From 49b85d32a9c5a56191fff6ab554d1d748fbf9baf Mon Sep 17 00:00:00 2001
From: Christian Pointner <equinox@helsinki.at>
Date: Wed, 13 Jul 2016 22:43:20 +0200
Subject: implemented actual normalizer


diff --git a/rhimport/normalizer.go b/rhimport/normalizer.go
index 15f71ed..d99984c 100644
--- a/rhimport/normalizer.go
+++ b/rhimport/normalizer.go
@@ -25,12 +25,72 @@
 package rhimport
 
 import (
+	"fmt"
+	"io"
 	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"strings"
 )
 
+type ffmpegResult struct {
+	output string
+	err    error
+}
+
+func runNormalizer(ctx *Context, src *os.File, size int64) (err error) {
+	if ctx.DeleteSourceFile {
+		defer os.Remove(src.Name())
+	}
+
+	basepath, filename := filepath.Split(src.Name())
+	ext := filepath.Ext(filename)
+	destName := strings.TrimSuffix(filename, ext) + "_normalized.flac"
+	rhl.Printf("NormalizeFile: '%s' -> '%s', using gain = %.2f dB", filename, destName, ctx.LoudnessCorr)
+
+	ctx.SourceFile = basepath + destName
+
+	ffmpeg := exec.Command("ffmpeg", "-loglevel", "warning", "-i", "-", "-filter:a", fmt.Sprintf("volume=%fdB", ctx.LoudnessCorr), "-map_metadata", "0", "-f", "flac", ctx.SourceFile)
+	var ffstdin io.WriteCloser
+	if ffstdin, err = ffmpeg.StdinPipe(); err != nil {
+		return
+	}
+
+	ffresult := make(chan ffmpegResult)
+	go func() {
+		output, err := ffmpeg.CombinedOutput()
+		ffresult <- ffmpegResult{strings.TrimSpace(string(output)), err}
+	}()
+
+	var written int64
+	for {
+		var w int64
+		w, err = io.CopyN(ffstdin, src, 512*1024)
+		if err != nil {
+			break
+		}
+		written += w
+		if ctx.ProgressCallBack != nil {
+			if keep := ctx.ProgressCallBack(2, "normalizing", float64(written), float64(size), ctx.ProgressCallBackData); !keep {
+				ctx.ProgressCallBack = nil
+			}
+		}
+	}
+	ffstdin.Close()
+	res := <-ffresult
+	if res.err != nil {
+		return fmt.Errorf("normalizer exited with error: %q, ffmpeg output: %s", res.err, res.output)
+	}
+	if err != nil && err != io.EOF {
+		return
+	}
+	return nil
+}
+
 func NormalizeFile(ctx *Context) (err error) {
 	if ctx.LoudnessCorr == 0.0 {
-		rhdl.Println("NormalizeFile: skipping normalization since the gain = 0.0dB")
+		rhl.Println("NormalizeFile: skipping normalization since the gain = 0.0dB")
 		if ctx.ProgressCallBack != nil {
 			if keep := ctx.ProgressCallBack(2, "normalizing", 1.0, 1.0, ctx.ProgressCallBackData); !keep {
 				ctx.ProgressCallBack = nil
@@ -39,7 +99,6 @@ func NormalizeFile(ctx *Context) (err error) {
 		return
 	}
 
-	rhl.Printf("NormalizeFile: using gain = %.2f dB", ctx.LoudnessCorr)
 	ctx.NormalizationLevel = 0 // don't do double normalization
 
 	var src *os.File
@@ -61,7 +120,16 @@ func NormalizeFile(ctx *Context) (err error) {
 		}
 	}
 
-	// TODO: call ffmpeg
+	if err = runNormalizer(ctx, src, size); err != nil {
+		rhl.Println("NormalizeFile error:", err)
+		if ctx.DeleteSourceFile {
+			os.Remove(ctx.SourceFile)
+			if ctx.DeleteSourceDir {
+				os.Remove(path.Dir(ctx.SourceFile))
+			}
+		}
+		return
+	}
 
 	if ctx.ProgressCallBack != nil {
 		if keep := ctx.ProgressCallBack(2, "normalizing", float64(size), float64(size), ctx.ProgressCallBackData); !keep {
-- 
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