Skip to content
This repository was archived by the owner on Oct 24, 2022. It is now read-only.

gcc: Take fec and number of encoders into account #87

Merged
merged 1 commit into from
Sep 16, 2022
Merged

gcc: Take fec and number of encoders into account #87

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Fix fec ratio, max-bitrate and consider encoders
  • Loading branch information
@gondaruk
gondaruk committed Sep 7, 2022
commit e6d2af195a9042c9a212d95b0713a234bfd2cbf1
124 changes: 69 additions & 55 deletions plugins/src/webrtcsink/imp.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,9 @@ const DEFAULT_DO_FEC: bool = true;
const DEFAULT_DO_RETRANSMISSION: bool = true;
const DEFAULT_ENABLE_DATA_CHANNEL_NAVIGATION: bool = false;
const DEFAULT_START_BITRATE: u32 = 2048000;
/* Start adding some FEC when the bitrate > 2Mbps as we found experimentally
* that it is not worth it below that threshold */
const DO_FEC_THRESHOLD: u32 = 2000000;

#[derive(Debug, Clone, Copy)]
struct CCInfo {
Expand Down Expand Up @@ -139,8 +142,12 @@ struct Session {
webrtc_pads: HashMap<u32, WebRTCPad>,
peer_id: String,
encoders: Vec<VideoEncoder>,
// Our Homegrown controller

// Our Homegrown controller (if cc_info.heuristic == Homegrown)
congestion_controller: Option<CongestionController>,
// Our BandwidthEstimator (if cc_info.heuristic == GoogleCongestionControl)
rtpgccbwe: Option<gst::Element>,

sdp: Option<gst_sdp::SDPMessage>,
stats: gst::Structure,

Expand Down Expand Up @@ -732,6 +739,7 @@ impl Session {
webrtcbin: gst::Element,
peer_id: String,
congestion_controller: Option<CongestionController>,
rtpgccbwe: Option<gst::Element>,
cc_info: CCInfo,
) -> Self {
Self {
Expand All @@ -742,6 +750,7 @@ impl Session {
cc_info,
rtprtxsend: None,
congestion_controller,
rtpgccbwe,
stats: gst::Structure::new_empty("application/x-webrtc-stats"),
sdp: None,
webrtc_pads: HashMap::new(),
Expand Down Expand Up @@ -961,6 +970,11 @@ impl Session {
}

self.encoders.push(enc);

if let Some(ref rtpgccbwe) = self.rtpgccbwe.as_ref() {
let max_bitrate = self.cc_info.max_bitrate * (self.encoders.len() as u32);
rtpgccbwe.set_property("max-bitrate", max_bitrate);
}
}

let appsrc = appsrc.downcast::<gst_app::AppSrc>().unwrap();
Expand Down Expand Up @@ -1362,48 +1376,49 @@ impl WebRTCSink {
webrtcbin.set_property("turn-server", turn_server);
}

match settings.cc_info.heuristic {
let rtpgccbwe = match settings.cc_info.heuristic {
WebRTCSinkCongestionControl::GoogleCongestionControl => {
webrtcbin.connect_closure(
"request-aux-sender",
false,
glib::closure!(@watch element, @strong session_id
=> move |_webrtcbin: gst::Element, _transport: gst::Object| {

let settings = element.imp().settings.lock().unwrap();
let cc = match gst::ElementFactory::make("rtpgccbwe", None) {
Err(err) => {
glib::g_warning!("webrtcsink",
"The `rtpgccbwe` element is not available \
not doing any congestion control: {err:?}"
);
return None;
},
Ok(e) => {
let max_bitrate = (settings.cc_info.max_bitrate as f64 * if settings.do_fec { 1.5 } else { 1.}) as u32;
e.set_properties(&[
let rtpgccbwe = match gst::ElementFactory::make("rtpgccbwe", None) {
Err(err) => {
glib::g_warning!(
"webrtcsink",
"The `rtpgccbwe` element is not available \
not doing any congestion control: {err:?}"
);
None
}
Ok(cc) => {
webrtcbin.connect_closure(
"request-aux-sender",
false,
glib::closure!(@watch element, @strong session_id, @weak-allow-none cc
=> move |_webrtcbin: gst::Element, _transport: gst::Object| {

let cc = cc.unwrap();
let settings = element.imp().settings.lock().unwrap();

