rpicamera: support two CSI cameras at once (#1573)

internal/conf/conf_test.go

@@ -202,7 +202,7 @@ func TestConfErrors(t *testing.T) {
 				"    source: rpiCamera\n" +
 				"  cam2:\n" +
 				"    source: rpiCamera\n",
-			"'rpiCamera' is used as source in two paths ('cam1' and 'cam2')",
+			"'rpiCamera' with same camera ID 0 is used as source in two paths, 'cam1' and 'cam2'",
 		},
 	} {
 		t.Run(ca.name, func(t *testing.T) {

internal/conf/path.go

@@ -195,8 +195,10 @@ func (pconf *PathConf) checkAndFillMissing(conf *Conf, name string) error {
 		}
 
 		for otherName, otherPath := range conf.Paths {
-			if otherPath != pconf && otherPath != nil && otherPath.Source == "rpiCamera" {
-				return fmt.Errorf("'rpiCamera' is used as source in two paths ('%s' and '%s')", name, otherName)
+			if otherPath != pconf && otherPath != nil &&
+				otherPath.Source == "rpiCamera" && otherPath.RPICameraCamID == pconf.RPICameraCamID {
+				return fmt.Errorf("'rpiCamera' with same camera ID %d is used as source in two paths, '%s' and '%s'",
+					pconf.RPICameraCamID, name, otherName)
 			}
 		}
 

internal/core/core.go

@@ -17,6 +17,7 @@ import (
 	"github.com/aler9/rtsp-simple-server/internal/externalcmd"
 	"github.com/aler9/rtsp-simple-server/internal/logger"
 	"github.com/aler9/rtsp-simple-server/internal/rlimit"
+	"github.com/aler9/rtsp-simple-server/internal/rpicamera"
 )
 
 var version = "v0.0.0"
@@ -84,6 +85,8 @@ func New(args []string) (*Core, bool) {
 	// do not check for errors
 	rlimit.Raise()
 
+	rpicamera.LibcameraSetup()
+
 	gin.SetMode(gin.ReleaseMode)
 
 	ctx, ctxCancel := context.WithCancel(context.Background())
@@ -186,6 +189,8 @@ outer:
 	p.ctxCancel()
 
 	p.closeResources(nil, false)
+
+	rpicamera.LibcameraCleanup()
 }
 
 func (p *Core) createResources(initial bool) error {

internal/rpicamera/libcamera.go

@@ -0,0 +1,47 @@
+//go:build rpicamera
+// +build rpicamera
+
+package rpicamera
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+func findLibrary(name string) (string, error) {
+	byts, err := exec.Command("ldconfig", "-p").Output()
+	if err == nil {
+		for _, line := range strings.Split(string(byts), "\n") {
+			f := strings.Split(line, " => ")
+			if len(f) == 2 && strings.Contains(f[1], name+".so") {
+				return f[1], nil
+			}
+		}
+	}
+
+	return "", fmt.Errorf("library '%s' not found", name)
+}
+
+func setupSymlink(name string) error {
+	lib, err := findLibrary(name)
+	if err != nil {
+		return err
+	}
+
+	os.Remove("/dev/shm/" + name + ".so.x.x.x")
+	return os.Symlink(lib, "/dev/shm/"+name+".so.x.x.x")
+}
+
+// LibcameraSetup creates libcamera simlinks that are version agnostic.
+func LibcameraSetup() {
+	setupSymlink("libcamera")
+	setupSymlink("libcamera-base")
+}
+
+// LibcameraCleanup removes files created by LibcameraSetup.
+func LibcameraCleanup() {
+	os.Remove("/dev/shm/libcamera-base.so.x.x.x")
+	os.Remove("/dev/shm/libcamera.so.x.x.x")
+}

internal/rpicamera/libcamera_disabled.go

@@ -0,0 +1,12 @@
+//go:build !rpicamera
+// +build !rpicamera
+
+package rpicamera
+
+// LibcameraSetup creates libcamera simlinks that are version agnostic.
+func LibcameraSetup() {
+}
+
+// LibcameraCleanup removes files created by LibcameraSetup.
+func LibcameraCleanup() {
+}

internal/rpicamera/rpicamera.go

@@ -53,45 +53,6 @@ func checkArch() error {
 	return nil
 }
 
-func findLibrary(name string) (string, error) {
-	byts, err := exec.Command("ldconfig", "-p").Output()
-	if err == nil {
-		for _, line := range strings.Split(string(byts), "\n") {
-			f := strings.Split(line, " => ")
-			if len(f) == 2 && strings.Contains(f[1], name+".so") {
-				return f[1], nil
-			}
-		}
-	}
-
-	return "", fmt.Errorf("library '%s' not found", name)
-}
-
-func setupSymlink(name string) error {
-	lib, err := findLibrary(name)
-	if err != nil {
-		return err
-	}
-
-	os.Remove("/dev/shm/" + name + ".so.x.x.x")
-	return os.Symlink(lib, "/dev/shm/"+name+".so.x.x.x")
-}
-
-// create libcamera simlinks that are version agnostic.
-func setupSymlinks() error {
-	err := setupSymlink("libcamera")
-	if err != nil {
-		return err
-	}
-
-	return setupSymlink("libcamera-base")
-}
-
-func removeSymlinks() {
-	os.Remove("/dev/shm/libcamera-base.so.x.x.x")
-	os.Remove("/dev/shm/libcamera.so.x.x.x")
-}
-
 func startEmbeddedExe(content []byte, env []string) (*exec.Cmd, error) {
 	tempPath := tempPathPrefix + strconv.FormatInt(time.Now().UnixNano(), 10)
 
@@ -172,12 +133,6 @@ func New(
 		return nil, err
 	}
 
-	err = setupSymlinks()
-	if err != nil {
-		return nil, err
-	}
-	defer removeSymlinks()
-
 	c := &RPICamera{
 		onData: onData,
 	}