support 4 bytes streaming

examples/bytesulaw2wav/main.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"bytes"
+	"os"
+
+	"github.com/pablodz/sopro/pkg/audioconfig"
+	"github.com/pablodz/sopro/pkg/cpuarch"
+	"github.com/pablodz/sopro/pkg/encoding"
+	"github.com/pablodz/sopro/pkg/fileformat"
+	"github.com/pablodz/sopro/pkg/method"
+	"github.com/pablodz/sopro/pkg/transcoder"
+)
+
+func main() {
+
+	data := []byte{0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 10, 4, 2, 3, 3, 5, 01, 7, 8, 1, 4, 0}
+	// Open the input file
+	in := bytes.NewBuffer(data)
+
+	// Create the output file
+	out, err := os.Create("./internal/samples/output.wav")
+	if err != nil {
+		panic(err)
+	}
+	defer out.Close()
+
+	// create a transcoder
+	t := &transcoder.Transcoder{
+		MethodT: method.BIT_LOOKUP_TABLE,
+		SourceConfigs: transcoder.TranscoderAudioConfig{
+			Endianness: cpuarch.LITTLE_ENDIAN,
+		},
+		TargetConfigs: transcoder.TranscoderAudioConfig{
+			Endianness: cpuarch.LITTLE_ENDIAN,
+		},
+		SizeBuffer: 1024,
+		Verbose:    true,
+	}
+
+	// Transcode the file
+	err = t.Mulaw2Wav(
+		&transcoder.AudioFileIn{
+			Data: in,
+			AudioFileGeneral: transcoder.AudioFileGeneral{
+				Format: fileformat.AUDIO_MULAW,
+				Config: audioconfig.MulawConfig{
+					BitDepth:   8,
+					Channels:   1,
+					Encoding:   encoding.SPACE_LOGARITHMIC, // ulaw is logarithmic
+					SampleRate: 8000,
+				},
+			},
+		},
+		&transcoder.AudioFileOut{
+			Data: out,
+			AudioFileGeneral: transcoder.AudioFileGeneral{
+				Format: fileformat.AUDIO_WAV,
+				Config: audioconfig.WavConfig{
+					BitDepth:   8,
+					Channels:   1,
+					Encoding:   encoding.SPACE_LOGARITHMIC,
+					SampleRate: 8000,
+				},
+			},
+		},
+	)
+
+	if err != nil {
+		panic(err)
+	}
+
+}

pkg/transcoder/mulaw2wav.go

@@ -2,6 +2,7 @@ package transcoder
 
 import (
 	"bufio"
+	"bytes"
 	"fmt"
 	"io"
 	"log"
@@ -148,6 +149,12 @@ func mulaw2WavLpcm(in *AudioFileIn, out *AudioFileOut, transcoder *Transcoder) (
 
 func graphIn(in *AudioFileIn) {
 	log.Println("[WARNING] Reading the whole file into memory. This may take a while...")
+	// check if in is *bytes.Buffer
+	if _, ok := in.Data.(*bytes.Buffer); ok {
+		log.Println("Input file is a bytes.Buffer")
+		return
+	}
+
 	// make an independent copy of the file
 	file := in.Data.(*os.File)
 	f, err := os.Open(file.Name())
@@ -179,6 +186,11 @@ func graphIn(in *AudioFileIn) {
 
 func graphOut(in *AudioFileIn, out *AudioFileOut) {
 	log.Println("[WARNING] Reading the whole file into memory. This may take a while...")
+	// check if in is *bytes.Buffer
+	if _, ok := in.Data.(*bytes.Buffer); ok {
+		log.Println("Input file is a bytes.Buffer")
+		return
+	}
 	file := in.Data.(*os.File)
 	f, err := os.Open(file.Name())
 	if err != nil {

pkg/transcoder/router.go

@@ -20,17 +20,18 @@ func (t *Transcoder) Mulaw2Wav(in *AudioFileIn, out *AudioFileOut) error {
 	outSpace := out.Config.(audioconfig.WavConfig).Encoding
 
 	switch {
-	case t.MethodT != method.BIT_LOOKUP_TABLE &&
+	case t.MethodT == method.BIT_LOOKUP_TABLE &&
 		inSpace == encoding.SPACE_LOGARITHMIC &&
 		outSpace == encoding.SPACE_LINEAR:
 		return mulaw2WavLpcm(in, out, t)
-	case t.MethodT != method.BIT_LOOKUP_TABLE &&
+	case t.MethodT == method.BIT_LOOKUP_TABLE &&
 		inSpace == encoding.SPACE_LOGARITHMIC &&
 		outSpace == encoding.SPACE_LOGARITHMIC:
 		return mulaw2WavLogpcm(in, out, t)
 	default:
 		return fmt.Errorf(
-			"%s: %s -> %s",
+			"[%s] %s: %s -> %s",
+			method.METHODS[t.MethodT],
 			ErrUnsupportedConversion,
 			encoding.ENCODINGS[inSpace],
 			encoding.ENCODINGS[outSpace],