run audio extraction

cmd/mxl-pattern/main.go

@@ -551,7 +551,7 @@ func run(ctx context.Context, args appArgs) (runErr error) {
 		runners = append(runners, namedRunner{
 			name: "audio",
 			run: func(ctx context.Context) error {
-				return runAudio(ctx, inst, *audioCfg)
+				return audio.Run(ctx, inst, *audioCfg)
 			},
 		})
 	}
@@ -664,157 +664,6 @@ func runVideo(ctx context.Context, inst *mxl.Instance, cfg video.Config) (runErr
 	}
 }
 
-func runAudio(
-	ctx context.Context,
-	inst *mxl.Instance,
-	cfg audio.Config,
-) (runErr error) {
-	flowJSON, err := json.Marshal(cfg.Definition)
-	if err != nil {
-		return fmt.Errorf("marshal audio flow definition: %w", err)
-	}
-
-	writer, isCreated, err := inst.NewWriter(string(flowJSON))
-	if err != nil {
-		return fmt.Errorf("create audio writer: %w", err)
-	}
-	defer func() {
-		if err := writer.Close(); err != nil {
-			runErr = errors.Join(
-				runErr,
-				fmt.Errorf("close audio writer: %w", err),
-			)
-		}
-	}()
-	if !isCreated {
-		log.Printf("reusing existing audio flow: %s", cfg.ID())
-	}
-
-	writerCfg := writer.Config()
-	if writerCfg.Common.Format != mxl.FormatAudio {
-		return fmt.Errorf(
-			"audio writer has format %s, want audio",
-			writerCfg.Common.Format,
-		)
-	}
-	if writerCfg.Continuous.ChannelCount != uint32(cfg.Channels()) {
-		return fmt.Errorf(
-			"audio writer has %d channels, configured generator expects %d",
-			writerCfg.Continuous.ChannelCount,
-			cfg.Channels(),
-		)
-	}
-
-	rate := writerCfg.Common.GrainRate
-	if rate != cfg.Rate() {
-		return fmt.Errorf(
-			"audio writer has sample rate %d/%d, configured generator expects %d/%d",
-			rate.Num,
-			rate.Den,
-			cfg.Rate().Num,
-			cfg.Rate().Den,
-		)
-	}
-
-	const baseFrequency = 1000.0
-
-	gen, err := audio.NewSineGenerator(cfg, baseFrequency)
-	if err != nil {
-		return fmt.Errorf("initialize audio generator: %w", err)
-	}
-
-	batch := audioBatchSize(rate)
-	maxBatch, err := writer.GetMaxWriteLengthSamples()
-	if err != nil {
-		return fmt.Errorf("get maximum audio write length: %w", err)
-	}
-	if maxBatch == 0 {
-		return fmt.Errorf("audio writer reported a maximum write length of zero samples")
-	}
-	if batch > maxBatch {
-		batch = maxBatch
-	}
-	index := mxl.CurrentIndex(rate)
-	if index < batch-1 {
-		return fmt.Errorf("current audio index %d is too small for batch size %d", index, batch)
-	}
-
-	log.Printf(
-		"writing audio flow sampleRate=%d/%d channels=%d batch=%d starting at idx=%d",
-		rate.Num,
-		rate.Den,
-		cfg.Channels(),
-		batch,
-		index,
-	)
-
-	var samplesWritten uint64
-
-	for {
-		select {
-		case <-ctx.Done():
-			log.Printf("stopping audio after %d samples", samplesWritten)
-			return nil
-		default:
-		}
-
-		access, err := writer.OpenSamples(index, int(batch))
-		if err != nil {
-			return fmt.Errorf(
-				"open %d audio samples at index %d: %w",
-				batch,
-				index,
-				err,
-			)
-		}
-
-		firstSample := index - batch + 1
-		for channel := uint64(0); channel < access.ChannelCount; channel++ {
-			first, second, err := access.ChannelFragments(channel)
-			if err != nil {
-				return cancelAudioSamples(
-					access,
-					fmt.Errorf(
-						"get fragments for audio channel %d at index %d: %w",
-						channel,
-						index,
-						err,
-					),
-				)
-			}
-
-			if err := gen.Generate(
-				uint(channel),
-				firstSample,
-				first,
-				second,
-			); err != nil {
-				return cancelAudioSamples(
-					access, fmt.Errorf(
-						"generate audio channel %d at index %d: %w",
-						channel,
-						index,
-						err,
-					),
-				)
-			}
-		}
-
-		if err := access.Commit(); err != nil {
-			return fmt.Errorf(
-				"commit %d audio samples at index %d: %w",
-				batch,
-				index,
-				err,
-			)
-		}
-
-		samplesWritten += batch
-		index += batch
-		mxl.SleepNs(mxl.NsUntilIndex(index, rate))
-	}
-}
-
 func buildTextOverlay(cfg video.Config) (overlay *generator.TextOverlay, resultErr error) {
 	if cfg.Overlay.Text == "" {
 		return nil, nil
@@ -856,28 +705,3 @@ func cancelVideoGrain(grain *mxl.GrainWriteAccess, cause error) error {
 	}
 	return cause
 }
-
-func audioBatchSize(rate mxl.Rational) uint64 {
-	if rate.Num <= 0 || rate.Den <= 0 {
-		return 1
-	}
-
-	samples := rate.Num / (100 * rate.Den)
-	if samples < 1 {
-		return 1
-	}
-	return uint64(samples)
-}
-
-func cancelAudioSamples(
-	access *mxl.SamplesWriteAccess,
-	cause error,
-) error {
-	if err := access.Cancel(); err != nil {
-		return errors.Join(
-			cause,
-			fmt.Errorf("cancel audio samples: %w", err),
-		)
-	}
-	return cause
-}