Add real ffmpeg-backed transcoding subsystem (bounded concurrency, streaming, HLS segmenting)

2026-08-23 00:10:55 -05:00
parent 6e2b875eaa
commit b6ec06f272
3 changed files with 361 additions and 0 deletions
@@ -0,0 +1,97 @@
+package transcoding
+
+import (
+	"bytes"
+	"context"
+	"os/exec"
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+func genTestFile(t *testing.T, dir string) string {
+	t.Helper()
+	if _, err := exec.LookPath("ffmpeg"); err != nil {
+		t.Skip("ffmpeg not installed")
+	}
+	out := filepath.Join(dir, "src.mp3")
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+	cmd := exec.CommandContext(ctx, "ffmpeg", "-f", "lavfi", "-i", "sine=frequency=440:duration=2", "-codec:a", "libmp3lame", out)
+	if combined, err := cmd.CombinedOutput(); err != nil {
+		t.Fatalf("ffmpeg: %v\n%s", err, combined)
+	}
+	return out
+}
+
+func TestStreamProducesOutput(t *testing.T) {
+	dir := t.TempDir()
+	src := genTestFile(t, dir)
+
+	m := NewManager("")
+	var buf bytes.Buffer
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+	if err := m.Stream(ctx, &buf, src, Options{Format: FormatMP3, MaxBitRateKbps: 64}); err != nil {
+		t.Fatalf("Stream: %v", err)
+	}
+	if buf.Len() == 0 {
+		t.Fatal("transcoded output is empty")
+	}
+}
+
+func TestStreamRespectsContextCancellation(t *testing.T) {
+	dir := t.TempDir()
+	src := genTestFile(t, dir)
+
+	m := NewManager("")
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel() // already cancelled before starting
+
+	var buf bytes.Buffer
+	err := m.Stream(ctx, &buf, src, Options{Format: FormatMP3})
+	if err == nil {
+		t.Fatal("expected an error when the context is already cancelled")
+	}
+}
+
+func TestParseFormat(t *testing.T) {
+	cases := map[string]Format{
+		"mp3":     FormatMP3,
+		"opus":    FormatOpus,
+		"aac":     FormatAAC,
+		"unknown": FormatMP3,
+		"":        FormatMP3,
+	}
+	for in, want := range cases {
+		if got := ParseFormat(in); got != want {
+			t.Errorf("ParseFormat(%q) = %q, want %q", in, got, want)
+		}
+	}
+}
+
+func TestBuildHLS(t *testing.T) {
+	dir := t.TempDir()
+	src := genTestFile(t, dir)
+
+	m := NewManager("")
+	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+	defer cancel()
+	session, err := m.BuildHLS(ctx, src, filepath.Join(dir, "cache"), Options{Format: FormatAAC, MaxBitRateKbps: 96})
+	if err != nil {
+		t.Fatalf("BuildHLS: %v", err)
+	}
+	if session.SegmentCount == 0 {
+		t.Fatal("expected at least one HLS segment")
+	}
+	playlist := session.Playlist(func(i int) string { return "seg" + string(rune('0'+i)) })
+	if playlist == "" {
+		t.Fatal("empty playlist")
+	}
+	if session.SegmentPath(0) == "" {
+		t.Fatal("SegmentPath(0) should resolve")
+	}
+	if session.SegmentPath(9999) != "" {
+		t.Fatal("SegmentPath out of range should return empty")
+	}
+}