fmp4mux: Port to aggregator as base class as preparation for supporting multiple streams

3 files changed, 390 insertions, 410 deletions

diff --git a/generic/fmp4/Cargo.toml b/generic/fmp4/Cargo.toml
index cd2d909b..ce80b4bd 100644
--- a/generic/fmp4/Cargo.toml
+++ b/generic/fmp4/Cargo.toml
@@ -11,6 +11,7 @@ rust-version = "1.57"
 [dependencies]
 anyhow = "1"
 gst = { package = "gstreamer", git = "https://gitlab.freedesktop.org/gstreamer/gstreamer-rs" }
+gst-base = { package = "gstreamer-base", git = "https://gitlab.freedesktop.org/gstreamer/gstreamer-rs" }
 gst-audio = { package = "gstreamer-audio", git = "https://gitlab.freedesktop.org/gstreamer/gstreamer-rs" }
 gst-video = { package = "gstreamer-video", git = "https://gitlab.freedesktop.org/gstreamer/gstreamer-rs" }
 once_cell = "1.0"
@@ -47,4 +48,4 @@ install_subdir = "gstreamer-1.0"
 versioning = false
 
 [package.metadata.capi.pkg_config]
-requires_private = "gstreamer-1.0, gstreamer-audio-1.0, gstreamer-video-1.0, gobject-2.0, glib-2.0, gmodule-2.0"
+requires_private = "gstreamer-1.0, gstreamer-base-1.0, gstreamer-audio-1.0, gstreamer-video-1.0, gobject-2.0, glib-2.0, gmodule-2.0"
diff --git a/generic/fmp4/src/fmp4mux/imp.rs b/generic/fmp4/src/fmp4mux/imp.rs
index 96117f70..0b600f34 100644
--- a/generic/fmp4/src/fmp4mux/imp.rs
+++ b/generic/fmp4/src/fmp4mux/imp.rs
@@ -9,6 +9,8 @@
 use gst::glib;
 use gst::prelude::*;
 use gst::subclass::prelude::*;
+use gst_base::prelude::*;
+use gst_base::subclass::prelude::*;
 
 use std::collections::VecDeque;
 use std::sync::Mutex;
@@ -72,7 +74,6 @@ struct Gop {
 
 #[derive(Default)]
 struct State {
-    segment: Option<gst::FormattedSegment<gst::ClockTime>>,
     caps: Option<gst::Caps>,
     intra_only: bool,
 
@@ -98,12 +99,11 @@ struct State {
     earliest_pts: Option<gst::ClockTime>,
     end_pts: Option<gst::ClockTime>,
 
-    headers_since_eos: bool,
+    generated_headers: bool,
 }
 
 pub(crate) struct FMP4Mux {
-    srcpad: gst::Pad,
-    sinkpad: gst::Pad,
+    sinkpad: gst_base::AggregatorPad,
     state: Mutex<State>,
     settings: Mutex<Settings>,
 }
@@ -113,18 +113,11 @@ impl FMP4Mux {
         &self,
         element: &super::FMP4Mux,
         state: &mut State,
+        segment: &gst::FormattedSegment<gst::ClockTime>,
         buffer: gst::Buffer,
     ) -> Result<(), gst::FlowError> {
         gst::trace!(CAT, obj: element, "Handling buffer {:?}", buffer);
 
-        let segment = match state.segment {
-            Some(ref segment) => segment,
-            None => {
-                gst::error!(CAT, obj: element, "Got buffer before segment");
-                return Err(gst::FlowError::Error);
-            }
-        };
-
         if state.caps.is_none() {
             gst::error!(CAT, obj: element, "Got buffer before caps");
             return Err(gst::FlowError::NotNegotiated);
@@ -393,10 +386,9 @@ impl FMP4Mux {
         element: &super::FMP4Mux,
         state: &mut State,
         settings: &Settings,
+        segment: &gst::FormattedSegment<gst::ClockTime>,
         pts: gst::ClockTime,
     ) -> Result<Option<gst::Event>, gst::FlowError> {
-        let segment = state.segment.as_ref().expect("no segment");
-
         // If we never sent a force-keyunit event then wait until the earliest PTS of the first GOP
         // is known and send one now.
         //
@@ -517,7 +509,7 @@ impl FMP4Mux {
             );
 
