semi working websocketsrc

examples/plugins/websocketsrc/websocketsrc.go

@@ -25,13 +25,20 @@
 package main
 
 import (
+	"context"
 	"fmt"
 	"net/http"
+	"sync"
+	"time"
 
 	"github.com/tinyzimmer/go-glib/glib"
 	"github.com/tinyzimmer/go-gst/gst"
+	"golang.org/x/net/websocket"
 )
 
+// MaxPayloadSize to accept over websocket connections. Also the size of buffers.
+const MaxPayloadSize = 1024
+
 // Defaults //
 var (
 	DefaultAddress            string = "0.0.0.0"
@@ -64,6 +71,7 @@ var properties = []*gst.ParamSpec{
 		DefaultPort,
 		gst.ParameterReadWrite,
 	),
+	// not implemented yet
 	gst.NewBoolParam(
 		"retrieve-remote-addr",
 		"Retrieve Remote Address",
@@ -75,19 +83,14 @@ var properties = []*gst.ParamSpec{
 
 // Internals //
 
-type state struct {
-	started           bool
-	server            *http.Server
-	needInitialEvents bool
-	needSegment       bool
-}
-
+// A private settings struct to hold the values of the above parameters
 type settings struct {
 	address            string
 	port               int
 	retrieveRemoteAddr bool
 }
 
+// Helper function to retrieve a settings object set to the default values.
 func defaultSettings() *settings {
 	return &settings{
 		address:            DefaultAddress,
@@ -96,15 +99,302 @@ func defaultSettings() *settings {
 	}
 }
 
-// Element implementation //
+// The internal state object
+type state struct {
+	serverStarted, channelsStarted, sentInitialEvents, sentSegment bool
+	server                                                         *http.Server
+	srcpad                                                         *gst.Pad
+	bufferpool                                                     *gst.BufferPool
+	bufferchan                                                     chan []byte
+	stopchan                                                       chan struct{}
 
+	mux     sync.Mutex
+	connmux sync.Mutex
+}
+
+// Base struct definition for the websocket src
 type websocketSrc struct {
 	settings *settings
 	state    *state
-	srcpad   *gst.Pad
 }
 
