encoders: vp8_encoder

encoders/vp8_encoder.go

@@ -1,2 +1,97 @@
-// vp8 encoder
+//go:build vp8enc
+// +build vp8enc
+
 package encoders
+
+import (
+	"bytes"
+	"fmt"
+	"image"
+	"unsafe"
+)
+import "C"
+
+const keyFrameInterval = 10
+
+type VP8Encoder struct {
+	buffer     *bytes.Buffer
+	realSize   image.Point
+	codecCtx   C.vpx_codec_ctx_t
+	vpxImage   C.vpx_image_t
+	yuvBuffer  []byte
+	frameCount uint
+}
+
+func newVP8Encoder(size image.Point, frameRate int) (Encoder, error) {
+	buffer := bytes.NewBuffer(make([]byte, 0))
+
+	var cfg C.vpx_codec_enc_cfg_t
+	if C.codec_enc_config_default(&cfg) != 0 {
+		return nil, fmt.Errorf("Can't init default enc. config")
+	}
+	cfg.g_w = C.uint(size.X)
+	cfg.g_h = C.uint(size.Y)
+	cfg.g_timebase.num = 1
+	cfg.g_timebase.den = C.int(frameRate)
+	cfg.rc_target_bitrate = 90000
+	cfg.g_error_resilient = 1
+
+	var vpxCodecCtx C.vpx_codec_ctx_t
+	if C.codec_enc_init(&vpxCodecCtx, &cfg) != 0 {
+		return nil, fmt.Errorf("Failed to initialize enc ctx")
+	}
+	var vpxImage C.vpx_image_t
+	if C.vpx_img_alloc(&vpxImage, C.VPX_IMG_FMT_I420, C.uint(size.X), C.uint(size.Y), 0) == nil {
+		return nil, fmt.Errorf("Can't alloc. vpx image")
+	}
+
+	return &VP8Encoder{
+		buffer:     buffer,
+		realSize:   size,
+		codecCtx:   vpxCodecCtx,
+		vpxImage:   vpxImage,
+		yuvBuffer:  make([]byte, size.X*size.Y*2),
+		frameCount: 0,
+	}, nil
+}
+
+func (e *VP8Encoder) Encode(frame *image.RGBA) ([]byte, error) {
+
+	encodedData := unsafe.Pointer(nil)
+	var flags C.int
+	if e.frameCount%keyFrameInterval == 0 {
+		flags |= C.VPX_EFLAG_FORCE_KF
+	}
+	frameSize := C.encode_frame(
+		&e.codecCtx,
+		&e.vpxImage,
+		C.int(e.frameCount),
+		flags,
+		unsafe.Pointer(&frame.Pix[0]),
+		unsafe.Pointer(&e.yuvBuffer[0]),
+		C.int(e.realSize.X),
+		C.int(e.realSize.Y),
+		&encodedData,
+	)
+	e.frameCount++
+	if int(frameSize) > 0 {
+		encoded := C.GoBytes(encodedData, frameSize)
+		return encoded, nil
+		return nil, nil
+	}
+	return nil, nil
+}
+
+func (e *VP8Encoder) VideoSize() (image.Point, error) {
+	return e.realSize, nil
+}
+
+func (e *VP8Encoder) Close() error {
+	C.vpx_img_free(&e.vpxImage)
+	C.vpx_codec_destroy(&e.codecCtx)
+	return nil
+}
+
+func init() {
+	registeredEncoders[VP8Codec] = newVP8Encoder
+}