diff --git a/gst-plugin-flv/src/flvdemux.rs b/gst-plugin-flv/src/flvdemux.rs
index 7feed304..553aeb81 100644
--- a/gst-plugin-flv/src/flvdemux.rs
+++ b/gst-plugin-flv/src/flvdemux.rs
@@ -16,6 +16,7 @@
 //  Boston, MA 02110-1301, USA.
 
 use std::cmp;
+use std::io::{Write, Cursor};
 
 use nom;
 use nom::IResult;
@@ -31,6 +32,7 @@ use gst_plugin::utils::Element;
 use gst_plugin::log::*;
 use gst_plugin::caps::Caps;
 use gst_plugin::caps;
+use gst_plugin::bytes::*;
 
 use slog::*;
 
@@ -195,8 +197,42 @@ impl AudioFormat {
                 })
             }
             flavors::SoundFormat::SPEEX => {
-                // TODO: This requires creating a Speex streamheader...
-                None
+                let mut header = Buffer::new_with_size(80).unwrap();
+                {
+                    let mut map = header.map_readwrite().unwrap();
+                    let mut data = Cursor::new(map.as_mut_slice());
+                    data.write(b"Speex   1.1.12").unwrap();
+                    data.write(&[0; 14]).unwrap();
+                    data.write_u32le(1).unwrap(); // version
+                    data.write_u32le(80).unwrap(); // header size
+                    data.write_u32le(16000).unwrap(); // sample rate
+                    data.write_u32le(1).unwrap(); // mode = wideband
+                    data.write_u32le(4).unwrap(); // mode bitstream version
+                    data.write_u32le(1).unwrap(); // channels
+                    data.write_i32le(-1).unwrap(); // bitrate
+                    data.write_u32le(0x50).unwrap(); // frame size
+                    data.write_u32le(0).unwrap(); // VBR
+                    data.write_u32le(1).unwrap(); // frames per packet
+                    data.write_u32le(0).unwrap(); // extra headers
+                    data.write_u32le(0).unwrap(); // reserved 1
+                    data.write_u32le(0).unwrap(); // reserved 2
+                }
+
+                let comment_size = 4 + 7 /* nothing */ + 4 + 1;
+
+                let mut comment = Buffer::new_with_size(comment_size).unwrap();
+                {
+                    let mut map = comment.map_readwrite().unwrap();
+                    let mut data = Cursor::new(map.as_mut_slice());
+                    data.write_u32le(7).unwrap(); // length of "nothing"
+                    data.write(b"nothing").unwrap(); // "vendor" string
+                    data.write_u32le(0).unwrap(); // number of elements
+                    data.write_u8(1);
+                }
+                Some(Caps::new_simple("audio/x-speex",
+                                      &[("streamheader",
+                                         &caps::Value::Array(vec![caps::Value::Buffer(header),
+                                                                  caps::Value::Buffer(comment)]))]))
             }
             flavors::SoundFormat::DEVICE_SPECIFIC => {
                 // Nobody knows
diff --git a/gst-plugin/Cargo.toml b/gst-plugin/Cargo.toml
index f25849f0..15415636 100644
--- a/gst-plugin/Cargo.toml
+++ b/gst-plugin/Cargo.toml
@@ -12,6 +12,7 @@ url = "1.1"
 bitflags = "0.7"
 slog = { version = "1.3", features = ["max_level_trace"] }
 lazy_static = "0.2"
+byteorder = "1.0"
 
