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extern crate gstreamer as gst;
use gst::prelude::*;
extern crate gstreamer_audio as gst_audio;
extern crate byte_slice_cast;
use byte_slice_cast::*;
use std::i16;
#[path = "../examples-common.rs"]
mod examples_common;
fn example_main() {
gst::init().unwrap();
let pipeline = gst::parse_launch(&format!(
"audiotestsrc name=src ! audio/x-raw,format={},channels=1 ! fakesink",
gst_audio::AUDIO_FORMAT_S16.to_string()
)).unwrap();
let pipeline = pipeline.dynamic_cast::<gst::Pipeline>().unwrap();
let src = pipeline.get_by_name("src").unwrap();
let src_pad = src.get_static_pad("src").unwrap();
src_pad.add_probe(gst::PadProbeType::BUFFER, |_, probe_info| {
if let Some(gst::PadProbeData::Buffer(ref buffer)) = probe_info.data {
let map = buffer.map_readable().unwrap();
let samples = if let Ok(samples) = map.as_slice_of::<i16>() {
samples
} else {
return gst::PadProbeReturn::Ok;
};
let sum: f64 = samples
.iter()
.map(|sample| {
let f = f64::from(*sample) / f64::from(i16::MAX);
f * f
})
.sum();
let rms = (sum / (samples.len() as f64)).sqrt();
println!("rms: {}", rms);
}
gst::PadProbeReturn::Ok
});
let ret = pipeline.set_state(gst::State::Playing);
assert_ne!(ret, gst::StateChangeReturn::Failure);
let bus = pipeline.get_bus().unwrap();
while let Some(msg) = bus.timed_pop(gst::CLOCK_TIME_NONE) {
use gst::MessageView;
match msg.view() {
MessageView::Eos(..) => break,
MessageView::Error(err) => {
println!(
"Error from {:?}: {} ({:?})",
err.get_src().map(|s| s.get_path_string()),
err.get_error(),
err.get_debug()
);
break;
}
_ => (),
}
}
let ret = pipeline.set_state(gst::State::Null);
assert_ne!(ret, gst::StateChangeReturn::Failure);
}
fn main() {
// tutorials_common::run is only required to set up the application environent on macOS
// (but not necessary in normal Cocoa applications where this is set up autmatically)
examples_common::run(example_main);
}