             let mut fmp4_header = None;
-            if !state.headers_since_eos {
+            if !state.generated_headers {
                 let mut buffer = state.stream_header.as_ref().unwrap().copy();
                 {
                     let buffer = buffer.get_mut().unwrap();
@@ -532,7 +524,7 @@ impl FMP4Mux {
                 fmp4_header = Some(buffer);
 
                 state.earliest_pts = Some(earliest_pts);
-                state.headers_since_eos = true;
+                state.generated_headers = true;
             }
 
             let mut buffers = drain_gops
@@ -719,389 +711,23 @@ impl FMP4Mux {
 
         Ok(Some((list, caps)))
     }
-
-    fn sink_chain(
-        &self,
-        _pad: &gst::Pad,
-        element: &super::FMP4Mux,
-        buffer: gst::Buffer,
-    ) -> Result<gst::FlowSuccess, gst::FlowError> {
-        let settings = self.settings.lock().unwrap().clone();
-
-        let mut upstream_events = vec![];
-
-        let buffers = {
-            let mut state = self.state.lock().unwrap();
-
-            let pts = buffer.pts();
-
-            // Queue up the buffer and update GOP tracking state
-            self.queue_input(element, &mut state, buffer)?;
-
-            // If we have a PTS with this buffer, check if a new force-keyunit event for the next
-            // fragment start has to be created
-            if let Some(pts) = pts {
-                if let Some(event) =
-                    self.create_force_keyunit_event(element, &mut state, &settings, pts)?
-                {
-                    upstream_events.push(event);
-                }
-            }
-
-            // If enough GOPs were queued, drain and create the output fragment
-            self.drain(element, &mut state, &settings, false)?
-        };
-
-        for event in upstream_events {
-            self.sinkpad.push_event(event);
-        }
-
-        if let Some(buffers) = buffers {
-            gst::trace!(CAT, obj: element, "Pushing buffer list {:?}", buffers);
-            self.srcpad.push_list(buffers)?;
-        }
-
-        Ok(gst::FlowSuccess::Ok)
-    }
-
-    fn sink_event(&self, pad: &gst::Pad, element: &super::FMP4Mux, mut event: gst::Event) -> bool {
-        use gst::EventView;
-
-        gst::trace!(CAT, obj: pad, "Handling event {:?}", event);
-
-        match event.view() {
-            EventView::Segment(ev) => {
-                let segment = match ev.segment().downcast_ref::<gst::ClockTime>() {
-                    Some(segment) => {
-                        gst::info!(CAT, obj: pad, "Received segment {:?}", segment);
-                        segment.clone()
-                    }
-                    None => {
-                        gst::warning!(
-                            CAT,
-                            obj: pad,
-                            "Received non-TIME segment, replacing with default TIME segment"
-                        );
-                        let segment = gst::FormattedSegment::new();
-                        event = gst::event::Segment::builder(&segment)
-                            .seqnum(event.seqnum())
-                            .build();
-                        segment
-                    }
-                };
-
-                self.state.lock().unwrap().segment = Some(segment);
-
-                self.srcpad.push_event(event)
-            }
-            EventView::Caps(ev) => {
-                let caps = ev.caps_owned();
-
-                gst::info!(CAT, obj: pad, "Received caps {:?}", caps);
-                let caps = {
-                    let settings = self.settings.lock().unwrap().clone();
-                    let mut state = self.state.lock().unwrap();
-
-                    let s = caps.structure(0).unwrap();
-
-                    match s.name() {
-                        "video/x-h264" | "video/x-h265" => {
-                            if !s.has_field_with_type("codec_data", gst::Buffer::static_type()) {
-                                gst::error!(CAT, obj: pad, "Received caps without codec_data");
-                                return false;
-                            }
-                        }
-                        "audio/mpeg" => {
-                            if !s.has_field_with_type("codec_data", gst::Buffer::static_type()) {
-                                gst::error!(CAT, obj: pad, "Received caps without codec_data");
-                                return false;
-                            }
-                            state.intra_only = true;
-                        }
-                        _ => unreachable!(),
-                    }
-
-                    state.caps = Some(caps);
-
-                    let (_, caps) = match self.update_header(element, &mut state, &settings, false)
-                    {
-                        Ok(Some(res)) => res,
-                        _ => {
-                            return false;
-                        }
-                    };
-
-                    caps
-                };
-
-                self.srcpad.push_event(gst::event::Caps::new(&caps))
-            }
-            EventView::Tag(_ev) => {
-                // TODO: Maybe store for putting into the headers of the next fragment?
-
-                pad.event_default(Some(element), event)
-            }
-            EventView::Gap(_ev) => {
-                // TODO: queue up and check if draining is needed now
-                // i.e. make the last sample much longer
-                true
-            }
-            EventView::Eos(_ev) => {
-                let settings = self.settings.lock().unwrap().clone();
-
-                let drained = self.drain(element, &mut self.state.lock().unwrap(), &settings, true);
-                let update_header =
-                    drained.is_ok() && settings.header_update_mode != super::HeaderUpdateMode::None;
-
-                match drained {
-                    Ok(Some(buffers)) => {
-                        gst::trace!(CAT, obj: element, "Pushing buffer list {:?}", buffers);
-
-                        if let Err(err) = self.srcpad.push_list(buffers) {
-                            gst::error!(
-                                CAT,
-                                obj: element,
-                                "Failed pushing EOS buffers downstream: {:?}",
-                                err,
-                            );
-                        }
-                    }
-                    Ok(None) => {}
-                    Err(err) => {
-                        gst::error!(CAT, obj: element, "Failed draining at EOS: {:?}", err);
-                    }
-                }
-
-                if update_header {
-                    let updated_header = self.update_header(
-                        element,
-                        &mut self.state.lock().unwrap(),
