diff --git a/Cargo.lock b/Cargo.lock
index bdaf8c3..cffe32d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,5 +1,18 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "either"
+version = "1.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "itertools"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "either 1.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "itoa"
 version = "0.4.6"
@@ -73,11 +86,14 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "wlstreamer"
 version = "0.3.0"
 dependencies = [
+ "itertools 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.117 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.59 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [metadata]
+"checksum either 1.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e78d4f1cc4ae33bbfc157ed5d5a5ef3bc29227303d595861deb238fcec4e9457"
+"checksum itertools 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "284f18f85651fe11e8a991b2adb42cb078325c996ed026d994719efcfca1d54b"
 "checksum itoa 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "dc6f3ad7b9d11a0c00842ff8de1b60ee58661048eb8049ed33c73594f359d7e6"
 "checksum proc-macro2 1.0.24 (registry+https://github.com/rust-lang/crates.io-index)" = "1e0704ee1a7e00d7bb417d0770ea303c1bccbabf0ef1667dae92b5967f5f8a71"
 "checksum quote 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)" = "aa563d17ecb180e500da1cfd2b028310ac758de548efdd203e18f283af693f37"
diff --git a/Cargo.toml b/Cargo.toml
index 5ab7e07..652fb25 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,3 +7,4 @@ edition = "2018"
 [dependencies]
 serde = { version = "1.0", features = ["derive"]}
 serde_json = "1.0"
+itertools = "0.9"
diff --git a/src/main.rs b/src/main.rs
index f519f28..307d42b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,66 +1,218 @@
+use itertools::Itertools;
 use serde::{Deserialize, Serialize};
 use std::cmp::Ordering;
+use std::collections::HashMap;
 use std::env;
 use std::io::{BufRead, BufReader, Error};
 use std::process::{Child, Command, Stdio};
 
-#[derive(Serialize, Deserialize, Debug)]
+#[derive(Serialize, Deserialize, Clone, Debug)]
+struct SwayScreenRect {
+    x: usize,
+    y: usize,
+    width: usize,
+    height: usize,
+}
+
+#[derive(Serialize, Deserialize, Clone, Debug)]
 struct SwayWorkspace {
-    id: u32,
+    id: usize,
     name: String,
-    focus: Vec<u32>,
+    focus: Vec<usize>,
     output: String,
     focused: bool,
+    rect: SwayScreenRect,
     visible: bool,
-    num: u32,
+    num: usize,
     #[serde(rename = "type")]
     type_name: String,
     representation: String,
 }
 
+#[derive(Serialize, Deserialize, Clone, Debug)]
+struct SwayOutputMode {
+    width: usize,
+    height: usize,
+    refresh: usize,
+}
+
+#[derive(Serialize, Deserialize, Clone, Debug)]
+struct SwayOutput {
+    id: usize,
+    name: String,
+    rect: SwayScreenRect,
+    layout: String,
+    orientation: String,
+    #[serde(rename = "type")]
+    type_name: String,
+    make: String,
+    model: String,
+    serial: String,
+    current_mode: SwayOutputMode,
+    focused: bool,
+}
+
+#[derive(Copy, Clone, Hash, Eq, Debug)]
+struct Resolution {
+    height: usize,
+    width: usize,
+}
+
+#[derive(Debug)]
 struct Config {
-    current_screen: String,
-    output: String,
+    current_output: String,
+    devices_from: usize,
+    current_device_index: usize,
     screen_blacklist: Vec<String>,
-    workspace_blacklist: Vec<u32>,
+    workspace_blacklist: Vec<usize>,
     verbose: bool,
+    resolutions: Vec<Resolution>,
+    outputs: HashMap<Resolution, usize>,
+}
+
+impl PartialEq<Resolution> for Resolution {
+    fn eq(&self, other: &Resolution) -> bool {
+        self.width == other.width && self.height == other.height
+    }
 }
 
 const VERSION: &'static str = env!("CARGO_PKG_VERSION");
 
