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|
//
// rhlibrary
//
// The Radio Helsinki Rivendell Library
//
//
// Copyright (C) 2016 Christian Pointner <equinox@helsinki.at>
//
// This file is part of rhlibrary.
//
// rhlibrary is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// any later version.
//
// rhlibrary is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with rhlibrary. If not, see <http://www.gnu.org/licenses/>.
//
package player
import (
"fmt"
"github.com/spreadspace/go-gstreamer"
"path"
)
func init() {
gst.Init(nil)
}
type loadResult struct {
err error
}
type loadRequest struct {
cart uint
cut uint
response chan<- loadResult
}
type playResult struct {
err error
}
type playRequest struct {
response chan<- playResult
}
type pauseResult struct {
err error
}
type pauseRequest struct {
response chan<- pauseResult
}
type stopResult struct {
err error
}
type stopRequest struct {
response chan<- stopResult
}
type Player struct {
pipe *gst.Element
bus *gst.Bus
basepath string
loadChan chan loadRequest
playChan chan playRequest
pauseChan chan pauseRequest
stopChan chan stopRequest
}
func (p *Player) onMessage(bus *gst.Bus, msg *gst.Message) {
switch msg.GetType() {
case gst.MESSAGE_EOS:
fmt.Printf("GStreamer Pipeline: EOS reached!\n")
p.pipe.SetState(gst.STATE_NULL)
case gst.MESSAGE_WARNING:
warn, _ := msg.ParseWarning()
fmt.Printf("GStreamer Pipeline Warning: %s\n", warn)
case gst.MESSAGE_ERROR:
p.pipe.SetState(gst.STATE_NULL)
err, _ := msg.ParseError()
fmt.Printf("GStreamer Pipeline Error: %s\n", err)
case gst.MESSAGE_ASYNC_DONE:
len, ok := p.pipe.QueryDuration(gst.FORMAT_TIME)
if ok {
fmt.Printf("GStreamer Pipeline: loaded file has length: %d.%d s\n", len/1000000000, len%1000000000)
} else {
fmt.Printf("GStreamer Pipeline Error: unable to query duration of file\n")
}
case gst.MESSAGE_STATE_CHANGED:
default:
fmt.Printf("GStreamer Message: unknown type '%s'\n", msg.GetTypeName())
}
}
func (p *Player) load(cart, cut uint) (resp loadResult) {
filename := path.Join(p.basepath, fmt.Sprintf("%06d_%03d.wav", cart, cut))
p.pipe.SetProperty("uri", "file://"+filename)
p.pipe.SetState(gst.STATE_PAUSED)
return
}
func (p *Player) play() (resp playResult) {
p.pipe.SetState(gst.STATE_PLAYING)
return
}
func (p *Player) pause() (resp pauseResult) {
p.pipe.SetState(gst.STATE_PAUSED)
return
}
func (p *Player) stop() (resp stopResult) {
p.pipe.SetState(gst.STATE_NULL)
return
}
func (p *Player) dispatchRequests() {
for {
select {
case req := <-p.loadChan:
req.response <- p.load(req.cart, req.cut)
case req := <-p.playChan:
req.response <- p.play()
case req := <-p.pauseChan:
req.response <- p.pause()
case req := <-p.stopChan:
req.response <- p.stop()
}
}
}
// *********************************************************
// Public Interface
type PlayerChan struct {
load chan<- loadRequest
play chan<- playRequest
pause chan<- pauseRequest
stop chan<- stopRequest
}
func (p *PlayerChan) Load(cart, cut uint) error {
resCh := make(chan loadResult)
req := loadRequest{}
req.cart = cart
req.cut = cut
req.response = resCh
p.load <- req
res := <-resCh
if res.err != nil {
return res.err
}
return nil
}
func (p *PlayerChan) Play() error {
resCh := make(chan playResult)
req := playRequest{}
req.response = resCh
p.play <- req
res := <-resCh
if res.err != nil {
return res.err
}
return nil
}
func (p *PlayerChan) Pause() error {
resCh := make(chan pauseResult)
req := pauseRequest{}
req.response = resCh
p.pause <- req
res := <-resCh
if res.err != nil {
return res.err
}
return nil
}
func (p *PlayerChan) Stop() error {
resCh := make(chan stopResult)
req := stopRequest{}
req.response = resCh
p.stop <- req
res := <-resCh
if res.err != nil {
return res.err
}
return nil
}
func (p *Player) GetInterface() *PlayerChan {
ch := &PlayerChan{}
ch.load = p.loadChan
ch.play = p.playChan
ch.pause = p.pauseChan
ch.stop = p.stopChan
return ch
}
func NewPlayer(basepath string) (p *Player, err error) {
p = &Player{}
p.basepath = path.Clean(basepath)
p.loadChan = make(chan loadRequest)
p.playChan = make(chan playRequest)
p.pauseChan = make(chan pauseRequest)
p.stopChan = make(chan stopRequest)
if p.pipe, err = gst.ElementFactoryMake("playbin", "autoplay"); err != nil {
return
}
if p.bus, err = p.pipe.GetBus(); err != nil {
return
}
p.bus.AddSignalWatch()
p.bus.Connect("message", func(bus *gst.Bus, msg *gst.Message) { p.onMessage(bus, msg) })
go p.dispatchRequests()
return
}
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