-// // ObjectSubclass // //
+// prepare verifies the src pad has been added to the element, and then sets up server
+// handlers and a buffer pool
+func (w *websocketSrc) prepare(elem *gst.Element) error {
+	w.state.mux.Lock()
+	defer w.state.mux.Unlock()
+
+	// Make sure we have a srcpad
+	if w.state.srcpad == nil {
+		w.setupSrcPad(elem)
+	}
+
+	elem.Log(CAT, gst.LevelDebug, "Creating channels for goroutines")
+
+	// Setup a channel for handling buffers
+	w.state.bufferchan = make(chan []byte)
+	w.state.stopchan = make(chan struct{})
+
+	elem.Log(CAT, gst.LevelDebug, "Setting up the HTTP server")
+
+	// Setup the HTTP server instance
+	w.state.server = &http.Server{
+		Addr:         fmt.Sprintf("%s:%d", w.settings.address, w.settings.port),
+		ReadTimeout:  300 * time.Second,
+		WriteTimeout: 300 * time.Second,
+		Handler: &websocket.Server{
+			// Don't check the Origin header
+			Handshake: func(*websocket.Config, *http.Request) error { return nil },
+			Handler: func(conn *websocket.Conn) {
+				elem.Log(CAT, gst.LevelInfo, fmt.Sprintf("Received new connection from: %s", conn.Request().RemoteAddr))
+
+				// Only allow a stream from one client at a time
+				w.state.connmux.Lock()
+				defer w.state.connmux.Unlock()
+
+				conn.PayloadType = websocket.BinaryFrame
+				conn.MaxPayloadBytes = MaxPayloadSize
+
+				for {
+					// Read the PayloadSize into a bytes slice
+					buf := make([]byte, conn.MaxPayloadBytes)
+					size, err := conn.Read(buf)
+					if err != nil {
+						elem.ErrorMessage(gst.DomainStream, gst.StreamErrorFailed, "Error reading bytes from client", err.Error())
+						return
+					}
+
+					// The goroutine listening for buffers will use the size to determine offsets,
+					// So trim the zeroes if we receive a buffer less than the requested size.
+					if size < conn.MaxPayloadBytes {
+						trimmed := make([]byte, size)
+						copy(trimmed, buf)
+						buf = trimmed
+					}
+
+					// Queue the buffer for processing
+					elem.Log(CAT, gst.LevelLog, fmt.Sprintf("Queueing %d bytes for processing", len(buf)))
+					w.state.bufferchan <- buf
+				}
+			},
+		},
+	}
+
+	elem.Log(CAT, gst.LevelDebug, "Configuring a buffer pool")
+
+	// Configure a buffer pool
+	w.state.bufferpool = gst.NewBufferPool()
+	cfg := w.state.bufferpool.GetConfig()
+	cfg.SetParams(nil, MaxPayloadSize, 0, 0)
+	w.state.bufferpool.SetConfig(cfg)
+	w.state.bufferpool.SetActive(true)
+
+	return nil
+}
+
+// This runs in a goroutine and checks for pause events or new buffers to push onto the pad.
+func (w *websocketSrc) watchChannels(elem *gst.Element) {
+	for {
+		select {
+
+		case data, more := <-w.state.bufferchan:
+			if !more {
+				elem.Log(CAT, gst.LevelInfo, "Buffer channel has closed, stopping processing")
+				return
+			}
+			elem.Log(CAT, gst.LevelDebug, "Retrieving buffer from the pool")
+
+			buf, ret := w.state.bufferpool.AcquireBuffer(nil)
+			if ret != gst.FlowOK {
+				elem.Log(CAT, gst.LevelError, fmt.Sprintf("Could not allocate buffer for data: %s", ret))
+				return
+			}
+
+			elem.Log(CAT, gst.LevelDebug, "Writing data to buffer")
+			buf.Map(gst.MapWrite).WriteData(data)
+			buf.Unmap()
+			buf.SetSize(int64(len(data)))
+
+			elem.Log(CAT, gst.LevelDebug, "Pushing buffer onto src pad")
+			w.pushPrelude(elem)
+			if ret := w.state.srcpad.Push(buf); ret == gst.FlowError {
+				elem.Log(CAT, gst.LevelError, fmt.Sprintf("Failed to push buffer to srcpad: %s", ret))
+				return
+			}
+
+		case <-w.state.stopchan:
+			elem.Log(CAT, gst.LevelInfo, "Received signal on stopchan to halt buffer processing")
+			return
+
+		}
+	}
+}
+
+// start will start the websocket server and the buffer processing goroutines.
+func (w *websocketSrc) start(elem *gst.Element) {
+	w.state.mux.Lock()
+	defer w.state.mux.Unlock()
+
+	if !w.state.serverStarted {
+		elem.Log(CAT, gst.LevelInfo, "Starting the HTTP server")
+		go w.startServer(elem)
+		w.state.serverStarted = true
+	}
+	if !w.state.channelsStarted {
+		elem.Log(CAT, gst.LevelInfo, "Starting channel goroutine")
+		go w.watchChannels(elem)
+		w.state.channelsStarted = true
+	}
+	elem.Log(CAT, gst.LevelInfo, "WebsocketSrc has started")
+}
+
+// starts the server, is called as a goroutine.
+func (w *websocketSrc) startServer(elem *gst.Element) {
