add crate for dealing with mp4; convert fragmentmuxer output from writer to vec

2 files changed, 305 insertions, 0 deletions

diff --git a/remuxer/mp4/src/boxes.rs b/remuxer/mp4/src/boxes.rs
new file mode 100644
index 0000000..d2c3918
--- /dev/null
+++ b/remuxer/mp4/src/boxes.rs
@@ -0,0 +1,268 @@
+/*
+    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) 2026 metamuffin <metamuffin.org>
+*/
+
+use crate::{BoxW, WriteBox};
+
+macro_rules! container_box {
+    ($typ:tt, $iden:literal) => {
+        pub struct $typ<T: Fn(&mut BoxW)>(pub T);
+        impl<T: Fn(&mut BoxW)> WriteBox for $typ<T> {
+            const BOXTYPE: [u8; 4] = *$iden;
+            fn write(&self, buf: &mut Vec<u8>) {
+                self.0(&mut BoxW(buf))
+            }
+        }
+    };
+}
+
+container_box!(Movie, b"moov");
+container_box!(Track, b"trak");
+container_box!(Edit, b"edts");
+container_box!(Media, b"mdia");
+container_box!(MediaInformation, b"minf");
+container_box!(DataInformation, b"dinf");
+container_box!(SampleTable, b"stbl");
+container_box!(MovieFragment, b"stbl");
+container_box!(TrackFragment, b"stbl");
+
+pub struct FileType<'a> {
+    pub major_brand: [u8; 4],
+    pub minor_version: u32,
+    pub compatible_brands: &'a [[u8; 4]],
+}
+impl WriteBox for FileType<'_> {
+    const BOXTYPE: [u8; 4] = *b"ftyp";
+    fn write(&self, buf: &mut Vec<u8>) {
+        buf.extend(self.major_brand);
+        buf.extend(self.minor_version.to_be_bytes());
+        for cb in self.compatible_brands {
+            buf.extend(cb);
+        }
+    }
+}
+
+pub struct MovieHeader {
+    pub creation_time: u64,
+    pub modification_time: u64,
+    pub timescale: u32,
+    pub duration: u64,
+    pub rate: u32,
+    pub volume: u16,
+    pub matrix: [u32; 9],
+    pub pre_defined: [u32; 6],
+    pub next_track_id: u32,
+}
+
+impl WriteBox for MovieHeader {
+    const BOXTYPE: [u8; 4] = *b"mvhd";
+    const VERSION: Option<u8> = Some(1);
+    fn write(&self, buf: &mut Vec<u8>) {
+        buf.extend(self.creation_time.to_be_bytes());
+        buf.extend(self.modification_time.to_be_bytes());
+        buf.extend(self.timescale.to_be_bytes());
+        buf.extend(self.duration.to_be_bytes());
+        buf.extend(self.rate.to_be_bytes());
+        buf.extend(self.volume.to_be_bytes());
+        buf.extend([0; 10]);
+        for e in self.matrix {
+            buf.extend(e.to_be_bytes());
+        }
+        buf.extend([0; 24]);
+        buf.extend(self.next_track_id.to_be_bytes());
+    }
+}
+impl Default for MovieHeader {
+    fn default() -> Self {
+        Self {
+            creation_time: 0,
+            modification_time: 0,
+            timescale: 0,
+            duration: 0,
+            rate: 0x00010000,
+            volume: 0x0100,
+            matrix: [0x00010000, 0, 0, 0, 0x00010000, 0, 0, 0, 0x00010000],
+            pre_defined: [0; 6],
+            next_track_id: 0,
+        }
+    }
+}
+
+#[derive(Default)]
+pub struct TrackHeader {
+    pub creation_time: u64,
+    pub modification_time: u64,
+    pub track_id: u32,
+    pub duration: u64,
+    pub layer: u16,
+    pub alternate_group: u16,
+    pub volume: u16,
+    pub matrix: [u32; 9],
+    pub width: u32,
+    pub height: u32,
+}
+impl WriteBox for TrackHeader {
+    const BOXTYPE: [u8; 4] = *b"tkhd";
+    const VERSION: Option<u8> = Some(1);
+    fn write(&self, buf: &mut Vec<u8>) {
+        buf.extend(self.creation_time.to_be_bytes());
+        buf.extend(self.modification_time.to_be_bytes());
+        buf.extend(self.track_id.to_be_bytes());
+        buf.extend([0; 4]);
+        buf.extend(self.duration.to_be_bytes());
+        buf.extend([0; 8]);
+        buf.extend(self.layer.to_be_bytes());
+        buf.extend(self.alternate_group.to_be_bytes());
+        buf.extend(self.volume.to_be_bytes());
+        buf.extend([0; 2]);
+        for e in self.matrix {
+            buf.extend(e.to_be_bytes());
+        }
+        buf.extend(self.width.to_be_bytes());
+        buf.extend(self.height.to_be_bytes());
+    }
+}
+
+pub struct EditList<'a> {
+    pub entries: &'a [EditListEntry],
+}
+pub struct EditListEntry {
+    pub edit_duration: u64,
+    pub media_time: u64,
+    pub media_rate: u32,
+}
+impl WriteBox for EditList<'_> {
+    const BOXTYPE: [u8; 4] = *b"elst";
+    fn write(&self, buf: &mut Vec<u8>) {
+        buf.extend((self.entries.len() as u32).to_be_bytes());
+        for e in self.entries {
+            buf.extend(e.edit_duration.to_be_bytes());
+            buf.extend(e.media_time.to_be_bytes());
