Sto cercando di unire le immagini in un video preesistente per creare un nuovo file video utilizzando AVFoundation su Mac.Miscelazione di immagini e video utilizzando AVFoundation
Finora ho letto la documentazione ad esempio Apple,
ASSETWriterInput for making Video from UIImages on Iphone Issues
Mix video with static image in CALayer using AVVideoCompositionCoreAnimationTool
AVFoundation Tutorial: Adding Overlays and Animations to Videos e pochi altri collegamenti in modo
Ora, questi hanno dimostrato di essere abbastanza utile a volte, ma il mio problema è che non sto creando una statica filigrana o una sovrapposizione esattamente voglio mettere in immagini tra le parti del video. Finora sono riuscito a ottenere il video e creare sezioni vuote per queste immagini da inserire ed esportarlo.
Il mio problema è ottenere le immagini per inserirle in queste sezioni vuote. L'unico modo che posso vedere per farlo è creare una serie di livelli animati per cambiare la loro opacità ai tempi corretti, ma non riesco a far funzionare l'animazione.
Il codice seguente è quello che sto utilizzando per creare i segmenti video e le animazioni dei livelli.
//https://developer.apple.com/library/ios/documentation/AudioVideo/Conceptual/AVFoundationPG/Articles/03_Editing.html#//apple_ref/doc/uid/TP40010188-CH8-SW7
// let's start by making our video composition
AVMutableComposition* mutableComposition = [AVMutableComposition composition];
AVMutableCompositionTrack* mutableCompositionTrack = [mutableComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
AVMutableVideoComposition* mutableVideoComposition = [AVMutableVideoComposition videoCompositionWithPropertiesOfAsset:gVideoAsset];
// if the first point's frame doesn't start on 0
if (gFrames[0].startTime.value != 0)
{
DebugLog("Inserting vid at 0");
// then add the video track to the composition track with a time range from 0 to the first point's startTime
[mutableCompositionTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, gFrames[0].startTime) ofTrack:gVideoTrack atTime:kCMTimeZero error:&gError];
}
if(gError)
{
DebugLog("Error inserting original video segment");
GetError();
}
// create our parent layer and video layer
CALayer* parentLayer = [CALayer layer];
CALayer* videoLayer = [CALayer layer];
parentLayer.frame = CGRectMake(0, 0, 1280, 720);
videoLayer.frame = CGRectMake(0, 0, 1280, 720);
[parentLayer addSublayer:videoLayer];
// create an offset value that should be added to each point where a new video segment should go
CMTime timeOffset = CMTimeMake(0, 600);
// loop through each additional frame
for(int i = 0; i < gFrames.size(); i++)
{
// create an animation layer and assign it's content to the CGImage of the frame
CALayer* Frame = [CALayer layer];
Frame.contents = (__bridge id)gFrames[i].frameImage;
Frame.frame = CGRectMake(0, 720, 1280, -720);
DebugLog("inserting empty time range");
// add frame point to the composition track starting at the point's start time
// insert an empty time range for the duration of the frame animation
[mutableCompositionTrack insertEmptyTimeRange:CMTimeRangeMake(CMTimeAdd(gFrames[i].startTime, timeOffset), gFrames[i].duration)];
// update the time offset by the duration
timeOffset = CMTimeAdd(timeOffset, gFrames[i].duration);
// make the layer completely transparent
Frame.opacity = 0.0f;
// create an animation for setting opacity to 0 on start
CABasicAnimation* frameAnim = [CABasicAnimation animationWithKeyPath:@"opacity"];
frameAnim.duration = 1.0f;
frameAnim.repeatCount = 0;
frameAnim.autoreverses = NO;
frameAnim.fromValue = [NSNumber numberWithFloat:0.0];
frameAnim.toValue = [NSNumber numberWithFloat:0.0];
frameAnim.beginTime = AVCoreAnimationBeginTimeAtZero;
frameAnim.speed = 1.0f;
[Frame addAnimation:frameAnim forKey:@"animateOpacity"];
// create an animation for setting opacity to 1
frameAnim = [CABasicAnimation animationWithKeyPath:@"opacity"];
frameAnim.duration = 1.0f;
frameAnim.repeatCount = 0;
frameAnim.autoreverses = NO;
frameAnim.fromValue = [NSNumber numberWithFloat:1.0];
frameAnim.toValue = [NSNumber numberWithFloat:1.0];
