void SetupReaderAndWriter()
{
NSError error = null;
// Create asset reader and asset writer
assetReader = AVAssetReader.FromAsset(asset, out error);
if (assetReader == null)
{
throw new NSErrorException(error);
}
assetWriter = AVAssetWriter.FromUrl(outputURL, AVFileType.QuickTimeMovie, out error);
if (assetWriter == null)
{
throw new NSErrorException(error);
}
// Create asset reader outputs and asset writer inputs for the first audio track and first video track of the asset
// Grab first audio track and first video track, if the asset has them
AVAssetTrack audioTrack = asset.TracksWithMediaType(AVMediaType.Audio).FirstOrDefault();
AVAssetTrack videoTrack = asset.TracksWithMediaType(AVMediaType.Video).FirstOrDefault();
SetupAssetReaderWriterForAudio(audioTrack);
SetupAssetReaserWriterForVideo(videoTrack);
}
private void SetupReaderAndWriter()
{
AVAsset localAsset = _asset;
NSUrl localOutputURL = _outputURL;
NSError error = null;
// Create asset reader and asset writer
_assetReader = new AVAssetReader(localAsset, out error);
if (_assetReader == null)
{
throw new NSErrorException(error);
}
_assetWriter = new AVAssetWriter(localOutputURL, AVFileType.QuickTimeMovie, out error);
if (_assetWriter == null)
{
throw new NSErrorException(error);
}
// Create asset reader outputs and asset writer inputs for the first audio track and first video track of the asset
// Grab first audio track and first video track, if the asset has them
AVAssetTrack audioTrack = localAsset.TracksWithMediaType(AVMediaType.Audio).FirstOrDefault();
AVAssetTrack videoTrack = localAsset.TracksWithMediaType(AVMediaType.Video).FirstOrDefault();
SetupAssetReaderWriterForAudio(audioTrack);
SetupAssetReaserWriterForVideo(videoTrack);
}
void ReadSampleBuffers(AVAsset asset)
{
NSError error;
assetReader = AVAssetReader.FromAsset(asset, out error);
if (error != null)
{
Console.WriteLine("Error creating Asset Reader: {0}", error.Description);
}
AVAssetTrack[] videoTracks = asset.TracksWithMediaType(AVMediaType.Video);
AVAssetTrack videoTrack = videoTracks [0];
CreateDecompressionSession(videoTrack);
var videoTrackOutput = AVAssetReaderTrackOutput.Create(videoTrack, (AVVideoSettingsUncompressed)null);
if (assetReader.CanAddOutput(videoTrackOutput))
{
assetReader.AddOutput(videoTrackOutput);
}
if (!assetReader.StartReading())
{
return;
}
while (assetReader.Status == AVAssetReaderStatus.Reading)
{
CMSampleBuffer sampleBuffer = videoTrackOutput.CopyNextSampleBuffer();
if (sampleBuffer != null)
{
VTDecodeFrameFlags flags = VTDecodeFrameFlags.EnableAsynchronousDecompression;
VTDecodeInfoFlags flagOut;
decompressionSession.DecodeFrame(sampleBuffer, flags, IntPtr.Zero, out flagOut);
sampleBuffer.Dispose();
if (presentationTimes.Count >= 5)
{
bufferSemaphore.Wait();
}
}
else if (assetReader.Status == AVAssetReaderStatus.Failed)
{
Console.WriteLine("Asset Reader failed with error: {0}", assetReader.Error.Description);
}
else if (assetReader.Status == AVAssetReaderStatus.Completed)
{
Console.WriteLine("Reached the end of the video.");
ChangeStatus();
ReadSampleBuffers(asset);
}
}
}
VTDecompressionSession CreateSession(AVAsset asset)
{
var videoTracks = asset.TracksWithMediaType(AVMediaType.Video);
var track = videoTracks[0];
var formatDescriptor = track.FormatDescriptions[0] as CMVideoFormatDescription;
var session = VTDecompressionSession.Create(
(sourceFrame, status, flags, buffer, presentationTimeStamp, presentationDuration) => {},
formatDescriptor);
return(session);
}
private void BuildTransitionComposition(AVMutableComposition composition, AVMutableVideoComposition videoComposition, AVMutableAudioMix audioMix)
{
CMTime nextClipStartTime = CMTime.Zero;
int clipsCount = Clips.Count;
// Make transitionDuration no greater than half the shortest clip duration.
