go-ffmpeg

Usage

Configuration

Find FFmpeg from your PATH

cfg, _ := ffmpeg.DefaultConfiguration()

Or point to a specific installation of FFmpeg

cfg, _ := ffmpeg.NewConfiguration("/path/to/ffmpeg", "/path/to/ffprobe")

Transcoding

job := cfg.NewJob()
job.AddInputFile("video.mp4")
job.AddOutputFile("out.avi")

statusChan, _ := job.Start(context.Background())
for status := range statusChan {
    switch v := status.(type) {
    case *ffmpeg.Progress:
        log.Printf("%#v", v)
    case *ffmpeg.Done:
        log.Printf("done")
        return
    case *ffmpeg.Error:
        log.Fatalf(v.Error())
    }
}

FFprobe

Whenever an input is added to a job, ffprobe is used to validate it and the result is returned.

metadata, _ := job.AddInputFile("video.mp4")
fmt.Printf("the video is %v seconds long", metadata.Format.Duration)

You can also probe an input first, and then add it to a job.

input, metadata, _ := cfg.Probe("video.mp4")
fmt.Printf("the video is %v seconds long", metadata.Format.Duration)
job.AddInput(input)

Streams (no windows support)

res, _ := http.Get("http://download.blender.org/peach/bigbuckbunny_movies/big_buck_bunny_480p_surround-fix.avi")
job.AddInputReader(res.Body)

file, _ := os.Create("out.mp4")
job.AddOutputWriter(file)

Options

Each of the following methods accept ffmpeg.CliOptions from ffmpeg.Option() and ffmpeg.Flag()

• Configuration.NewJob()
• Job.AddInput()
• Job.AddInputFile()
• Job.AddInputReader()
• Job.AddOutputFile()
• Job.AddOutputWriter()

Need to overwrite a file?

cfg.NewJob(ffmpeg.Flag("-y"))

Need to export using a specific codec and apply a filter?

job.AddInputFile(
    "out.mp4",
    ffmpeg.Option("-codec:v", "libx264"),
    ffmpeg.Option("-filter:v", "scale=640:360"),
)

Debugging

If there a problem with ffmpeg, you can read it's raw output like this:

job.StartDebug(context.Background(), os.Stderr)

Streams on windows

A somewhat convoluted way to get a data stream back from ffmpeg is to setup a http server and output to it.

go http.ListenAndServe(":8080", func(w http.ResponseWriter, r *http.Request) {
    // read output data from r.Body
})

job.AddOutputFile("http://localhost:8080")