From fda746c5fdf3b38890129e47bca2cb27fa7e6aa7 Mon Sep 17 00:00:00 2001
From: iawia002 <z2d@jifangcheng.com>
Date: Fri, 10 Aug 2018 16:04:43 +0800
Subject: [PATCH] utils/ffmpeg: integrate merge functions into a file [ci skip]

---
 downloader/downloader.go | 45 ++++--------------------------
 utils/ffmpeg.go          | 59 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+), 39 deletions(-)
 create mode 100644 utils/ffmpeg.go

diff --git a/downloader/downloader.go b/downloader/downloader.go
index 4846d28ef..ab775afe9 100644
--- a/downloader/downloader.go
+++ b/downloader/downloader.go
@@ -2,13 +2,11 @@ package downloader
 
 import (
 	"bufio"
-	"bytes"
 	"encoding/json"
 	"fmt"
 	"io"
 	"log"
 	"os"
-	"os/exec"
 	"sort"
 	"strings"
 	"time"
@@ -320,45 +318,14 @@ func (v VideoData) Download(refer string) {
 		return
 	}
 	// merge
-	mergeFileName := title + ".txt" // merge list file should be in the current directory
-	filePath := utils.FilePath(title, "mp4", false)
-	fmt.Printf("Merging video parts into %s\n", filePath)
-	var cmd *exec.Cmd
-	if strings.Contains(v.Site, "youtube") {
-		// merge audio and video
-		cmds := []string{
-			"-y",
-		}
-		for _, part := range parts {
-			cmds = append(cmds, "-i", part)
-		}
-		cmds = append(
-			cmds, "-c:v", "copy", "-c:a", "aac", "-strict", "experimental",
-			filePath,
-		)
-		cmd = exec.Command("ffmpeg", cmds...)
+	fmt.Printf("Merging video parts into %s\n", mergedFilePath)
+	var err error
+	if v.Site == "YouTube youtube.com" {
+		err = utils.MergeAudioAndVideo(parts, mergedFilePath)
 	} else {
-		// write ffmpeg input file list
-		mergeFile, _ := os.Create(mergeFileName)
-		for _, part := range parts {
-			mergeFile.Write([]byte(fmt.Sprintf("file '%s'\n", part)))
-		}
-		mergeFile.Close()
-
-		cmd = exec.Command(
-			"ffmpeg", "-y", "-f", "concat", "-safe", "-1",
-			"-i", mergeFileName, "-c", "copy", "-bsf:a", "aac_adtstoasc", filePath,
-		)
+		err = utils.MergeToMP4(parts, mergedFilePath, title)
 	}
-	var stderr bytes.Buffer
-	cmd.Stderr = &stderr
-	err := cmd.Run()
 	if err != nil {
-		log.Fatal(fmt.Sprint(err) + "\n" + stderr.String())
-	}
-	// remove parts
-	os.Remove(mergeFileName)
-	for _, part := range parts {
-		os.Remove(part)
+		log.Println(err)
 	}
 }
diff --git a/utils/ffmpeg.go b/utils/ffmpeg.go
new file mode 100644
index 000000000..7cab56e1b
--- /dev/null
+++ b/utils/ffmpeg.go
@@ -0,0 +1,59 @@
+package utils
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+func runMergeCmd(cmd *exec.Cmd, paths []string, mergeFilePath string) error {
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+	err := cmd.Run()
+	if err != nil {
+		return fmt.Errorf("%s\n%s", err, stderr.String())
+	}
+
+	if mergeFilePath != "" {
+		os.Remove(mergeFilePath)
+	}
+	// remove parts
+	for _, path := range paths {
+		os.Remove(path)
+	}
+	return nil
+}
+
+// MergeAudioAndVideo merge audio and video
+func MergeAudioAndVideo(paths []string, mergedFilePath string) error {
+	cmds := []string{
+		"-y",
+	}
+	for _, path := range paths {
+		cmds = append(cmds, "-i", path)
+	}
+	cmds = append(
+		cmds, "-c:v", "copy", "-c:a", "aac", "-strict", "experimental",
+		mergedFilePath,
+	)
+	return runMergeCmd(exec.Command("ffmpeg", cmds...), paths, "")
+}
+
+// MergeToMP4 merge video parts to MP4
+func MergeToMP4(paths []string, mergedFilePath string, filename string) error {
+	mergeFilePath := filename + ".txt" // merge list file should be in the current directory
+
+	// write ffmpeg input file list
+	mergeFile, _ := os.Create(mergeFilePath)
+	for _, path := range paths {
+		mergeFile.Write([]byte(fmt.Sprintf("file '%s'\n", path)))
+	}
+	mergeFile.Close()
+
+	cmd := exec.Command(
+		"ffmpeg", "-y", "-f", "concat", "-safe", "-1",
+		"-i", mergeFilePath, "-c", "copy", "-bsf:a", "aac_adtstoasc", mergedFilePath,
+	)
+	return runMergeCmd(cmd, paths, mergeFilePath)
+}