117 lines
2.7 KiB
Go
117 lines
2.7 KiB
Go
package av
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import (
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"errors"
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"fmt"
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"image/jpeg"
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"os"
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"time"
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"github.com/asticode/go-astiav"
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)
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func ExtractVideoThumbnail(videoPath string, imagePath string) error {
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astiav.SetLogLevel(astiav.LogLevelQuiet)
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formatCtx := astiav.AllocFormatContext()
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defer formatCtx.Free()
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err := formatCtx.OpenInput(videoPath, nil, nil)
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if err != nil {
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return fmt.Errorf("failed opening input: %w", err)
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}
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err = formatCtx.FindStreamInfo(nil)
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if err != nil {
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return fmt.Errorf("failed finding stream info: %w", err)
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}
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stream, codec, err := formatCtx.FindBestStream(
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astiav.MediaTypeVideo, -1, -1)
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if err != nil {
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return fmt.Errorf("failed finding best video stream: %w", err)
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}
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codecParameters := stream.CodecParameters()
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decoder := astiav.FindDecoder(codec.ID())
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if decoder == nil {
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return fmt.Errorf("no decoder found for codec %s", codec.String())
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}
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codecCtx := astiav.AllocCodecContext(decoder)
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defer codecCtx.Free()
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err = codecParameters.ToCodecContext(codecCtx)
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if err != nil {
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return fmt.Errorf("failed setting codec parameters: %w", err)
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}
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err = codecCtx.Open(decoder, nil)
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if err != nil {
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return fmt.Errorf("failed opening codec: %w", err)
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}
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packet := astiav.AllocPacket()
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defer packet.Free()
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frame := astiav.AllocFrame()
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defer frame.Free()
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startTime := time.Now()
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timeout := 5 * time.Second
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// read frames until we find a video frame or timeout
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for time.Since(startTime) < timeout {
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err := formatCtx.ReadFrame(packet)
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if err != nil {
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if errors.Is(err, astiav.ErrEof) {
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return fmt.Errorf("end of file reached before finding video frame")
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}
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return fmt.Errorf("failed reading frame: %w", err)
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}
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if packet.StreamIndex() != stream.Index() {
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packet.Unref()
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continue
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}
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err = codecCtx.SendPacket(packet)
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if err != nil {
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return fmt.Errorf("failed sending packet to decoder: %w", err)
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}
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err = codecCtx.ReceiveFrame(frame)
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if err != nil {
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if errors.Is(err, astiav.ErrEagain) || errors.Is(err, astiav.ErrEof) {
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packet.Unref()
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continue
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}
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return fmt.Errorf("failed receiving frame from decoder: %w", err)
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}
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img, err := frame.Data().GuessImageFormat()
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if err != nil {
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return fmt.Errorf("failed guessing image format: %w", err)
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}
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err = frame.Data().ToImage(img)
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if err != nil {
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return fmt.Errorf("failed converting frame to image: %w", err)
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}
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packet.Unref()
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file, err := os.Create(imagePath)
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if err != nil {
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return fmt.Errorf("failed creating image file: %w", err)
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}
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defer file.Close()
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err = jpeg.Encode(file, img, nil)
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if err != nil {
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return fmt.Errorf("failed encoding image: %w", err)
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}
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return nil
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}
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return fmt.Errorf("timeout while waiting for video frame")
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}
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