 [build-dependencies]
 gcc = "0.3"
diff --git a/gst-plugin/src/bytes.rs b/gst-plugin/src/bytes.rs
new file mode 100644
index 00000000..8590885a
--- /dev/null
+++ b/gst-plugin/src/bytes.rs
@@ -0,0 +1,149 @@
+//  Copyright (C) 2016 Sebastian Dröge <sebastian@centricular.com>
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Library General Public
+//  License as published by the Free Software Foundation; either
+//  version 2 of the License, or (at your option) any later version.
+//
+//  This library is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+//  Library General Public License for more details.
+//
+//  You should have received a copy of the GNU Library General Public
+//  License along with this library; if not, write to the
+//  Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+//  Boston, MA 02110-1301, USA.
+
+pub use byteorder::{ReadBytesExt, WriteBytesExt, LittleEndian, BigEndian};
+use std::io;
+
+pub trait ReadBytesExtShort: io::Read {
+    fn read_u16le(&mut self) -> io::Result<u16> {
+        self.read_u16::<LittleEndian>()
+    }
+    fn read_i16le(&mut self) -> io::Result<i16> {
+        self.read_i16::<LittleEndian>()
+    }
+    fn read_u32le(&mut self) -> io::Result<u32> {
+        self.read_u32::<LittleEndian>()
+    }
+    fn read_i32le(&mut self) -> io::Result<i32> {
+        self.read_i32::<LittleEndian>()
+    }
+    fn read_u64le(&mut self) -> io::Result<u64> {
+        self.read_u64::<LittleEndian>()
+    }
+    fn read_i64le(&mut self) -> io::Result<i64> {
+        self.read_i64::<LittleEndian>()
+    }
+    fn read_uintle(&mut self, nbytes: usize) -> io::Result<u64> {
+        self.read_uint::<LittleEndian>(nbytes)
+    }
+    fn read_intle(&mut self, nbytes: usize) -> io::Result<i64> {
+        self.read_int::<LittleEndian>(nbytes)
+    }
+    fn read_f32le(&mut self) -> io::Result<f32> {
+        self.read_f32::<LittleEndian>()
+    }
+    fn read_f64le(&mut self) -> io::Result<f64> {
+        self.read_f64::<LittleEndian>()
+    }
+    fn read_u16be(&mut self) -> io::Result<u16> {
+        self.read_u16::<BigEndian>()
+    }
+    fn read_i16be(&mut self) -> io::Result<i16> {
+        self.read_i16::<BigEndian>()
+    }
+    fn read_u32be(&mut self) -> io::Result<u32> {
+        self.read_u32::<BigEndian>()
+    }
+    fn read_i32be(&mut self) -> io::Result<i32> {
+        self.read_i32::<BigEndian>()
+    }
+    fn read_u64be(&mut self) -> io::Result<u64> {
+        self.read_u64::<BigEndian>()
+    }
+    fn read_i64be(&mut self) -> io::Result<i64> {
+        self.read_i64::<BigEndian>()
+    }
+    fn read_uintbe(&mut self, nbytes: usize) -> io::Result<u64> {
+        self.read_uint::<BigEndian>(nbytes)
+    }
+    fn read_intbe(&mut self, nbytes: usize) -> io::Result<i64> {
+        self.read_int::<BigEndian>(nbytes)
+    }
+    fn read_f32be(&mut self) -> io::Result<f32> {