-                        &settings,
-                        true,
-                    );
-                    match updated_header {
-                        Ok(Some((buffer_list, caps))) => {
-                            match settings.header_update_mode {
-                                super::HeaderUpdateMode::None => unreachable!(),
-                                super::HeaderUpdateMode::Rewrite => {
-                                    let mut q = gst::query::Seeking::new(gst::Format::Bytes);
-                                    if self.srcpad.peer_query(&mut q) && q.result().0 {
-                                        // Seek to the beginning with a default bytes segment
-                                        self.srcpad.push_event(gst::event::Segment::new(
-                                            &gst::FormattedSegment::<gst::format::Bytes>::new(),
-                                        ));
-
-                                        self.srcpad.push_event(gst::event::Caps::new(&caps));
-                                        if let Err(err) = self.srcpad.push_list(buffer_list) {
-                                            gst::error!(
-                                                CAT,
-                                                obj: element,
-                                                "Failed pushing updated header buffer downstream: {:?}",
-                                                err,
-                                            );
-                                        }
-                                    } else {
-                                        gst::error!(CAT, obj: element, "Can't rewrite header because downstream is not seekable");
-                                    }
-                                }
-                                super::HeaderUpdateMode::Update => {
-                                    self.srcpad.push_event(gst::event::Caps::new(&caps));
-                                    if let Err(err) = self.srcpad.push_list(buffer_list) {
-                                        gst::error!(
-                                            CAT,
-                                            obj: element,
-                                            "Failed pushing updated header buffer downstream: {:?}",
-                                            err,
-                                        );
-                                    }
-                                }
-                            }
-                        }
-                        Ok(None) => {}
-                        Err(err) => {
-                            gst::error!(
-                                CAT,
-                                obj: element,
-                                "Failed to generate updated header: {:?}",
-                                err
-                            );
-                        }
-                    }
-                }
-                self.state.lock().unwrap().headers_since_eos = false;
-
-                pad.event_default(Some(element), event)
-            }
-            EventView::FlushStop(_ev) => {
-                let mut state = self.state.lock().unwrap();
-
-                state.segment = None;
-                state.queued_gops.clear();
-                state.queued_duration = gst::ClockTime::ZERO;
-                state.dts_offset = None;
-                state.last_force_keyunit_time = None;
-                state.current_offset = 0;
-                state.fragment_offsets.clear();
-
-                pad.event_default(Some(element), event)
-            }
-            _ => pad.event_default(Some(element), event),
-        }
-    }
-
-    fn sink_query(
-        &self,
-        pad: &gst::Pad,
-        element: &super::FMP4Mux,
-        query: &mut gst::QueryRef,
-    ) -> bool {
-        use gst::QueryViewMut;
-
-        gst::trace!(CAT, obj: pad, "Handling query {:?}", query);
-
-        match query.view_mut() {
-            QueryViewMut::Caps(q) => {
-                let state = self.state.lock().unwrap();
-
-                let allowed_caps = if let Some(ref caps) = state.caps {
-                    // TODO: Maybe allow codec_data changes and similar?
-                    caps.clone()
-                } else {
-                    pad.pad_template_caps()
-                };
-
-                if let Some(filter_caps) = q.filter() {
-                    let res = filter_caps
-                        .intersect_with_mode(&allowed_caps, gst::CapsIntersectMode::First);
-                    q.set_result(&res);
-                } else {
-                    q.set_result(&allowed_caps);
-                }
-
-                true
-            }
-            _ => pad.query_default(Some(element), query),
-        }
-    }
-
-    fn src_event(&self, pad: &gst::Pad, element: &super::FMP4Mux, event: gst::Event) -> bool {
-        use gst::EventView;
-
-        gst::trace!(CAT, obj: pad, "Handling event {:?}", event);
-
-        match event.view() {
-            EventView::Seek(_ev) => false,
-            _ => pad.event_default(Some(element), event),
-        }
-    }
-
-    fn src_query(
-        &self,
-        pad: &gst::Pad,
-        element: &super::FMP4Mux,
-        query: &mut gst::QueryRef,
-    ) -> bool {
-        use gst::QueryViewMut;
-
-        gst::trace!(CAT, obj: pad, "Handling query {:?}", query);
-
-        match query.view_mut() {
-            QueryViewMut::Seeking(q) => {
-                // We can't really handle seeking, it would break everything
-                q.set(false, gst::ClockTime::ZERO.into(), gst::ClockTime::NONE);
-                true
-            }
-            QueryViewMut::Latency(q) => {
-                if !self.sinkpad.peer_query(q.query_mut()) {
-                    return false;
-                }
-
-                let settings = self.settings.lock().unwrap();
-                let (live, min, max) = q.result();
-                gst::info!(
-                    CAT,
-                    obj: pad,
-                    "Upstream latency: live {}, min {}, max {}",
-                    live,
-                    min,
-                    max.display()
-                );
-                let (min, max) = (
-                    min + settings.fragment_duration,
-                    max.opt_add(settings.fragment_duration),
-                );
-                gst::info!(
-                    CAT,
-                    obj: pad,
-                    "Returning latency: live {}, min {}, max {}",
-                    live,
-                    min,
-                    max.display()
-                );
-                q.set(live, min, max);
-
-                true
-            }
-            _ => pad.query_default(Some(element), query),
-        }
-    }
 }
 
