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
+}