+        self.read_f32::<BigEndian>()
+    }
+    fn read_f64be(&mut self) -> io::Result<f64> {
+        self.read_f64::<BigEndian>()
+    }
+}
+
+impl<T> ReadBytesExtShort for T where T: ReadBytesExt {}
+
+pub trait WriteBytesExtShort: WriteBytesExt {
+    fn write_u16le(&mut self, n: u16) -> io::Result<()> {
+        self.write_u16::<LittleEndian>(n)
+    }
+    fn write_i16le(&mut self, n: i16) -> io::Result<()> {
+        self.write_i16::<LittleEndian>(n)
+    }
+    fn write_u32le(&mut self, n: u32) -> io::Result<()> {
+        self.write_u32::<LittleEndian>(n)
+    }
+    fn write_i32le(&mut self, n: i32) -> io::Result<()> {
+        self.write_i32::<LittleEndian>(n)
+    }
+    fn write_u64le(&mut self, n: u64) -> io::Result<()> {
+        self.write_u64::<LittleEndian>(n)
+    }
+    fn write_i64le(&mut self, n: i64) -> io::Result<()> {
+        self.write_i64::<LittleEndian>(n)
+    }
+    fn write_uintle(&mut self, n: u64, nbytes: usize) -> io::Result<()> {
+        self.write_uint::<LittleEndian>(n, nbytes)
+    }
+    fn write_intle(&mut self, n: i64, nbytes: usize) -> io::Result<()> {
+        self.write_int::<LittleEndian>(n, nbytes)
+    }
+    fn write_f32le(&mut self, n: f32) -> io::Result<()> {
+        self.write_f32::<LittleEndian>(n)
+    }
+    fn write_f64le(&mut self, n: f64) -> io::Result<()> {
+        self.write_f64::<LittleEndian>(n)
+    }
+    fn write_u16be(&mut self, n: u16) -> io::Result<()> {
+        self.write_u16::<BigEndian>(n)
+    }
+    fn write_i16be(&mut self, n: i16) -> io::Result<()> {
+        self.write_i16::<BigEndian>(n)
+    }
+    fn write_u32be(&mut self, n: u32) -> io::Result<()> {
+        self.write_u32::<BigEndian>(n)
+    }
+    fn write_i32be(&mut self, n: i32) -> io::Result<()> {
+        self.write_i32::<BigEndian>(n)
+    }
+    fn write_u64be(&mut self, n: u64) -> io::Result<()> {
+        self.write_u64::<BigEndian>(n)
+    }
+    fn write_i64be(&mut self, n: i64) -> io::Result<()> {
+        self.write_i64::<BigEndian>(n)
+    }
+    fn write_uintbe(&mut self, n: u64, nbytes: usize) -> io::Result<()> {
+        self.write_uint::<BigEndian>(n, nbytes)
+    }
+    fn write_intbe(&mut self, n: i64, nbytes: usize) -> io::Result<()> {
+        self.write_int::<BigEndian>(n, nbytes)
+    }
+    fn write_f32be(&mut self, n: f32) -> io::Result<()> {
+        self.write_f32::<BigEndian>(n)
+    }
+    fn write_f64be(&mut self, n: f64) -> io::Result<()> {
+        self.write_f64::<BigEndian>(n)
+    }
+}
+
+impl<T> WriteBytesExtShort for T where T: WriteBytesExt {}
diff --git a/gst-plugin/src/caps.rs b/gst-plugin/src/caps.rs
index cc1ea66f..a154380d 100644
--- a/gst-plugin/src/caps.rs
+++ b/gst-plugin/src/caps.rs
@@ -20,18 +20,18 @@ use std::os::raw::c_void;
 use std::ffi::CString;
 use std::ffi::CStr;
 use std::mem;
-use std::borrow::Cow;
 use std::fmt;
 
