Merge pull request #6 from braheezy/mp3

Pure Go MP3 encoding support
braheezy · Sep 29, 2023 · f721f5d · f721f5d
2 parents 78152a6 + 6647f3b
commit f721f5d
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Showing 17 changed files with 2,367 additions and 62 deletions.
diff --git a/cmd/convert_mp3.go b/cmd/convert_mp3.go
@@ -1,5 +1,3 @@
-//go:build !windows
-
 package cmd
 
 import (
@@ -8,9 +6,9 @@ import (
 	"log"
 	"os"
 
+	"github.com/braheezy/goqoa/pkg/mp3"
 	"github.com/braheezy/goqoa/pkg/qoa"
 	"github.com/tosone/minimp3"
-	"github.com/viert/go-lame"
 )
 
 func decodeMp3(inputData *[]byte) ([]int16, *qoa.QOA) {
@@ -39,27 +37,13 @@ func decodeMp3(inputData *[]byte) ([]int16, *qoa.QOA) {
 
 func encodeMp3(outputFile string, q *qoa.QOA, decodedData []int16) {
 	fmt.Println("Output format is MP3")
+
 	mp3File, err := os.Create(outputFile)
 	if err != nil {
 		log.Fatalf("Error creating MP3 file: %v", err)
 	}
 	defer mp3File.Close()
+	mp3Encoder := mp3.NewEncoder(int(q.SampleRate), int(q.Channels))
 
-	mp3Encoder := lame.NewEncoder(mp3File)
-	defer mp3Encoder.Close()
-
-	mp3Encoder.SetNumChannels(int(q.Channels))
-	mp3Encoder.SetInSamplerate(int(q.SampleRate))
-
-	// Convert the PCM data to a []byte
-	pcmBytes := make([]byte, len(decodedData)*2) // Assuming 16-bit PCM (2 bytes per sample)
-	for i, val := range decodedData {
-		binary.LittleEndian.PutUint16(pcmBytes[i*2:], uint16(val))
-	}
-
-	// Encode and write the PCM data to the MP3 file
-	_, err = mp3Encoder.Write(pcmBytes)
-	if err != nil {
-		log.Fatalf("Error encoding audio data to MP3: %v", err)
-	}
+	mp3Encoder.Write(mp3File, decodedData)
 }
diff --git a/cmd/convert_mp3_windows.go b/cmd/convert_mp3_windows.go
diff --git a/cmd/goqoa_test.go b/cmd/goqoa_test.go
@@ -6,7 +6,6 @@ import (
 	"encoding/hex"
 	"fmt"
 	"os"
-	"runtime"
 	"strings"
 	"testing"
 
@@ -52,25 +51,16 @@ func TestConvertCmd(t *testing.T) {
 			inputFormat:  "flac",
 			outputFormat: "qoa",
 		},
-	}
-	if runtime.GOOS != "windows" {
-		mp3TestCases := []struct {
-			audioFormat  string
-			inputFormat  string
-			outputFormat string
-		}{
-			{
-				audioFormat:  "mp3",
-				inputFormat:  "mp3",
-				outputFormat: "qoa",
-			},
-			{
-				audioFormat:  "mp3",
-				inputFormat:  "qoa",
-				outputFormat: "mp3",
-			},
-		}
-		tt = append(tt, mp3TestCases...)
+		{
+			audioFormat:  "mp3",
+			inputFormat:  "mp3",
+			outputFormat: "qoa",
+		},
+		{
+			audioFormat:  "mp3",
+			inputFormat:  "qoa",
+			outputFormat: "mp3",
+		},
 	}
 
 	for _, tc := range tt {
@@ -100,7 +90,7 @@ func TestConvertCmd(t *testing.T) {
 		actualChecksumStr := hex.EncodeToString(actualChecksum[:])
 
 		// Compare the checksums
-		require.Equalf(t, expectedChecksumStr, actualChecksumStr, "Conversion failed for %s -> %s", tc.inputFormat, tc.outputFormat)
+		require.Equalf(t, expectedChecksumStr, actualChecksumStr, "(%s) Conversion failed for %s -> %s", tc.audioFormat, tc.inputFormat, tc.outputFormat)
 
 		os.Remove(outputFilename)
 	}

diff --git a/cmd/testdata/mp3/test.qoa.mp3 b/cmd/testdata/mp3/test.qoa.mp3
diff --git a/go.mod b/go.mod
@@ -11,7 +11,6 @@ require (
 	github.com/spf13/cobra v1.7.0
 	github.com/stretchr/testify v1.8.4
 	github.com/tosone/minimp3 v1.0.2
-	github.com/viert/go-lame v0.0.0-20201108052322-bb552596b11d
 )
 
 require (

diff --git a/go.sum b/go.sum
@@ -40,8 +40,6 @@ github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcU
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/tosone/minimp3 v1.0.2 h1:htFE2EbP7Y4CJ8KGW9c55tKWRpzv9kXkEmCYGxFzVjA=
 github.com/tosone/minimp3 v1.0.2/go.mod h1:N6vjknGR7PboMTyJVhe/7RHNQiIc0jWZxFKlSWdfzwc=
-github.com/viert/go-lame v0.0.0-20201108052322-bb552596b11d h1:LptdD7GTUZeklomtW5vZ1AHwBvDBUCZ2Ftpaz7uEI7g=
-github.com/viert/go-lame v0.0.0-20201108052322-bb552596b11d/go.mod h1:EqTcYM7y4JlSfeTI47pmNu3EZQuCuLQefsQyg1Imlz8=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=

diff --git a/pkg/mp3/bitstream.go b/pkg/mp3/bitstream.go
@@ -0,0 +1,58 @@
+// bitstream.go manages writes to the bitstream
+package mp3
+
+const (
+	// Minimum size of the buffer in bytes
+	MINIMUM = 4
+	// Maximum length of word written or read from bit stream
+	MAX_LENGTH  = 32
+	BUFFER_SIZE = 4096
+)
+
+type bitstream struct {
+	data         []uint8
+	dataSize     int
+	dataPosition int
+	cache        uint32
+	cacheBits    int
+}
+
+func (bs *bitstream) open(size int) {
+	bs.data = make([]uint8, size)
+	bs.dataSize = size
+	bs.dataPosition = 0
+	bs.cache = 0
+	bs.cacheBits = 32
+}
+
+func (bs *bitstream) putBits(val uint32, N uint) {
+	if bs.cacheBits > int(N) {
+		bs.cacheBits -= int(N)
+		bs.cache |= val << uint32(bs.cacheBits)
+	} else {
+		if bs.dataPosition+4 >= bs.dataSize {
+			newCapacity := bs.dataSize + (bs.dataSize >> 1)
+			newSlice := make([]byte, newCapacity)
+			copy(newSlice, bs.data)
+			bs.data = newSlice
+			bs.dataSize = newCapacity
+		}
+		N -= uint(bs.cacheBits)
+		bs.cache |= val >> N
+		bs.data[bs.dataPosition] = uint8(bs.cache >> 24)
+		bs.data[bs.dataPosition+1] = uint8(bs.cache >> 16)
+		bs.data[bs.dataPosition+2] = uint8(bs.cache >> 8)
+		bs.data[bs.dataPosition+3] = uint8(bs.cache)
+
+		bs.dataPosition += 4
+		bs.cacheBits = int(32 - N)
+		if N != 0 {
+			bs.cache = val << uint(bs.cacheBits)
+		} else {
+			bs.cache = 0
+		}
+	}
+}
+func (bs *bitstream) getBitsCount() int {
+	return bs.dataPosition*8 + 32 - bs.cacheBits
+}