Kulexiu/KulexiuForStudent/KulexiuForStudent/Common/Tools/KSVideoHelper.m

//
//  KSVideoHelper.m
//  KulexiuForTeacher
//
//  Created by 王智 on 2022/4/12.
//

#import "KSVideoHelper.h"
#import <AVFoundation/AVAsset.h>
#import <AVFoundation/AVAssetImageGenerator.h>
#import <AVFoundation/AVTime.h>
#import <SDWebImage/SDImageCache.h>

@implementation KSVideoHelper

+ (void)getVideoPreviewImageUrl:(NSString *)videoUrl forImageView:(UIImageView *)imageView placeholder:(UIImage *)placeHolder {
    videoUrl = [videoUrl getUrlEndcodeString];
    [[SDImageCache sharedImageCache] queryCacheOperationForKey:videoUrl done:^(UIImage * _Nullable image, NSData * _Nullable data, SDImageCacheType cacheType) {
        //是否有缓存图片
        if(image){
            imageView.image = image;
        }else{
            //获取视频第一帧
            [self getVideoFirstViewImage:videoUrl forImageView:imageView placeHolderImage:placeHolder];
        }
    }];
}

// 获取视频第一帧
+ (void)getVideoFirstViewImage:(NSString *)videoURL forImageView:(UIImageView *)imageView placeHolderImage:(UIImage *)placeHolder {
   
    NSString *url = [videoURL getUrlEndcodeString];
    __block UIImage *videoImage;
    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:[NSURL URLWithString:url] options:nil];
        NSParameterAssert(asset);
        AVAssetImageGenerator *assetImageGenerator =[[AVAssetImageGenerator alloc] initWithAsset:asset];
        assetImageGenerator.appliesPreferredTrackTransform = YES;
        assetImageGenerator.apertureMode =AVAssetImageGeneratorApertureModeEncodedPixels;
        CGImageRef thumbnailImageRef = NULL;
        NSError *thumbnailImageGenerationError = nil;
        thumbnailImageRef = [assetImageGenerator copyCGImageAtTime:CMTimeMake(0, 60)actualTime:NULL error:&thumbnailImageGenerationError];
        if(!thumbnailImageRef)
        NSLog(@"thumbnailImageGenerationError %@",thumbnailImageGenerationError);
        videoImage = thumbnailImageRef ? [[UIImage alloc]initWithCGImage:thumbnailImageRef]: nil;
        
        dispatch_async(dispatch_get_main_queue(), ^{
            //主线程更新UI
            if(videoImage){
                imageView.image = videoImage;
                //缓存图片
                [[SDImageCache sharedImageCache] storeImage:videoImage forKey:videoURL toDisk:NO completion:^{
                    
                }];
                
            }else{
                //如果不是视频就设置图片
                [imageView sd_setImageWithURL:[NSURL URLWithString:[videoURL getUrlEndcodeString]] placeholderImage:placeHolder];
            }
        });
          
    });
}

+ (void)getVideoDuration:(NSString *)videoUrl displayInLabel:(UILabel *)displayLabel {
    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:[NSURL URLWithString:videoUrl] options:nil];
        float second = asset.duration.value / asset.duration.timescale;
        NSString *durationString = [NSString stringWithFormat:@"%.0f",second];
        NSInteger duration = [durationString integerValue];
        NSString *timeDesc = @"00:00";
        if (duration / 60 > 0) {
            NSInteger secondTime = duration % 60;
            NSString *secondStr = @"";
            if (secondTime < 10) {
                secondStr = [NSString stringWithFormat:@"0%zd",secondTime];
            } else {
                secondStr = [NSString stringWithFormat:@"%zd",secondTime];
            }
            timeDesc = [NSString stringWithFormat:@"%2ld:%@", duration / 60, secondStr];
        }
        else {
            NSInteger secondTime = duration % 60;
            NSString *secondStr = @"";
            if (secondTime < 10) {
                secondStr = [NSString stringWithFormat:@"0%zd",secondTime];
            } else {
                secondStr = [NSString stringWithFormat:@"%zd",secondTime];
            }
            timeDesc = [NSString stringWithFormat:@"00:%@", secondStr];
        }
        dispatch_async(dispatch_get_main_queue(), ^{
            displayLabel.text = timeDesc;
        });
    });
}

@end