 fn help() {
-    println!("Wrapper around wf-recorder and ffmpeg that automatically switches the screen being recorded based on current window focus");
-    println!("");
     println!("Usage: wlstreamer [options]");
+    println!("Wrapper around wf-recorder and ffmpeg that automatically switches the screen being recorded based on current window focus");
     println!("");
     println!("Options:");
     println!("  --not-ws <ws-num>         Do not show this workspace. Can be used multiple times. Example: 3");
     println!("  --not-screen <screen>     Do not show this screen. Can be used multiple times. Example: HDMI-A-1");
-    println!("  -o|--output <output>      Output to this device. Defaults to /dev/video0");
+    println!("  -d|--devices-from <id>    Use video devices starting at $id. Defaults to 0. /dev/video$id will be used as output. See DIFFERENT RESOLUTIONS below.");
     println!("  -v|--version              Display version and exit");
     println!("  --verbose                 Verbose logging");
     println!("");
     println!(
         "If there are no screens available for streaming, a black screen will be shown instead."
     );
+    println!("");
+    println!("DIFFERENT RESOLUTIONS");
+    println!("");
+    println!("When running outputs with different resolutions, the resulting stream will be the smallest possible resolution that can fit all output resolutions.");
+    println!("For example, two outputs, one 1600x1200, another 1920x1080, will result in an output stream of 1920x1200. Any remaining space will be padded black.");
+    println!("Another example, two outputs, one 640x480, another 1920x1080, will result in an output stream of 1920x1080. Space will only be padded black on the smaller screen.");
+    println!("");
+    println!("To support this behaviour, wlstreamer needs access to a v4l2loopback device for each resolution, included the combined upscaled one if applicable.");
+    println!("For the first example above, this would mean you would need 3 devices. For the second, you'd need two. If all your outputs have the same resolution, you only need an output device.");
+    println!("");
+    println!("DYNAMICALLY CHANGING RESOLUTIONS");
+    println!("");
+    println!("As long as you have enough v4l2loopback devices available for new resolutions, it should be fine to change resolutions on an output.");
+    println!("However, if your resolution is either wider or taller than the output resolution, this will result in failures, since dynamically changing the v4l2loopback device resolution is not possible.");
+
     std::process::exit(0);
 }
 
-fn record_screen(config: &mut Config, valid_screens: &Vec<String>) -> Result<Child, Error> {
-    if valid_screens.len() == 0 {
-        let cmd = Command::new("ffmpeg")
+fn stream_black(config: &mut Config) -> Result<Vec<Child>, Error> {
+    let mut cmd = Command::new("ffmpeg")
+        .args(&[
+            "-i",
+            format!(
+                "color=c=black:s={}x{}:r=25/1",
+                config.resolutions[0].width, config.resolutions[0].height
+            )
+            .as_str(),
+            "-vcodec",
+            "rawvideo",
+            "-pix_fmt",
+            "yuyv422",
+            "-f",
+            "v4l2",
+            format!("/dev/video{}", config.devices_from).as_str(),
+        ])
+        .stdin(Stdio::piped())
+        .stdout(if config.verbose {
+            Stdio::piped()
+        } else {
+            Stdio::inherit()
+        })
+        .stderr(if config.verbose {
+            Stdio::piped()
+        } else {
+            Stdio::inherit()
+        })
+        .spawn()?;
+
+    config.current_output = "".to_string();
+
+    return Ok(vec![cmd]);
+}
+
+fn record_screen(config: &mut Config, output: SwayOutput) -> Result<Vec<Child>, Error> {
+    let resolution = Resolution {
+        height: output.current_mode.height,
+        width: output.current_mode.width,
+    };
+
+    let device_number = match config.outputs.get(&resolution) {
+        Some(device_number) => *device_number,
+        None => {
+            config
+                .outputs
+                .insert(resolution, config.current_device_index);
+            config.current_device_index += 1;
+            config.current_device_index
+        }
+    };
+
+    if config.verbose {
+        println!("Using device number {}", device_number);
+    }
+
+    let output_str = format!("--file=/dev/video{}", device_number);
+    let screen_str = format!("-o{}", output.name.as_str());
+    let recorder = Command::new("wf-recorder")
+        .args(&[
+            "--muxer=v4l2",
+            "--codec=rawvideo",
+            "--pixel-format=yuyv422",
+            screen_str.as_str(),
+            output_str.as_str(),
+        ])
+        .stdin(Stdio::piped())
+        .stdout(if config.verbose {
+            Stdio::inherit()
+        } else {
+            Stdio::piped()
+        })
+        .stderr(if config.verbose {
+            Stdio::inherit()
+        } else {
+            Stdio::piped()
+        })
+        .spawn()?;
+
+    config.current_output = output.name.as_str().to_string();
+
+    let mut processes = vec![recorder];
+
+    if device_number != config.devices_from {
+        if config.verbose {
+            println!("Does not have the maximum combined resolution, filtering through ffmpeg");
+        }
+
+        let upscaler = Command::new("ffmpeg")
             .args(&[
-                "-f",
-                "lavfi",
                 "-i",
-                "color=c=black:s=1920x1080:r=25/1",
+                format!("/dev/video{}", device_number).as_str(),
                 "-vcodec",
                 "rawvideo",
                 "-pix_fmt",
                 "yuyv422",
                 "-f",
                 "v4l2",
-                config.output.as_str(),
+                "-vf",
+                format!("scale={}:{}:force_original_aspect_ratio=decrease,pad={}:{}:(ow-iw)/2:(oh-ih)/2,setsar=1",
+                    config.resolutions[0].width, config.resolutions[0].height,
+                    config.resolutions[0].width, config.resolutions[0].height).as_str(),
+                format!("/dev/video{}", config.devices_from).as_str(),
             ])
             .stdin(Stdio::piped())
             .stdout(if config.verbose {
@@ -75,46 +227,94 @@ fn record_screen(config: &mut Config, valid_screens: &Vec<String>) -> Result<Chi
             })
             .spawn()?;
 