CMTime transitionDuration = TransitionDuration;
Console.WriteLine("Clips Count:" + clipsCount);
Console.WriteLine("Clips Range Count:" + ClipTimeRanges.Count);
for (int i = 0; i < clipsCount; i++)
{
NSValue clipTimeRange = ClipTimeRanges [i];
if (clipTimeRange != null)
{
CMTime halfClipDuration = clipTimeRange.CMTimeRangeValue.Duration;
halfClipDuration.TimeScale *= 2;
transitionDuration = CMTime.GetMinimum(transitionDuration, halfClipDuration);
}
}
// Add two video tracks and two audio tracks.
var compositionVideoTracks = new AVMutableCompositionTrack [] {
composition.AddMutableTrack(AVMediaType.Video, 0),
composition.AddMutableTrack(AVMediaType.Video, 0)
};
var compositionAudioTracks = new AVMutableCompositionTrack [] {
composition.AddMutableTrack(AVMediaType.Audio, 0),
composition.AddMutableTrack(AVMediaType.Audio, 0)
};
var passThroughTimeRanges = new CMTimeRange[clipsCount];
var transitionTimeRanges = new CMTimeRange[clipsCount];
// Place clips into alternating video & audio tracks in composition, overlapped by transitionDuration.
for (int i = 0; i < clipsCount; i++)
{
int alternatingIndex = i % 2;
AVAsset asset = Clips [i];
NSValue clipTimeRange = ClipTimeRanges [i];
CMTimeRange timeRangeInAsset;
if (clipTimeRange != null)
{
timeRangeInAsset = clipTimeRange.CMTimeRangeValue;
}
else
{
timeRangeInAsset = new CMTimeRange();
timeRangeInAsset.Start = CMTime.Zero;
timeRangeInAsset.Duration = asset.Duration;
}
NSError error;
AVAssetTrack clipVideoTrack = asset.TracksWithMediaType(AVMediaType.Video) [0];
compositionVideoTracks [alternatingIndex].InsertTimeRange(timeRangeInAsset, clipVideoTrack, nextClipStartTime, out error);
AVAssetTrack clipAudioTrack = asset.TracksWithMediaType(AVMediaType.Audio) [0];
compositionAudioTracks [alternatingIndex].InsertTimeRange(timeRangeInAsset, clipAudioTrack, nextClipStartTime, out error);
// Remember the time range in which this clip should pass through.
// First clip ends with a transition.
// Second clip begins with a transition.
// Exclude that transition from the pass through time ranges
CMTimeRange timeRange = new CMTimeRange();
timeRange.Start = nextClipStartTime;
timeRange.Duration = timeRangeInAsset.Duration;
passThroughTimeRanges [i] = timeRange;
if (i > 0)
{
passThroughTimeRanges[i].Start = CMTime.Add(passThroughTimeRanges[i].Start, transitionDuration);
passThroughTimeRanges[i].Duration = CMTime.Subtract(passThroughTimeRanges[i].Duration, transitionDuration);
}
if (i + 1 < clipsCount)
{
passThroughTimeRanges[i].Duration = CMTime.Subtract(passThroughTimeRanges[i].Duration, transitionDuration);
}
// The end of this clip will overlap the start of the next by transitionDuration.
// (Note: this arithmetic falls apart if timeRangeInAsset.duration < 2 * transitionDuration.)
nextClipStartTime = CMTime.Add(nextClipStartTime, timeRangeInAsset.Duration);
nextClipStartTime = CMTime.Subtract(nextClipStartTime, transitionDuration);
// Remember the time range for the transition to the next item
if (i + 1 < clipsCount)
{
transitionTimeRanges [i] = new CMTimeRange()
{
Start = nextClipStartTime,
Duration = transitionDuration
};
}
}
List <AVVideoCompositionInstruction> instructions = new List <AVVideoCompositionInstruction> ();
List <AVMutableAudioMixInputParameters> trackMixArray = new List <AVMutableAudioMixInputParameters> ();
// Set up the video composition if we are to perform crossfade transitions between clips.
