diff --git a/src/muxer/hls/mp4/mod.rs b/src/muxer/hls/mp4/mod.rs
index 3cbbad5..9ca103b 100644
--- a/src/muxer/hls/mp4/mod.rs
+++ b/src/muxer/hls/mp4/mod.rs
@@ -1,5 +1,6 @@
 mod mp4muxer;
 mod atoms;
+mod samples;
 
 use std::sync::{mpsc, Arc};
 use std::error::Error;
@@ -8,9 +9,9 @@ use crate::util;
 
 pub struct MP4Muxer {
     v: mpsc::Receiver<util::NALUPacket>,
-    v_samples: Vec<Vec<u8>>,
+    v_samples: samples::SampleQueue,
     a: mpsc::Receiver<util::NALUPacket>,
-    a_samples: Vec<Vec<u8>>,
+    a_samples: samples::SampleQueue,
     metadata: Arc<util::Metadata>,
     err_in: mpsc::Sender<Box<dyn Error + Send + Sync>>,
 }
@@ -21,8 +22,14 @@ pub fn new_muxer(v: mpsc::Receiver<util::NALUPacket>, a: mpsc::Receiver<util::NA
         a: a,
         metadata: metadata,
         err_in: err_in,
-        v_samples: Vec::new(),
-        a_samples: Vec::new(),
+        v_samples: samples::SampleQueue {
+            queue: Vec::new(),
+            default_duration: 1000,
+        },
+        a_samples: samples::SampleQueue {
+            queue: Vec::new(),
+            default_duration: 960,
+        },
     };
     muxer.gen_init()?;
     return Ok(muxer);
diff --git a/src/muxer/hls/mp4/mp4muxer.rs b/src/muxer/hls/mp4/mp4muxer.rs
index d93c927..f4a7740 100644
--- a/src/muxer/hls/mp4/mp4muxer.rs
+++ b/src/muxer/hls/mp4/mp4muxer.rs
@@ -18,7 +18,7 @@ impl mp4::MP4Muxer {
         let v_cc = self.v.recv()?;
         return match v_cc.packet_type {
             util::NALUPacketType::Video(util::VideoCodec::AV1) => {
-                self.v_samples.push(v_cc.packet_data.clone());
+                self.v_samples.push(v_cc.packet_data.clone(), 0x02000000);
                 Ok(get_av1_stsd(v_cc.packet_data, &self.metadata))
             },
             _ => Err(Box::new(util::MuxerError::InvalidCodec))
diff --git a/src/muxer/hls/mp4/samples.rs b/src/muxer/hls/mp4/samples.rs
new file mode 100644
index 0000000..db5c512
--- /dev/null
+++ b/src/muxer/hls/mp4/samples.rs
@@ -0,0 +1,20 @@
+pub struct Sample {
+    pub data: Vec<u8>,
+    pub size: u32,
+    pub flags: u32,
+}
+
+pub struct SampleQueue {
+    pub queue: Vec<Sample>,
+    pub default_duration: u32,
+}
+
+impl SampleQueue {
+    pub fn push(&mut self, data: Vec<u8>, flags: u32) {
+        self.queue.push(Sample {
+            size: data.len() as u32,
+            data: data,
+            flags: flags,
+        })
+    }
+}