+	if err := w.state.server.ListenAndServe(); err != nil {
+		if err == http.ErrServerClosed {
+			elem.Log(CAT, gst.LevelInfo, "Server exited cleanly")
+			return
+		}
+		elem.ErrorMessage(gst.DomainResource, gst.ResourceErrorFailed, "Failed to start websocket server", err.Error())
+	}
+}
+
+// Checks if initial stream events were sent and pushes them onto the pad if needed.
+func (w *websocketSrc) pushPrelude(elem *gst.Element) {
+	w.state.mux.Lock()
+	defer w.state.mux.Unlock()
+
+	if !w.state.sentInitialEvents {
+		elem.Log(CAT, gst.LevelDebug, "Sending stream start event")
+
+		streamid := "blahblahblah"
+		ev := gst.NewStreamStartEvent(streamid)
+		if res := w.state.srcpad.PushEvent(ev); !res {
+			elem.ErrorMessage(gst.DomainLibrary, gst.LibraryErrorFailed, "Failed to notify elements of stream start", "")
+			return
+		}
+		w.state.sentInitialEvents = true
+	}
+	if !w.state.sentSegment {
+		elem.Log(CAT, gst.LevelDebug, "Sending new segment event")
+
+		ev := gst.NewSegmentEvent(gst.NewFormattedSegment(gst.FormatTime))
+		if res := w.state.srcpad.PushEvent(ev); !res {
+			elem.ErrorMessage(gst.DomainLibrary, gst.LibraryErrorFailed, "Failed to notify elements of new segment", "")
+			return
+		}
+		w.state.sentSegment = true
+	}
+}
+
+// Stops the goroutines and the websocket server
+func (w *websocketSrc) stop(elem *gst.Element) {
+	w.state.mux.Lock()
+	defer w.state.mux.Unlock()
+
+	if w.state.channelsStarted {
+		elem.Log(CAT, gst.LevelInfo, "Sending stop signal to go routines")
+		w.state.stopchan <- struct{}{}
+		w.state.channelsStarted = false
+	}
+
+	if w.state.serverStarted {
+		elem.Log(CAT, gst.LevelInfo, "Shutting down HTTP server")
+		w.state.server.Shutdown(context.Background())
+		w.state.serverStarted = false
+	}
+}
+
+// Just stops the buffer processing routine, but leaves the server running
+func (w *websocketSrc) pause(elem *gst.Element) {
+	w.state.mux.Lock()
+	defer w.state.mux.Unlock()
+	elem.Log(CAT, gst.LevelDebug, "Sending stop signal to go routines")
+	w.state.stopchan <- struct{}{}
+	w.state.channelsStarted = false
+}
+
+// Tears down all resources for the element.
+func (w *websocketSrc) unprepare(elem *gst.Element) {
+	w.state.mux.Lock()
+	defer w.state.mux.Unlock()
+
+	elem.Log(CAT, gst.LevelDebug, "Freeing pads and buffers")
+
+	w.state.bufferpool.SetActive(false)
+	w.state.bufferpool.Unref()
+
+	elem.Log(CAT, gst.LevelDebug, "Closing channels and clearing state")
+
+	close(w.state.bufferchan)
+	close(w.state.stopchan)
+	w.state = &state{}
+}
+
+// Sets up a src pad for an element and adds the necessary callbacks.
+func (w *websocketSrc) setupSrcPad(elem *gst.Element) {
+	// Configure the src pad
+	elem.Log(CAT, gst.LevelDebug, "Configuring the src pad")
+
+	w.state.srcpad = gst.NewPadFromTemplate(elem.GetPadTemplates()[0], "src")
+	elem.AddPad(w.state.srcpad)
+
+	// Set a function for handling events
+	w.state.srcpad.SetEventFunction(func(pad *gst.Pad, parent *gst.Object, event *gst.Event) bool {
+		var ret bool
+
+		pad.Log(CAT, gst.LevelLog, fmt.Sprintf("Handling event: %s", event.Type()))
+
+		switch event.Type() {
+		case gst.EventTypeReconfigure:
+			ret = true
+		case gst.EventTypeLatency:
+			ret = true
+		default:
+			ret = false
+		}
+
+		if ret {
+			pad.Log(CAT, gst.LevelDebug, fmt.Sprintf("Handled event: %s", event.Type()))
+		} else {
+			pad.Log(CAT, gst.LevelLog, fmt.Sprintf("Didn't handle event: %s", event.Type()))
+		}
+
+		return ret
+	})
+
+	// Set a query handler for the src pad
+	w.state.srcpad.SetQueryFunction(func(pad *gst.Pad, parent *gst.Object, query *gst.Query) bool {
+		var ret bool
+
+		pad.Log(CAT, gst.LevelLog, fmt.Sprintf("Handling query: %s", query.Type()))
+
+		switch query.Type() {
+		case gst.QueryLatency:
+			query.SetLatency(true, 0, gst.ClockTimeNone)
+			ret = true
+		case gst.QueryScheduling:
+			query.SetScheduling(gst.SchedulingFlagSequential, 1, -1, 0)
+			query.AddSchedulingMode(gst.PadModePush)
+			ret = true
+		case gst.QueryCaps:
+			query.SetCapsResult(gst.NewAnyCaps())
+			ret = true
+		default:
+			ret = false
+		}
+
+		if ret {
+			pad.Log(CAT, gst.LevelDebug, fmt.Sprintf("Handled query: %s", query.Type()))
+		} else {
+			pad.Log(CAT, gst.LevelLog, fmt.Sprintf("Didn't handle query: %s", query.Type()))
+		}
+
+		return ret
+	})
+}
+
+// * ObjectSubclass * //
 
