Add FFmpeg service and integrate with video handler for HLS generation

Author: Prateet-Github

Dockerfile

@@ -0,0 +1,24 @@
+# Builder
+FROM golang:1.25 AS builder
+
+WORKDIR /app
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+
+RUN CGO_ENABLED=0 GOOS=linux go build -o worker ./cmd/worker
+
+# Runtime 
+FROM debian:bookworm-slim
+
+RUN apt-get update && \
+  apt-get install -y ffmpeg ca-certificates && \
+  rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+COPY --from=builder /app/worker .
+
+CMD ["./worker"]

cmd/worker/main.go

@@ -4,6 +4,7 @@ import (
 	"log"
 
 	"github.com/Prateet-Github/worker-go/internal/config"
+	"github.com/Prateet-Github/worker-go/internal/ffmpeg"
 	"github.com/Prateet-Github/worker-go/internal/handlers"
 	"github.com/Prateet-Github/worker-go/internal/queue"
 	"github.com/Prateet-Github/worker-go/internal/s3"
@@ -17,9 +18,11 @@ func main() {
 	server := queue.NewServer(cfg)
 
 	s3Client := s3.NewClient(cfg)
+	ffmpegService := ffmpeg.NewService()
 	videoHandler := handlers.NewVideoHandler(
 		s3Client,
 		cfg,
+		ffmpegService,
 	)
 
 	mux := asynq.NewServeMux()

internal/config/config.go

@@ -20,9 +20,9 @@ type Config struct {
 }
 
 func Load() *Config {
-	err := godotenv.Load()
-	if err != nil {
-		log.Fatal("Error loading .env file")
+
+	if err := godotenv.Load(); err != nil {
+		log.Println(".env not found, using environment variables")
 	}
 
 	return &Config{

internal/ffmpeg/service.go

@@ -0,0 +1,53 @@
+package ffmpeg
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+type Service struct{}
+
+func NewService() *Service {
+	return &Service{}
+}
+
+func (s *Service) GenerateHLS(
+	ctx context.Context,
+	inputPath string,
+	outputDir string,
+) error {
+
+	if err := os.MkdirAll(outputDir, 0755); err != nil {
+		return err
+	}
+
+	args := []string{
+		"-y",
+		"-i", inputPath,
+
+		"-c:v", "libx264",
+		"-c:a", "aac",
+
+		"-f", "hls",
+		"-hls_time", "6",
+		"-hls_playlist_type", "vod",
+
+		"-hls_segment_filename",
+		fmt.Sprintf("%s/segment_%%03d.ts", outputDir),
+
+		fmt.Sprintf("%s/master.m3u8", outputDir),
+	}
+
+	cmd := exec.CommandContext(
+		ctx,
+		"ffmpeg",
+		args...,
+	)
+
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	return cmd.Run()
+}

internal/handlers/video.go

@@ -6,6 +6,7 @@ import (
 	"log"
 
 	"github.com/Prateet-Github/worker-go/internal/config"
+	"github.com/Prateet-Github/worker-go/internal/ffmpeg"
 	"github.com/Prateet-Github/worker-go/internal/queue"
 	"github.com/Prateet-Github/worker-go/internal/s3"
 
@@ -18,15 +19,18 @@ import (
 type VideoHandler struct {
 	s3Client *awss3.Client
 	cfg      *config.Config
+	ffmpeg   *ffmpeg.Service
 }
 
 func NewVideoHandler(
 	s3Client *awss3.Client,
 	cfg *config.Config,
+	ffmpeg *ffmpeg.Service,
 ) *VideoHandler {
 	return &VideoHandler{
 		s3Client: s3Client,
 		cfg:      cfg,
+		ffmpeg:   ffmpeg,
 	}
 }
 
@@ -41,23 +45,57 @@ func (h *VideoHandler) ProcessVideo(
 		return err
 	}
 
-	localPath := filepath.Join(
+	// localPath := filepath.Join(
+	// 	"temp",
+	// 	payload.VideoID+".mp4",
+	// )
+
+	workspace := filepath.Join(
 		"temp",
-		payload.VideoID+".mp4",
+		payload.VideoID,
+	)
+
+	inputPath := filepath.Join(
+		workspace,
+		"input.mp4",
 	)
 
+	outputDir := filepath.Join(
+		workspace,
+		"hls",
+	)
+
+	log.Println("Starting download...")
+
 	err := s3.DownloadFile(
 		h.s3Client,
 		h.cfg.S3RawBucket,
 		payload.S3Key,
-		localPath,
+		inputPath,
 	)
 
 	if err != nil {
 		return err
 	}
 
-	log.Println("Download completed:", localPath)
+	log.Println("Download complete")
+
+log.Println("Calling FFmpeg...")
+
+	if err := h.ffmpeg.GenerateHLS(
+		ctx,
+		inputPath,
+		outputDir,
+	); err != nil {
+		log.Printf("GenerateHLS failed: %v\n", err)
+		return err
+	}
+
+	log.Println("FFmpeg finished")
+
+	log.Println("HLS generated successfully")
+
+	log.Println("Download completed:", inputPath)
 
 	log.Println("Processing video...")
 	log.Println("Video ID:", payload.VideoID)