-        config.current_screen = "".to_string();
+        processes.push(upscaler);
+    }
+    format!("/dev/video{}", device_number).as_str();
 
-        return Ok(cmd);
-    } else {
-        let output_str = format!("--file={}", config.output.as_str());
-        let screen_str = format!("-o{}", valid_screens[0]);
-        println!("Outputting to {}", config.output.as_str());
-        let cmd = Command::new("wf-recorder")
-            .args(&[
-                "--muxer=v4l2",
-                "--codec=rawvideo",
-                "--pixel-format=yuyv422",
-                screen_str.as_str(),
-                output_str.as_str(),
-            ])
-            .stdin(Stdio::piped())
-            .stdout(if config.verbose {
-                Stdio::inherit()
-            } else {
-                Stdio::piped()
-            })
-            .stderr(if config.verbose {
-                Stdio::inherit()
-            } else {
-                Stdio::piped()
-            })
-            .spawn()?;
-
-        config.current_screen = valid_screens[0].as_str().to_string();
-
-        return Ok(cmd);
-    };
+    return Ok(processes);
 }
 
-fn get_valid_screens_for_recording(config: &Config) -> Vec<String> {
-    let mut command = "swaymsg -t get_workspaces";
+fn get_outputs(config: &mut Config) -> Vec<SwayOutput> {
+    let command = "swaymsg -t get_outputs";
     let output = Command::new("sh")
         .args(&["-c", command])
         .output()
-        .expect("Couldn't get current focus");
+        .expect("Error running swaymsg");
+
+    let stdout_string = String::from_utf8(output.stdout).expect("Invalid UTF-8 from get_outputs");
+    let outputs: Vec<SwayOutput> =
+        serde_json::from_str(stdout_string.as_str()).expect("Invalid json from get_outputs");
+
+    if config.verbose {
+        println!("Found outputs");
+        for elem in outputs.iter() {
+            println!("{:?}", elem);
+        }
+    }
+
+    return outputs;
+}
+
+fn get_output(config: &mut Config, screen: &str) -> SwayOutput {
+    let outputs = get_outputs(config);
+    let output = match outputs.iter().find(|o| o.name == screen) {
+        Some(o) => o.to_owned(),
+        None => panic!("Could not find output"),
+    };
+
+    return output.clone();
+}
+
+fn get_resolutions(config: &mut Config) -> Vec<Resolution> {
+    let outputs = get_outputs(config);
+    let mut resolutions: Vec<Resolution> = outputs
+        .iter()
+        .map(|o| Resolution {
+            height: o.current_mode.height,
+            width: o.current_mode.width,
+        })
+        .unique()
+        .collect_vec();
+
+    if config.verbose {
+        println!("{:?}", resolutions);
+    }
+
+    let combined_resolution: Resolution = resolutions.iter().fold(
+        Resolution {
+            width: 0,
+            height: 0,
+        },
+        |acc, r| Resolution {
+            height: if acc.height > r.height {
+                acc.height
+            } else {
+                r.height
+            },
+            width: if acc.width > r.width {
+                acc.width
+            } else {
+                r.width
+            },
+        },
+    );
+
+    if config.verbose {
+        println!("Combined maximum resolution {:?}", combined_resolution);
+    }
+
+    resolutions.insert(0, combined_resolution);
+    resolutions = resolutions.into_iter().unique().collect_vec();
+
+    return resolutions;
+}
+
+fn get_valid_screens_for_recording(config: &Config) -> Vec<SwayWorkspace> {
+    let command = "swaymsg -t get_workspaces";
+    let output = Command::new("sh")
+        .args(&["-c", command])
+        .output()
+        .expect("Error running swaymsg");
 
