all: use bufio.Reader to improve reading speed

examples/video/main.go

@@ -15,6 +15,7 @@
 package main
 
 import (
+	"bufio"
 	"bytes"
 	_ "embed"
 	"fmt"
@@ -81,7 +82,7 @@ func main() {
 		fmt.Println("Play the default video. You can specify a video file as an argument.")
 	}
 
-	player, err := newMPEGPlayer(in)
+	player, err := newMPEGPlayer(bufio.NewReader(in))
 	if err != nil {
 		log.Fatal(err)
 	}

internal/graphicsdriver/metal/mtl/mtl_darwin_test.go

@@ -15,6 +15,7 @@
 package mtl_test
 
 import (
+	"bufio"
 	"fmt"
 	"image"
 	"image/color"
@@ -147,7 +148,7 @@ func readPNG(name string) (image.Image, error) {
 	defer func() {
 		_ = f.Close()
 	}()
-	return png.Decode(f)
+	return png.Decode(bufio.NewReader(f))
 }
 
 // imageEq reports whether images m, n are considered equivalent. Two images are considered