Send presigned encoded audio URL to the frontend

backend/media/get_audio.go

@@ -13,17 +13,20 @@ import (
 
 	"git.netflux.io/rob/clipper/config"
 	"git.netflux.io/rob/clipper/generated/store"
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/service/s3"
 	"go.uber.org/zap"
 )
 
 type GetAudioProgress struct {
 	PercentComplete float32
 	Peaks           []int16
+	URL             string
 }
 
 type GetAudioProgressReader interface {
 	Next() (GetAudioProgress, error)
-	Close() error
+	Close(string) error
 }
 
 // audioGetter manages getting and processing audio from Youtube.
@@ -106,6 +109,7 @@ func (s *audioGetterState) getAudio(ctx context.Context, r io.ReadCloser, mediaS
 		return
 	}
 
+	var presignedAudioURL string
 	var wg sync.WaitGroup
 	wg.Add(2)
 
@@ -123,6 +127,16 @@ func (s *audioGetterState) getAudio(ctx context.Context, r io.ReadCloser, mediaS
 			return
 		}
 
+		input := s3.GetObjectInput{
+			Bucket: aws.String(s.config.S3Bucket),
+			Key:    aws.String(s3Key),
+		}
+		request, err := s.s3API.PresignGetObject(ctx, &input, s3.WithPresignExpires(getAudioExpiresIn))
+		if err != nil {
+			s.CloseWithError(fmt.Errorf("error generating presigned URL: %v", err))
+		}
+		presignedAudioURL = request.URL
+
 		if _, err = s.store.SetEncodedAudioUploaded(ctx, store.SetEncodedAudioUploadedParams{
 			ID:                   mediaSet.ID,
 			AudioEncodedS3Bucket: sqlString(s.config.S3Bucket),
@@ -172,8 +186,8 @@ func (s *audioGetterState) getAudio(ctx context.Context, r io.ReadCloser, mediaS
 	wg.Wait()
 
 	// Finally, close the progress reader so that the subsequent call to Next()
-	// returns io.EOF.
+	// returns the presigned URL and io.EOF.
-	s.Close()
+	s.Close(presignedAudioURL)
 }
 
 // getAudioProgressReader accepts a byte stream containing little endian
@@ -188,6 +202,7 @@ type getAudioProgressReader struct {
 	currPeaks       []int16
 	currCount       int
 	framesProcessed int64
+	url             string
 	progress        chan GetAudioProgress
 	errorChan       chan error
 }
@@ -212,7 +227,9 @@ func (w *getAudioProgressReader) CloseWithError(err error) {
 	w.errorChan <- err
 }
 
-func (w *getAudioProgressReader) Close() error {
+// Close cloes the reader and returns the provided URL to the calling code.
+func (w *getAudioProgressReader) Close(url string) error {
+	w.url = url
 	close(w.progress)
 	return nil
 }
@@ -222,7 +239,7 @@ func (w *getAudioProgressReader) Next() (GetAudioProgress, error) {
 		select {
 		case progress, ok := <-w.progress:
 			if !ok {
-				return GetAudioProgress{Peaks: w.currPeaks, PercentComplete: w.percentComplete()}, io.EOF
+				return GetAudioProgress{Peaks: w.currPeaks, PercentComplete: w.percentComplete(), URL: w.url}, io.EOF
 			}
 			return progress, nil
 		case err := <-w.errorChan:

backend/media/service.go

@@ -24,7 +24,8 @@ import (
 )
 
 const (
-	getVideoExpiresIn = time.Hour * 1
+	getVideoExpiresIn = time.Hour
+	getAudioExpiresIn = time.Hour
 )
 
 const (
@@ -327,7 +328,10 @@ func (s *MediaSetService) GetAudio(ctx context.Context, id uuid.UUID, numBins in
 		return nil, fmt.Errorf("error getting media set: %v", err)
 	}
 
