/// <summary>
/// Write audio, video and presentation data for this segment. This can be a long-running process.
/// It can be cancelled with the Stop method.
/// </summary>
/// <param name="noRecompression"></param>
/// <returns>A message string indicates a serious problem. Null for normal termination.</returns>
public String Encode()
{
if (cancel)
{
return(null);
}
if ((startTime == DateTime.MinValue) || (endTime == DateTime.MinValue))
{
return("Invalid timespan.");
}
if (useSlideStream && norecompression)
{
return("A slide stream cannot be processed in 'no recompression' mode.");
}
progressTracker.EndValue = (int)((TimeSpan)(endTime - startTime)).TotalSeconds;
if (useSlideStream)
{
slideStream = new SlideStreamMgr(job, segment, logMgr, 29.97, writer.FrameWidth, writer.FrameHeight); //Using slides in place of the video
}
else
{
videoStream = new StreamMgr(segment.VideoDescriptor.VideoCname, segment.VideoDescriptor.VideoName, startTime, endTime, norecompression, PayloadType.dynamicVideo);
}
audiorecompression = !norecompression;
//In this case we actually do need to recompress just the audio:
if ((norecompression) && (segment.AudioDescriptor.Length != 1))
{
audiorecompression = true;
}
audioStreams = new StreamMgr[segment.AudioDescriptor.Length];
for (int i = 0; i < segment.AudioDescriptor.Length; i++)
{
audioStreams[i] = new StreamMgr(segment.AudioDescriptor[i].AudioCname, segment.AudioDescriptor[i].AudioName, startTime, endTime, !audiorecompression, PayloadType.dynamicAudio);
}
if (cancel)
{
return(null);
}
actualSegmentStart = 0;
actualSegmentEnd = 0;
if (norecompression)
{
if (useSlideStream)
{
//Not supported
}
else
{
// Warn and log an error if a problem is detected with the media type, but try to proceed anyway.
videoStream.ValidateCompressedMT(profileData.VideoMediaType, logMgr);
// Make the last MT available to the caller to pass to the next segment to facilitate the checking.
//this.compressedVideoMediaType = videoStream.GetFinalCompressedVideoMediaType();
}
if (audioStreams.Length == 1)
{
//There is truly no recompression in this case.
///as above, do the same check with the Audio MediaType. Log a warning if the MT changed, but attempt to proceed.
audioStreams[0].ValidateCompressedMT(profileData.AudioMediaType, logMgr);
//this.compressedAudioMediaType = audioStreams[0].GetFinalCompressedAudioMediaType();
progressTracker.AVStatusMessage = "Writing Raw AV";
}
else
{
//In this case we have to recompress audio in order to do the mixing, but that should be relatively quick.
//Note that the WMSDK docs say that SetInputProps must be set before BeginWriting. This implies that
//alternating between writing compressed and uncompressed samples is not supported. Therefore we will
//first recompress the mixed audio, then deliver compressed samples to the writer.
for (int i = 0; i < audioStreams.Length; i++)
{
progressTracker.AVStatusMessage = "Reading Audio (" + (i + 1).ToString() + " of " + audioStreams.Length.ToString() + ")";
if (cancel)
{
return(null);
}
if (!audioStreams[i].ToRawWMFile(progressTracker))
{
return("Failed to configure a raw audio profile.");
}
}
progressTracker.AVStatusMessage = "Mixing Audio";
mixer = new AudioMixer(audioStreams, this.logMgr);
/// PRI3: We could tell the mixer to recompress with the previous segment's MT (if any).
