gst-plugins-rs/generic/fmp4/examples/hls_live.rs
Mathieu Duponchelle 526f34d98b fmp4mux: HLS live example
Producing two audio playlists, a video playlist and a super
manifest, and implementing basic trimming of old segments.
2022-03-02 10:01:38 +00:00

580 lines
18 KiB
Rust

// Copyright (C) 2022 Mathieu Duponchelle <mathieu@centricular.com>
//
// This Source Code Form is subject to the terms of the Mozilla Public License, v2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at
// <https://mozilla.org/MPL/2.0/>.
//
// SPDX-License-Identifier: MPL-2.0
// This creates a live HLS stream with one video playlist and two video playlists.
// Basic trimming is implemented
use gst::prelude::*;
use std::collections::VecDeque;
use std::path::{Path, PathBuf};
use std::sync::{Arc, Mutex};
use anyhow::{anyhow, Error};
use chrono::{DateTime, Duration, SecondsFormat, Utc};
use m3u8_rs::{
AlternativeMedia, AlternativeMediaType, MasterPlaylist, MediaPlaylist, MediaSegment,
VariantStream,
};
struct State {
video_streams: Vec<VideoStream>,
audio_streams: Vec<AudioStream>,
all_mimes: Vec<String>,
path: PathBuf,
wrote_manifest: bool,
}
impl State {
fn maybe_write_manifest(&mut self) {
if self.wrote_manifest {
return;
}
if self.all_mimes.len() < self.video_streams.len() + self.audio_streams.len() {
return;
}
let mut all_mimes = self.all_mimes.clone();
all_mimes.sort();
all_mimes.dedup();
let playlist = MasterPlaylist {
version: 7,
variants: self
.video_streams
.iter()
.map(|stream| {
let mut path = PathBuf::new();
path.push(&stream.name);
path.push("manifest.m3u8");
VariantStream {
uri: path.as_path().display().to_string(),
bandwidth: stream.bitrate.to_string(),
codecs: Some(all_mimes.join(",")),
resolution: Some(format!("{}x{}", stream.width, stream.height)),
audio: Some("audio".to_string()),
..Default::default()
}
})
.collect(),
alternatives: self
.audio_streams
.iter()
.map(|stream| {
let mut path = PathBuf::new();
path.push(&stream.name);
path.push("manifest.m3u8");
AlternativeMedia {
media_type: AlternativeMediaType::Audio,
uri: Some(path.as_path().display().to_string()),
group_id: "audio".to_string(),
language: Some(stream.lang.clone()),
name: stream.name.clone(),
default: stream.default,
autoselect: stream.default,
channels: Some("2".to_string()),
..Default::default()
}
})
.collect(),
independent_segments: true,
..Default::default()
};
println!("Writing master manifest to {}", self.path.display());
let mut file = std::fs::File::create(&self.path).unwrap();
playlist
.write_to(&mut file)
.expect("Failed to write master playlist");
self.wrote_manifest = true;
}
}
struct Segment {
date_time: DateTime<Utc>,
duration: gst::ClockTime,
path: String,
}
struct UnreffedSegment {
removal_time: DateTime<Utc>,
path: String,
}
struct StreamState {
path: PathBuf,
segments: VecDeque<Segment>,
trimmed_segments: VecDeque<UnreffedSegment>,
start_date_time: Option<DateTime<Utc>>,
start_time: Option<gst::ClockTime>,
media_sequence: i32,
segment_index: u32,
}
struct VideoStream {
name: String,
bitrate: u32,
width: i32,
height: i32,
}
struct AudioStream {
name: String,
lang: String,
default: bool,
wave: String,
}
pub fn make_element(element: &str, name: Option<&str>) -> Result<gst::Element, Error> {
gst::ElementFactory::make(element, name)
.map_err(|_| anyhow!("Failed to make element {}", element))
}
fn trim_segments(state: &mut StreamState) {
// Arbitrary 5 segments window
while state.segments.len() > 5 {
let segment = state.segments.pop_front().unwrap();
state.media_sequence += 1;
state.trimmed_segments.push_back(UnreffedSegment {
// HLS spec mandates that segments are removed from the filesystem no sooner
// than the duration of the longest playlist + duration of the segment.