 func (w *websocketSrc) New() gst.GoElement {
 	return &websocketSrc{
@@ -131,61 +421,132 @@ func (w *websocketSrc) ClassInit(klass *gst.ElementClass) {
 	klass.InstallProperties(properties)
 }
 
-// // Object // //
-func (w *websocketSrc) SetProperty(self *gst.Object, id uint, value *glib.Value) {}
+// * Object * //
+func (w *websocketSrc) SetProperty(self *gst.Object, id uint, value *glib.Value) {
+	prop := properties[id]
 
-func (w *websocketSrc) GetProperty(self *gst.Object, id uint) *glib.Value { return nil }
+	switch prop.Name() {
+	case "address":
+		val, err := value.GetString()
+		if err != nil {
+			gst.ToElement(self).ErrorMessage(gst.DomainLibrary, gst.LibraryErrorFailed,
+				"Could not get string from GValue",
+				err.Error(),
+			)
+			return
+		}
+		w.settings.address = val
+	case "port":
+		val, err := value.GoValue()
+		if err != nil {
+			gst.ToElement(self).ErrorMessage(gst.DomainLibrary, gst.LibraryErrorFailed,
+				"Could not get go value from GValue",
+				err.Error(),
+			)
+			return
+		}
+		intval, ok := val.(int)
+		if !ok {
+			gst.ToElement(self).ErrorMessage(gst.DomainLibrary, gst.LibraryErrorFailed,
+				fmt.Sprintf("Could not coerce govalue %v to integer", val),
+				err.Error(),
+			)
+			return
+		}
+		w.settings.port = intval
+	case "retrieve-remote-addr":
+		val, err := value.GoValue()
+		if err != nil {
+			gst.ToElement(self).ErrorMessage(gst.DomainLibrary, gst.LibraryErrorFailed,
+				"Could not get go value from GValue",
+				err.Error(),
+			)
+			return
+		}
+		boolval, ok := val.(bool)
+		if !ok {
+			gst.ToElement(self).ErrorMessage(gst.DomainLibrary, gst.LibraryErrorFailed,
+				fmt.Sprintf("Could not coerce govalue %v to bool", val),
+				err.Error(),
+			)
+			return
+		}
+		w.settings.retrieveRemoteAddr = boolval
+	default:
+		gst.ToElement(self).ErrorMessage(gst.DomainLibrary, gst.LibraryErrorSettings,
+			fmt.Sprintf("Cannot set invalid property %s", prop.Name()), "")
+
+	}
+}
+
+func (w *websocketSrc) GetProperty(self *gst.Object, id uint) *glib.Value {
+	prop := properties[id]
+
+	var localVal interface{}
+
+	switch prop.Name() {
+	case "address":
+		localVal = w.settings.address
+	case "port":
+		localVal = w.settings.port
+	case "retrieve-remote-addr":
+		localVal = w.settings.retrieveRemoteAddr
+	default:
+		gst.ToElement(self).ErrorMessage(gst.DomainLibrary, gst.LibraryErrorSettings,
+			fmt.Sprintf("Cannot get invalid property %s", prop.Name()), "")
+		return nil
+	}
+
+	val, err := glib.GValue(localVal)
+	if err != nil {
+		gst.ToElement(self).ErrorMessage(gst.DomainLibrary, gst.LibraryErrorFailed,
+			fmt.Sprintf("Could not convert %v to GValue", localVal),
+			err.Error(),
+		)
+	}
+
+	return val
+}
 
