diff --git a/src/muxer/hls/mp4/atoms.rs b/src/muxer/hls/mp4/atoms.rs
index ccc9148..640c71a 100644
--- a/src/muxer/hls/mp4/atoms.rs
+++ b/src/muxer/hls/mp4/atoms.rs
@@ -1,3 +1,7 @@
+use std::sync::Arc;
+
+use crate::util;
+
 trait MP4Atom {
     fn size(&self) -> u32;
 
@@ -16,12 +20,38 @@ struct WindowMatrix {
     w: u32,
 }
 
+impl Default for WindowMatrix {
+    fn default() -> Self {
+        WindowMatrix {
+            a: 1 << 16,
+            b: 0,
+            u: 0,
+            c: 0,
+            d: 1 << 16,
+            v: 0,
+            x: 0,
+            y: 0,
+            w: 1 << 30,
+        }
+    }
+}
+
 struct Edits {
     duration: u64,
-    start: u64,
+    start: i64,
     play_rate: u32,
 }
 
+impl Default for Edits {
+    fn default() -> Self {
+        Edits {
+            duration: 0,
+            start: 0,
+            play_rate: 1 << 16,
+        }
+    }
+}
+
 pub struct MOOV {
     mvhd: MVHD,
     traks: [TRAK; 2],
@@ -41,6 +71,23 @@ struct MVHD {
     next_track_id: u32,
 }
 
+impl Default for MVHD {
+    fn default() -> Self {
+        MVHD {
+            version: 0,
+            flags: 0,
+            create_time: 0,
+            modify_time: 0,
+            time_scale: 1000,
+            duration: 0,
+            playrate: 1 << 16,
+            volume: 1 << 8,
+            matrix: WindowMatrix {..Default::default()},
+            next_track_id: 2,
+        }
+    }
+}
+
 struct TRAK {
     tkhd: TKHD,
     edts: EDTS,
@@ -53,7 +100,6 @@ struct TKHD {
     create_time: u64,
     modify_time: u64,
     track_id: u32,
-    time_scale: u32,
     duration: u64,
     layer: u16,
     alt_group: u16,
@@ -63,10 +109,35 @@ struct TKHD {
     height: u32,
 }
 
+impl Default for TKHD {
+    fn default() -> Self {
+        TKHD {
+            version: 0,
+            flags: 1,
+            create_time: 0,
+            modify_time: 0,
+            track_id: 0,
+            duration: 0,
+            layer: 0,
+            alt_group: 0,
+            volume: 0,
+            matrix: WindowMatrix {..Default::default()},
+            width: 0,
+            height: 0,
+        }
+    }
+}
+
 struct EDTS {
     elst: ELST,
 }
 
+impl Default for EDTS {
+    fn default() -> Self {
+        EDTS {elst: ELST {..Default::default()}}
+    }
+}
+
 struct ELST {
     version: u8,
     flags: u32,
@@ -74,6 +145,17 @@ struct ELST {
     edits: Vec<Edits>,
 }
 
+impl Default for ELST {
+    fn default() -> Self {
+        ELST {
+            version: 0,
+            flags: 0,
+            num_edits: 1,
+            edits: vec![Edits {..Default::default() }],
+        }
+    }
+}
+
 struct MDIA {
     mdhd: MDHD,
     hdlr: HDLR,
@@ -90,6 +172,20 @@ struct MDHD {
     language: u32,
 }
 
+impl Default for MDHD {
+    fn default() -> Self {
+        MDHD {
+            version: 0,
+            flags: 0,
+            create_time: 0,
+            modify_time: 0,
+            time_scale: 0,
+            duration: 0,
+            language: 21956,
+        }
+    }
+}
+
 struct HDLR {
     version: u8,
     flags: u32,
@@ -97,6 +193,17 @@ struct HDLR {
     name: String,
 }
 
+impl Default for HDLR {
+    fn default() -> Self {
+        HDLR {
+            version: 0,
+            flags: 0,
+            handler: 0,
+            name: String::from(""),
+        }
+    }
+}
+
 enum MINF {
     Video(MINF_V),
     Audio(MINF_A),
@@ -115,6 +222,17 @@ struct VMHD {
     opcolor: [u16; 3],
 }
 
+impl Default for VMHD {
+    fn default() -> Self {
+        VMHD {
+            version: 0,
+            flags: 0,
+            mode: 0,
+            opcolor: [0,0,0],
+        }
+    }
+}
+
 struct MINF_A {
     smhd: SMHD,
     dinf: DINF,
@@ -127,10 +245,28 @@ struct SMHD {
     balance: u16,
 }
 
+impl Default for SMHD {
+    fn default() -> Self {
+        SMHD {
+            version: 0,
+            flags: 0,
+            balance: 0,
+        }
+    }
+}
+
 struct DINF {
     dref: DREF,
 }
 