for (int i = 0; i < clipsCount; i++)
{
int alternatingIndex = i % 2;
AVMutableVideoCompositionInstruction passThroughInstructions = AVMutableVideoCompositionInstruction.Create() as AVMutableVideoCompositionInstruction;
passThroughInstructions.TimeRange = passThroughTimeRanges [i];
AVMutableVideoCompositionLayerInstruction passThroughLayerInstructions = AVMutableVideoCompositionLayerInstruction.FromAssetTrack(compositionVideoTracks [alternatingIndex]);
passThroughInstructions.LayerInstructions = new AVVideoCompositionLayerInstruction[] { passThroughLayerInstructions };
instructions.Add(passThroughInstructions);
if (i + 1 < clipsCount)
{
var transitionInstruction = AVMutableVideoCompositionInstruction.Create() as AVMutableVideoCompositionInstruction;
transitionInstruction.TimeRange = transitionTimeRanges [i];
var fromLayer = AVMutableVideoCompositionLayerInstruction.FromAssetTrack(compositionVideoTracks [alternatingIndex]);
var toLayer = AVMutableVideoCompositionLayerInstruction.FromAssetTrack(compositionVideoTracks [1 - alternatingIndex]);
// Fade in the toLayer by setting a ramp from 0.0 to 1.0.
toLayer.SetOpacityRamp(0.0f, 1.0f, transitionTimeRanges [i]);
transitionInstruction.LayerInstructions = new AVVideoCompositionLayerInstruction[]
{
toLayer,
fromLayer,
};
instructions.Add(transitionInstruction);
// Add AudioMix to fade in the volume ramps
var trackMix = AVMutableAudioMixInputParameters.FromTrack(compositionAudioTracks[0]);
trackMix.SetVolumeRamp(1f, 0f, transitionTimeRanges[0]);
trackMixArray.Add(trackMix);
trackMix = AVMutableAudioMixInputParameters.FromTrack(compositionAudioTracks[1]);
trackMix.SetVolumeRamp(0f, 1f, transitionTimeRanges[0]);
trackMix.SetVolumeRamp(1f, 1f, passThroughTimeRanges[1]);
trackMixArray.Add(trackMix);
}
}
videoComposition.Instructions = instructions.ToArray();
audioMix.InputParameters = trackMixArray.ToArray();
}
void buildTransitionComposition(AVMutableComposition composition, AVMutableVideoComposition videoComposition)
{
CMTime nextClipStartTime = CMTime.Zero;
int clipsCount = Clips.Count;
// Make transitionDuration no greater than half the shortest clip duration.
CMTime transitionDuration = TransitionDuration;
foreach (var clipTimeRange in ClipTimeRanges)
{
if (clipTimeRange == null)
{
continue;
}
CMTime halfClipDuration = clipTimeRange.CMTimeRangeValue.Duration;
halfClipDuration.TimeScale *= 2;
transitionDuration = CMTime.GetMinimum(transitionDuration, halfClipDuration);
}
// Add two video tracks and two audio tracks.
var compositionVideoTracks = new AVMutableCompositionTrack [2];
var compositionAudioTracks = new AVMutableCompositionTrack [2];
compositionVideoTracks [0] = composition.AddMutableTrack(AVMediaType.Video, 0);
compositionVideoTracks [1] = composition.AddMutableTrack(AVMediaType.Video, 0);
compositionAudioTracks [0] = composition.AddMutableTrack(AVMediaType.Audio, 0);
compositionAudioTracks [1] = composition.AddMutableTrack(AVMediaType.Audio, 0);
var passThroughTimeRanges = new CMTimeRange[clipsCount];
var transitionTimeRanges = new CMTimeRange[clipsCount];
// Place clips into alternating video & audio tracks in composition, overlapped by transitionDuration.
for (int i = 0; i < clipsCount; i++)
{
int alternatingIndex = i % 2;
AVAsset asset = Clips [i];
NSValue clipTimeRange = ClipTimeRanges [i];
CMTimeRange timeRangeInAsset;
if (clipTimeRange != null)
{
timeRangeInAsset = clipTimeRange.CMTimeRangeValue;
}
else
{
timeRangeInAsset = new CMTimeRange {
Start = CMTime.Zero,
Duration = asset.Duration
};
}
NSError error = new NSError();
AVAssetTrack clipVideoTrack = asset.TracksWithMediaType(AVMediaType.Video) [0];
compositionVideoTracks [alternatingIndex].InsertTimeRange(timeRangeInAsset, clipVideoTrack, nextClipStartTime, out error);
AVAssetTrack clipAudioTrack = asset.TracksWithMediaType(AVMediaType.Audio) [0];
compositionAudioTracks [alternatingIndex].InsertTimeRange(timeRangeInAsset, clipAudioTrack, nextClipStartTime, out error);
// Remember the time range in which this clip should pass through.
