Add hardware acceleration support to FFmpeg

cmd/ffmpeg/hardware.go

@@ -0,0 +1,112 @@
+package ffmpeg
+
+import (
+	"github.com/rs/zerolog/log"
+	"os/exec"
+	"strings"
+)
+
+const (
+	EngineSoftware     = "software"
+	EngineVAAPI        = "vaapi"        // Intel iGPU and AMD GPU
+	EngineV4L2         = "v4l2"         // Raspberry Pi 3 and 4
+	EngineCUDA         = "cuda"         // NVidia on Windows and Linux
+	EngineDXVA2        = "dxva2"        // Intel on Windows
+	EngineVideoToolbox = "videotoolbox" // macOS
+)
+
+var cache = map[string]string{}
+
+// MakeHardware converts software FFmpeg args to hardware args
+// empty engine for autoselect
+func MakeHardware(args *Args, engine string) {
+	for i, codec := range args.codecs {
+		if len(codec) < 12 {
+			continue // skip short line (-c:v libx264...)
+		}
+
+		// get current codec name
+		name := cut(codec, ' ', 1)
+		switch name {
+		case "libx264":
+			name = "h264"
+		case "libx265":
+			name = "h265"
+		case "mjpeg":
+		default:
+			continue // skip unsupported codec
+		}
+
+		// temporary disable probe for H265 and MJPEG
+		if engine == "" && name == "h264" {
+			if engine = cache[name]; engine == "" {
+				engine = ProbeHardware(name)
+				cache[name] = engine
+			}
+		}
+
+		switch engine {
+		case EngineVAAPI:
+			args.input = "-hwaccel vaapi -hwaccel_output_format vaapi " + args.input
+			args.codecs[i] = defaults[name+"/"+engine]
+
+			for i, filter := range args.filters {
+				if strings.HasPrefix(filter, "scale=") {
+					args.filters[i] = "scale_vaapi=" + filter[6:]
+				}
+			}
+
+			// fix if input doesn't support hwaccel, do nothing when support
+			args.InsertFilter("format=vaapi|nv12,hwupload")
+
+		case EngineCUDA:
+			args.input = "-hwaccel cuda -hwaccel_output_format cuda -extra_hw_frames 2 " + args.input
+			args.codecs[i] = defaults[name+"/"+engine]
+
+			for i, filter := range args.filters {
+				if strings.HasPrefix(filter, "scale=") {
+					args.filters[i] = "scale_cuda=" + filter[6:]
+				}
+			}
+
+		case EngineDXVA2:
+			args.input = "-hwaccel dxva2 -hwaccel_output_format dxva2_vld " + args.input
+			args.codecs[i] = defaults[name+"/"+engine]
+
+			for i, filter := range args.filters {
+				if strings.HasPrefix(filter, "scale=") {
+					args.filters[i] = "scale_qsv=" + filter[6:]
+				}
+			}
+
+			args.InsertFilter("hwmap=derive_device=qsv,format=qsv")
+
+		case EngineVideoToolbox:
+			args.input = "-hwaccel videotoolbox -hwaccel_output_format videotoolbox_vld " + args.input
+			args.codecs[i] = defaults[name+"/"+engine]
+
+		case EngineV4L2:
+			args.codecs[i] = defaults[name+"/"+engine]
+		}
+	}
+}
+
+func run(arg ...string) bool {
+	err := exec.Command(defaults["bin"], arg...).Run()
+	log.Printf("%v %v", arg, err)
+	return err == nil
+}
+
+func cut(s string, sep byte, pos int) string {
+	for n := 0; n < pos; n++ {
+		if i := strings.IndexByte(s, sep); i > 0 {
+			s = s[i+1:]
+		} else {
+			return ""
+		}
+	}
+	if i := strings.IndexByte(s, sep); i > 0 {
+		return s[:i]
+	}
+	return s
+}