 #[glib::object_subclass]
 impl ObjectSubclass for FMP4Mux {
     const NAME: &'static str = "GstFMP4Mux";
     type Type = super::FMP4Mux;
-    type ParentType = gst::Element;
+    type ParentType = gst_base::Aggregator;
     type Class = Class;
 
     fn with_class(klass: &Self::Class) -> Self {
         let templ = klass.pad_template("sink").unwrap();
-        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
-            .chain_function(|pad, parent, buffer| {
-                FMP4Mux::catch_panic_pad_function(
-                    parent,
-                    || Err(gst::FlowError::Error),
-                    |fmp4mux, element| fmp4mux.sink_chain(pad, element, buffer),
-                )
-            })
-            .event_function(|pad, parent, event| {
-                FMP4Mux::catch_panic_pad_function(
-                    parent,
-                    || false,
-                    |fmp4mux, element| fmp4mux.sink_event(pad, element, event),
-                )
-            })
-            .query_function(|pad, parent, query| {
-                FMP4Mux::catch_panic_pad_function(
-                    parent,
-                    || false,
-                    |fmp4mux, element| fmp4mux.sink_query(pad, element, query),
-                )
-            })
-            .flags(gst::PadFlags::ACCEPT_INTERSECT)
-            .build();
-
-        let templ = klass.pad_template("src").unwrap();
-        let srcpad = gst::Pad::builder_with_template(&templ, Some("src"))
-            .event_function(|pad, parent, event| {
-                FMP4Mux::catch_panic_pad_function(
-                    parent,
-                    || false,
-                    |fmp4mux, element| fmp4mux.src_event(pad, element, event),
-                )
-            })
-            .query_function(|pad, parent, query| {
-                FMP4Mux::catch_panic_pad_function(
-                    parent,
-                    || false,
-                    |fmp4mux, element| fmp4mux.src_query(pad, element, query),
-                )
-            })
-            .flags(gst::PadFlags::FIXED_CAPS | gst::PadFlags::ACCEPT_TEMPLATE)
-            .build();
+        let sinkpad =
+            gst::PadBuilder::<gst_base::AggregatorPad>::from_template(&templ, Some("sink"))
+                .flags(gst::PadFlags::ACCEPT_INTERSECT)
+                .build();
 