-	if mediaSet.AudioRawS3UploadedAt.Valid {
+	// We need both raw and encoded audio to have been uploaded successfully.
+	// Otherwise, we cannot return both peaks and a presigned URL for use by the
+	// player.
+	if mediaSet.AudioRawS3UploadedAt.Valid && mediaSet.AudioEncodedS3UploadedAt.Valid {
 		return s.getAudioFromS3(ctx, mediaSet, numBins)
 	}
 
@@ -361,9 +365,11 @@ func (s *MediaSetService) getAudioFromS3(ctx context.Context, mediaSet store.Med
 	state := getAudioFromS3State{
 		getAudioProgressReader: getAudioProgressReader,
 		s3Reader:               NewModuloBufReader(output.Body, int(mediaSet.AudioChannels)*SizeOfInt16),
+		s3API:                  s.s3,
+		config:                 s.config,
 		logger:                 s.logger,
 	}
-	go state.run(ctx)
+	go state.run(ctx, mediaSet)
 
 	return &state, nil
 }
@@ -372,10 +378,12 @@ type getAudioFromS3State struct {
 	*getAudioProgressReader
 
 	s3Reader io.ReadCloser
+	s3API    S3API
+	config   config.Config
 	logger   *zap.SugaredLogger
 }
 
-func (s *getAudioFromS3State) run(ctx context.Context) {
+func (s *getAudioFromS3State) run(ctx context.Context, mediaSet store.MediaSet) {
 	done := make(chan error)
 	var err error
 
@@ -407,7 +415,16 @@ outer:
 		return
 	}
 
-	if iterErr := s.Close(); iterErr != nil {
+	input := s3.GetObjectInput{
+		Bucket: aws.String(s.config.S3Bucket),
+		Key:    aws.String(mediaSet.AudioEncodedS3Key.String),
+	}
+	request, err := s.s3API.PresignGetObject(ctx, &input, s3.WithPresignExpires(getAudioExpiresIn))
+	if err != nil {
+		s.CloseWithError(fmt.Errorf("error generating presigned URL: %v", err))
+	}
+
+	if iterErr := s.Close(request.URL); iterErr != nil {
 		s.logger.Errorf("getAudioFromS3State: error closing progress iterator: %v", iterErr)
 	}
 }

backend/server/server.go

@@ -129,6 +129,7 @@ func (c *mediaSetServiceController) GetAudio(request *pbmediaset.GetAudioRequest
 
 		progressPb := pbmediaset.GetAudioProgress{
 			PercentComplete: progress.PercentComplete,
+			Url:             progress.URL,
 			Peaks:           peaks,
 		}
 		stream.Send(&progressPb)

frontend/src/Overview.tsx

@@ -1,5 +1,9 @@
 import { useState, useEffect, useRef, MouseEvent } from 'react';
-import { MediaSetServiceClientImpl, MediaSet } from './generated/media_set';
+import {
+  MediaSetServiceClientImpl,
+  MediaSet,
+  GetAudioProgress,
+} from './generated/media_set';
 import { Frames, newRPC, VideoPosition } from './App';
 import { WaveformCanvas } from './WaveformCanvas';
 import { from, Observable } from 'rxjs';
@@ -116,6 +120,15 @@ export const Overview: React.FC<Props> = ({
       });
       const peaks = audioProgressStream.pipe(map((progress) => progress.peaks));
       setPeaks(peaks);
+
+      let url = '';
+      // TODO: probably a nicer way to do this.
+      await audioProgressStream.forEach((progress: GetAudioProgress) => {
+        if (progress.url != '') {
+          url = progress.url;
+        }
+      });
+      console.log('got audio URL', url);
     })();
   }, [mediaSet]);
 

proto/media_set.proto

@@ -24,6 +24,7 @@ message MediaSet {
 message GetAudioProgress {
   repeated int32 peaks = 1;
   float percent_complete = 2;
+  string url = 3;
 }
 
 message GetRequest {