// This is 15 seconds (12.5 + 2.5) in our case, we use 20 seconds to be on the
// safe side
removal_time: segment
.date_time
.checked_add_signed(Duration::seconds(20))
.unwrap(),
path: segment.path.clone(),
});
}
while let Some(segment) = state.trimmed_segments.front() {
if segment.removal_time < state.segments.front().unwrap().date_time {
let segment = state.trimmed_segments.pop_front().unwrap();
let mut path = state.path.clone();
path.push(segment.path);
println!("Removing {}", path.display());
std::fs::remove_file(path).expect("Failed to remove old segment");
} else {
break;
}
}
}
fn update_manifest(state: &mut StreamState) {
// Now write the manifest
let mut path = state.path.clone();
path.push("manifest.m3u8");
println!("writing manifest to {}", path.display());
trim_segments(state);
let playlist = MediaPlaylist {
version: 7,
target_duration: 2.5,
media_sequence: state.media_sequence,
segments: state
.segments
.iter()
.enumerate()
.map(|(idx, segment)| MediaSegment {
uri: segment.path.to_string(),
duration: (segment.duration.nseconds() as f64
/ gst::ClockTime::SECOND.nseconds() as f64) as f32,
map: Some(m3u8_rs::Map {
uri: "init.cmfi".into(),
..Default::default()
}),
program_date_time: if idx == 0 {
Some(
segment
.date_time
.to_rfc3339_opts(SecondsFormat::Millis, false),
)
} else {
None
},
..Default::default()
})
.collect(),
end_list: false,
playlist_type: None,
i_frames_only: false,
start: None,
independent_segments: true,
..Default::default()
};
let mut file = std::fs::File::create(path).unwrap();
playlist
.write_to(&mut file)
.expect("Failed to write media playlist");
}
fn setup_appsink(appsink: &gst_app::AppSink, name: &str, path: &Path, is_video: bool) {
let mut path: PathBuf = path.into();
path.push(name);
let state = Arc::new(Mutex::new(StreamState {
segments: VecDeque::new(),
trimmed_segments: VecDeque::new(),
path,
start_date_time: None,
start_time: gst::ClockTime::NONE,
media_sequence: 0,
segment_index: 0,
}));
appsink.set_buffer_list(true);
appsink.set_callbacks(
gst_app::AppSinkCallbacks::builder()
.new_sample(move |sink| {
let sample = sink.pull_sample().map_err(|_| gst::FlowError::Eos)?;
let mut state = state.lock().unwrap();
// The muxer only outputs non-empty buffer lists
let mut buffer_list = sample.buffer_list_owned().expect("no buffer list");
assert!(!buffer_list.is_empty());
let mut first = buffer_list.get(0).unwrap();
// Each list contains a full segment, i.e. does not start with a DELTA_UNIT
assert!(!first.flags().contains(gst::BufferFlags::DELTA_UNIT));
// If the buffer has the DISCONT and HEADER flag set then it contains the media
// header, i.e. the `ftyp`, `moov` and other media boxes.
