serve dlna: add more builtin mime types to cover standard audio/video

Add a minimal number of mime types to augment go's built in types
for environments which don't have access to a mime.types file (eg
Termux on android)

Fixes #3475

cmd/serve/dlna/cds.go

@@ -5,6 +5,7 @@ import (
 	"encoding/xml"
 	"fmt"
 	"log"
+	"mime"
 	"net/http"
 	"net/url"
 	"os"
@@ -12,6 +13,7 @@ import (
 	"path/filepath"
 	"regexp"
 	"sort"
+	"strings"
 
 	"github.com/anacrolix/dms/dlna"
 	"github.com/anacrolix/dms/upnp"
@@ -21,6 +23,39 @@ import (
 	"github.com/rclone/rclone/vfs"
 )
 
+// Add a minimal number of mime types to augment go's built in types
+// for environments which don't have access to a mime.types file (eg
+// Termux on android)
+func init() {
+	for _, t := range []struct {
+		mimeType   string
+		extensions string
+	}{
+		{"audio/flac", ".flac"},
+		{"audio/mpeg", ".mpga,.mpega,.mp2,.mp3,.m4a"},
+		{"audio/ogg", ".oga,.ogg,.opus,.spx"},
+		{"audio/x-wav", ".wav"},
+		{"image/tiff", ".tiff,.tif"},
+		{"video/dv", ".dif,.dv"},
+		{"video/fli", ".fli"},
+		{"video/mpeg", ".mpeg,.mpg,.mpe"},
+		{"video/MP2T", ".ts"},
+		{"video/mp4", ".mp4"},
+		{"video/quicktime", ".qt,.mov"},
+		{"video/ogg", ".ogv"},
+		{"video/webm", ".webm"},
+		{"video/x-msvideo", ".avi"},
+		{"video/x-matroska", ".mpv,.mkv"},
+	} {
+		for _, ext := range strings.Split(t.extensions, ",") {
+			err := mime.AddExtensionType(ext, t.mimeType)
+			if err != nil {
+				panic(err)
+			}
+		}
+	}
+}
+
 type contentDirectoryService struct {
 	*server
 	upnp.Eventing