+impl Default for DINF {
+    fn default() -> Self {
+        DINF {
+            dref: DREF {..Default::default() },
+        }
+    }
+}
+
 struct DREF {
     version: u8,
     flags: u32,
@@ -138,6 +274,21 @@ struct DREF {
     refs: Vec<Refs>
 }
 
+impl Default for DREF {
+    fn default() -> Self {
+        DREF {
+            version: 0,
+            flags: 0,
+            num_refs: 1,
+            refs: vec![Refs::RefURL(URL {
+                version: 0,
+                flags: 1,
+                url: String::from(""),
+            })],
+        }
+    }
+}
+
 enum Refs {
     RefURL(URL),
     RefURN(URN),
@@ -207,6 +358,17 @@ struct STTS {
     entries: Vec<STTSEntry>,
 }
 
+impl Default for STTS {
+    fn default() -> Self {
+        STTS {
+            version: 0,
+            flags: 0,
+            num_entries: 0,
+            entries: Vec::new(),
+        }
+    }
+}
+
 struct STTSEntry {
     count_consec: u32,
     duration: u32,
@@ -219,6 +381,17 @@ struct STSC {
     entries: Vec<STSCEntry>,
 }
 
+impl Default for STSC {
+    fn default() -> Self {
+        STSC {
+            version: 0,
+            flags: 0,
+            num_entries: 0,
+            entries: Vec::new(),
+        }
+    }
+}
+
 struct STSCEntry {
     chunk_idx: u32,
     samples_per: u32,
@@ -233,6 +406,18 @@ struct STSZ {
     entries: Vec<u32>,
 }
 
+impl Default for STSZ {
+    fn default() -> Self {
+        STSZ {
+            version: 0,
+            flags: 0,
+            common_size: 0,
+            num_entries: 0,
+            entries: Vec::new(),
+        }
+    }
+}
+
 struct STCO {
     version: u8,
     flags: u32,
@@ -240,10 +425,29 @@ struct STCO {
     entries: Vec<u32>,
 }
 
+impl Default for STCO {
+    fn default() -> Self {
+        STCO {
+            version: 0,
+            flags: 0,
+            num_entries: 0,
+            entries: Vec::new(),
+        }
+    }
+}
+
 struct MVEX {
     trexs: [TREX; 2],
 }
 
+impl Default for MVEX {
+    fn default() -> Self {
+        MVEX {
+            trexs: [TREX {track_id: 1, ..Default::default()}, TREX{track_id: 2, ..Default::default()}],
+        }
+    }
+}
+
 struct TREX {
     version: u8,
     flags: u32,
@@ -254,3 +458,111 @@ struct TREX {
     default_flags: u32,
 }
 