//
// This might be the initial header or the updated header at the end of the stream.
if first
.flags()
.contains(gst::BufferFlags::DISCONT | gst::BufferFlags::HEADER)
{
let mut path = state.path.clone();
std::fs::create_dir_all(&path).expect("failed to create directory");
path.push("init.cmfi");
println!("writing header to {}", path.display());
let map = first.map_readable().unwrap();
std::fs::write(path, &map).expect("failed to write header");
drop(map);
// Remove the header from the buffer list
buffer_list.make_mut().remove(0, 1);
// If the list is now empty then it only contained the media header and nothing
// else.
if buffer_list.is_empty() {
return Ok(gst::FlowSuccess::Ok);
}
// Otherwise get the next buffer and continue working with that.
first = buffer_list.get(0).unwrap();
}
// If the buffer only has the HEADER flag set then this is a segment header that is
// followed by one or more actual media buffers.
assert!(first.flags().contains(gst::BufferFlags::HEADER));
let mut path = state.path.clone();
let basename = format!(
"segment_{}.{}",
state.segment_index,
if is_video { "cmfv" } else { "cmfa" }
);
state.segment_index += 1;
path.push(&basename);
let segment = sample
.segment()
.expect("no segment")
.downcast_ref::<gst::ClockTime>()
.expect("no time segment");
let pts = segment
.to_running_time(first.pts().unwrap())
.expect("can't get running time");
if state.start_time.is_none() {
state.start_time = Some(pts);
}
if state.start_date_time.is_none() {
let now_utc = Utc::now();
let now_gst = sink.clock().unwrap().time().unwrap();
let pts_clock_time = pts + sink.base_time().unwrap();
let diff = now_gst.checked_sub(pts_clock_time).unwrap();
let pts_utc = now_utc
.checked_sub_signed(Duration::nanoseconds(diff.nseconds() as i64))
.unwrap();
state.start_date_time = Some(pts_utc);
}
let duration = first.duration().unwrap();
let mut file = std::fs::File::create(&path).expect("failed to open fragment");
for buffer in &*buffer_list {
use std::io::prelude::*;
let map = buffer.map_readable().unwrap();
file.write_all(&map).expect("failed to write fragment");
}
let date_time = state
.start_date_time
.unwrap()
.checked_add_signed(Duration::nanoseconds(
pts.opt_checked_sub(state.start_time)
.unwrap()
.unwrap()
.nseconds() as i64,
))
.unwrap();
println!(
"wrote segment with date time {} to {}",
date_time,
path.display()
);
state.segments.push_back(Segment {
duration,
path: basename.to_string(),
date_time,
});
update_manifest(&mut state);
Ok(gst::FlowSuccess::Ok)
})
.eos(move |_sink| {
unreachable!();
})
.build(),
);
}
fn probe_encoder(state: Arc<Mutex<State>>, enc: gst::Element) {
enc.static_pad("src").unwrap().add_probe(
gst::PadProbeType::EVENT_DOWNSTREAM,
move |_pad, info| match info.data {
Some(gst::PadProbeData::Event(ref ev)) => match ev.view() {
gst::EventView::Caps(e) => {
let mime = gst_pbutils::codec_utils_caps_get_mime_codec(&e.caps().to_owned());
let mut state = state.lock().unwrap();
state.all_mimes.push(mime.unwrap().into());
state.maybe_write_manifest();
gst::PadProbeReturn::Remove
}
_ => gst::PadProbeReturn::Ok,
},
_ => gst::PadProbeReturn::Ok,
},
);
}
impl VideoStream {
fn setup(
&self,
state: Arc<Mutex<State>>,
pipeline: &gst::Pipeline,
path: &Path,
) -> Result<(), Error> {
let src = make_element("videotestsrc", None)?;
let raw_capsfilter = make_element("capsfilter", None)?;
let timeoverlay = make_element("timeoverlay", None)?;
let enc = make_element("x264enc", None)?;
let h264_capsfilter = make_element("capsfilter", None)?;
let mux = make_element("cmafmux", None)?;