// TODO: Bind properties with @element's
cc.set_properties(&[
("min-bitrate", &settings.cc_info.min_bitrate),
("estimated-bitrate", &settings.cc_info.start_bitrate),
("max-bitrate", &max_bitrate),
("max-bitrate", &settings.cc_info.max_bitrate),
]);

// TODO: Bind properties with @element's

e
}
};
cc.connect_notify(Some("estimated-bitrate"),
glib::clone!(@weak element, @strong session_id
=> move |bwe, pspec| {
element.imp().set_bitrate(&element, &session_id,
bwe.property::<u32>(pspec.name()));
}
));

cc.connect_notify(Some("estimated-bitrate"),
glib::clone!(@weak element, @strong session_id
=> move |bwe, pspec| {
element.imp().set_bitrate(&element, &session_id,
bwe.property::<u32>(pspec.name()));
}
));
Some(cc)
}),
);

Some(cc)
}),
);
}
};

webrtcbin.connect_closure(
"deep-element-added",
Expand All @@ -1421,9 +1436,11 @@ impl WebRTCSink {
}
}),
);

rtpgccbwe
}
_ => (),
}
_ => None,
};

pipeline.add(&webrtcbin).unwrap();

Expand Down Expand Up @@ -1553,18 +1570,14 @@ impl WebRTCSink {
webrtcbin.clone(),
peer_id.clone(),
match settings.cc_info.heuristic {
WebRTCSinkCongestionControl::Homegrown => {
let max_bitrate = (settings.cc_info.max_bitrate as f64
* if settings.do_fec { 1.5 } else { 1. })
as u32;
Some(CongestionController::new(
&peer_id,
settings.cc_info.min_bitrate,
max_bitrate,
))
}
WebRTCSinkCongestionControl::Homegrown => Some(CongestionController::new(
&peer_id,
settings.cc_info.min_bitrate,
settings.cc_info.max_bitrate,
)),
_ => None,
},
rtpgccbwe,
settings.cc_info,
);

Expand All @@ -1589,7 +1602,7 @@ impl WebRTCSink {

session.stats_sigid = Some(rtp_session.connect_notify(Some("twcc-stats"),
glib::clone!(@strong session_id_str, @weak webrtcbin, @weak element => @default-panic, move |sess, pspec| {
// Run the Loss-based control algortithm on new peer TWCC feedbacks
// Run the Loss-based control algorithm on new peer TWCC feedbacks
element.imp().process_loss_stats(&element, &session_id_str, &sess.property::<gst::Structure>(pspec.name()));
})
));
Expand Down Expand Up @@ -1778,22 +1791,23 @@ impl WebRTCSink {
}

fn set_bitrate(&self, element: &super::WebRTCSink, peer_id: &str, bitrate: u32) {
let settings = element.imp().settings.lock().unwrap();
let mut state = element.imp().state.lock().unwrap();

if let Some(session) = state.sessions.get_mut(peer_id) {
let fec_ratio = {
// Start adding some FEC when the bitrate > 2Mbps as we found experimentally
// that it is not worth it below that threshold
if bitrate <= 2_000_000 || session.cc_info.max_bitrate <= 2_000_000 {
0f64
if settings.do_fec && bitrate > DO_FEC_THRESHOLD {
(bitrate as f64 - DO_FEC_THRESHOLD as f64)
/ (session.cc_info.max_bitrate as f64 - DO_FEC_THRESHOLD as f64)
} else {
(bitrate as f64 - 2_000_000.)
/ (session.cc_info.max_bitrate as f64 - 2_000_000.)
0f64
}
};

let fec_percentage = fec_ratio * 50f64;
let encoders_bitrate = ((bitrate as f64) / (1. + (fec_percentage / 100.))) as i32;
let encoders_bitrate = ((bitrate as f64)
/ (1. + (fec_percentage / 100.))
/ (session.encoders.len() as f64)) as i32;

if let Some(ref rtpxsend) = session.rtprtxsend.as_ref() {
rtpxsend.set_property("stuffing-kbps", (bitrate as f64 / 1000.) as i32);
Expand Down