         Self {
-            srcpad,
             sinkpad,
             settings: Mutex::default(),
             state: Mutex::default(),
@@ -1153,7 +779,7 @@ impl ObjectImpl for FMP4Mux {
 
     fn set_property(
         &self,
-        _obj: &Self::Type,
+        obj: &Self::Type,
         _id: usize,
         value: &glib::Value,
         pspec: &glib::ParamSpec,
@@ -1161,7 +787,12 @@ impl ObjectImpl for FMP4Mux {
         match pspec.name() {
             "fragment-duration" => {
                 let mut settings = self.settings.lock().unwrap();
-                settings.fragment_duration = value.get().expect("type checked upstream");
+                let fragment_duration = value.get().expect("type checked upstream");
+                if settings.fragment_duration != fragment_duration {
+                    settings.fragment_duration = fragment_duration;
+                    drop(settings);
+                    obj.set_latency(fragment_duration, None);
+                }
             }
 
             "header-update-mode" => {
@@ -1213,37 +844,379 @@ impl ObjectImpl for FMP4Mux {
         self.parent_constructed(obj);
 
         obj.add_pad(&self.sinkpad).unwrap();
-        obj.add_pad(&self.srcpad).unwrap();
+        obj.set_latency(Settings::default().fragment_duration, None);
     }
 }
 
 impl GstObjectImpl for FMP4Mux {}
 
 impl ElementImpl for FMP4Mux {
-    #[allow(clippy::single_match)]
-    fn change_state(
+    fn release_pad(&self, _element: &Self::Type, _pad: &gst::Pad) {}
+
+    fn request_new_pad(
         &self,
-        element: &Self::Type,
-        transition: gst::StateChange,
-    ) -> Result<gst::StateChangeSuccess, gst::StateChangeError> {
-        gst::trace!(CAT, obj: element, "Changing state {:?}", transition);
+        _element: &Self::Type,
+        _templ: &gst::PadTemplate,
+        _name: Option<String>,
+        _caps: Option<&gst::Caps>,
+    ) -> Option<gst::Pad> {
+        None
+    }
+}
+
+impl AggregatorImpl for FMP4Mux {
+    fn sink_query(
+        &self,
+        aggregator: &Self::Type,
+        aggregator_pad: &gst_base::AggregatorPad,
+        query: &mut gst::QueryRef,
+    ) -> bool {
+        use gst::QueryViewMut;
 
-        let res = self.parent_change_state(element, transition)?;
+        gst::trace!(CAT, obj: aggregator_pad, "Handling query {:?}", query);
+
+        match query.view_mut() {
+            QueryViewMut::Caps(q) => {
+                let state = self.state.lock().unwrap();
+
+                let allowed_caps = if let Some(ref caps) = state.caps {
+                    // TODO: Maybe allow codec_data changes and similar?
+                    caps.clone()
+                } else {
+                    aggregator_pad.pad_template_caps()
+                };
+
+                if let Some(filter_caps) = q.filter() {
+                    let res = filter_caps
+                        .intersect_with_mode(&allowed_caps, gst::CapsIntersectMode::First);
+                    q.set_result(&res);
+                } else {
+                    q.set_result(&allowed_caps);
+                }
 
-        match transition {
-            gst::StateChange::PausedToReady => {
-                *self.state.lock().unwrap() = State::default();
+                true
             }
-            _ => (),
+            _ => self.parent_sink_query(aggregator, aggregator_pad, query),
         }
+    }
+
+    fn sink_event_pre_queue(
+        &self,
+        aggregator: &Self::Type,
+        aggregator_pad: &gst_base::AggregatorPad,
+        mut event: gst::Event,
+    ) -> Result<gst::FlowSuccess, gst::FlowError> {
+        use gst::EventView;
 
