3 files changed, 71 insertions, 43 deletions

diff --git a/remuxer/src/muxers/matroska.rs b/remuxer/src/muxers/matroska.rs
index 47210c9..c2f22e7 100644
--- a/remuxer/src/muxers/matroska.rs
+++ b/remuxer/src/muxers/matroska.rs
@@ -8,15 +8,25 @@ use crate::muxers::FragmentMuxer;
 use anyhow::Result;
 use std::io::Write;
 use winter_ebml::{EbmlHeader, EbmlToVec};
-use winter_matroska::{Cluster, Info, MatroskaFile, Segment, Tracks};
+use winter_matroska::{MatroskaFile, Segment};
+
+fn write_fragment_shared(out: &mut dyn Write, mut segment: Segment, webm: bool) -> Result<()> {
+    segment.info.muxing_app =
+        concat!(env!("CARGO_PKG_NAME"), "/", env!("CARGO_PKG_VERSION")).to_string();
+    if webm {
+        if let Some(tracks) = &mut segment.tracks {
+            for track in &mut tracks.entries {
+                if let Some(video) = &mut track.video {
+                    video.colour = None;
+                    video.projection = None;
+                    video.display_unit = 0; // pixels
+                    video.display_width = Some(video.pixel_width);
+                    video.display_height = Some(video.pixel_height);
+                }
+            }
+        }
+    }
 
-fn write_fragment_shared(
-    out: &mut dyn Write,
-    info: Info,
-    tracks: Tracks,
-    cluster: Cluster,
-    webm: bool,
-) -> Result<()> {
     let file = MatroskaFile {
         ebml_header: EbmlHeader {
             ebml_version: 1,
@@ -28,12 +38,7 @@ fn write_fragment_shared(
             doc_type_read_version: 2,
             ..Default::default()
         },
-        segment: Segment {
-            info,
-            tracks: Some(tracks),
-            clusters: vec![cluster],
-            ..Default::default()
-        },
+        segment,
     };
     out.write_all(&file.to_vec())?;
     Ok(())
@@ -41,23 +46,13 @@ fn write_fragment_shared(
 
 pub struct MatroskaFragmentMuxer;
 impl FragmentMuxer for MatroskaFragmentMuxer {
-    fn write_fragment(
-        out: &mut dyn Write,
-        info: Info,
-        tracks: Tracks,
-        cluster: Cluster,
-    ) -> Result<()> {
-        write_fragment_shared(out, info, tracks, cluster, false)
+    fn write_fragment(out: &mut dyn Write, segment: Segment) -> Result<()> {
+        write_fragment_shared(out, segment, false)
     }
 }
 pub struct WebmFragmentMuxer;
 impl FragmentMuxer for WebmFragmentMuxer {
-    fn write_fragment(
-        out: &mut dyn Write,
-        info: Info,
-        tracks: Tracks,
-        cluster: Cluster,
-    ) -> Result<()> {
-        write_fragment_shared(out, info, tracks, cluster, true)
+    fn write_fragment(out: &mut dyn Write, segment: Segment) -> Result<()> {
+        write_fragment_shared(out, segment, true)
     }
 }
diff --git a/remuxer/src/muxers/mod.rs b/remuxer/src/muxers/mod.rs
index 8752373..ae544eb 100644
--- a/remuxer/src/muxers/mod.rs
+++ b/remuxer/src/muxers/mod.rs
@@ -5,36 +5,32 @@
 */
 
 pub mod matroska;
+pub mod mpeg4;
 
 use crate::{
     ContainerFormat,
-    muxers::matroska::{MatroskaFragmentMuxer, WebmFragmentMuxer},
+    muxers::{
+        matroska::{MatroskaFragmentMuxer, WebmFragmentMuxer},
+        mpeg4::Mpeg4FragmentMuxer,
+    },
 };
 use anyhow::Result;
 use std::io::Write;
-use winter_matroska::{Cluster, Info, Tracks};
+use winter_matroska::Segment;
 
 pub trait FragmentMuxer {
-    fn write_fragment(
-        out: &mut dyn Write,
-        info: Info,
-        tracks: Tracks,
-        cluster: Cluster,
-    ) -> Result<()>;
+    fn write_fragment(out: &mut dyn Write, segment: Segment) -> Result<()>;
 }
 
 pub fn write_fragment(
     container: ContainerFormat,
     out: &mut dyn Write,
-    info: Info,
-    tracks: Tracks,
-    cluster: Cluster,
+    segment: Segment,
 ) -> Result<()> {
     match container {
-        ContainerFormat::Matroska => {
-            MatroskaFragmentMuxer::write_fragment(out, info, tracks, cluster)
-        }
-        ContainerFormat::Webm => WebmFragmentMuxer::write_fragment(out, info, tracks, cluster),
+        ContainerFormat::Matroska => MatroskaFragmentMuxer::write_fragment(out, segment),
+        ContainerFormat::Webm => WebmFragmentMuxer::write_fragment(out, segment),
+        ContainerFormat::Mpeg4 => Mpeg4FragmentMuxer::write_fragment(out, segment),
         _ => unimplemented!(),
     }
 }
diff --git a/remuxer/src/muxers/mpeg4.rs b/remuxer/src/muxers/mpeg4.rs
new file mode 100644
index 0000000..437f117
--- /dev/null
+++ b/remuxer/src/muxers/mpeg4.rs
@@ -0,0 +1,37 @@
+/*
+    This file is part of jellything (https://codeberg.org/metamuffin/jellything)
+    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
+    Copyright (C) 2025 metamuffin <metamuffin.org>
+*/
+
+use crate::muxers::{FragmentMuxer, matroska::MatroskaFragmentMuxer};
+use anyhow::Result;
+use std::{
+    io::{Cursor, Write, copy},
+    process::{Command, Stdio},
+    thread::spawn,
+};
+use winter_matroska::Segment;
+
+pub struct Mpeg4FragmentMuxer;
+impl FragmentMuxer for Mpeg4FragmentMuxer {
+    fn write_fragment(out: &mut dyn Write, segment: Segment) -> Result<()> {
+        let mut mk_frag = Vec::new();
+        MatroskaFragmentMuxer::write_fragment(&mut mk_frag, segment)?;
+
+        let mut child = Command::new("ffmpeg")
+            .args(
+                "-hide_banner -f matroska -i pipe:0 -c copy -f mp4 -movflags frag_keyframe+empty_moov pipe:1"
+                    .split(" "),
+            )
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped())
+            .spawn()?;
+
+        let mut stdin = child.stdin.take().unwrap();
+        let mut stdout = child.stdout.take().unwrap();
+        spawn(move || copy(&mut Cursor::new(mk_frag), &mut stdin));
+        copy(&mut stdout, out)?;
+        Ok(())
+    }
+}