Implement automatic model and Whisper.dll downloading

Additionally, made the following changes:
∙ - Allow listening only on local interfaces
∙ - Update project structure

internal/api/handler.go

@@ -0,0 +1,45 @@
+package api
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/labstack/echo/v4"
+)
+
+type TranscribeResponse struct {
+	Text string `json:"text"`
+}
+
+func Transcribe(c echo.Context, whisperState *WhisperState) error {
+	audioPath, err := saveFormFile("file", c)
+	if err != nil {
+		c.Logger().Errorf("Error reading file: %s", err)
+		return err
+	}
+
+	whisperState.mutex.Lock()
+	buffer, err := whisperState.media.LoadAudioFile(audioPath, true)
+	if err != nil {
+		c.Logger().Errorf("Error loading audio file data: %s", err)
+	}
+
+	err = whisperState.context.RunFull(whisperState.params, buffer)
+
+	result, err := getResult(whisperState.context)
+	if err != nil {
+		c.Logger().Error(err)
+	}
+
+	defer whisperState.mutex.Unlock()
+
+	if len(result) == 0 {
+		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "Internal server error"})
+	}
+
+	response := TranscribeResponse{
+		Text: strings.TrimLeft(result, " "),
+	}
+
+	return c.JSON(http.StatusOK, response)
+}

internal/api/state.go

@@ -0,0 +1,75 @@
+package api
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/xzeldon/whisper-api-server/pkg/whisper"
+)
+
+type WhisperState struct {
+	model   *whisper.Model
+	context *whisper.IContext
+	media   *whisper.IMediaFoundation
+	params  *whisper.FullParams
+	mutex   sync.Mutex
+}
+
+func InitializeWhisperState(modelPath string) (*WhisperState, error) {
+	lib, err := whisper.New(whisper.LlDebug, whisper.LfUseStandardError, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	model, err := lib.LoadModel(modelPath)
+	if err != nil {
+		return nil, err
+	}
+
+	context, err := model.CreateContext()
+	if err != nil {
+		return nil, err
+	}
+
+	media, err := lib.InitMediaFoundation()
+	if err != nil {
+		return nil, err
+	}
+
+	params, err := context.FullDefaultParams(whisper.SsBeamSearch)
+	if err != nil {
+		return nil, err
+	}
+
+	params.AddFlags(whisper.FlagNoContext)
+	params.AddFlags(whisper.FlagTokenTimestamps)
+
+	fmt.Printf("Params CPU Threads : %d\n", params.CpuThreads())
+
+	return &WhisperState{
+		model:   model,
+		context: context,
+		media:   media,
+		params:  params,
+	}, nil
+}
+
+func getResult(ctx *whisper.IContext) (string, error) {
+	results := &whisper.ITranscribeResult{}
+	ctx.GetResults(whisper.RfTokens|whisper.RfTimestamps, &results)
+
+	length, err := results.GetSize()
+	if err != nil {
+		return "", err
+	}
+
+	segments := results.GetSegments(length.CountSegments)
+
+	var result string
+
+	for _, seg := range segments {
+		result += seg.Text()
+	}
+
+	return result, nil
+}

internal/api/utils.go

@@ -0,0 +1,48 @@
+package api
+
+import (
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/labstack/echo/v4"
+)
+
+func saveFormFile(name string, c echo.Context) (string, error) {
+	file, err := c.FormFile(name)
+	if err != nil {
+		return "", err
+	}
+
+	src, err := file.Open()
+	if err != nil {
+		return "", err
+	}
+	defer src.Close()
+
+	ext := filepath.Ext(file.Filename)
+	filename := time.Now().Format(time.RFC3339)
+	filename = "./tmp/" + sanitizeFilename(filename) + ext
+
+	dst, err := os.Create(filename)
+	if err != nil {
+		return "", err
+	}
+	defer dst.Close()
+
+	if _, err = io.Copy(dst, src); err != nil {
+		return "", err
+	}
+
+	return filename, nil
+}
+
+func sanitizeFilename(filename string) string {
+	invalidChars := []string{`\`, `/`, `:`, `*`, `?`, `"`, `<`, `>`, `|`}
+	for _, char := range invalidChars {
+		filename = strings.ReplaceAll(filename, char, "-")
+	}
+	return filename
+}