frameAnim.beginTime = AVCoreAnimationBeginTimeAtZero + CMTimeGetSeconds(gFrames[i].startTime);
frameAnim.speed = 1.0f;
[Frame addAnimation:frameAnim forKey:@"animateOpacity"];
// create an animation for setting opacity to 0
frameAnim = [CABasicAnimation animationWithKeyPath:@"opacity"];
frameAnim.duration = 1.0f;
frameAnim.repeatCount = 0;
frameAnim.autoreverses = NO;
frameAnim.fromValue = [NSNumber numberWithFloat:0.0];
frameAnim.toValue = [NSNumber numberWithFloat:0.0];
frameAnim.beginTime = AVCoreAnimationBeginTimeAtZero + CMTimeGetSeconds(gFrames[i].endTime);
frameAnim.speed = 1.0f;
[Frame addAnimation:frameAnim forKey:@"animateOpacity"];
// add the frame layer to our parent layer
[parentLayer addSublayer:Frame];
gError = nil;
// if there's another point after this one
if(i < gFrames.size()-1)
{
// add our video file to the composition with a range of this point's end and the next point's start
[mutableCompositionTrack insertTimeRange:CMTimeRangeMake(gFrames[i].startTime,
CMTimeMake(gFrames[i+1].startTime.value - gFrames[i].startTime.value, 600))
ofTrack:gVideoTrack
atTime:CMTimeAdd(gFrames[i].startTime, timeOffset) error:&gError];
}
// else just add our video file with a range of this points end point and the videos duration
else
{
[mutableCompositionTrack insertTimeRange:CMTimeRangeMake(gFrames[i].startTime, CMTimeSubtract(gVideoAsset.duration, gFrames[i].startTime)) ofTrack:gVideoTrack atTime:CMTimeAdd(gFrames[i].startTime, timeOffset) error:&gError];
}
if(gError)
{
char errorMsg[256];
sprintf(errorMsg, "Error inserting original video segment at: %d", i);
DebugLog(errorMsg);
GetError();
}
}
Ora in quel segmento opacità del fotogrammi è impostata su 0.0f, tuttavia quando ho impostato a 1.0f tutto ciò che fa è sufficiente posizionare l'ultimo di questi fotogrammi in cima al video per l'intera durata.
Dopo che la vide viene esportato utilizzando un AVAssetExportSession come mostrato di seguito
mutableVideoComposition.animationTool = [AVVideoCompositionCoreAnimationTool videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];
// create a layer instruction for our newly created animation tool
AVMutableVideoCompositionLayerInstruction *layerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:gVideoTrack];
AVMutableVideoCompositionInstruction *instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
[instruction setTimeRange:CMTimeRangeMake(kCMTimeZero, [mutableComposition duration])];
[layerInstruction setOpacity:1.0f atTime:kCMTimeZero];
[layerInstruction setOpacity:0.0f atTime:mutableComposition.duration];
instruction.layerInstructions = [NSArray arrayWithObject:layerInstruction];
// set the instructions on our videoComposition
mutableVideoComposition.instructions = [NSArray arrayWithObject:instruction];
// export final composition to a video file
// convert the videopath into a url for our AVAssetWriter to create a file at
NSString* vidPath = CreateNSString(outputVideoPath);
NSURL* vidURL = [NSURL fileURLWithPath:vidPath];
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mutableComposition presetName:AVAssetExportPreset1280x720];
exporter.outputFileType = AVFileTypeMPEG4;
exporter.outputURL = vidURL;
exporter.videoComposition = mutableVideoComposition;
exporter.timeRange = CMTimeRangeMake(kCMTimeZero, mutableComposition.duration);
// Asynchronously export the composition to a video file and save this file to the camera roll once export completes.
[exporter exportAsynchronouslyWithCompletionHandler:^{
dispatch_async(dispatch_get_main_queue(), ^{
if (exporter.status == AVAssetExportSessionStatusCompleted)
{
DebugLog("!!!file created!!!");
_Close();
}
else if(exporter.status == AVAssetExportSessionStatusFailed)
{
DebugLog("failed damn");
DebugLog(cStringCopy([[[exporter error] localizedDescription] UTF8String]));
DebugLog(cStringCopy([[[exporter error] description] UTF8String]));
_Close();
}
else
{
DebugLog("NoIdea");
_Close();
}
});
}];
}
Ho la sensazione che l'animazione non viene avviato ma non so. Sto andando nel modo giusto a questo proposito per unire i dati di immagine in un video come questo?
Qualsiasi assistenza sarebbe molto apprezzata.