gstreamer-rs/tutorials/src/bin/basic-tutorial-8.rs

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use std::sync::{Arc, Mutex};
extern crate byte_slice_cast;
use byte_slice_cast::*;
extern crate gstreamer as gst;
use gst::prelude::*;
extern crate gstreamer_audio as gst_audio;
use gst_audio::AudioInfo;
extern crate gstreamer_app as gst_app;
use gst_app::{AppSink, AppSrc};
extern crate glib;
use glib::source::SourceId;
const CHUNK_SIZE: usize = 1024; // Amount of bytes we are sending in each buffer
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const SAMPLE_RATE: u32 = 44_100; // Samples per second we are sending
#[derive(Debug)]
struct CustomData {
source_id: Option<SourceId>,
num_samples: u64, // Number of samples generated so far (for timestamp generation)
// For waveform generation
a: f64,
b: f64,
c: f64,
d: f64,
appsrc: AppSrc,
appsink: AppSink,
}
impl CustomData {
fn new(appsrc: &AppSrc, appsink: &AppSink) -> CustomData {
CustomData {
source_id: None,
num_samples: 0,
a: 0.0,
b: 1.0,
c: 0.0,
d: 1.0,
appsrc: appsrc.clone(),
appsink: appsink.clone(),
}
}
}
fn main() {
// Initialize GStreamer
if let Err(err) = gst::init() {
eprintln!("Failed to initialize Gst: {}", err);
return;
}
let appsrc = gst::ElementFactory::make("appsrc", "audio_source").unwrap();
let tee = gst::ElementFactory::make("tee", "tee").unwrap();
let audio_queue = gst::ElementFactory::make("queue", "audio_queue").unwrap();
let audio_convert1 = gst::ElementFactory::make("audioconvert", "audio_convert1").unwrap();
let audio_resample = gst::ElementFactory::make("audioresample", "audio_resample").unwrap();
let audio_sink = gst::ElementFactory::make("autoaudiosink", "audio_sink").unwrap();
let video_queue = gst::ElementFactory::make("queue", "video_queue").unwrap();
let audio_convert2 = gst::ElementFactory::make("audioconvert", "audio_convert2").unwrap();
let visual = gst::ElementFactory::make("wavescope", "visual").unwrap();
let video_convert = gst::ElementFactory::make("videoconvert", "video_convert").unwrap();
let video_sink = gst::ElementFactory::make("autovideosink", "video_sink").unwrap();
let app_queue = gst::ElementFactory::make("queue", "app_queue").unwrap();
let appsink = gst::ElementFactory::make("appsink", "app_sink").unwrap();
let pipeline = gst::Pipeline::new("test-pipeline");
visual.set_property_from_str("shader", "none");
visual.set_property_from_str("style", "lines");
pipeline
.add_many(&[
&appsrc,
&tee,
&audio_queue,
&audio_convert1,
&audio_resample,
&audio_sink,
&video_queue,
&audio_convert2,
&visual,
&video_convert,
&video_sink,
&app_queue,
&appsink,
])
.unwrap();
gst::Element::link_many(&[&appsrc, &tee]).unwrap();
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gst::Element::link_many(&[&audio_queue, &audio_convert1, &audio_resample, &audio_sink])
.unwrap();
gst::Element::link_many(&[
&video_queue,
&audio_convert2,
&visual,
&video_convert,
&video_sink,
]).unwrap();
gst::Element::link_many(&[&app_queue, &appsink]).unwrap();
let tee_audio_pad = tee.get_request_pad("src_%u").unwrap();
println!(
"Obtained request pad {} for audio branch",
tee_audio_pad.get_name()
);
let queue_audio_pad = audio_queue.get_static_pad("sink").unwrap();
tee_audio_pad.link(&queue_audio_pad).into_result().unwrap();
let tee_video_pad = tee.get_request_pad("src_%u").unwrap();
println!(
"Obtained request pad {} for video branch",
tee_video_pad.get_name()
);
let queue_video_pad = video_queue.get_static_pad("sink").unwrap();
tee_video_pad.link(&queue_video_pad).into_result().unwrap();