-        Ok(res)
+        gst::trace!(CAT, obj: aggregator_pad, "Handling event {:?}", event);
+
+        match event.view() {
+            EventView::Segment(ev) => {
+                if ev.segment().format() != gst::Format::Time {
+                    gst::warning!(
+                        CAT,
+                        obj: aggregator_pad,
+                        "Received non-TIME segment, replacing with default TIME segment"
+                    );
+                    let segment = gst::FormattedSegment::<gst::ClockTime>::new();
+                    event = gst::event::Segment::builder(&segment)
+                        .seqnum(event.seqnum())
+                        .build();
+                }
+                self.parent_sink_event_pre_queue(aggregator, aggregator_pad, event)
+            }
+            _ => self.parent_sink_event_pre_queue(aggregator, aggregator_pad, event),
+        }
+    }
+
+    fn sink_event(
+        &self,
+        aggregator: &Self::Type,
+        aggregator_pad: &gst_base::AggregatorPad,
+        event: gst::Event,
+    ) -> bool {
+        use gst::EventView;
+
+        gst::trace!(CAT, obj: aggregator_pad, "Handling event {:?}", event);
+
+        match event.view() {
+            EventView::Segment(ev) => {
+                // Already fixed-up above to always be a TIME segment
+                let segment = ev
+                    .segment()
+                    .clone()
+                    .downcast::<gst::ClockTime>()
+                    .expect("non-TIME segment");
+                gst::info!(CAT, obj: aggregator_pad, "Received segment {:?}", segment);
+                aggregator.update_segment(&segment);
+
+                self.parent_sink_event(aggregator, aggregator_pad, event)
+            }
+            EventView::Caps(ev) => {
+                let caps = ev.caps_owned();
+
+                gst::info!(CAT, obj: aggregator_pad, "Received caps {:?}", caps);
+                let caps = {
+                    let settings = self.settings.lock().unwrap().clone();
+                    let mut state = self.state.lock().unwrap();
+
+                    let s = caps.structure(0).unwrap();
+
+                    match s.name() {
+                        "video/x-h264" | "video/x-h265" => {
+                            if !s.has_field_with_type("codec_data", gst::Buffer::static_type()) {
+                                gst::error!(
+                                    CAT,
+                                    obj: aggregator_pad,
+                                    "Received caps without codec_data"
+                                );
+                                return false;
+                            }
+                        }
+                        "audio/mpeg" => {
+                            if !s.has_field_with_type("codec_data", gst::Buffer::static_type()) {
+                                gst::error!(
+                                    CAT,
+                                    obj: aggregator_pad,
+                                    "Received caps without codec_data"
+                                );
+                                return false;
+                            }
+                            state.intra_only = true;
+                        }
+                        _ => unreachable!(),
+                    }
+
+                    state.caps = Some(caps);
+
+                    let (_, caps) =
+                        match self.update_header(aggregator, &mut state, &settings, false) {
+                            Ok(Some(res)) => res,
+                            _ => {
+                                return false;
+                            }
+                        };
+
+                    caps
+                };
+
+                aggregator.set_src_caps(&caps);
+
+                self.parent_sink_event(aggregator, aggregator_pad, event)
+            }
+            EventView::Tag(_ev) => {
+                // TODO: Maybe store for putting into the headers of the next fragment?
+
+                self.parent_sink_event(aggregator, aggregator_pad, event)
+            }
+            EventView::Gap(_ev) => {
+                // TODO: queue up and check if draining is needed now
+                // i.e. make the last sample much longer
+                true
+            }
+            _ => self.parent_sink_event(aggregator, aggregator_pad, event),
+        }
+    }
+
+    fn src_query(&self, aggregator: &Self::Type, query: &mut gst::QueryRef) -> bool {
+        use gst::QueryViewMut;
+
+        gst::trace!(CAT, obj: aggregator, "Handling query {:?}", query);
+
+        match query.view_mut() {
+            QueryViewMut::Seeking(q) => {
+                // We can't really handle seeking, it would break everything
+                q.set(false, gst::ClockTime::ZERO.into(), gst::ClockTime::NONE);
+                true
+            }
+            _ => self.parent_src_query(aggregator, query),
+        }
+    }
+
+    fn src_event(&self, aggregator: &Self::Type, event: gst::Event) -> bool {
+        use gst::EventView;
+
+        gst::trace!(CAT, obj: aggregator, "Handling event {:?}", event);
+
+        match event.view() {
+            EventView::Seek(_ev) => false,
+            _ => self.parent_src_event(aggregator, event),
+        }
+    }
+
+    fn flush(&self, aggregator: &Self::Type) -> Result<gst::FlowSuccess, gst::FlowError> {
+        self.parent_flush(aggregator)?;
+
+        let mut state = self.state.lock().unwrap();
+
+        state.queued_gops.clear();
+        state.queued_duration = gst::ClockTime::ZERO;
+        state.dts_offset = None;
+        state.last_force_keyunit_time = None;
+        state.current_offset = 0;
+        state.fragment_offsets.clear();
+
+        Ok(gst::FlowSuccess::Ok)
+    }
+
+    fn stop(&self, aggregator: &Self::Type) -> Result<(), gst::ErrorMessage> {
+        gst::trace!(CAT, obj: aggregator, "Stopping");
+
+        let _ = self.parent_stop(aggregator);
