Recherche avancée

Sur d’autres sites (10870)

• What's the difference between H265, x265, x264, H264 and which of these uses GPU instead of CPU and how to use H265 GPU NVIDIA acceleration in ffmpeg ?

  30 juillet 2022, par Fab98

  I'm not sure if
x264/5
use CPU and if h264/5 use GPU and also if h265 is basically HEVC_NVENC for NVIDIA GPU acceleration. So, if you could give me more info about these encoding types it would be great. I understood that, summing up a lot, x26* use CPU and are slower but more accurate while h26* are the opposite but h265 is the most recent and optimal trade off.
Furthermore, I was trying to convert a video using GPU acceleration and my question is :

  


  Does the following command tell to the GPU to use h265 to encode a video holding the same audio and at upgrading it at its maximum video quality ? Furthermore, are there other ways to express the same command ?

  


  ffmpeg.exe -hwaccel_output_format cuda -i "input" -c:v hevc_nvenc -preset medium -rc constqp -qp 0 -c:a copy "output"


  


• How to kill command Exec in difference Function in Golang

  26 juillet 2022, par Tammam

  i'm making screen record web based using command exec to run FFMPEG. here I created a startRecording function but I am still confused about stopping the command process in the stopRecording function, because the command is executed in the startRecording function. How to stop a process that is already running in the srartRecording function in the stopRecording function ?

  


  here my code

  


  //Handler to create room/start record
func RoomCreate(c *fiber.Ctx) error {
    fileName := "out.mp4"
    fmt.Println(fileName)
    if len(os.Args) > 1 {
        fileName = os.Args[1]
    }

    

    errCh := make(chan error, 2)
    ctx, cancelFn := context.WithCancel(context.Background())
    // Call to function startRecording
    go func() { errCh <- startRecording(ctx, fileName) }()

    go func() {
        errCh <- nil
    }()
    err := <-errCh
    cancelFn()
    if err != nil && err != context.Canceled {
        log.Fatalf("Execution failed: %v", err)
    }
    
    return c.Redirect(fmt.Sprintf("/room/%s", guuid.New().String()))
}



//Function to run command FFMPEG
func startRecording(ctx context.Context, fileName string) error {
    ctx, cancelFn := context.WithCancel(ctx)
    defer cancelFn()
    // Build ffmpeg
    ffmpeg := exec.Command("ffmpeg",
        "-f", "gdigrab",
        "-framerate", "30",
        "-i", "desktop",
        "-f", "mp4",
        fileName,
    )
    // Stdin for sending data
    stdin, err := ffmpeg.StdinPipe()
    if err != nil {
        return err
    }
    //var buf bytes.Buffer
    defer stdin.Close()
    // Run it in the background
    errCh := make(chan error, 1)

    go func() {
        fmt.Printf("Executing: %v\n", strings.Join(ffmpeg.Args, " "))
        
        if err := ffmpeg.Run(); err != nil {
            return
        }
        //fmt.Printf("FFMPEG output:\n%v\n", string(out))
        errCh <- err
    }()
    // Just start sending a bunch of frames
    for {
        
        // Check if we're done, otherwise go again
        select {
        case <-ctx.Done():
            return ctx.Err()
        case err := <-errCh:
            return err
        default:
        }
    }
}

//Here function to stop Recording
func stopRecording(ctx context.Context) error {
//Code stop recording in here
} 


  


  Thanks for advance

  


• difference overlay filter ffmpeg like photoshop/affinity photo

  14 janvier, par Owen Quinlan

  In photoshop and affinity photo there is a nice overlay filter that basically subtracts the overlaying layer from the one bellow to make a "difference map"

  


  Example :
Base image :
Screenshot Mario Kart 1

  


  Overlaying image :
Screenshot Mario Kart 2

  


  Resulting output :
Diff from two screenshots

  


  This is an example diff of overlaying a PNG with a JpegXL(I think) compressed image and then brightened :
Diff generated from image compression

  


  Location of filter in photoshop :
Photoshop screenshot

  


  Is there anyway to accomplish this with a filter in ffmpeg for an entire video ?