/// For now we just use the
/// mixer's voting mechanism to choose the 'dominant' input (uncompressed) format,
/// and make the profile from one of the streams that uses that format.
mixer.Recompress(progressTracker);
progressTracker.AVStatusMessage = "Writing Raw AV";
}
}
else // Recompress both audio and video
{
//In order to recompress, we first need to convert each stream to a raw wmv/wma
//A slide stream starts life uncompressed, so just initialize decks.
if (!useSlideStream)
{
progressTracker.AVStatusMessage = "Reading Video";
if (!videoStream.ToRawWMFile(progressTracker))
{
return("Failed to configure the raw video profile.");
}
}
else
{
if (!slideStream.Init(progressTracker))
{
return("Failed to prepare slide decks.");
}
}
for (int i = 0; i < audioStreams.Length; i++)
{
progressTracker.AVStatusMessage = "Reading Audio (" + (i + 1).ToString() + " of " + audioStreams.Length.ToString() + ")";
if (cancel)
{
return(null);
}
if (!audioStreams[i].ToRawWMFile(progressTracker))
{
return("Failed to configure a raw audio profile.");
}
}
mixer = new AudioMixer(audioStreams, this.logMgr);
writer.GetInputProps();
//The SDK allows us to reconfigure the MediaTypes on the fly if we are writing uncompressed samples.
//We do this at the beginning of every segment, even though most of the time it is probably the same MT.
writer.ConfigAudio(mixer.UncompressedAudioMediaType);
if (useSlideStream)
{
writer.ConfigVideo(slideStream.UncompressedMediaType);
//writer.DebugPrintVideoProps();
}
else
{
writer.ConfigVideo(videoStream.GetUncompressedVideoMediaType());
}
progressTracker.CurrentValue = 0;
progressTracker.AVStatusMessage = "Transcoding AV";
}
//Now all the config and prep is done, so write the segment.
writeSegment();
//If there is a Presentation stream, process it here unless the slides were used for the video stream.
if ((!useSlideStream) && (this.segment.PresentationDescriptor != null) &&
(this.segment.PresentationDescriptor.PresentationCname != null))
{
progressTracker.CurrentValue = 0;
progressTracker.ShowPercentComplete = false;
progressTracker.AVStatusMessage = "Writing Presentation";
/// The offset for PresentationMgr is a timespan in ticks to be subtracted from each absolute timestamp
/// to make a new absolute timestamp which has been adjusted for accumulted time skipped (or overlap) between
/// segments, or time during which there is missing AV data at the beginning of the first segment.
/// It is calculated as: actualSegmentStart - jobStart - offset
/// where:
/// actualSegmentStart: Time of the first AV write for the current segment
/// JobStart: user requested start time for the first segment in this job (Presentation data reference time)
/// offset: calculated actual duration of all segments previous to this one.
///
/// Note that the presentation output will use the user-specified jobStart as the reference time.
/// During playback, relative timings of presentation events will be calculated by subtracting the reference time.
/// Also note that the reference time may not be the same as the actualSegmentStart for the first segment of the
/// job in the case where there is missing data at the beginning. This often (always) happens if we
/// begin processing an archive from the beginning, since it takes several seconds to get the first AV bits
/// into the database after the ArchiveService joins a venue.
//long thisSegmentOffset = this.actualSegmentStart - startTime.Ticks;
//long tmpoffset = this.actualSegmentStart-jobStart-offset;
//Debug.WriteLine ("this segment offset. actualSegmentStart = " + this.actualSegmentStart.ToString() +
// " jobStart = " + jobStart.ToString() + " offset = " + offset.ToString() +
// " offset to presenterMgr = " + tmpoffset.ToString());
long previousSegmentEndTime = 0;
if (m_PreviousSegment != null)
{
previousSegmentEndTime = m_PreviousSegment.actualSegmentEnd;
}
presentationMgr = new PresentationMgr(this.segment.PresentationDescriptor, this.actualSegmentStart, this.actualSegmentEnd,
this.actualSegmentStart - jobStart - offset, this.logMgr, previousSegmentEndTime, progressTracker);
if (cancel)
{
return(null);
}
String errmsg = presentationMgr.Process();
if (errmsg != null)
{
this.logMgr.WriteLine(errmsg);
this.logMgr.ErrorLevel = 5;
}
progressTracker.ShowPercentComplete = true;
}
if ((useSlideStream) && (slideStream != null))
{
slideStream.Dispose();
}
return(null);
}
