Read from camera times-out on go1.14rc1

[at-wat]

It's not a problem for now, but I would like to leave a note.

Following test just checks OnEnded callback.

package main

import (
	"testing"
	"time"

	"github.com/pion/mediadevices"
	_ "github.com/pion/mediadevices/pkg/codec/vpx"
	"github.com/pion/mediadevices/pkg/frame"
	"github.com/pion/webrtc/v2"
)

func TestMain(t *testing.T) {
	configs := map[string]webrtc.Configuration{
		"WithSTUN": {
			ICEServers: []webrtc.ICEServer{
				{URLs: []string{"stun:stun.l.google.com:19302"}},
			},
		},
		"WithoutSTUN": {
			ICEServers: []webrtc.ICEServer{},
		},
	}
	for name, config := range configs {
		t.Run(name, func(t *testing.T) {
			peerConnection, err := webrtc.NewPeerConnection(config)
			if err != nil {
				t.Fatal(err)
			}

			md := mediadevices.NewMediaDevices(peerConnection)

			s, err := md.GetUserMedia(mediadevices.MediaStreamConstraints{
				Video: func(c *mediadevices.MediaTrackConstraints) {
					c.CodecName = videoCodecName
					c.FrameFormat = frame.FormatI420
					c.Enabled = true
					c.Width = 640
					c.Height = 480
				},
			})
			if err != nil {
				t.Fatal(err)
			}
			trackers := s.GetTracks()
			if len(trackers) != 1 {
				t.Fatal("wrong number of the tracks")
			}
			peerConnection.AddTrack(trackers[0].Track())
			trackers[0].OnEnded(func(err error) {
				t.Error(err)
			})
			time.Sleep(10 * time.Second)
			trackers[0].OnEnded(func(err error) {})
			peerConnection.Close()
			trackers[0].Stop()
			time.Sleep(time.Second)
		})
	}
}

with treating camera read timeout as error:

diff --git a/pkg/driver/camera/camera_linux.go b/pkg/driver/camera/camera_linux.go
index cee43b2..f7202f8 100644
--- a/pkg/driver/camera/camera_linux.go
+++ b/pkg/driver/camera/camera_linux.go
@@ -4,6 +4,7 @@ package camera
 import "C"
 
 import (
+       "errors"
        "image"
        "io"
 
@@ -97,6 +98,7 @@ func (c *camera) VideoRecord(p prop.Media) (video.Reader, error) {
                        switch err.(type) {
                        case nil:
                        case *webcam.Timeout:
+                               return nil, errors.New("read timeout")
                                continue
                        default:
                                // Camera has been stopped.

It fails with stun server only on go1.14rc1.

$ go1.14rc1 test . -v
=== RUN   TestMain
=== RUN   TestMain/WithSTUN
    TestMain/WithSTUN: main_test.go:51: read timeout
=== RUN   TestMain/WithoutSTUN
--- FAIL: TestMain (32.97s)
    --- FAIL: TestMain/WithSTUN (21.91s)
    --- PASS: TestMain/WithoutSTUN (11.06s)
FAIL
FAIL	github.com/pion/mediadevices/examples/simple	32.986s
FAIL
$ go1.13 test . -v
=== RUN   TestMain
=== RUN   TestMain/WithSTUN
=== RUN   TestMain/WithoutSTUN
--- PASS: TestMain (27.74s)
    --- PASS: TestMain/WithSTUN (16.67s)
    --- PASS: TestMain/WithoutSTUN (11.07s)
PASS
ok  	github.com/pion/mediadevices/examples/simple	27.756s

I will check it again once next RC of Go1.14 gets available.

[at-wat]

After trying a while, I get that the failure also accures without stun server setting, but the frequency is much lower.

[at-wat]

Looks being fixed on release Go1.14.