examples: app*: refactor error enum to a utils module

The module also contains create_element, link_elements and set_state functions
to help reduce boilerplate.
This commit is contained in:
Philippe Normand 2017-08-04 10:54:11 +01:00 committed by Sebastian Dröge
parent 86fc001e35
commit 7326377f5f
3 changed files with 83 additions and 102 deletions

View file

@ -5,56 +5,23 @@ use gst_app::*;
extern crate glib;
use std::fmt;
use std::u64;
use std::i16;
use std::i32;
#[derive(Debug)]
enum AppSinkExError {
InitFailed(glib::Error),
ElementNotFound(&'static str),
ElementLinkFailed(&'static str, &'static str),
SetStateError(&'static str),
ElementError(std::string::String, glib::Error, std::string::String),
}
pub mod utils;
impl fmt::Display for AppSinkExError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
AppSinkExError::InitFailed(ref e) => {
write!(f, "GStreamer initialization failed: {:?}", e)
}
AppSinkExError::ElementNotFound(ref e) => write!(f, "Element {} not found", e),
AppSinkExError::ElementLinkFailed(ref e1, ref e2) => {
write!(f, "Link failed between {} and {}", e1, e2)
}
AppSinkExError::SetStateError(ref state) => {
write!(f, "Pipeline failed to switch to state {}", state)
}
AppSinkExError::ElementError(ref element, ref err, ref debug) => {
write!(f, "Error from {}: {} ({:?})", element, err, debug)
}
}
}
}
fn create_pipeline() -> Result<Pipeline, AppSinkExError> {
gst::init().map_err(|e| AppSinkExError::InitFailed(e))?;
fn create_pipeline() -> Result<Pipeline, utils::ExampleError> {
gst::init().map_err(|e| utils::ExampleError::InitFailed(e))?;
let pipeline = gst::Pipeline::new(None);
let src = gst::ElementFactory::make("audiotestsrc", None)
.ok_or(AppSinkExError::ElementNotFound("audiotestsrc"))?;
let sink = gst::ElementFactory::make("appsink", None)
.ok_or(AppSinkExError::ElementNotFound("appsink"))?;
let src = utils::create_element("audiotestsrc")?;
let sink = utils::create_element("appsink")?;
pipeline
.add_many(&[&src, &sink])
.expect("Unable to add elements in the pipeline");
gst::Element::link(&src, &sink)
.map_err(|_| {
AppSinkExError::ElementLinkFailed("audiotestsrc", "appsink")
})?;
utils::link_elements(&src, &sink)?;
let appsink = sink.clone()
.dynamic_cast::<AppSink>()
@ -105,12 +72,10 @@ fn create_pipeline() -> Result<Pipeline, AppSinkExError> {
Ok(pipeline)
}
fn main_loop() -> Result<(), AppSinkExError> {
fn main_loop() -> Result<(), utils::ExampleError> {
let pipeline = create_pipeline()?;
if let gst::StateChangeReturn::Failure = pipeline.set_state(gst::State::Playing) {
return Err(AppSinkExError::SetStateError("playing"));
}
utils::set_state(&pipeline, gst::State::Playing)?;
let bus = pipeline
.get_bus()
@ -125,10 +90,8 @@ fn main_loop() -> Result<(), AppSinkExError> {
match msg.view() {
MessageView::Eos(..) => break,
MessageView::Error(err) => {
if let gst::StateChangeReturn::Failure = pipeline.set_state(gst::State::Null) {
return Err(AppSinkExError::SetStateError("null"));
}
return Err(AppSinkExError::ElementError(
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(),
@ -138,9 +101,7 @@ fn main_loop() -> Result<(), AppSinkExError> {
}
}
if let gst::StateChangeReturn::Failure = pipeline.set_state(gst::State::Null) {
return Err(AppSinkExError::SetStateError("null"));
}
utils::set_state(&pipeline, gst::State::Null)?;
Ok(())
}