+impl Default for TREX {
+    fn default() -> Self {
+        TREX {
+            version: 0,
+            flags: 0,
+            track_id: 0,
+            default_desc_idx: 1,
+            default_duration: 0,
+            default_size: 0,
+            default_flags: 0,
+        }
+    }
+}
+
+pub fn construct_moov(stsd_v: STSD, stsd_a: STSD, metadata: &Arc<util::Metadata>) -> MOOV {
+    let mvhd = MVHD {..Default::default() };
+    let traks = [new_trak(stsd_v, &metadata), new_trak(stsd_a, &metadata)];
+    let mvex = MVEX {..Default::default() };
+    return MOOV {
+        mvhd: mvhd,
+        traks: traks,
+        mvex: mvex,
+    }
+}
+
+fn new_trak(stsd: STSD, metadata: &Arc<util::Metadata>) -> TRAK {
+    let mut tkhd = TKHD {..Default::default() };
+    match stsd.entry {
+        SampleEntry::Visual(_) => {
+            tkhd.width = metadata.video.width << 16;
+            tkhd.height = metadata.video.height << 16;
+            tkhd.track_id = 1;
+        },
+        SampleEntry::Sound(_) => {
+            tkhd.alt_group = 1;
+            tkhd.volume = 1 << 8;
+            tkhd.track_id = 2;
+        }
+    }
+    let edts = EDTS { ..Default::default()};
+    let mdia = new_mdia(stsd, metadata);
+    return TRAK {
+        tkhd: tkhd,
+        edts: edts,
+        mdia: mdia,
+    }
+}
+
+fn new_mdia(stsd: STSD, metadata: &Arc<util::Metadata>) -> MDIA {
+    let mut mdhd = MDHD {..Default::default() };
+    let mut hdlr = HDLR {..Default::default() };
+    match stsd.entry {
+        SampleEntry::Visual(_) => {
+            mdhd.time_scale = (metadata.video.framerate * 1000.0) as u32;
+            hdlr.handler = u32::from_be_bytes(*b"vide");
+            hdlr.name = String::from("VideoHandler");
+        },
+        SampleEntry::Sound(_) => {
+            mdhd.time_scale = metadata.audio.samplerate;
+            hdlr.handler = u32::from_be_bytes(*b"soun");
+            hdlr.name = String::from("SoundHandler");
+        }
+    }
+    let minf = new_minf(stsd, metadata);
+    todo!();
+}
+
+fn new_minf(stsd: STSD, metadata: &Arc<util::Metadata>) -> MINF {
+    match stsd.entry {
+        SampleEntry::Visual(_) => MINF::Video(new_minf_v(stsd, metadata)),
+        SampleEntry::Sound(_) => MINF::Audio(new_minf_a(stsd, metadata))
+    }
+}
+
+fn new_minf_v(stsd: STSD, metadata: &Arc<util::Metadata>) -> MINF_V {
+    let vmhd = VMHD {..Default::default() };
+    let dinf = DINF {..Default::default() };
+    let stbl = new_stbl(stsd, metadata);
+    return MINF_V {
+        vmhd: vmhd,
+        dinf: dinf,
+        stbl: stbl,
+    }
+}
+
+
+fn new_minf_a(stsd: STSD, metadata: &Arc<util::Metadata>) -> MINF_A {
+    let smhd = SMHD {..Default::default() };
+    let dinf = DINF {..Default::default() };
+    let stbl = new_stbl(stsd, metadata);
+    return MINF_A {
+        smhd: smhd,
+        dinf: dinf,
+        stbl: stbl,
+    }
+}
+
+fn new_stbl(stsd: STSD, metadata: &Arc<util::Metadata>) -> STBL {
+    STBL {
+        stsd: stsd,
+        stts: STTS{..Default::default()},
+        stsc: STSC{..Default::default()},
+        stsz: STSZ{..Default::default()},
+        stco: STCO{..Default::default()},
+        opts: Vec::new(),
+    }
+}
+
diff --git a/src/muxer/hls/mp4/mp4muxer.rs b/src/muxer/hls/mp4/mp4muxer.rs
index 92f585d..0172001 100644
--- a/src/muxer/hls/mp4/mp4muxer.rs
+++ b/src/muxer/hls/mp4/mp4muxer.rs
@@ -8,7 +8,7 @@ impl mp4::MP4Muxer {
     pub fn gen_init(&mut self) -> Result<(), Box<dyn Error>> {
         let stsd_v = self.handle_a_cc()?;
         let stsd_a = self.handle_v_cc()?;
-        let init_tree = self.construct_moov(stsd_v, stsd_a);
+        let init_tree = mp4::atoms::construct_moov(stsd_v, stsd_a, &self.metadata);
         Ok(())
     }
 
@@ -33,10 +33,6 @@ impl mp4::MP4Muxer {
             _ => Err(Box::new(util::MuxerError::InvalidCodec))
         }
     }
-
-    fn construct_moov(&self, stsd_v: mp4::atoms::STSD, stsd_a: mp4::atoms::STSD) -> mp4::atoms::MOOV {
-        todo!();
-    }
 }
 
 fn get_av1_stsd(mut sample: Vec<u8>, metadata: &Arc<util::Metadata>) -> mp4::atoms::STSD {
@@ -47,7 +43,7 @@ fn get_av1_stsd(mut sample: Vec<u8>, metadata: &Arc<util::Metadata>) -> mp4::ato
     // More complicated to parse than is worth doing.
     let mut dummy_mp4_cc_binding = vec![0x81u8, 0x05, 0x0d, 0x00];
     dummy_mp4_cc_binding.append(&mut av1c);
-    let cc = mp4::atoms::CodecConfig {atom_name: "av1C".as_bytes().try_into().unwrap(), data: dummy_mp4_cc_binding};
+    let cc = mp4::atoms::CodecConfig {atom_name: *b"av1C", data: dummy_mp4_cc_binding};
     let v_sample_entry = mp4::atoms::VisualSampleEntry {
         dref_idx: 1,
         width: metadata.video.width as u16,
@@ -84,7 +80,7 @@ fn get_opus_stsd(sample: Vec<u8>, metadata: &Arc<util::Metadata>) -> mp4::atoms:
         channels: metadata.audio.channels as u16,
         sample_size: 16,
         sample_rate: metadata.audio.samplerate,
-        codec_config: mp4::atoms::CodecConfig { atom_name: "dOps".as_bytes().try_into().unwrap(), data: opus_binding}
+        codec_config: mp4::atoms::CodecConfig { atom_name: *b"dOps", data: opus_binding}
     };
     return mp4::atoms::STSD {
         version: 0,