Merge pull request #29 from hbomb79/master

feat(context): added WithContext method for Transcoder

Author: xfrr

ffmpeg/ffmpeg.go

@@ -3,6 +3,7 @@ package ffmpeg
 import (
 	"bufio"
 	"bytes"
+	"context"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -28,6 +29,7 @@ type Transcoder struct {
 	outputPipeReader *io.ReadCloser
 	inputPipeWriter  *io.WriteCloser
 	outputPipeWriter *io.WriteCloser
+	commandContext   *context.Context
 }
 
 // New ...
@@ -82,7 +84,15 @@ func (t *Transcoder) Start(opts transcoder.Options) (<-chan transcoder.Progress,
 	}
 
 	// Initialize command
-	cmd := exec.Command(t.config.FfmpegBinPath, args...)
+	// If a context object was supplied to this Transcoder before
+	// starting, use this context when creating the command to allow
+	// the command to be killed when the context expires
+	var cmd *exec.Cmd
+	if t.commandContext == nil {
+		cmd = exec.Command(t.config.FfmpegBinPath, args...)
+	} else {
+		cmd = exec.CommandContext(*t.commandContext, t.config.FfmpegBinPath, args...)
+	}
 
 	// If progresss enabled, get stderr pipe and start progress process
 	if t.config.ProgressEnabled && !t.config.Verbose {
@@ -160,6 +170,14 @@ func (t *Transcoder) WithAdditionalOptions(opts transcoder.Options) transcoder.T
 	return t
 }
 
+// WithContext is to be used on a Transcoder *before Starting* to
+// pass in a context.Context object that can be used to kill
+// a running transcoder process. Usage of this method is optional
+func (t *Transcoder) WithContext(ctx *context.Context) transcoder.Transcoder {
+	t.commandContext = ctx
+	return t
+}
+
 // validate ...
 func (t *Transcoder) validate() error {
 	if t.config.FfmpegBinPath == "" {
@@ -192,7 +210,7 @@ func (t *Transcoder) validate() error {
 }
 
 // GetMetadata Returns metadata for the specified input file
-func (t *Transcoder) GetMetadata() ( transcoder.Metadata, error) {
+func (t *Transcoder) GetMetadata() (transcoder.Metadata, error) {
 
 	if t.config.FfprobeBinPath != "" {
 		var outb, errb bytes.Buffer

transcoder.go

@@ -1,6 +1,7 @@
 package transcoder
 
 import (
+	"context"
 	"io"
 )
 
@@ -13,5 +14,6 @@ type Transcoder interface {
 	OutputPipe(w *io.WriteCloser, r *io.ReadCloser) Transcoder
 	WithOptions(opts Options) Transcoder
 	WithAdditionalOptions(opts Options) Transcoder
+	WithContext(ctx *context.Context) Transcoder
 	GetMetadata() (Metadata, error)
 }