Switch appsink example to failure based error handling

This commit is contained in:
Sebastian Dröge 2017-11-11 15:53:03 +01:00
parent d857fbd349
commit 90700aa9b2
2 changed files with 72 additions and 26 deletions

View file

@ -17,7 +17,8 @@ futures = { version = "0.1", optional = true }
tokio-core = { version = "0.1", optional = true }
send-cell = "0.1"
byte-slice-cast = "0.1"
failure = "0.0.1"
failure = { git = "https://github.com/withoutboats/failure.git" }
failure_derive = { git = "https://github.com/withoutboats/failure_derive.git" }
[features]
gst-player = ["gstreamer-player"]

View file

@ -1,27 +1,49 @@
#[macro_use]
extern crate gstreamer as gst;
use gst::prelude::*;
extern crate gstreamer_app as gst_app;
extern crate gstreamer_audio as gst_audio;
extern crate glib;
extern crate byte_slice_cast;
use byte_slice_cast::*;
use std::i16;
use std::i32;
use std::error::Error as StdError;
pub mod utils;
extern crate failure;
#[macro_use]
extern crate failure_derive;
#[allow(unused_imports)]
use failure::{Error, Fail};
#[derive(Debug, Fail)]
#[fail(display = "Missing element {}", _0)]
struct MissingElement(&'static str);
#[derive(Debug, Fail)]
#[fail(display = "Received error from {}: {} (debug: {:?})", src, error, debug)]
struct ErrorMessage {
src: String,
error: String,
debug: Option<String>,
#[cause] cause: glib::Error,
}
fn create_pipeline() -> Result<gst::Pipeline, Error> {
gst::init()?;
fn create_pipeline() -> Result<gst::Pipeline, utils::ExampleError> {
gst::init().map_err(utils::ExampleError::InitFailed)?;
let pipeline = gst::Pipeline::new(None);
let src = utils::create_element("audiotestsrc")?;
let sink = utils::create_element("appsink")?;
let src =
gst::ElementFactory::make("audiotestsrc", None).ok_or(MissingElement("audiotestsrc"))?;
let sink = gst::ElementFactory::make("appsink", None).ok_or(MissingElement("appsink"))?;
pipeline
.add_many(&[&src, &sink])
.expect("Unable to add elements in the pipeline");
utils::link_elements(&src, &sink)?;
pipeline.add_many(&[&src, &sink])?;
src.link(&sink)?;
let appsink = sink.clone()
.dynamic_cast::<gst_app::AppSink>()
@ -49,17 +71,39 @@ fn create_pipeline() -> Result<gst::Pipeline, utils::ExampleError> {
Some(sample) => sample,
};
let buffer = sample
.get_buffer()
.expect("Unable to extract buffer from the sample");
let buffer = if let Some(buffer) = sample.get_buffer() {
buffer
} else {
gst_element_error!(
appsink,
gst::ResourceError::Failed,
("Failed to get buffer from appsink")
);
let map = buffer
.map_readable()
.expect("Unable to map buffer for reading");
return gst::FlowReturn::Error;
};
let map = if let Some(map) = buffer.map_readable() {
map
} else {
gst_element_error!(
appsink,
gst::ResourceError::Failed,
("Failed to map buffer readable")
);
return gst::FlowReturn::Error;
};
let samples = if let Ok(samples) = map.as_slice().as_slice_of::<i16>() {
samples
} else {
gst_element_error!(
appsink,
gst::ResourceError::Failed,
("Failed to interprete buffer as S16 PCM")
);
return gst::FlowReturn::Error;
};
@ -80,10 +124,10 @@ fn create_pipeline() -> Result<gst::Pipeline, utils::ExampleError> {
Ok(pipeline)
}
fn main_loop() -> Result<(), utils::ExampleError> {
fn main_loop() -> Result<(), Error> {
let pipeline = create_pipeline()?;
utils::set_state(&pipeline, gst::State::Playing)?;
pipeline.set_state(gst::State::Playing).into_result()?;
let bus = pipeline
.get_bus()
@ -95,18 +139,19 @@ fn main_loop() -> Result<(), utils::ExampleError> {
match msg.view() {
MessageView::Eos(..) => break,
MessageView::Error(err) => {
utils::set_state(&pipeline, gst::State::Null)?;
return Err(utils::ExampleError::ElementError(
msg.get_src().get_path_string(),
err.get_error(),
err.get_debug().unwrap(),
));
pipeline.set_state(gst::State::Null).into_result()?;
Err(ErrorMessage {
src: msg.get_src().get_path_string(),
error: err.get_error().description().into(),
debug: err.get_debug(),
cause: err.get_error(),
})?;
}
_ => (),
}
}
utils::set_state(&pipeline, gst::State::Null)?;
pipeline.set_state(gst::State::Null).into_result()?;
Ok(())
}