View file

@ -5,61 +5,27 @@ use gst_app::*;
extern crate glib;
use std::fmt;
use std::u64;
use std::thread;
pub mod utils;
const WIDTH: usize = 320;
const HEIGHT: usize = 240;
#[derive(Debug)]
enum AppSrcExError {
InitFailed(glib::Error),
ElementNotFound(&'static str),
ElementLinkFailed(&'static str, &'static str),
SetStateError(&'static str),
ElementError(std::string::String, glib::Error, std::string::String),
}
impl fmt::Display for AppSrcExError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
AppSrcExError::InitFailed(ref e) => {
write!(f, "GStreamer initialization failed: {:?}", e)
}
AppSrcExError::ElementNotFound(ref e) => write!(f, "Element {} not found", e),
AppSrcExError::ElementLinkFailed(ref e1, ref e2) => {
write!(f, "Link failed between {} and {}", e1, e2)
}
AppSrcExError::SetStateError(ref state) => {
write!(f, "Pipeline failed to switch to state {}", state)
}
AppSrcExError::ElementError(ref element, ref err, ref debug) => {
write!(f, "Error from {}: {} ({:?})", element, err, debug)
}
}
}
}
fn create_pipeline() -> Result<(Pipeline, AppSrc), AppSrcExError> {
gst::init().map_err(|e| AppSrcExError::InitFailed(e))?;
fn create_pipeline() -> Result<(Pipeline, AppSrc), utils::ExampleError> {
gst::init().map_err(|e| utils::ExampleError::InitFailed(e))?;
let pipeline = gst::Pipeline::new(None);
let src = gst::ElementFactory::make("appsrc", None)
.ok_or(AppSrcExError::ElementNotFound("appsrc"))?;
let videoconvert = gst::ElementFactory::make("videoconvert", None)
.ok_or(AppSrcExError::ElementNotFound("videoconvert"))?;
let sink = gst::ElementFactory::make("autovideosink", None)
.ok_or(AppSrcExError::ElementNotFound("autovideosink"))?;
let src = utils::create_element("appsrc")?;
let videoconvert = utils::create_element("videoconvert")?;
let sink = utils::create_element("autovideosink")?;
pipeline
.add_many(&[&src, &videoconvert, &sink])
.expect("Unable to add elements in the pipeline");
gst::Element::link(&src, &videoconvert)
.map_err(|_| AppSrcExError::ElementLinkFailed("src", "videoconvert"))?;
gst::Element::link(&videoconvert, &sink)
.map_err(|_| AppSrcExError::ElementLinkFailed("videoconvert", "sink"))?;
utils::link_elements(&src, &videoconvert)?;
utils::link_elements(&videoconvert, &sink)?;
let appsrc = src.clone()
.dynamic_cast::<AppSrc>()
@ -80,7 +46,7 @@ fn create_pipeline() -> Result<(Pipeline, AppSrc), AppSrcExError> {
Ok((pipeline, appsrc))
}
fn main_loop() -> Result<(), AppSrcExError> {
fn main_loop() -> Result<(), utils::ExampleError> {
let (pipeline, appsrc) = create_pipeline()?;
thread::spawn(move || {
@ -111,9 +77,7 @@ fn main_loop() -> Result<(), AppSrcExError> {
appsrc.end_of_stream();
});
if let gst::StateChangeReturn::Failure = pipeline.set_state(gst::State::Playing) {
return Err(AppSrcExError::SetStateError("playing"));
}
utils::set_state(&pipeline, gst::State::Playing)?;
let bus = pipeline
.get_bus()
@ -128,8 +92,8 @@ fn main_loop() -> Result<(), AppSrcExError> {
match msg.view() {
MessageView::Eos(..) => break,
MessageView::Error(err) => {
pipeline.set_state(gst::State::Null);
return Err(AppSrcExError::ElementError(
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(),
@ -139,9 +103,7 @@ fn main_loop() -> Result<(), AppSrcExError> {
}
}
if let gst::StateChangeReturn::Failure = pipeline.set_state(gst::State::Null) {
return Err(AppSrcExError::SetStateError("null"));
}
utils::set_state(&pipeline, gst::State::Null)?;
Ok(())
}

View file

@ -0,0 +1,58 @@
extern crate gstreamer as gst;
use gst::*;
extern crate glib;
use std::fmt;
#[derive(Debug)]
pub enum ExampleError {
InitFailed(glib::Error),
ElementNotFound(&'static str),
ElementLinkFailed(::std::string::String, ::std::string::String),
SetStateError(::std::string::String),
ElementError(::std::string::String, glib::Error, ::std::string::String),
}
impl fmt::Display for ExampleError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
ExampleError::InitFailed(ref e) => {
write!(f, "GStreamer initialization failed: {:?}", e)
}
ExampleError::ElementNotFound(ref e) => write!(f, "Element {} not found", e),
ExampleError::ElementLinkFailed(ref e1, ref e2) => {
write!(f, "Link failed between {} and {}", e1, e2)
}
ExampleError::SetStateError(ref state) => {
write!(f, "Pipeline failed to switch to state {}", state)
}
ExampleError::ElementError(ref element, ref err, ref debug) => {
write!(f, "Error from {}: {} ({:?})", element, err, debug)
}
}
}
}
pub fn create_element(name: &'static str) -> Result<gst::Element, ExampleError> {
gst::ElementFactory::make(name, None).ok_or(ExampleError::ElementNotFound(name))
}
pub fn link_elements(e1: &gst::Element, e2: &gst::Element) -> Result<(), ExampleError> {
match gst::Element::link(e1, e2) {
Ok(o) => Ok(o),
Err(_) => Err(ExampleError::ElementLinkFailed(
e1.get_name(),
e2.get_name(),
)),
}
}
pub fn set_state(e: &gst::Pipeline, state: gst::State) -> Result<(), ExampleError> {
if let gst::StateChangeReturn::Failure = e.set_state(state) {
return Err(ExampleError::SetStateError(
gst::Element::state_get_name(state).unwrap(),
));
}
Ok(())
}