 use buffer::*;
 
 #[derive(Debug, PartialEq, Eq, Clone)]
-pub enum Value<'a> {
+pub enum Value {
     Bool(bool),
     Int(i32),
-    String(Cow<'a, str>),
+    String(String),
     Fraction(i32, i32),
     Buffer(Buffer),
+    Array(Vec<Value>),
 }
 
 pub struct Caps(*mut c_void);
@@ -47,6 +47,75 @@ const TYPE_BOOLEAN: usize = (5 << 2);
 const TYPE_INT: usize = (6 << 2);
 const TYPE_STRING: usize = (16 << 2);
 
+impl Value {
+    fn to_gvalue(&self) -> GValue {
+        extern "C" {
+            fn g_value_init(value: *mut GValue, gtype: usize);
+            fn g_value_set_boolean(value: *mut GValue, value: i32);
+            fn g_value_set_int(value: *mut GValue, value: i32);
+            fn g_value_set_string(value: *mut GValue, value: *const c_char);
+            fn gst_value_set_fraction(value: *mut GValue, value_n: i32, value_d: i32);
+            fn gst_fraction_get_type() -> usize;
+            fn g_value_set_boxed(value: *mut GValue, boxed: *const c_void);
+            fn gst_buffer_get_type() -> usize;
+            fn gst_value_array_get_type() -> usize;
+            fn gst_value_array_append_and_take_value(value: *mut GValue, element: *mut GValue);
+        }
+
+        let mut gvalue: GValue = unsafe { mem::zeroed() };
+
+        match *self {
+            Value::Bool(v) => unsafe {
+                g_value_init(&mut gvalue as *mut GValue, TYPE_BOOLEAN);
+                g_value_set_boolean(&mut gvalue as *mut GValue, if v { 1 } else { 0 });
+            },
+            Value::Int(v) => unsafe {
+                g_value_init(&mut gvalue as *mut GValue, TYPE_INT);
+                g_value_set_int(&mut gvalue as *mut GValue, v);
+            },
+            Value::String(ref v) => unsafe {
+                let v_cstr = CString::new(String::from(v.clone())).unwrap();
+
+                g_value_init(&mut gvalue as *mut GValue, TYPE_STRING);
+                g_value_set_string(&mut gvalue as *mut GValue, v_cstr.as_ptr());
+            },
+            Value::Fraction(v_n, v_d) => unsafe {
+                g_value_init(&mut gvalue as *mut GValue, gst_fraction_get_type());
+                gst_value_set_fraction(&mut gvalue as *mut GValue, v_n, v_d);
+            },
+            Value::Buffer(ref buffer) => unsafe {
+                g_value_init(&mut gvalue as *mut GValue, gst_buffer_get_type());
+                g_value_set_boxed(&mut gvalue as *mut GValue, buffer.as_ptr());
+            },
+            Value::Array(ref array) => unsafe {
+                g_value_init(&mut gvalue as *mut GValue, gst_value_array_get_type());
+
+                for e in array {
+                    let mut e_value = e.to_gvalue();
+                    gst_value_array_append_and_take_value(&mut gvalue as *mut GValue,
+                                                          &mut e_value as *mut GValue);
+                    // Takes ownership, invalidate GValue
+                    e_value.typ = 0;
+                }
+            },
+        }
+
+        gvalue
+    }
+}
+
+impl Drop for GValue {
+    fn drop(&mut self) {
+        extern "C" {
+            fn g_value_unset(value: *mut GValue);
+        }
+
+        if self.typ != 0 {
+            unsafe { g_value_unset(self as *mut GValue) }
+        }
+    }
+}
+
 impl Caps {
     pub fn new_empty() -> Self {
         extern "C" {
@@ -64,7 +133,7 @@ impl Caps {
         Caps(unsafe { gst_caps_new_any() })
     }
 
-    pub fn new_simple<'a>(name: &str, values: &[(&'a str, &'a Value<'a>)]) -> Self {
+    pub fn new_simple(name: &str, values: &[(&str, &Value)]) -> Self {
         extern "C" {
             fn gst_caps_append_structure(caps: *mut c_void, structure: *mut c_void);
             fn gst_structure_new_empty(name: *const c_char) -> *mut c_void;
@@ -103,54 +172,14 @@ impl Caps {
     pub fn set_simple(&mut self, values: &[(&str, &Value)]) {
         extern "C" {
             fn gst_caps_set_value(caps: *mut c_void, name: *const c_char, value: *const GValue);
-            fn g_value_init(value: *mut GValue, gtype: usize);
-            fn g_value_unset(value: *mut GValue);
-            fn g_value_set_boolean(value: *mut GValue, value: i32);
-            fn g_value_set_int(value: *mut GValue, value: i32);
-            fn g_value_set_string(value: *mut GValue, value: *const c_char);
-            fn gst_value_set_fraction(value: *mut GValue, value_n: i32, value_d: i32);
-            fn gst_fraction_get_type() -> usize;
-            fn g_value_set_boxed(value: *mut GValue, boxed: *const c_void);
-            fn gst_buffer_get_type() -> usize;
         }
 
         for value in values {
             let name_cstr = CString::new(value.0).unwrap();
-            let mut gvalue: GValue = unsafe { mem::zeroed() };
+            let mut gvalue = value.1.to_gvalue();
 