let tee_app_pad = tee.get_request_pad("src_%u").unwrap();
let queue_app_pad = app_queue.get_static_pad("sink").unwrap();
tee_app_pad.link(&queue_app_pad).into_result().unwrap();
// configure appsrc
let info = AudioInfo::new(gst_audio::AudioFormat::S16le, SAMPLE_RATE, 1)
.build()
.unwrap();
let audio_caps = info.to_caps().unwrap();
let appsrc = appsrc
.clone()
.dynamic_cast::<AppSrc>()
.expect("Source element is expected to be an appsrc!");
appsrc.set_caps(&audio_caps);
appsrc.set_property_format(gst::Format::Time);
let appsink = appsink
.clone()
.dynamic_cast::<AppSink>()
.expect("Sink element is expected to be an appsink!");
let data: Arc<Mutex<CustomData>> = Arc::new(Mutex::new(CustomData::new(&appsrc, &appsink)));
let data_clone = Arc::clone(&data);
appsrc.connect_need_data(move |_, _size| {
let data = &data_clone;
let mut d = data.lock().unwrap();
if d.source_id.is_none() {
println!("start feeding");
let data_clone = Arc::clone(data);
d.source_id = Some(glib::source::idle_add(move || {
let data = &data_clone;
let (appsrc, buffer) = {
let mut data = data.lock().unwrap();
let mut buffer = gst::Buffer::with_size(CHUNK_SIZE).unwrap();
let num_samples = CHUNK_SIZE / 2; /* Each sample is 16 bits */
let pts = gst::SECOND
.mul_div_floor(data.num_samples, SAMPLE_RATE as u64)
.expect("u64 overflow");
let duration = gst::SECOND
.mul_div_floor(num_samples as u64, SAMPLE_RATE as u64)
.expect("u64 overflow");
{
let buffer = buffer.get_mut().unwrap();
{
let mut samples = buffer.map_writable().unwrap();
let samples = samples.as_mut_slice().as_mut_slice_of::<i16>().unwrap();
// Generate some psychodelic waveforms
data.c += data.d;
data.d -= data.c / 1000.0;
let freq = 1100.0 + 1000.0 * data.d;
for sample in samples.iter_mut() {
data.a += data.b;
data.b -= data.a / freq;
*sample = 500 * (data.a as i16);
}
data.num_samples += num_samples as u64;
}
buffer.set_pts(pts);
buffer.set_duration(duration);
}
(data.appsrc.clone(), buffer)
};
match appsrc.push_buffer(buffer) {
gst::FlowReturn::Ok => glib::Continue(true),
_ => glib::Continue(false),
}
}));
}
});
let data_clone = Arc::clone(&data);
appsrc.connect_enough_data(move |_| {
let data = &data_clone;
let mut data = data.lock().unwrap();
if let Some(source) = data.source_id.take() {
println!("stop feeding");
glib::source::source_remove(source);
}
});
// configure appsink
appsink.set_emit_signals(true);
appsink.set_caps(&audio_caps);
let data_clone = Arc::clone(&data);
appsink.connect_new_sample(move |_| {
let appsink = {
let data = &data_clone.lock().unwrap();
data.appsink.clone()
};
if let Some(_sample) = appsink.pull_sample() {
use std::io::{self, Write};
// The only thing we do in this example is print a * to indicate a received buffer
print!("*");
let _ = io::stdout().flush();
}
gst::FlowReturn::Ok
});
pipeline
.set_state(gst::State::Playing)
.into_result()
.expect("Unable to set the pipeline to the Playing state.");
let main_loop = glib::MainLoop::new(None, false);
let main_loop_clone = main_loop.clone();
let bus = pipeline.get_bus().unwrap();
bus.connect_message(move |_, msg| match msg.view() {
gst::MessageView::Error(err) => {
let main_loop = &main_loop_clone;
eprintln!(
"Error received from element {:?}: {}",
err.get_src().map(|s| s.get_path_string()),
err.get_error()
);
eprintln!("Debugging information: {:?}", err.get_debug());
main_loop.quit();
}
_ => (),
});
bus.add_signal_watch();
main_loop.run();
pipeline
.set_state(gst::State::Null)
.into_result()
.expect("Unable to set the pipeline to the Null state.");
}