ReadBox<&mut R> for MoofBox {
+    fn read_box(reader: &mut R, size: u64) -> Result<Self> {
+        let start = box_start(reader)?;
+
+        let mut mfhd = None;
+        let mut trafs = Vec::new();
+
+        let mut current = reader.seek(SeekFrom::Current(0))?;
+        let end = start + size;
+        while current < end {
+            // Get box header.
+            let header = BoxHeader::read(reader)?;
+            let BoxHeader { name, size: s } = header;
+
+            match name {
+                BoxType::MfhdBox => {
+                    mfhd = Some(MfhdBox::read_box(reader, s)?);
+                }
+                BoxType::TrafBox => {
+                    let traf = TrafBox::read_box(reader, s)?;
+                    trafs.push(traf);
+                }
+                _ => {
+                    // XXX warn!()
+                    skip_box(reader, s)?;
+                }
+            }
+            current = reader.seek(SeekFrom::Current(0))?;
+        }
+
+        if mfhd.is_none() {
+            return Err(Error::BoxNotFound(BoxType::MfhdBox));
+        }
+
+        skip_bytes_to(reader, start + size)?;
+
+        Ok(MoofBox {
+            mfhd: mfhd.unwrap(),
+            trafs,
+        })
+    }
+}
+
+impl<W: Write> WriteBox<&mut W> for MoofBox {
+    fn write_box(&self, writer: &mut W) -> Result<u64> {
+        let size = self.box_size();
+        BoxHeader::new(self.box_type(), size).write(writer)?;
+
+        self.mfhd.write_box(writer)?;
+        for traf in self.trafs.iter() {
+            traf.write_box(writer)?;
+        }
+        Ok(0)
+    }
+}
diff --git a/src/mp4box/tfhd.rs b/src/mp4box/tfhd.rs
new file mode 100644
index 0000000..cdc1464
--- /dev/null
+++ b/src/mp4box/tfhd.rs
@@ -0,0 +1,97 @@
+use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
+use std::io::{Read, Seek, Write};
+
+use crate::mp4box::*;
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct TfhdBox {
+    pub version: u8,
+    pub flags: u32,
+    pub track_id: u32,
+}
+
+impl Default for TfhdBox {
+    fn default() -> Self {
+        TfhdBox {
+            version: 0,
+            flags: 0,
+            track_id: 0,
+        }
+    }
+}
+
+impl TfhdBox {
+    pub fn get_type(&self) -> BoxType {
+        BoxType::TfhdBox
+    }
+
+    pub fn get_size(&self) -> u64 {
+        HEADER_SIZE + HEADER_EXT_SIZE + 4
+    }
+}
+
+impl Mp4Box for TfhdBox {
+    fn box_type(&self) -> BoxType {
+        return self.get_type();
+    }
+
+    fn box_size(&self) -> u64 {
+        return self.get_size();
+    }
+}
+
+impl<R: Read + Seek> ReadBox<&mut R> for TfhdBox {
+    fn read_box(reader: &mut R, size: u64) -> Result<Self> {
+        let start = box_start(reader)?;
+
+        let (version, flags) = read_box_header_ext(reader)?;
+        let track_id = reader.read_u32::<BigEndian>()?;
+
+        skip_bytes_to(reader, start + size)?;
+
+        Ok(TfhdBox {
+            version,
+            flags,
+            track_id,
+        })
+    }
+}
+
+impl<W: Write> WriteBox<&mut W> for TfhdBox {
+    fn write_box(&self, writer: &mut W) -> Result<u64> {
+        let size = self.box_size();
+        BoxHeader::new(self.box_type(), size).write(writer)?;
+
+        write_box_header_ext(writer, self.version, self.flags)?;
+        writer.write_u32::<BigEndian>(self.track_id)?;
+
+        Ok(size)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::mp4box::BoxHeader;
+    use std::io::Cursor;
+
+    #[test]
+    fn test_tfhd() {
+        let src_box = TfhdBox {
+            version: 0,
+            flags: 0,
+            track_id: 1,
+        };
+        let mut buf = Vec::new();
+        src_box.write_box(&mut buf).unwrap();
+        assert_eq!(buf.len(), src_box.box_size() as usize);
+
+        let mut reader = Cursor::new(&buf);
+        let header = BoxHeader::read(&mut reader).unwrap();
+        assert_eq!(header.name, BoxType::TfhdBox);
+        assert_eq!(src_box.box_size(), header.size);
+
+        let dst_box = TfhdBox::read_box(&mut reader, header.size).unwrap();
+        assert_eq!(src_box, dst_box);
+    }
+}
diff --git a/src/mp4box/traf.rs b/src/mp4box/traf.rs
new file mode 100644
index 0000000..c966dfe
--- /dev/null
+++ b/src/mp4box/traf.rs
@@ -0,0 +1,80 @@
+use std::io::{Read, Seek, SeekFrom, Write};
+
+use crate::mp4box::*;
+use crate::mp4box::{tfhd::TfhdBox};
+
+#[derive(Debug, Clone, PartialEq, Default)]
+pub struct TrafBox {
+    pub tfhd: TfhdBox,
+}
+
+impl TrafBox {
+    pub fn get_type(&self) -> BoxType {
+        BoxType::TrafBox
+    }
+
+    pub fn get_size(&self) -> u64 {
+        let mut size = HEADER_SIZE;
+        size += self.tfhd.box_size();
+        size
+    }
+}
+
+impl Mp4Box for TrafBox {
+    fn box_type(&self) -> BoxType {
+        return self.get_type();
+    }
+
+    fn box_size(&self) -> u64 {
+        return self.get_size();
+    }
+}
+
+impl<R: Read + Seek> ReadBox<&mut R> for TrafBox {
+    fn read_box(reader: &mut R, size: u64) -> Result<Self> {
+        let start = box_start(reader)?;
+
+        let mut tfhd = None;
+
+        let mut current = reader.seek(SeekFrom::Current(0))?;
+        let end = start + size;
+        while current < end {
+            // Get box header.
+            let header = BoxHeader::read(reader)?;
+            let BoxHeader { name, size: s } = header;
+
+            match name {
+                BoxType::TfhdBox => {
+                    tfhd = Some(TfhdBox::read_box(reader, s)?);
+                }
+                _ => {
+                    // XXX warn!()
+                    skip_box(reader, s)?;
+                }
+            }
+
+            current = reader.seek(SeekFrom::Current(0))?;
+        }
+
+        if tfhd.is_none() {
+            return Err(Error::BoxNotFound(BoxType::TfhdBox));
+        }
+
+        skip_bytes_to(reader, start + size)?;
+
+        Ok(TrafBox {
+            tfhd: tfhd.unwrap(),
+        })
+    }
+}
+
+impl<W: Write> WriteBox<&mut W> for TrafBox {
+    fn write_box(&self, writer: &mut W) -> Result<u64> {
+        let size = self.box_size();
+        BoxHeader::new(self.box_type(), size).write(writer)?;
+
+        self.tfhd.write_box(writer)?;
+
+        Ok(size)
+    }
+}
diff --git a/src/reader.rs b/src/reader.rs
index 7a58a9f..c2c46ba 100644
--- a/src/reader.rs
+++ b/src/reader.rs
@@ -9,6 +9,7 @@ pub struct Mp4Reader<R> {
     reader: R,
     pub ftyp: FtypBox,
     pub moov: MoovBox,
+    pub moofs: Vec<MoofBox>,
 