+        *self.state.lock().unwrap() = State::default();
+        Ok(())
+    }
+
+    fn start(&self, aggregator: &Self::Type) -> Result<(), gst::ErrorMessage> {
+        gst::trace!(CAT, obj: aggregator, "Starting");
+
+        self.parent_start(aggregator)?;
+        *self.state.lock().unwrap() = State::default();
+        Ok(())
+    }
+
+    fn negotiate(&self, _aggregator: &Self::Type) -> bool {
+        true
+    }
+
+    fn aggregate(
+        &self,
+        aggregator: &Self::Type,
+        _timeout: bool,
+    ) -> Result<gst::FlowSuccess, gst::FlowError> {
+        let settings = self.settings.lock().unwrap().clone();
+
+        let is_eos;
+        let mut upstream_events = vec![];
+
+        let buffers = {
+            let mut state = self.state.lock().unwrap();
+
+            let segment = match self
+                .sinkpad
+                .segment()
+                .clone()
+                .downcast::<gst::ClockTime>()
+                .ok()
+            {
+                Some(segment) => segment,
+                None => {
+                    gst::error!(CAT, obj: aggregator, "Got buffer before segment");
+                    return Err(gst::FlowError::Error);
+                }
+            };
+
+            let buffer = self.sinkpad.pop_buffer();
+            is_eos = buffer.is_none() && self.sinkpad.is_eos();
+
+            if let Some(buffer) = buffer {
+                let pts = buffer.pts();
+
+                // Queue up the buffer and update GOP tracking state
+                self.queue_input(aggregator, &mut state, &segment, buffer)?;
+
+                // If we have a PTS with this buffer, check if a new force-keyunit event for the next
+                // fragment start has to be created
+                if let Some(pts) = pts {
+                    if let Some(event) = self.create_force_keyunit_event(
+                        aggregator, &mut state, &settings, &segment, pts,
+                    )? {
+                        upstream_events.push(event);
+                    }
+                }
+            }
+
+            // If enough GOPs were queued, drain and create the output fragment
+            self.drain(aggregator, &mut state, &settings, is_eos)?
+        };
+
+        for event in upstream_events {
+            self.sinkpad.push_event(event);
+        }
+
+        if let Some(buffers) = buffers {
+            gst::trace!(CAT, obj: aggregator, "Pushing buffer list {:?}", buffers);
+            aggregator.finish_buffer_list(buffers)?;
+        }
+
+        if is_eos {
+            if settings.header_update_mode != super::HeaderUpdateMode::None {
+                let updated_header = self.update_header(
+                    aggregator,
+                    &mut self.state.lock().unwrap(),
+                    &settings,
+                    true,
+                );
+                match updated_header {
+                    Ok(Some((buffer_list, caps))) => {
+                        match settings.header_update_mode {
+                            super::HeaderUpdateMode::None => unreachable!(),
+                            super::HeaderUpdateMode::Rewrite => {
+                                let src_pad = aggregator.src_pad();
+                                let mut q = gst::query::Seeking::new(gst::Format::Bytes);
+                                if src_pad.peer_query(&mut q) && q.result().0 {
+                                    // Seek to the beginning with a default bytes segment
+                                    aggregator
+                                        .update_segment(
+                                            &gst::FormattedSegment::<gst::format::Bytes>::new(),
+                                        );
+
+                                    aggregator.set_src_caps(&caps);
+
+                                    if let Err(err) = aggregator.finish_buffer_list(buffer_list) {
+                                        gst::error!(
+                                            CAT,
+                                            obj: aggregator,
+                                            "Failed pushing updated header buffer downstream: {:?}",
+                                            err,
+                                        );
+                                    }
+                                } else {
+                                    gst::error!(
+                                        CAT,
+                                        obj: aggregator,
+                                        "Can't rewrite header because downstream is not seekable"
+                                    );
+                                }
+                            }
+                            super::HeaderUpdateMode::Update => {
+                                aggregator.set_src_caps(&caps);
+                                if let Err(err) = aggregator.finish_buffer_list(buffer_list) {
+                                    gst::error!(
+                                        CAT,
+                                        obj: aggregator,
+                                        "Failed pushing updated header buffer downstream: {:?}",
+                                        err,
+                                    );
+                                }
+                            }
+                        }
+                    }
+                    Ok(None) => {}
+                    Err(err) => {
+                        gst::error!(
+                            CAT,
+                            obj: aggregator,
+                            "Failed to generate updated header: {:?}",
+                            err
+                        );
+                    }
+                }
+            }
+
+            // Need to generate new headers if started again after EOS
+            self.state.lock().unwrap().generated_headers = false;
+
+            Err(gst::FlowError::Eos)
+        } else {
+            Ok(gst::FlowSuccess::Ok)
+        }
     }
 }
 
