test(audio): ffprobe/ffmpeg must cap streams, ffprobe must narrow its output (#49), red

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/adapters/audio/ffprobe_test.go

@@ -184,3 +184,34 @@ func TestAllowedDemuxers_ExcludeThePlaylistFormats(t *testing.T) {
 		assert.Contains(t, strings.Split(audio.AllowedDemuxers, ","), good)
 	}
 }
+
+func TestFFprobeProbe_CapsTheStreamCountBeforeTheInput(t *testing.T) {
+	// A 1.3 MB file declaring 900 streams cost ~570 MB of RSS in ffprobe (#49) against
+	// a 512 Mi pod. -max_streams is an input option: it must precede the path.
+	bin, argvFile := argvStub(t)
+
+	_, err := (&audio.FFprobe{Bin: bin}).Probe(context.Background(), "/spool/upload-1")
+
+	require.NoError(t, err)
+	args := argvOf(t, argvFile)
+	ms := indexOf(args, "-max_streams")
+	require.GreaterOrEqual(t, ms, 0, "argv: %v", args)
+	assert.Equal(t, "32", args[ms+1])
+	assert.Less(t, ms, len(args)-1, "must come before the path, which stays last")
+}
+
+func TestFFprobeProbe_AsksOnlyForTheFieldsParseProbeReads(t *testing.T) {
+	// -show_format/-show_streams print every tag: a 120 MB WAV produced 491 MB of JSON
+	// that cmd.Output() buffers in Go (#49).
+	bin, argvFile := argvStub(t)
+
+	_, err := (&audio.FFprobe{Bin: bin}).Probe(context.Background(), "/spool/upload-1")
+
+	require.NoError(t, err)
+	args := argvOf(t, argvFile)
+	assert.Equal(t, -1, indexOf(args, "-show_format"), "argv: %v", args)
+	assert.Equal(t, -1, indexOf(args, "-show_streams"), "argv: %v", args)
+	se := indexOf(args, "-show_entries")
+	require.GreaterOrEqual(t, se, 0, "argv: %v", args)
+	assert.Equal(t, "format=duration:stream=codec_type:stream_disposition=attached_pic", args[se+1])
+}