let appsink = make_element("appsink", None)?;
pipeline.add_many(&[
&src,
&raw_capsfilter,
&timeoverlay,
&enc,
&h264_capsfilter,
&mux,
&appsink,
])?;
gst::Element::link_many(&[
&src,
&raw_capsfilter,
&timeoverlay,
&enc,
&h264_capsfilter,
&mux,
&appsink,
])?;
raw_capsfilter.set_property(
"caps",
gst::Caps::builder("video/x-raw")
.field("format", "I420")
.field("width", self.width)
.field("height", self.height)
.field("framerate", gst::Fraction::new(30, 1))
.build(),
);
h264_capsfilter.set_property(
"caps",
gst::Caps::builder("video/x-h264")
.field("profile", "main")
.build(),
);
src.set_property("is-live", true);
enc.set_property("bframes", 0u32);
enc.set_property("bitrate", self.bitrate / 1000u32);
enc.set_property_from_str("tune", "zerolatency");
mux.set_property("fragment-duration", gst::ClockTime::from_mseconds(2500));
mux.set_property_from_str("header-update-mode", "update");
mux.set_property("write-mehd", true);
probe_encoder(state, enc);
let appsink = appsink.downcast::<gst_app::AppSink>().unwrap();
setup_appsink(&appsink, &self.name, path, true);
Ok(())
}
}
impl AudioStream {
fn setup(
&self,
state: Arc<Mutex<State>>,
pipeline: &gst::Pipeline,
path: &Path,
) -> Result<(), Error> {
let src = make_element("audiotestsrc", None)?;
let enc = make_element("avenc_aac", None)?;
let mux = make_element("cmafmux", None)?;
let appsink = make_element("appsink", None)?;
pipeline.add_many(&[&src, &enc, &mux, &appsink])?;
gst::Element::link_many(&[&src, &enc, &mux, &appsink])?;
src.set_property("is-live", true);
src.set_property_from_str("wave", &self.wave);
mux.set_property("fragment-duration", gst::ClockTime::from_mseconds(2500));
mux.set_property_from_str("header-update-mode", "update");
mux.set_property("write-mehd", true);
probe_encoder(state, enc);
let appsink = appsink.downcast::<gst_app::AppSink>().unwrap();
setup_appsink(&appsink, &self.name, path, false);
Ok(())
}
}
fn main() -> Result<(), Error> {
gst::init()?;
gstfmp4::plugin_register_static()?;
let path = PathBuf::from("hls_live_stream");
let pipeline = gst::Pipeline::new(None);
std::fs::create_dir_all(&path).expect("failed to create directory");
let mut manifest_path = path.clone();
manifest_path.push("manifest.m3u8");
let state = Arc::new(Mutex::new(State {
video_streams: vec![VideoStream {
name: "video_0".to_string(),
bitrate: 2_048_000,
width: 1280,
height: 720,
}],
audio_streams: vec![
AudioStream {
name: "audio_0".to_string(),
lang: "eng".to_string(),
default: true,
wave: "sine".to_string(),
},
AudioStream {
name: "audio_1".to_string(),
lang: "fre".to_string(),
default: false,
wave: "white-noise".to_string(),
},
],
all_mimes: vec![],
path: manifest_path.clone(),
wrote_manifest: false,
}));
{
let state_lock = state.lock().unwrap();
for stream in &state_lock.video_streams {
stream.setup(state.clone(), &pipeline, &path)?;
}
for stream in &state_lock.audio_streams {
stream.setup(state.clone(), &pipeline, &path)?;
}
}
pipeline.set_state(gst::State::Playing)?;
let bus = pipeline
.bus()
.expect("Pipeline without bus. Shouldn't happen!");
for msg in bus.iter_timed(gst::ClockTime::NONE) {
use gst::MessageView;
match msg.view() {
MessageView::Eos(..) => {
println!("EOS");
break;
}
MessageView::Error(err) => {
pipeline.set_state(gst::State::Null)?;
eprintln!(
"Got error from {}: {} ({})",
msg.src()
.map(|s| String::from(s.path_string()))
.unwrap_or_else(|| "None".into()),
err.error(),
err.debug().unwrap_or_else(|| "".into()),
);
break;
}
_ => (),
}
}
pipeline.set_state(gst::State::Null)?;
Ok(())
}