ffmpeg.go

// Package ffmpeg provides a library interface to the ffmpeg command
// line interface.
package ffmpeg

//go:generate go run _gen/main.go -option pix_fmts
//go:generate go run _gen/main.go -option codecs
//go:generate go run _gen/main.go -option formats

import (
	"os/exec"

	multierror "github.com/hashicorp/go-multierror"
)

// Command creates a new Cmd instance
func Command(global GlobalOptions, files ...*File) (*Cmd, error) {
	var i, o []*File
	var err *multierror.Error

	for _, file := range files {
		switch file.typ {
		case fileTypeInput:
			if file.err != nil {
				err = multierror.Append(err, file.err)
			} else {
				i = append(i, file)
			}
		case fileTypeOutput:
			if file.err != nil {
				err = multierror.Append(err, file.err)
			} else {
				o = append(o, file)
			}
		}
	}

	if err.ErrorOrNil() != nil {
		return nil, err
	}

	var r []string
	if global != nil {
		r = append(r, global.Flags()...)
	}
	for _, input := range i {
		r = append(r, input.Flags()...)
	}
	for _, ouput := range o {
		r = append(r, ouput.Flags()...)
	}

	// suppress printing the banner
	// disable stdin interaction
	// stop and exit on error
	args := []string{"-hide_banner", "-nostdin", "-xerror"}
	args = append(args, r...)

	cmd := exec.Command("ffmpeg", args...)
	cmd.Env = append(cmd.Env, "AV_LOG_FORCE_NOCOLOR=TRUE")

	return &Cmd{
		Args: args,
		cmd:  cmd,
	}, nil
}