     tracks: Vec<Mp4Track>,
     size: u64,
@@ -20,6 +21,7 @@ impl<R: Read + Seek> Mp4Reader<R> {
 
         let mut ftyp = None;
         let mut moov = None;
+        let mut moofs = Vec::new();
 
         let mut current = start;
         while current < size {
@@ -42,7 +44,8 @@ impl<R: Read + Seek> Mp4Reader<R> {
                     moov = Some(MoovBox::read_box(&mut reader, s)?);
                 }
                 BoxType::MoofBox => {
-                    skip_box(&mut reader, s)?;
+                    let moof = MoofBox::read_box(&mut reader, s)?;
+                    moofs.push(moof);
                 }
                 _ => {
                     // XXX warn!()
@@ -75,6 +78,7 @@ impl<R: Read + Seek> Mp4Reader<R> {
             reader,
             ftyp: ftyp.unwrap(),
             moov: moov.unwrap(),
+            moofs,
             size,
             tracks,
         })
@@ -104,6 +108,14 @@ impl<R: Read + Seek> Mp4Reader<R> {
         self.moov.mvhd.timescale
     }
 
+    pub fn is_fragmented(&self) -> bool {
+        if self.moofs.len() != 0 {
+            true
+        } else {
+            false
+        }
+    }
+
     pub fn tracks(&self) -> &[Mp4Track] {
         &self.tracks
     }
diff --git a/src/track.rs b/src/track.rs
index bee3854..7800c46 100644
--- a/src/track.rs
+++ b/src/track.rs
@@ -131,19 +131,10 @@ impl Mp4Track {
         }
     }
 
-    pub fn frame_rate(&self) -> Ratio<u64> {
+    pub fn frame_rate(&self) -> f64 {
         let dur_msec = self.duration().as_millis() as u64;
         if dur_msec > 0 {
-            Ratio::new(self.sample_count() as u64 * 1_000, dur_msec)
-        } else {
-            Ratio::new(0, 0)
-        }
-    }
-
-    pub fn frame_rate_f64(&self) -> f64 {
-        let fr = self.frame_rate();
-        if fr.to_integer() > 0 {
-            *fr.numer() as f64 / *fr.denom() as f64
+            ((self.sample_count() as u64 * 1000) / dur_msec) as f64
         } else {
             0.0
         }
diff --git a/tests/lib.rs b/tests/lib.rs
index 1cc8a48..4208e3e 100644
--- a/tests/lib.rs
+++ b/tests/lib.rs
@@ -102,7 +102,7 @@ fn test_read_mp4() {
     assert_eq!(track1.width(), 320);
     assert_eq!(track1.height(), 240);
     assert_eq!(track1.bitrate(), 0); // XXX
-    assert_eq!(track1.frame_rate().to_integer(), 25); // XXX
+    assert_eq!(track1.frame_rate(), 25.00); // XXX
 
     // track #2
     let track2 = mp4.tracks().get(1).unwrap();