mjpeg

Documentation

Overview

Package mjpeg contains an MJPEG video format writer.

Examples

Let's see an example how to turn the JPEG files 1.jpg, 2.jpg, ..., 10.jpg into a movie file:

checkErr := func(err error) {
    if err != nil {
        panic(err)
    }
}

// Video size: 200x100 pixels, FPS: 2
aw, err := mjpeg.New("test.avi", 200, 100, 2)
checkErr(err)

// Create a movie from images: 1.jpg, 2.jpg, ..., 10.jpg
for i := 1; i <= 10; i++ {
    data, err := ioutil.ReadFile(fmt.Sprintf("%d.jpg", i))
    checkErr(err)
    checkErr(aw.AddFrame(data))
}

checkErr(aw.Close())

Example to add an image.Image as a frame to the video:

aw, err := mjpeg.New("test.avi", 200, 100, 2)
checkErr(err)

var img image.Image
// Acquire / initialize image, e.g.:
// img = image.NewRGBA(image.Rect(0, 0, 200, 100))

buf := &bytes.Buffer{}
checkErr(jpeg.Encode(buf, img, nil))
checkErr(aw.AddFrame(buf.Bytes()))

checkErr(aw.Close())

Index

• Variables
• type AviWriter
  • func New(aviFile string, width, height, fps int32) (awr AviWriter, err error)

Variables

var (
	// ErrTooLarge reports if more frames cannot be added,
	// else the video file would get corrupted.
	ErrTooLarge = errors.New("Video file too large")
)

Types

type AviWriter

type AviWriter interface {
	// AddFrame adds a frame from a JPEG encoded data slice.
	AddFrame(jpegData []byte) error

	// Close finalizes and closes the avi file.
	Close() error
}

AviWriter is an *.avi video writer. The video codec is MJPEG.

func New

func New(aviFile string, width, height, fps int32) (awr AviWriter, err error)

New returns a new AviWriter. The Close() method of the AviWriter must be called to finalize the video file.