FEAT: Return Playback URL in Get Videos

cms/internal/services/mediaconvert.go

@@ -3,6 +3,8 @@ package services
 import (
 	"context"
 	"fmt"
+	"path"
+	"strings"
 
 	"github.com/aws/aws-sdk-go-v2/aws"
 	"github.com/aws/aws-sdk-go-v2/service/mediaconvert"
@@ -15,6 +17,11 @@ type MediaConvert interface {
 	QueueEncodingJob(ctx context.Context, key string) (string, error)
 }
 
+// segmentLengthSeconds is how long each HLS segment runs. Six seconds is the
+// common default: long enough to keep the playlist and the request count down,
+// short enough that a player can switch rendition without a long stall.
+const segmentLengthSeconds = 6
+
 type MediaConvertConcrete struct {
 	MediaConvertClient *mediaconvert.Client
 	Role               string
@@ -24,7 +31,14 @@ type MediaConvertConcrete struct {
 
 func (svc MediaConvertConcrete) QueueEncodingJob(ctx context.Context, key string) (string, error) {
 	input := fmt.Sprintf("s3://%s/%s", svc.InputBucket, key)
-	destination := fmt.Sprintf("s3://%s/%s", svc.OutputBucket, key)
+
+	// HlsGroupSettings.Destination is a *filename base*, not a directory and
+	// not a finished name: MediaConvert appends each output's NameModifier and
+	// the extensions it needs. Giving each video its own folder keeps the
+	// master playlist, the variant playlists and the segments together, and
+	// keeps two videos from interleaving their segments in one prefix.
+	base := strings.TrimSuffix(key, path.Ext(key))
+	destination := fmt.Sprintf("s3://%s/%s/index", svc.OutputBucket, base)
 
 	job, err := svc.MediaConvertClient.CreateJob(ctx, &mediaconvert.CreateJobInput{
 		Role: &svc.Role,
@@ -42,24 +56,42 @@ func (svc MediaConvertConcrete) QueueEncodingJob(ctx context.Context, key string
 			},
 			OutputGroups: []types.OutputGroup{
 				{
-					Name: aws.String("File Group"),
+					Name: aws.String("HLS Group"),
 					OutputGroupSettings: &types.OutputGroupSettings{
-						Type: types.OutputGroupTypeFileGroupSettings,
-						FileGroupSettings: &types.FileGroupSettings{
-							Destination: &destination,
+						Type: types.OutputGroupTypeHlsGroupSettings,
+						HlsGroupSettings: &types.HlsGroupSettings{
+							Destination:   &destination,
+							SegmentLength: aws.Int32(segmentLengthSeconds),
+							// 0 lets the last segment be as short as it needs to
+							// be rather than padding the ones before it.
+							MinSegmentLength: aws.Int32(0),
 						},
 					},
 					Outputs: []types.Output{
 						{
+							// One rendition. A ladder is another entry here per
+							// rendition, each with its own NameModifier and
+							// height — the master playlist lists whatever is
+							// present, so nothing downstream changes.
+							NameModifier: aws.String("_720p"),
 							ContainerSettings: &types.ContainerSettings{
-								Container: types.ContainerTypeMp4,
+								Container:    types.ContainerTypeM3u8,
+								M3u8Settings: &types.M3u8Settings{},
 							},
 							VideoDescription: &types.VideoDescription{
+								Height: aws.Int32(720),
 								CodecSettings: &types.VideoCodecSettings{
 									Codec: types.VideoCodecH264,
 									H264Settings: &types.H264Settings{
 										RateControlMode: types.H264RateControlModeQvbr,
-										MaxBitrate:      aws.Int32(5000000),
+										MaxBitrate:      aws.Int32(3000000),
+										// A segment has to start on a keyframe,
+										// so the GOP is pinned to a divisor of
+										// the segment length. Left to follow the
+										// source, segments come out uneven and
+										// players stall at the joins.
+										GopSizeUnits: types.H264GopSizeUnitsSeconds,
+										GopSize:      aws.Float64(2),
 									},
 								},
 							},