 #[repr(C)]
 pub(crate) struct Class {
-    parent: gst::ffi::GstElementClass,
+    parent: gst_base::ffi::GstAggregatorClass,
     variant: super::Variant,
 }
 
@@ -1252,7 +1225,7 @@ unsafe impl ClassStruct for Class {
 }
 
 impl std::ops::Deref for Class {
-    type Target = glib::Class<gst::Element>;
+    type Target = glib::Class<gst_base::Aggregator>;
 
     fn deref(&self) -> &Self::Target {
         unsafe { &*(&self.parent as *const _ as *const _) }
@@ -1268,7 +1241,7 @@ unsafe impl<T: FMP4MuxImpl> IsSubclassable<T> for super::FMP4Mux {
     }
 }
 
-pub(crate) trait FMP4MuxImpl: ElementImpl {
+pub(crate) trait FMP4MuxImpl: AggregatorImpl {
     const VARIANT: super::Variant;
 }
 
@@ -1348,6 +1321,8 @@ impl ElementImpl for ISOFMP4Mux {
     }
 }
 
+impl AggregatorImpl for ISOFMP4Mux {}
+
 impl FMP4MuxImpl for ISOFMP4Mux {
     const VARIANT: super::Variant = super::Variant::ISO;
 }
@@ -1428,6 +1403,8 @@ impl ElementImpl for CMAFMux {
     }
 }
 
+impl AggregatorImpl for CMAFMux {}
+
 impl FMP4MuxImpl for CMAFMux {
     const VARIANT: super::Variant = super::Variant::CMAF;
 }
@@ -1508,6 +1485,8 @@ impl ElementImpl for DASHMP4Mux {
     }
 }
 
+impl AggregatorImpl for DASHMP4Mux {}
+
 impl FMP4MuxImpl for DASHMP4Mux {
     const VARIANT: super::Variant = super::Variant::DASH;
 }
diff --git a/generic/fmp4/src/fmp4mux/mod.rs b/generic/fmp4/src/fmp4mux/mod.rs
index 567195ff..0311c417 100644
--- a/generic/fmp4/src/fmp4mux/mod.rs
+++ b/generic/fmp4/src/fmp4mux/mod.rs
@@ -13,19 +13,19 @@ mod boxes;
 mod imp;
 
 glib::wrapper! {
-    pub(crate) struct FMP4Mux(ObjectSubclass<imp::FMP4Mux>) @extends gst::Element, gst::Object;
+    pub(crate) struct FMP4Mux(ObjectSubclass<imp::FMP4Mux>) @extends gst_base::Aggregator, gst::Element, gst::Object;
 }
 
 glib::wrapper! {
-    pub(crate) struct ISOFMP4Mux(ObjectSubclass<imp::ISOFMP4Mux>) @extends FMP4Mux, gst::Element, gst::Object;
+    pub(crate) struct ISOFMP4Mux(ObjectSubclass<imp::ISOFMP4Mux>) @extends FMP4Mux, gst_base::Aggregator, gst::Element, gst::Object;
 }
 
 glib::wrapper! {
-    pub(crate) struct CMAFMux(ObjectSubclass<imp::CMAFMux>) @extends FMP4Mux, gst::Element, gst::Object;
+    pub(crate) struct CMAFMux(ObjectSubclass<imp::CMAFMux>) @extends FMP4Mux, gst_base::Aggregator, gst::Element, gst::Object;
 }
 
 glib::wrapper! {
-    pub(crate) struct DASHMP4Mux(ObjectSubclass<imp::DASHMP4Mux>) @extends FMP4Mux, gst::Element, gst::Object;
+    pub(crate) struct DASHMP4Mux(ObjectSubclass<imp::DASHMP4Mux>) @extends FMP4Mux, gst_base::Aggregator, gst::Element, gst::Object;
 }
 
 pub fn register(plugin: &gst::Plugin) -> Result<(), glib::BoolError> {