clip: add more logging to debug failed clips

Clips are failing reporting 'start time specified exceeds duration of
manifest'. This may happen for webrtc streams where the clip request
comes in but the segments and manifest hasn't been written yet to S3. I
n this case, the start time would fall past the latest segment and this
error case would be hit -- however, we have several retries for this
exact scenario.

Based on logs, there are 10 retries every 5 seconds in
addition to 3 studio retries - this should be sufficient for the latest
segments to be written to S3 and the clip request would eventually
succeed. This is not happening so we're adding the additional logging to
ensure latest manifests are being downloaded on retry attempts.

clients/manifest.go

@@ -15,6 +15,7 @@ import (
 
 	"github.com/cenkalti/backoff/v4"
 	"github.com/grafov/m3u8"
+	"github.com/livepeer/catalyst-api/log"
 	"github.com/livepeer/catalyst-api/video"
 )
 
@@ -223,6 +224,7 @@ func ClipInputManifest(requestID, sourceURL, clipTargetUrl string, startTimeUnix
 	if err != nil {
 		return nil, fmt.Errorf("error clipping: failed to download original manifest: %w", err)
 	}
+	log.Log(requestID, "Downloaded manifest to clip", "segments", origManifest.Count())
 
 	// Generate the absolute path URLS for segmens from the manifest's relative path
 	// TODO: optimize later and only get absolute path URLs for the start/end segments

video/clip.go

@@ -113,7 +113,7 @@ func ClipManifest(requestID string, manifest *m3u8.MediaPlaylist, startTime, end
 	// Find the segment index that correlates with the specified startTime
 	// but error out it exceeds the  manifest's duration.
 	if startTime > manifestDuration {
-		return nil, []ClipSegmentInfo{}, fmt.Errorf("error clipping: start time specified exceeds duration of manifest")
+		return nil, []ClipSegmentInfo{}, fmt.Errorf("error clipping: start time (%f) specified exceeds duration of manifest (%f)", startTime, manifestDuration)
 	} else {
 		clipStartSegmentInfo, err = getRelevantSegment(manifest.Segments, startTime, 0)
 		if err != nil {