-            match *value.1 {
-                Value::Bool(v) => unsafe {
-                    g_value_init(&mut gvalue as *mut GValue, TYPE_BOOLEAN);
-                    g_value_set_boolean(&mut gvalue as *mut GValue, if v { 1 } else { 0 });
-                    gst_caps_set_value(self.0, name_cstr.as_ptr(), &mut gvalue as *mut GValue);
-                    g_value_unset(&mut gvalue as *mut GValue);
-                },
-                Value::Int(v) => unsafe {
-                    g_value_init(&mut gvalue as *mut GValue, TYPE_INT);
-                    g_value_set_int(&mut gvalue as *mut GValue, v);
-                    gst_caps_set_value(self.0, name_cstr.as_ptr(), &mut gvalue as *mut GValue);
-                    g_value_unset(&mut gvalue as *mut GValue);
-                },
-                Value::String(ref v) => unsafe {
-                    let v_cstr = CString::new(String::from((*v).clone())).unwrap();
-
-                    g_value_init(&mut gvalue as *mut GValue, TYPE_STRING);
-                    g_value_set_string(&mut gvalue as *mut GValue, v_cstr.as_ptr());
-                    gst_caps_set_value(self.0, name_cstr.as_ptr(), &mut gvalue as *mut GValue);
-                    g_value_unset(&mut gvalue as *mut GValue);
-                },
-                Value::Fraction(v_n, v_d) => unsafe {
-                    g_value_init(&mut gvalue as *mut GValue, gst_fraction_get_type());
-                    gst_value_set_fraction(&mut gvalue as *mut GValue, v_n, v_d);
-                    gst_caps_set_value(self.0, name_cstr.as_ptr(), &mut gvalue as *mut GValue);
-                    g_value_unset(&mut gvalue as *mut GValue);
-                },
-                Value::Buffer(ref buffer) => unsafe {
-                    g_value_init(&mut gvalue as *mut GValue, gst_buffer_get_type());
-                    g_value_set_boxed(&mut gvalue as *mut GValue, buffer.as_ptr());
-                    gst_caps_set_value(self.0, name_cstr.as_ptr(), &mut gvalue as *mut GValue);
-                    g_value_unset(&mut gvalue as *mut GValue);
-                },
+            unsafe {
+                gst_caps_set_value(self.0, name_cstr.as_ptr(), &mut gvalue as *mut GValue);
             }
         }
     }
@@ -195,6 +224,16 @@ impl Clone for Caps {
     }
 }
 
+impl Drop for Caps {
+    fn drop(&mut self) {
+        extern "C" {
+            fn gst_mini_object_unref(mini_object: *mut c_void);
+        }
+
+        unsafe { gst_mini_object_unref(self.0) }
+    }
+}
+
 impl fmt::Debug for Caps {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.write_str(&self.to_string())
@@ -222,12 +261,14 @@ mod tests {
         init();
 
         let caps = Caps::new_simple("foo/bar",
-                                    vec![("int", &Value::Int(12)),
-                                         ("bool", &Value::Bool(true)),
-                                         ("string", &Value::String("bla".into())),
-                                         ("fraction", &Value::Fraction(1, 2))]);
+                                    &[("int", &Value::Int(12)),
+                                      ("bool", &Value::Bool(true)),
+                                      ("string", &Value::String("bla".into())),
+                                      ("fraction", &Value::Fraction(1, 2)),
+                                      ("array",
+                                       &Value::Array(vec![Value::Int(1), Value::Int(2)]))]);
         assert_eq!(caps.to_string(),
                    "foo/bar, int=(int)12, bool=(boolean)true, string=(string)bla, \
-                    fraction=(fraction)1/2");
+                    fraction=(fraction)1/2, array=(int)< 1, 2 >");
     }
 }
diff --git a/gst-plugin/src/lib.rs b/gst-plugin/src/lib.rs
index 147e19b0..07b64e83 100644
--- a/gst-plugin/src/lib.rs
+++ b/gst-plugin/src/lib.rs
@@ -24,6 +24,7 @@ extern crate bitflags;
 extern crate slog;
 #[macro_use]
 extern crate lazy_static;
+extern crate byteorder;
 
 #[macro_use]
 pub mod utils;
@@ -38,3 +39,4 @@ pub mod sink;
 pub mod demuxer;
 pub mod log;
 pub mod caps;
+pub mod bytes;