split transcoder service helpers

internal/service/transcoder_ffmpeg_probe.go

@@ -0,0 +1,152 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"go.uber.org/zap"
+)
+
+func (t *TranscoderService) runFFmpeg(ctx context.Context, job *hlsJob, source string) {
+	bin, err := t.resolveFFmpegPath()
+	if err != nil {
+		t.log.Warn("ffmpeg unavailable", zap.String("media_id", job.mediaID), zap.Error(err))
+		t.mu.Lock()
+		delete(t.jobs, job.mediaID)
+		t.mu.Unlock()
+		t.hub.Publish("transcode", map[string]any{
+			"media_id": job.mediaID,
+			"status":   "error",
+			"error":    err.Error(),
+		})
+		return
+	}
+
+	playlist := filepath.Join(job.outputDir, "index.m3u8")
+	segments := filepath.Join(job.outputDir, "seg_%05d.ts")
+
+	args := buildFFmpegArgs(t.cfg, source, playlist, segments)
+
+	cmd := exec.CommandContext(ctx, bin, args...) // #nosec G204 -- bin is resolved by resolveFFmpegPath and args are passed without a shell.
+	cmd.Stderr = os.Stderr
+
+	t.log.Info("transcode started",
+		zap.String("media_id", job.mediaID),
+		zap.String("encoder", job.encoder),
+		zap.String("source", source),
+	)
+	t.hub.Publish("transcode", map[string]any{
+		"media_id": job.mediaID,
+		"encoder":  job.encoder,
+		"status":   "started",
+	})
+
+	if err := cmd.Run(); err != nil && !errors.Is(ctx.Err(), context.Canceled) {
+		t.log.Warn("ffmpeg exited",
+			zap.String("media_id", job.mediaID),
+			zap.Error(err),
+		)
+	}
+
+	t.mu.Lock()
+	delete(t.jobs, job.mediaID)
+	t.mu.Unlock()
+
+	t.hub.Publish("transcode", map[string]any{
+		"media_id": job.mediaID,
+		"status":   "stopped",
+		"duration": time.Since(job.startedAt).Seconds(),
+	})
+}
+
+func (t *TranscoderService) resolveFFmpegPath() (string, error) {
+	var lastErr error
+	for _, bin := range executableCandidates(strings.TrimSpace(t.cfg.App.FFmpegPath), "ffmpeg") {
+		if err := validateFFmpegForTranscode(context.Background(), bin, t.effectiveEncoder()); err != nil {
+			lastErr = err
+			continue
+		}
+		t.cfg.App.FFmpegPath = bin
+		return bin, nil
+	}
+	if lastErr != nil {
+		return "", fmt.Errorf("no usable ffmpeg found for HLS transcode: %w", lastErr)
+	}
+	return "", fmt.Errorf("ffmpeg not found in PATH or common local app directories; configure app.ffmpeg_path to an existing local ffmpeg")
+}
+
+func (t *TranscoderService) effectiveEncoder() string {
+	if !t.cfg.Transcoder.HardwareAccel {
+		return ""
+	}
+	return normalizedHardwareEncoder(t.cfg.Transcoder.Encoder)
+}
+
+func normalizedHardwareEncoder(encoder string) string {
+	switch strings.ToLower(strings.TrimSpace(encoder)) {
+	case "nvenc", "qsv", "vaapi":
+		return strings.ToLower(strings.TrimSpace(encoder))
+	default:
+		return ""
+	}
+}
+
+func validateFFmpegForTranscode(ctx context.Context, bin, encoder string) error {
+	required := requiredVideoEncoder(encoder)
+	out, err := commandOutput(ctx, 8*time.Second, bin, "-hide_banner", "-encoders")
+	if err != nil {
+		return fmt.Errorf("%s cannot list encoders: %w", bin, err)
+	}
+	if !hasFFmpegListEntry(string(out), required) {
+		return fmt.Errorf("%s does not provide required encoder %s", bin, required)
+	}
+
+	out, err = commandOutput(ctx, 8*time.Second, bin, "-hide_banner", "-muxers")
+	if err != nil || !hasFFmpegListEntry(string(out), "hls") {
+		out, err = commandOutput(ctx, 8*time.Second, bin, "-hide_banner", "-formats")
+		if err != nil {
+			return fmt.Errorf("%s cannot list muxers/formats: %w", bin, err)
+		}
+	}
+	if !hasFFmpegListEntry(string(out), "hls") {
+		return fmt.Errorf("%s does not provide hls muxer", bin)
+	}
+	return nil
+}
+
+func requiredVideoEncoder(encoder string) string {
+	switch encoder {
+	case "nvenc":
+		return "h264_nvenc"
+	case "qsv":
+		return "h264_qsv"
+	case "vaapi":
+		return "h264_vaapi"
+	default:
+		return "libx264"
+	}
+}
+
+func hasFFmpegListEntry(output, name string) bool {
+	for _, line := range strings.Split(output, "\n") {
+		fields := strings.Fields(line)
+		for _, field := range fields {
+			if field == name {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// HumanFFmpegProfile is exposed for the admin UI / settings view.
+func (t *TranscoderService) HumanFFmpegProfile() string {
+	return fmt.Sprintf("ffmpeg=%s, encoder=%s, output=%s",
+		t.cfg.App.FFmpegPath, t.cfg.Transcoder.Encoder, filepath.Join(t.cfg.Cache.CacheDir, "hls"))
+}