// First clip ends with a transition.
// Second clip begins with a transition.
// Exclude that transition from the pass through time ranges
passThroughTimeRanges [i] = new CMTimeRange {
Start = nextClipStartTime,
Duration = timeRangeInAsset.Duration
};
if (i > 0)
{
passThroughTimeRanges[i].Start = CMTime.Add(passThroughTimeRanges[i].Start, transitionDuration);
passThroughTimeRanges[i].Duration = CMTime.Subtract(passThroughTimeRanges[i].Duration, transitionDuration);
}
if (i + 1 < clipsCount)
{
passThroughTimeRanges[i].Duration = CMTime.Subtract(passThroughTimeRanges[i].Duration, transitionDuration);
}
// The end of this clip will overlap the start of the next by transitionDuration.
// (Note: this arithmetic falls apart if timeRangeInAsset.duration < 2 * transitionDuration.)
nextClipStartTime = CMTime.Add(nextClipStartTime, timeRangeInAsset.Duration);
nextClipStartTime = CMTime.Subtract(nextClipStartTime, transitionDuration);
// Remember the time range for the transition to the next item.
if (i + 1 < clipsCount)
{
transitionTimeRanges [i] = new CMTimeRange()
{
Start = nextClipStartTime,
Duration = transitionDuration
};
}
}
// Set up the video composition to perform cross dissolve or diagonal wipe transitions between clips.
var instructions = new List <AVVideoCompositionInstruction> ();
// Cycle between "pass through A", "transition from A to B", "pass through B"
for (int i = 0; i < clipsCount; i++)
{
int alternatingIndex = i % 2;
// if (videoComposition.CustomVideoCompositorClass != null) {
// var videoInstruction = new CustomVideoCompositionInstruction (compositionVideoTracks [alternatingIndex].TrackID, passThroughTimeRanges [i]);
// instructions.Add (videoInstruction);
// } else {
// // Pass through clip i.
// var passThroughInstruction = AVMutableVideoCompositionInstruction.Create () as AVMutableVideoCompositionInstruction;
// passThroughInstruction.TimeRange = passThroughTimeRanges [i];
// var passThroughLayer = AVMutableVideoCompositionLayerInstruction.FromAssetTrack (compositionVideoTracks [alternatingIndex]);
// passThroughInstruction.LayerInstructions = new [] { passThroughLayer };
// instructions.Add (passThroughInstruction);
//
// }
//TODO: Remove following call if previous works
if (videoComposition.CustomVideoCompositorClass.Name != "nil")
{
var videoInstruction = new CustomVideoCompositionInstruction(compositionVideoTracks [alternatingIndex].TrackID, passThroughTimeRanges [i]);
instructions.Add(videoInstruction);
}
else
{
// Pass through clip i.
var passThroughInstruction = AVMutableVideoCompositionInstruction.Create() as AVMutableVideoCompositionInstruction;
passThroughInstruction.TimeRange = passThroughTimeRanges [i];
var passThroughLayer = AVMutableVideoCompositionLayerInstruction.FromAssetTrack(compositionVideoTracks [alternatingIndex]);
passThroughInstruction.LayerInstructions = new [] { passThroughLayer };
instructions.Add(passThroughInstruction);
}
if (i + 1 < clipsCount)
{
// Add transition from clip i to clip i+1.