     let stdout_string =
         String::from_utf8(output.stdout).expect("Invalid UTF-8 from get_workspaces");
@@ -156,16 +356,20 @@ fn get_valid_screens_for_recording(config: &Config) -> Vec<String> {
             Ordering::Greater
         }
     });
-    return workspaces.into_iter().map(|w| w.output).collect();
+
+    return workspaces;
 }
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     let mut config = Config {
-        current_screen: "".to_string(),
-        output: "/dev/video0".to_string(),
+        current_output: "".to_string(),
+        devices_from: 0,
+        current_device_index: 0,
         screen_blacklist: Vec::new(),
         workspace_blacklist: Vec::new(),
         verbose: false,
+        resolutions: Vec::new(),
+        outputs: HashMap::new(),
     };
     let args: Vec<String> = env::args().collect();
 
@@ -180,13 +384,14 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             i += 1;
             config
                 .workspace_blacklist
-                .push(args[i].clone().parse::<u32>().unwrap());
+                .push(args[i].clone().parse::<usize>().unwrap());
         } else if arg == "--not-screen" {
             i += 1;
             config.screen_blacklist.push(args[i].clone());
-        } else if arg == "-o" || arg == "--output" {
+        } else if arg == "-d" || arg == "--devices-from" {
             i += 1;
-            config.output = args[i].clone();
+            config.devices_from = args[i].clone().parse::<usize>().unwrap();
+            config.current_device_index = config.devices_from;
         } else if arg == "--verbose" {
             config.verbose = true;
         } else if arg == "-v" || arg == "--version" {
@@ -201,8 +406,11 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         i += 1;
     }
 
-    let valid_screens = get_valid_screens_for_recording(&config);
-    let mut recorder = record_screen(&mut config, &valid_screens)?;
+    config.resolutions = get_resolutions(&mut config);
+    config
+        .outputs
+        .insert(config.resolutions[0], config.devices_from);
+    config.current_device_index += 1;
 
     let stdout = match Command::new("sh")
         .args(&["-c", "swaymsg -t subscribe -m \"['window']\""])
@@ -213,28 +421,37 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         .stdout
     {
         Some(stdout) => stdout,
-        None => panic!("Could not open stdout"),
+        None => panic!("Could not open swaymsg stdout"),
     };
 
     let reader = BufReader::new(stdout);
-    reader.lines().filter_map(|line| line.ok()).for_each(|_| {
-        println!("Switched focus");
-        let valid_screens = get_valid_screens_for_recording(&config);
-        if valid_screens.len() > 0 && valid_screens[0] == config.current_screen {
-            return;
-        }
+    reader
+        .lines()
+        .filter_map(|line| line.ok())
+        .for_each(|_| -> Result<(), Error> {
+            println!("Switched focus");
+            let valid_screens = get_valid_screens_for_recording(&config);
+            if valid_screens.len() > 0 && valid_screens[0].output == config.current_output {
+                return Ok(());
+            }
+            let output = get_output(&mut config, valid_screens[0].output.as_str());
+            for recorder in recorders.iter() {
+                match recorder.kill() {
+                    Ok(_) => {}
+                    Err(err) => panic!("{:?}", err),
+                };
+            }
 
-        match recorder.kill() {
-            Ok(_) => {}
-            Err(err) => panic!("{:?}", err),
-        };
+            let mut recorders: Vec<Child> = if valid_screens.len() != 0 {
+                stream_black(&mut config)?
+            } else {
+                let output = get_output(&mut config, valid_screens[0].output.as_str());
+                record_screen(&mut config, output)?
+            };
+            println!("Recording {}", config.current_output);
 
-        recorder = match record_screen(&mut config, &valid_screens) {
-            Ok(recorder) => recorder,
-            Err(err) => panic!("{:?}", err),
-        };
-        println!("Recording {}", config.current_screen);
-    });
+            Ok(())
+        });
 
     Ok(())
 }