 func (w *websocketSrc) Constructed(self *gst.Object) {
-	w.srcpad = gst.ToElement(self).GetStaticPad("src")
-
-	w.srcpad.SetEventFunction(func(pad *gst.Pad, parent *gst.Object, event *gst.Event) bool {
-		var ret bool
-
-		self.Log(CAT, gst.LevelLog, fmt.Sprintf("Handling event: %s", event.Type()))
-
-		switch event.Type() {
-		case gst.EventTypeFlushStart:
-			// TODO
-		case gst.EventTypeFlushStop:
-			// TODO
-		case gst.EventTypeReconfigure:
-			ret = true
-		case gst.EventTypeLatency:
-			ret = true
-		default:
-			ret = false
-		}
-
-		if ret {
-			self.Log(CAT, gst.LevelLog, fmt.Sprintf("Handled event: %s", event.Type()))
-		} else {
-			self.Log(CAT, gst.LevelLog, fmt.Sprintf("Didn't handle event: %s", event.Type()))
-		}
-
-		return ret
-	})
-
-	w.srcpad.SetQueryFunction(func(pad *gst.Pad, parent *gst.Object, query *gst.Query) bool {
-		var ret bool
-
-		self.Log(CAT, gst.LevelLog, fmt.Sprintf("Handling query: %s", query.Type()))
-
-		switch query.Type() {
-		case gst.QueryLatency:
-			query.SetLatency(true, 0, gst.ClockTimeNone)
-			ret = true
-		case gst.QueryScheduling:
-			query.SetScheduling(gst.SchedulingFlagSequential, 1, -1, 0)
-			query.AddSchedulingMode(gst.PadModePush)
-			ret = true
-		case gst.QueryCaps:
-			query.SetCapsResult(query.ParseCaps())
-			ret = true
-		default:
-			ret = false
-		}
-
-		return ret
-	})
+	elem := gst.ToElement(self)
+	w.setupSrcPad(elem)
+}
+
+// * Element * //
+
+func (w *websocketSrc) ChangeState(self *gst.Element, transition gst.StateChange) (ret gst.StateChangeReturn) {
+	self.Log(CAT, gst.LevelTrace, fmt.Sprintf("Changing state: %s", transition))
+
+	ret = gst.StateChangeSuccess
+
+	switch transition {
+	case gst.StateChangeNullToReady:
+		if err := w.prepare(self); err != nil {
+			self.ErrorMessage(gst.DomainResource, gst.ResourceErrorFailed, err.Error(), "")
+			return gst.StateChangeFailure
+		}
+	case gst.StateChangePlayingToPaused:
+		w.pause(self)
+	case gst.StateChangeReadyToNull:
+		w.unprepare(self)
+	}
+
+	// Apply the transition to the parent element
+	if ret = self.ParentChangeState(transition); ret == gst.StateChangeFailure {
+		return
+	}
+
+	switch transition {
+	case gst.StateChangeReadyToPaused:
+		ret = gst.StateChangeNoPreroll
+	case gst.StateChangePausedToPlaying:
+		w.start(self)
+	case gst.StateChangePlayingToPaused:
+		ret = gst.StateChangeNoPreroll
+	case gst.StateChangePausedToReady:
+		w.stop(self)
+	}
+
+	return
 }