internal/resources/download.go

@@ -0,0 +1,38 @@
+package resources
+
+import (
+	"io"
+	"net/http"
+	"os"
+
+	"github.com/schollz/progressbar/v3"
+)
+
+func DownloadFile(url string, filepath string) error {
+	out, err := os.Create(filepath)
+	if err != nil {
+		return err
+	}
+	defer out.Close()
+
+	resp, err := http.Get(url)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	fileSize := resp.ContentLength
+	bar := progressbar.DefaultBytes(
+		fileSize,
+		"Downloading",
+	)
+
+	writer := io.MultiWriter(out, bar)
+
+	_, err = io.Copy(writer, resp.Body)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

internal/resources/model.go

@@ -0,0 +1,29 @@
+package resources
+
+import (
+	"fmt"
+	"path/filepath"
+)
+
+func GetModel(modelType string) (string, error) {
+	fileURL := fmt.Sprintf("https://huggingface.co/ggerganov/whisper.cpp/resolve/main/%s", modelType)
+	filePath := modelType
+
+	isModelFileExists := IsFileExists(filePath)
+
+	if !isModelFileExists {
+		fmt.Println("Model not found.")
+		err := DownloadFile(fileURL, filePath)
+		if err != nil {
+			return "", err
+		}
+	}
+
+	absPath, err := filepath.Abs(filePath)
+	if err != nil {
+		return "", err
+	}
+
+	fmt.Printf("Model found: %s\n", absPath)
+	return filePath, nil
+}

internal/resources/utils.go

@@ -0,0 +1,13 @@
+package resources
+
+import "os"
+
+func IsFileExists(filename string) bool {
+	_, err := os.Stat(filename)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return false
+		}
+	}
+	return true
+}

internal/resources/whisper.go

@@ -0,0 +1,78 @@
+package resources
+
+import (
+	"archive/zip"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+)
+
+func GetWhisperDll(version string) (string, error) {
+	fileUrl := fmt.Sprintf("https://github.com/Const-me/Whisper/releases/download/%s/Library.zip", version)
+	fileToExtract := "Binary/Whisper.dll"
+
+	isWhisperDllExists := IsFileExists("Whisper.dll")
+
+	if !isWhisperDllExists {
+		fmt.Println("Whisper DLL not found.")
+		archivePath, err := os.CreateTemp("", "WhisperLibrary-*.zip")
+		if err != nil {
+			return "", err
+		}
+		defer archivePath.Close()
+
+		err = DownloadFile(fileUrl, archivePath.Name())
+		if err != nil {
+			return "", err
+		}
+
+		err = extractFile(archivePath.Name(), fileToExtract)
+		if err != nil {
+			return "", err
+		}
+	}
+
+	absPath, err := filepath.Abs("Whisper.dll")
+	if err != nil {
+		return "", err
+	}
+
+	fmt.Printf("Library found: %s\n", absPath)
+	return "Whisper.dll", nil
+}
+
+func extractFile(archivePath string, fileToExtract string) error {
+	reader, err := zip.OpenReader(archivePath)
+	if err != nil {
+		return err
+	}
+	defer reader.Close()
+
+	for _, file := range reader.File {
+		if file.Name == fileToExtract {
+			targetPath := filepath.Base(fileToExtract)
+
+			writer, err := os.Create(targetPath)
+			if err != nil {
+				return err
+			}
+			defer writer.Close()
+
+			src, err := file.Open()
+			if err != nil {
+				return err
+			}
+			defer src.Close()
+
+			_, err = io.Copy(writer, src)
+			if err != nil {
+				return err
+			}
+
+			return nil
+		}
+	}
+
+	return fmt.Errorf("File not found in the archive")
+}