public static RemoteSegmentWithData[] DedupeSegments(IList <RemoteSegmentWithData> segments)
{
// ugggh don't really need a dictionary but HashSet doesn't allow retrieveal of values
var unique = new Dictionary <RemoteSegment, RemoteSegmentWithData>(segments.Count);
foreach (var segment in segments)
{
var exists = unique.ContainsKey(segment);
if (exists)
{
var current = unique[segment];
Contract.Ensures(unique.Remove(segment));
var data = current.Data.Concat(segment.Data).ToArray();
var combined = new RemoteSegmentWithData(current.Source, current.Offsets, data);
unique.Add(combined, combined);
}
else
{
unique.Add(segment, segment);
}
}
return(unique.Values.ToArray());
}
private async Task <IEnumerable <RemoteSegmentWithData> > DownloadRemoteMetadata(
long audioRecordingId,
IEnumerable <ImportedEvent> events)
{
// now download the metadata for the audio recording
Log.Debug($"Requesting metadata for audio recording media {audioRecordingId}");
var audioRecording = await this.audioRecordingService.GetAudioRecording(audioRecordingId);
Log.Trace(
$"Metadata for audio recording media {audioRecordingId} retrieved, generating segments for associated events");
// now generate the segments
// we need to floor the duration to ensure later rounding does round past the limit of the recording
Log.Verbose($"Audio recording duration {audioRecording.DurationSeconds} will be floored");
var limit = audioRecording.DurationSeconds.Floor().AsIntervalFromZero();
var results = new List <RemoteSegmentWithData>(20);
foreach (var importedEvent in events)
{
var target = (importedEvent.EventStartSeconds.Value, importedEvent.EventEndSeconds.Value).AsInterval();
// determine how much padding is required (dynamically scales with event size
var padding = this.AnalysisDurationSeconds(target.Size());
if (target.Size() + padding > MediaService.MediaDownloadMaximumSeconds)
{
var newPadding = MediaService.MediaDownloadMaximumSeconds - target.Size();
Log.Warn(
$"Audio event size {audioRecordingId},{target} and padding {padding} exceeds maximum media " +
$"download amount - trimming padding from {padding}, to {newPadding}");
padding = newPadding;
}
// grow target to required analysis length
// we round the grow size to the nearest integer so that we reduce caching combinatorics in the workbench
Log.Trace($"Growing target event from {audioRecordingId},{target} by {padding} seconds");
var analysisRange = target.Grow(limit, padding, 0);
var segment = new RemoteSegmentWithData(audioRecording, analysisRange, importedEvent.AsArray());
results.Add(segment);
}
return(DedupeSegments(results));
}