Video cropping
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Use the Short Video SDK cropping module to crop videos by duration and aspect ratio, audio by duration, and images by aspect ratio on iOS.
Supported editions
| Edition | Supported |
| Professional | Yes |
| Standard | Yes |
| Basic | Yes |
Related classes
| Class | Description |
| AliyunCrop | Provides audio and video cropping, parameter configuration, and callback settings. |
| AliyunImageCrop | Provides image cropping, parameter configuration, and callback settings. |
Important Audio and video cropping is asynchronous. AliyunCrop instances must be member variables, not local variables. Switching to the background during cropping causes failure.
Regular cropping
Regular cropping re-encodes the video. You can configure output resolution, bitrate, frame rate, keyframe interval, encoding format, and video quality.
For more information about operation parameters, see AliyunCrop.
Perform initialization
// Call the initialization method to create a cropping object.
self.crop = [[AliyunCrop alloc] initWithDelegate:self];Set input path, output path, and time range
// Specify the input path and output path of the video.
self.crop.inputPath = [self.class resourcePath:@"input.mp4"];
self.crop.outputPath = [self.class resourcePath:@"output.mp4"];
// Specify the points in time to start and end cropping. Unit: seconds.
self.crop.startTime = 0.0;
self.crop.endTime = 5.0;Note Ensure the output directory exists before cropping.
Set cropping parameters
// Specify the resolution of the output video.
self.crop.outputSize = CGSizeMake(720, 720);
// Specify the cropping area.
self.crop.rect = CGRectMake(0, (1280-720) / 2, 720, 720);
// Specify the cropping mode.
self.crop.cropMode = AliyunCropModeScaleAspectCut;
// Specify the bitrate. Unit: bit/s.
self.crop.bitrate = 1000 * 1000;
// Specify the frame rate.
self.cropl.fps = 30;
// Specify the keyframe interval.
self.crop.gop = 90;
// Specify the video quality.
self.crop.videoQuality = AliyunVideoQualityHight;
// Set the encoding mode to hardware encoding.
self.crop.encodeMode = 1;Start cropping
[self.crop startCrop]; Set callbacks
// The callback that is returned when an error occurs during cropping.
- (void)cropOnError:(int)error {
}
// The callback for cropping progress.
- (void)cropTaskOnProgress:(float)progress {
}
// The callback that is returned when the cropping is complete.
- (void)cropTaskOnComplete {
}
// The callback that is returned when the cropping is canceled.
- (void)cropTaskOnCancel {
}Fast cropping
Fast cropping trims the video to a specified duration without re-encoding. Other parameters cannot be configured.
For more information about operation parameters, see AliyunCrop.
Perform initialization
// Call the initialization method to create a cropping object.
self.crop = [[AliyunCrop alloc] initWithDelegate:self];Enable fast cropping
// Enable cropping optimization to allow fast cropping.
self.crop.shouldOptimize = YES;Set input path, output path, and time range
// Specify the input path and output path of the video.
self.crop.inputPath = [self.class resourcePath:@"input.mp4"];
self.crop.outputPath = [self.class resourcePath:@"output.mp4"];
// Specify the points in time to start and end cropping.
self.crop.startTime = 0.0;
self.crop.endTime = 5.0;Note Ensure the output directory exists before cropping.
Start cropping
[self.crop startCrop]; Set callbacks
// The callback that is returned when an error occurs during cropping.
- (void)cropOnError:(int)error {
}
// The callback for cropping progress.
- (void)cropTaskOnProgress:(float)progress {
}
// The callback that is returned when the cropping is complete.
- (void)cropTaskOnComplete {
}
// The callback that is returned when the cropping is canceled.
- (void)cropTaskOnCancel {
}Audio cropping
For more information about operation parameters, see AliyunCrop.
Perform initialization
// Call the initialization method to create a cropping object.
self.crop = [[AliyunCrop alloc] initWithDelegate:self];Set input path, output path, and time range
// Specify the input path and output path of the audio file.
self.crop.inputPath = [self.class resourcePath:@"input.mp3"];
self.crop.outputPath = [self.class resourcePath:@"output.mp3"];
// Specify the points in time to start and end cropping. Unit: seconds.
self.crop.startTime = 0.0;
self.crop.endTime = 5.0;Note Ensure the output directory exists before cropping.
Start cropping
[self.crop startCrop]; Set callbacks
// The callback that is returned when an error occurs during cropping.
- (void)cropOnError:(int)error {
}
// The callback for cropping progress.
- (void)cropTaskOnProgress:(float)progress {
}
// The callback that is returned when the cropping is complete.
- (void)cropTaskOnComplete {
}
// The callback that is returned when the cropping is canceled.
- (void)cropTaskOnCancel {
}Image cropping
For more information about operation parameters, see AliyunImageCrop.
Perform initialization
// Call the initialization method to create a cropping object.
AliyunImageCrop *imageCrop = [[AliyunImageCrop alloc] init];Specify the input image
imageCrop.originImage = image;Set cropping parameters
// Specify the resolution of the output image.
imageCrop.outputSize = CGSizeMake(200, 200);
// (Optional) Specify the cropping area. Unit: pixels.
imageCrop.cropRect = CGRectMake(50, 0, 200, 200);
// (Optional) Specify the image cropping mode.
imageCrop.cropMode = AliyunImageCropModeAspectCut;Generate the cropped image
UIImage *outputImage = [imageCrop generateImage];Is this page helpful?