ace/drivers/video/ppm.go
2022-10-02 10:50:08 +00:00

91 lines
2.0 KiB
Go

package video
import (
"context"
"image"
"image/color"
"io"
"time"
"github.com/nfnt/resize"
"github.com/pion/mediadevices/pkg/frame"
"github.com/pion/mediadevices/pkg/io/video"
"github.com/pion/mediadevices/pkg/prop"
"github.com/sirupsen/logrus"
_ "github.com/jbuchbinder/gopnm"
)
const DefaultFPS float32 = 60.0
type PPMStreamDriver struct {
Height, Width int
FPS float32
PPMImage <-chan io.ReadCloser
closed <-chan struct{}
cancel func()
}
func (v *PPMStreamDriver) Open() error {
defer logrus.Debug("device opened")
ctx, cancel := context.WithCancel(context.Background())
v.closed = ctx.Done()
v.cancel = cancel
return nil
}
func (v *PPMStreamDriver) Close() error {
v.cancel()
return nil
}
func (v *PPMStreamDriver) Properties() []prop.Media {
return []prop.Media{
{
Video: prop.Video{
Width: v.Width,
Height: v.Height,
FrameRate: v.FPS,
FrameFormat: frame.FormatYUYV,
},
},
}
}
func (v *PPMStreamDriver) VideoRecord(p prop.Media) (video.Reader, error) {
logrus.Debug(p)
canvas := image.NewYCbCr(
image.Rect(0, 0, p.Width, p.Height),
image.YCbCrSubsampleRatio420,
)
r := video.ReaderFunc(func() (img image.Image, release func(), err error) {
select {
case <-v.closed:
return nil, func() {}, io.EOF
case ppmF := <-v.PPMImage:
defer ppmF.Close()
img, _, err := image.Decode(ppmF)
if err != nil {
return nil, func() {}, err
}
// resize image and draw it to canvas
resized := resize.Resize(uint(p.Width), uint(p.Height), img, resize.Lanczos3)
for y := 0; y < resized.Bounds().Dy(); y++ {
for x := 0; x < resized.Bounds().Dx(); x++ {
r, g, b, _ := resized.At(x, y).RGBA()
Y, Cb, Cr := color.RGBToYCbCr(uint8(r), uint8(g), uint8(b))
canvas.Y[canvas.YOffset(x, y)] = Y
canvas.Cb[canvas.COffset(x, y)] = Cb
canvas.Cr[canvas.COffset(x, y)] = Cr
}
}
case <-time.After(time.Second / time.Duration(p.FrameRate)):
}
return canvas, func() {}, nil
})
return r, nil
}