add struct for transcoded media info. use it for calculating bitrate …

…of transcoded results (#135)

transcode/manifest.go

@@ -72,20 +72,21 @@ func GetSourceSegmentURLs(sourceManifestURL string, manifest m3u8.MediaPlaylist)
 
 // Generate a Master manifest, plus one Rendition manifest for each Profile we're transcoding, then write them to storage
 // Returns the master manifest URL on success
-func GenerateAndUploadManifests(sourceManifest m3u8.MediaPlaylist, targetOSURL string, transcodeProfiles []clients.EncodedProfile) (string, error) {
+func GenerateAndUploadManifests(sourceManifest m3u8.MediaPlaylist, targetOSURL string, transcodedStats []RenditionStats) (string, error) {
 	// Generate the master + rendition output manifests
 	masterPlaylist := m3u8.NewMasterPlaylist()
 
-	for i, profile := range transcodeProfiles {
+	for i, profile := range transcodedStats {
 		// For each profile, add a new entry to the master manifest
+		bitsPerSecond := uint32(float64(profile.Bytes) * 8000.0 / float64(profile.DurationMs))
 		masterPlaylist.Append(
 			fmt.Sprintf("rendition-%d/rendition.m3u8", i),
 			&m3u8.MediaPlaylist{
 				TargetDuration: sourceManifest.TargetDuration,
 			},
 			m3u8.VariantParams{
 				Name:       fmt.Sprintf("%d-%s", i, profile.Name),
-				Bandwidth:  uint32(1), // TODO: Don't hardcode - this should come from the transcoder output
+				Bandwidth:  bitsPerSecond,
 				FrameRate:  float64(profile.FPS),
 				Resolution: fmt.Sprintf("%dx%d", profile.Width, profile.Height),
 			},

transcode/manifest_test.go

@@ -7,7 +7,6 @@ import (
 	"testing"
 
 	"github.com/grafov/m3u8"
-	"github.com/livepeer/catalyst-api/clients"
 	"github.com/stretchr/testify/require"
 )
 
@@ -106,18 +105,22 @@ func TestItCanGenerateAndWriteManifests(t *testing.T) {
 	masterManifestURL, err := GenerateAndUploadManifests(
 		*sourceMediaPlaylist,
 		outputDir,
-		[]clients.EncodedProfile{
+		[]RenditionStats{
 			{
-				Name:   "lowlowlow",
-				FPS:    60,
-				Width:  800,
-				Height: 600,
+				Name:       "lowlowlow",
+				FPS:        60,
+				Width:      800,
+				Height:     600,
+				Bytes:      1,
+				DurationMs: 8000,
 			},
 			{
-				Name:   "super-high-def",
-				FPS:    30,
-				Width:  1080,
-				Height: 720,
+				Name:       "super-high-def",
+				FPS:        30,
+				Width:      1080,
+				Height:     720,
+				Bytes:      1,
+				DurationMs: 8000,
 			},
 		},
 	)

transcode/transcode.go

@@ -81,6 +81,7 @@ func RunTranscodeProcess(transcodeRequest TranscodeSegmentRequest, streamName st
 	targetOSURL := segmentedUploadURL.ResolveReference(relativeTranscodeURL)
 	// Grab some useful parameters to be used later from the TranscodeSegmentRequest
 	sourceManifestOSURL := transcodeRequest.UploadURL
+	// transcodeProfiles are desired constraints for transcoding process
 	transcodeProfiles := transcodeRequest.Profiles
 
 	// If Profiles haven't been overridden, use the default set
@@ -115,6 +116,10 @@ func RunTranscodeProcess(transcodeRequest TranscodeSegmentRequest, streamName st
 
 	// Generate a unique ID to use when talking to the Broadcaster
 	manifestID := "manifest-" + config.RandomTrailer(8)
+	// transcodedStats hold actual info from transcoded results within requested constraints (this usually differs from requested profiles)
+	transcodedStats := statsFromProfiles(transcodeProfiles)
+
+	// Iterate through the segment URLs and transcode them
 	// Use channel to queue segments
 	queue := make(chan segmentInfo, len(sourceSegmentURLs))
 	for segmentIndex, u := range sourceSegmentURLs {
@@ -130,7 +135,7 @@ func RunTranscodeProcess(transcodeRequest TranscodeSegmentRequest, streamName st
 		go func() {
 			defer completed.Done()
 			for segment := range queue {
-				err := transcodeSegment(segment, streamName, manifestID, transcodeRequest, transcodeProfiles, targetOSURL)
+				err := transcodeSegment(segment, streamName, manifestID, transcodeRequest, transcodeProfiles, targetOSURL, transcodedStats)
 				if err != nil {
 					errors <- err
 					return
@@ -152,7 +157,7 @@ func RunTranscodeProcess(transcodeRequest TranscodeSegmentRequest, streamName st
 	}
 
 	// Build the manifests and push them to storage
-	manifestManifestURL, err := GenerateAndUploadManifests(sourceManifest, targetOSURL.String(), transcodeProfiles)
+	manifestManifestURL, err := GenerateAndUploadManifests(sourceManifest, targetOSURL.String(), transcodedStats)
 	if err != nil {
 		return outputs, err
 	}
@@ -172,7 +177,7 @@ func RunTranscodeProcess(transcodeRequest TranscodeSegmentRequest, streamName st
 	return outputs, nil
 }
 
-func transcodeSegment(segment segmentInfo, streamName, manifestID string, transcodeRequest TranscodeSegmentRequest, transcodeProfiles []clients.EncodedProfile, targetOSURL *url.URL) error {
+func transcodeSegment(segment segmentInfo, streamName, manifestID string, transcodeRequest TranscodeSegmentRequest, transcodeProfiles []clients.EncodedProfile, targetOSURL *url.URL, transcodedStats []RenditionStats) error {
 	rc, err := clients.DownloadOSURL(segment.Input.URL)
 	if err != nil {
 		return fmt.Errorf("failed to download source segment %q: %s", segment.Input, err)
@@ -214,6 +219,9 @@ func transcodeSegment(segment segmentInfo, streamName, manifestID string, transc
 		if err != nil {
 			return fmt.Errorf("failed to upload master playlist: %s", err)
 		}
+		// bitrate calculation
+		transcodedStats[renditionIndex].Bytes += int64(len(transcodedSegment.MediaData))
+		transcodedStats[renditionIndex].DurationMs += float64(segment.Input.DurationMillis)
 	}
 	return nil
 }
@@ -258,3 +266,25 @@ type segmentInfo struct {
 	Input SourceSegment
 	Index int
 }
+
+func statsFromProfiles(profiles []clients.EncodedProfile) []RenditionStats {
+	stats := []RenditionStats{}
+	for _, profile := range profiles {
+		stats = append(stats, RenditionStats{
+			Name:   profile.Name,
+			Width:  profile.Width,  // TODO: extract this from actual media retrieved from B
+			Height: profile.Height, // TODO: extract this from actual media retrieved from B
+			FPS:    profile.FPS,    // TODO: extract this from actual media retrieved from B
+		})
+	}
+	return stats
+}
+
+type RenditionStats struct {
+	Name       string
+	Width      int64
+	Height     int64
+	FPS        int64
+	Bytes      int64
+	DurationMs float64
+}