// if (videoComposition.CustomVideoCompositorClass != null) {
// var videoInstruction = new CustomVideoCompositionInstruction (new NSNumber [] {
// compositionVideoTracks [0].TrackID,
// compositionVideoTracks [1].TrackID
// }, transitionTimeRanges [1]);
//
// if (alternatingIndex == 0) {
// videoInstruction.ForegroundTrackID = compositionVideoTracks [alternatingIndex].TrackID;
// videoInstruction.BackgroundTrackID = compositionVideoTracks [1 - alternatingIndex].TrackID;
// }
//
// instructions.Add (videoInstruction);
// } else {
// var transitionInstruction = AVMutableVideoCompositionInstruction.Create () as AVMutableVideoCompositionInstruction;
// transitionInstruction.TimeRange = transitionTimeRanges [i];
// var fromLayer = AVMutableVideoCompositionLayerInstruction.FromAssetTrack (compositionVideoTracks [alternatingIndex]);
// var toLayer = AVMutableVideoCompositionLayerInstruction.FromAssetTrack (compositionVideoTracks [1 - alternatingIndex]);
// transitionInstruction.LayerInstructions = new [] { toLayer, fromLayer };
// instructions.Add (transitionInstruction);
// }
// TODO: remove following call if previous works
if (videoComposition.CustomVideoCompositorClass.Name != "nil")
{
NSNumber[] sources = new NSNumber[] {
new NSNumber(compositionVideoTracks [0].TrackID),
new NSNumber(compositionVideoTracks [1].TrackID)
};
var videoInstructions = new CustomVideoCompositionInstruction(sources, transitionTimeRanges [i]);
if (alternatingIndex == 0)
{
videoInstructions.ForegroundTrackID = compositionVideoTracks [alternatingIndex].TrackID;
videoInstructions.BackgroundTrackID = compositionVideoTracks [1 - alternatingIndex].TrackID;
}
instructions.Add(videoInstructions);
Console.WriteLine("Add transition from clip i to clip i+1");
}
else
{
AVMutableVideoCompositionInstruction transitionInstruction = AVMutableVideoCompositionInstruction.Create() as AVMutableVideoCompositionInstruction;
transitionInstruction.TimeRange = transitionTimeRanges [i];
AVMutableVideoCompositionLayerInstruction fromLayer = AVMutableVideoCompositionLayerInstruction.FromAssetTrack(compositionVideoTracks [alternatingIndex]);
AVMutableVideoCompositionLayerInstruction toLayer = AVMutableVideoCompositionLayerInstruction.FromAssetTrack(compositionVideoTracks [1 - alternatingIndex]);
transitionInstruction.LayerInstructions = new AVVideoCompositionLayerInstruction[] {
fromLayer,
toLayer,
};
instructions.Add(transitionInstruction);
}
}
}
videoComposition.Instructions = instructions.ToArray();
}
void ReadSampleBuffers(AVAsset asset)
{
NSError error;
assetReader = AVAssetReader.FromAsset (asset, out error);
if (error != null)
Console.WriteLine ("Error creating Asset Reader: {0}", error.Description);
AVAssetTrack[] videoTracks = asset.TracksWithMediaType (AVMediaType.Video);
AVAssetTrack videoTrack = videoTracks [0];
CreateDecompressionSession (videoTrack);
var videoTrackOutput = AVAssetReaderTrackOutput.Create (videoTrack, (AVVideoSettingsUncompressed)null);
if (assetReader.CanAddOutput (videoTrackOutput))
assetReader.AddOutput (videoTrackOutput);
if (!assetReader.StartReading ())
return;
while (assetReader.Status == AVAssetReaderStatus.Reading) {
CMSampleBuffer sampleBuffer = videoTrackOutput.CopyNextSampleBuffer ();
if (sampleBuffer != null) {
VTDecodeFrameFlags flags = VTDecodeFrameFlags.EnableAsynchronousDecompression;
VTDecodeInfoFlags flagOut;
decompressionSession.DecodeFrame (sampleBuffer, flags, IntPtr.Zero, out flagOut);
sampleBuffer.Dispose ();
if (presentationTimes.Count >= 5)
bufferSemaphore.Wait ();
} else if (assetReader.Status == AVAssetReaderStatus.Failed) {
Console.WriteLine ("Asset Reader failed with error: {0}", assetReader.Error.Description);
} else if (assetReader.Status == AVAssetReaderStatus.Completed) {
Console.WriteLine("Reached the end of the video.");
ChangeStatus ();
ReadSampleBuffers (asset);
}
}
}