+            buf.extend(e.media_rate.to_be_bytes());
+        }
+    }
+}
+
+#[derive(Default)]
+pub struct MediaHeader {
+    pub creation_time: u64,
+    pub modification_time: u64,
+    pub timescale: u32,
+    pub duration: u64,
+    pub language: [u8; 3],
+    pub pre_defined: u16,
+}
+impl WriteBox for MediaHeader {
+    const BOXTYPE: [u8; 4] = *b"mdhd";
+    const VERSION: Option<u8> = Some(1);
+    fn write(&self, buf: &mut Vec<u8>) {
+        buf.extend(self.creation_time.to_be_bytes());
+        buf.extend(self.modification_time.to_be_bytes());
+        buf.extend(self.timescale.to_be_bytes());
+        buf.extend(self.duration.to_be_bytes());
+        buf.extend(
+            ((self.language[0] as u16 & 0b11111 << 10)
+                | (self.language[1] as u16 & 0b11111 << 5)
+                | (self.language[2] as u16 & 0b11111 << 0))
+                .to_be_bytes(),
+        );
+        buf.extend([0; 2]);
+    }
+}
+
+pub struct Handler {
+    pub handler_type: u32,
+    pub name: String,
+}
+impl WriteBox for Handler {
+    const BOXTYPE: [u8; 4] = *b"hdlr";
+    const VERSION: Option<u8> = Some(0);
+    fn write(&self, buf: &mut Vec<u8>) {
+        buf.extend([0; 4]);
+        buf.extend(self.handler_type.to_be_bytes());
+        buf.extend([0; 12]);
+        buf.extend(self.name.as_bytes());
+    }
+}
+
+#[derive(Default)]
+pub struct VideoMediaHandler {
+    pub graphicsmode: u16,
+    pub opcolor: [u16; 3],
+}
+impl WriteBox for VideoMediaHandler {
+    const BOXTYPE: [u8; 4] = *b"vmhd";
+    const VERSION: Option<u8> = Some(0);
+    fn write(&self, buf: &mut Vec<u8>) {
+        buf.extend(self.graphicsmode.to_be_bytes());
+        buf.extend(self.opcolor[0].to_be_bytes());
+        buf.extend(self.opcolor[1].to_be_bytes());
+        buf.extend(self.opcolor[2].to_be_bytes());
+    }
+}
+
+#[derive(Default)]
+pub struct SoundMediaHandler {
+    pub balance: u16,
+}
+impl WriteBox for SoundMediaHandler {
+    const BOXTYPE: [u8; 4] = *b"smhd";
+    const VERSION: Option<u8> = Some(0);
+    fn write(&self, buf: &mut Vec<u8>) {
+        buf.extend(self.balance.to_be_bytes());
+    }
+}
+
+pub struct DataReference<'a> {
+    pub entries: &'a [()],
+}
+impl WriteBox for DataReference<'_> {
+    const BOXTYPE: [u8; 4] = *b"dref";
+    const VERSION: Option<u8> = Some(0);
+    fn write(&self, buf: &mut Vec<u8>) {
+        buf.extend([0; 4]);
+    }
+}
+
+pub struct MovieFragmentHeader {
+    pub sequence_number: u32,
+}
+impl WriteBox for MovieFragmentHeader {
+    const BOXTYPE: [u8; 4] = *b"mfhd";
+    const VERSION: Option<u8> = Some(0);
+    fn write(&self, buf: &mut Vec<u8>) {
+        buf.extend(self.sequence_number.to_be_bytes());
+    }
+}
+
+pub struct TrackFragmentHeader {
+    pub track_id: u32,
+}
+impl WriteBox for TrackFragmentHeader {
+    const BOXTYPE: [u8; 4] = *b"tfhd";
+    fn write(&self, buf: &mut Vec<u8>) {
+        buf.extend(self.track_id.to_be_bytes());
+    }
+}
+
+pub struct TrackFragmentBaseMediaDecodeTime {
+    pub base_media_decode_time: u64,
+}
+impl WriteBox for TrackFragmentBaseMediaDecodeTime {
+    const BOXTYPE: [u8; 4] = *b"tfdt";
+    fn write(&self, buf: &mut Vec<u8>) {
+        buf.extend(self.base_media_decode_time.to_be_bytes());
+    }
+}
+
+pub struct TrackRun {
+    pub data_offset: i32,
+}
+impl WriteBox for TrackRun {
+    const BOXTYPE: [u8; 4] = *b"trun";
+    fn write(&self, buf: &mut Vec<u8>) {
+        buf.extend(self.data_offset.to_be_bytes());
+    }
+}
diff --git a/remuxer/mp4/src/lib.rs b/remuxer/mp4/src/lib.rs
new file mode 100644
index 0000000..cb728fa
--- /dev/null
+++ b/remuxer/mp4/src/lib.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) 2026 metamuffin <metamuffin.org>
+*/
+
+mod boxes;
+pub use boxes::*;
+
+pub struct BoxW<'a>(&'a mut Vec<u8>);
+impl<'a> BoxW<'a> {
+    pub fn new(buffer: &'a mut Vec<u8>) -> Self {
+        Self(buffer)
+    }
+    pub fn write<T: WriteBox>(&mut self, b: T) {
+        let start = self.0.len();
+        self.0.extend(0u32.to_be_bytes());
+        self.0.extend(T::BOXTYPE);
+
+        if let Some(ver) = T::VERSION {
+            self.0.push(ver);
+            self.0.extend(&b.flags().to_be_bytes()[1..]);
+        }
+        b.write(self.0);
+        let size = (self.0.len() - start) as u32;
+        self.0[start..start + 4].copy_from_slice(&size.to_be_bytes());
+    }
+}
+
+pub trait WriteBox {
+    const BOXTYPE: [u8; 4];
+    const VERSION: Option<u8> = None;
+    fn write(&self, buf: &mut Vec<u8>);
+    fn flags(&self) -> u32 {
+        0
+    }
+}