gst/gst_buffer_pool.go

@@ -44,13 +44,17 @@ type BufferPoolAcquireParams struct {
 // AcquireBuffer acquires a buffer from this pool.
 func (b *BufferPool) AcquireBuffer(params *BufferPoolAcquireParams) (*Buffer, FlowReturn) {
 	var buf *C.GstBuffer
-	gparams := &C.GstBufferPoolAcquireParams{
-		format: C.GstFormat(params.Format),
-		start:  C.gint64(params.Start),
-		stop:   C.gint64(params.Stop),
-		flags:  C.GstBufferPoolAcquireFlags(params.Flags),
+	if params != nil {
+		gparams := (*C.GstBufferPoolAcquireParams)(C.malloc(C.sizeof_GstBufferPoolAcquireParams))
+		defer C.free(unsafe.Pointer(gparams))
+		gparams.format = C.GstFormat(params.Format)
+		gparams.start = C.gint64(params.Start)
+		gparams.stop = C.gint64(params.Stop)
+		gparams.flags = C.GstBufferPoolAcquireFlags(params.Flags)
+		ret := C.gst_buffer_pool_acquire_buffer(b.Instance(), &buf, gparams)
+		return wrapBuffer(buf), FlowReturn(ret)
 	}
-	ret := C.gst_buffer_pool_acquire_buffer(b.Instance(), &buf, gparams)
+	ret := C.gst_buffer_pool_acquire_buffer(b.Instance(), &buf, nil)
 	return wrapBuffer(buf), FlowReturn(ret)
 }
 
@@ -111,7 +115,7 @@ func (b *BufferPool) SetActive(active bool) (ok bool) {
 // state as possible. The new state can then be retrieved and refined with GetConfig.
 //
 // This function takes ownership of the given structure.
-func (b *BufferPool) SetConfig(cfg BufferPoolConfig) bool {
+func (b *BufferPool) SetConfig(cfg *BufferPoolConfig) bool {
 	return gobool(C.gst_buffer_pool_set_config(b.Instance(), cfg.Instance()))
 }
 
@@ -194,6 +198,14 @@ func (b *BufferPoolConfig) SetAllocator(allocator *Allocator, params *Allocation
 
 // SetParams configures the config with the given parameters.
 func (b *BufferPoolConfig) SetParams(caps *Caps, size, minBuffers, maxBuffers uint) {
+	if caps == nil {
+		C.gst_buffer_pool_config_set_params(
+			b.Instance(),
+			nil,
+			C.guint(size), C.guint(minBuffers), C.guint(maxBuffers),
+		)
+		return
+	}
 	C.gst_buffer_pool_config_set_params(
 		b.Instance(),
 		caps.Instance(),

gst/gst_segment.go

@@ -21,21 +21,40 @@ func NewSegment() *Segment {
 	return wrapSegment(C.gst_segment_new())
 }
 
+// NewFormattedSegment returns a new Segment with the given format.
+func NewFormattedSegment(f Format) *Segment {
+	segment := NewSegment()
+	segment.SetFormat(f)
+	return segment
+}
+
 // Instance returns the underlying GstSegment instance.
 func (s *Segment) Instance() *C.GstSegment { return s.ptr }
 
 // GetFlags returns the flags on this segment.
 func (s *Segment) GetFlags() SegmentFlags { return SegmentFlags(s.Instance().flags) }
 
+// SetFlags sets the flags on this segment.
+func (s *Segment) SetFlags(flags SegmentFlags) { s.Instance().flags = C.GstSegmentFlags(flags) }
+
 // GetRate returns the rate for this segment.
 func (s *Segment) GetRate() float64 { return float64(s.Instance().rate) }
 
+// SetRate sets the rate for this segment.
+func (s *Segment) SetRate(rate float64) { s.Instance().rate = C.gdouble(rate) }
+
 // GetAppliedRate returns the applied rate for this segment.
 func (s *Segment) GetAppliedRate() float64 { return float64(s.Instance().applied_rate) }
 
+// SetAppliedRate sets the applied rate for this segment
+func (s *Segment) SetAppliedRate(rate float64) { s.Instance().applied_rate = C.gdouble(rate) }
+
 // GetFormat returns the format for this segment.
 func (s *Segment) GetFormat() Format { return Format(s.Instance().format) }
 
+// SetFormat sets the format on this segment.
+func (s *Segment) SetFormat(f Format) { s.Instance().format = C.GstFormat(f) }
+
 // GetBase returns the base for this segment.
 func (s *Segment) GetBase() uint64 { return uint64(s.Instance().base) }