How to get frame from video on iOS

Question

In my app I want to take frames from a video for filtering them. I try to take frame frim video by time offset. This is my code:

- (UIImage*)getVideoFrameForTime:(NSDate*)time {

    CGImageRef thumbnailImageRef = NULL;

    NSError *igError = nil;

    NSTimeInterval timeinterval = [time timeIntervalSinceDate:self.videoFilterStart];

    CMTime atTime = CMTimeMakeWithSeconds(timeinterval, 1000);
    thumbnailImageRef =
    [self.assetImageGenerator copyCGImageAtTime:atTime
                                     actualTime:NULL
                                          error:&igError];

    if (!thumbnailImageRef) {
        NSLog(@"thumbnailImageGenerationError %@", igError );
    }

    UIImage *image = thumbnailImageRef ? [[UIImage alloc] initWithCGImage:thumbnailImageRef] : nil;

    return image;
}

Unfortunately, I see only frames which located on integer seconds: 1, 2, 3.. Even when time interval is non-integer (1.5, etc).

How to get frames at any non-integer interval?

Possible duplicate of [Grab frames from video using Swift](http://stackoverflow.com/questions/32286320/grab-frames-from-video-using-swift) — shallowThought, Jan 18 '17 at 15:24

Marouane Lanouari · Answer 1 · 2017-01-19T21:30:27.637

1

Use this project to get more frame details The corresponding project on github: iFrameExtractor.git

edited Jan 19 '17 at 21:30

answered Jan 18 '17 at 15:22

Marouane Lanouari

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thnx a lot, i will check it. – Eugene Trapeznikov Jan 18 '17 at 15:38
you have check the solution ? – Marouane Lanouari Jan 19 '17 at 12:59

score 1 · Accepted Answer · edited May 23 '17 at 12:24

1

Thnx to @shallowThought I found an answer in this question Grab frames from video using Swift

You just need to add this two lines

assetImgGenerate.requestedTimeToleranceAfter = kCMTimeZero;
assetImgGenerate.requestedTimeToleranceBefore = kCMTimeZero;

edited May 23 '17 at 12:24

Community

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answered Jan 19 '17 at 10:13

Eugene Trapeznikov

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score 0 · Answer 3 · answered Jan 18 '17 at 15:17

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If I remember correctly NSDate's accuracy only goes up to the second which explains why frames are only take on integer seconds. You'll have to use a different type of input to get frames at non-integer seconds.

answered Jan 18 '17 at 15:17

TheAmateurProgrammer

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Unfortunately, no. I logged timeinterval and it is float. Also, If create CMTime like this `CMTime atTime = CMTimeMakeWithSeconds(3, 1000);` and change 3 to 3.5 result will be the same. – Eugene Trapeznikov Jan 18 '17 at 15:37
What happens if you do `CMTimeMakeWithSeconds(3, 1)` and `CMTimeMakeWithSeconds(3.5, 1)` – TheAmateurProgrammer Jan 18 '17 at 15:45
I will see two equal frames – Eugene Trapeznikov Jan 19 '17 at 10:12

How to get frame from video on iOS

3 Answers3