iOS 列表加载视频桢图片

我这边没有去缓存加载，直接从本地沙盒取，防止sd缓存过高

//
//  UIImageView+GYVideoImage.m
//  GuiYuSiri
//
//  Created by wbb on 2023/2/27.
//

#import "UIImageView+GYVideoImage.h"
#import <SDWebImage/SDImageCache.h>

@implementation UIImageView (GYVideoImage)
- (void)gy_videoImageWithVideoURL:(NSURL *)videoURL {
    [self gy_videoImageWithVideoURL:videoURL atTime:1];
}
- (void)gy_videoImageWithVideoURL:(NSURL *)videoURL atTime:(NSTimeInterval)time {
    //本地查找是否有图片
    SDImageCache *cache =  [SDImageCache sharedImageCache];
    NSString *filepath= [cache cachePathForKey:videoURL.absoluteString];
    UIImage *memoryImage =  [UIImage imageWithContentsOfFile:filepath];
    if (memoryImage) {
        [self setImage:memoryImage];
        return;
    }
    if (!time) {
        time = 1;
    }
    
    //如果都不存在，开启异步线程截取对应时间点的画面，转成图片缓存至磁盘
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        
        
        AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:videoURL options:nil];
        AVAssetImageGenerator *assetGen = [[AVAssetImageGenerator alloc] initWithAsset:asset];
        assetGen.apertureMode = AVAssetImageGeneratorApertureModeEncodedPixels;
        assetGen.appliesPreferredTrackTransform = YES;
        CFTimeInterval thumbnailImageTime = time;
        CMTime time = CMTimeMake(thumbnailImageTime, 60);//CMTimeMakeWithSeconds(0.0, 600);
        NSError *error = nil;
        CMTime actualTime;
        CGImageRef image = [assetGen copyCGImageAtTime:time actualTime:&actualTime error:&error];
        UIImage *thumbnailImage = [[UIImage alloc] initWithCGImage:image];
        CGImageRelease(image);

        CGFloat width = ViewWidth - 32 - 12;
        CGSize imageSize = thumbnailImage.size;
        CGFloat height = imageSize.height/imageSize.width*1.f * width;
        // 图片压缩
        UIImage *videoImage = [GlobalFunc thumbnailWithImageWithoutScale:thumbnailImage size:CGSizeMake(width, height)];
        
        dispatch_async(dispatch_get_main_queue(), ^{
            SDImageCache * cache =  [SDImageCache sharedImageCache];
            [cache storeImage:videoImage forKey:videoURL.absoluteString toDisk:YES completion:nil];
            [self setImage:videoImage];
        });
        
    });
    
}
@end

下面这种情况属于三级缓存，先从缓存查找，再从本地磁盘中查找，然后获取视频桢图片

//
//  UIImageView+GYVideoImage.m
//  GuiYuSiri
//
//  Created by wbb on 2023/2/27.
//

#import "UIImageView+GYVideoImage.h"
#import <SDWebImage/SDImageCache.h>

@implementation UIImageView (GYVideoImage)
- (void)gy_videoImageWithVideoURL:(NSURL *)videoURL {
    [self gy_videoImageWithVideoURL:videoURL atTime:1];
}
- (void)gy_videoImageWithVideoURL:(NSURL *)videoURL atTime:(NSTimeInterval)time {
    
    //先从缓存中查找是否有图片
    SDImageCache *cache =  [SDImageCache sharedImageCache];
    UIImage *memoryImage =  [cache imageFromMemoryCacheForKey:videoURL.absoluteString];
    if (memoryImage) {
        [self setImage:memoryImage];
        return;
    }else{
        //再从磁盘中查找是否有图片
        UIImage *diskImage =  [cache imageFromDiskCacheForKey:videoURL.absoluteString];
        if (diskImage) {
            [self setImage:diskImage];
            return;
        }
    }
    if (!time) {
        time = 1;
    }
    //如果都不存在，开启异步线程截取对应时间点的画面，转成图片缓存至磁盘
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
//        AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:videoURL options:nil];
//        NSParameterAssert(asset);
//        AVAssetImageGenerator *assetImageGenerator =[[AVAssetImageGenerator alloc] initWithAsset:asset];
//        assetImageGenerator.appliesPreferredTrackTransform = YES;
//        assetImageGenerator.apertureMode = AVAssetImageGeneratorApertureModeEncodedPixels;
//        CGImageRef thumbnailImageRef = NULL;
//        CFTimeInterval thumbnailImageTime = time;
//        NSError *thumbnailImageGenerationError = nil;
//        thumbnailImageRef = [assetImageGenerator copyCGImageAtTime:CMTimeMake(thumbnailImageTime, 60)actualTime:NULL error:&thumbnailImageGenerationError];
//        if(!thumbnailImageRef)
//            NSLog(@"thumbnailImageGenerationError %@",thumbnailImageGenerationError);
//        UIImage*thumbnailImage = thumbnailImageRef ? [[UIImage alloc]initWithCGImage: thumbnailImageRef] : nil;
        
        
        
        AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:videoURL options:nil];
        AVAssetImageGenerator *assetGen = [[AVAssetImageGenerator alloc] initWithAsset:asset];
        assetGen.apertureMode = AVAssetImageGeneratorApertureModeEncodedPixels;
        assetGen.appliesPreferredTrackTransform = YES;
        CFTimeInterval thumbnailImageTime = time;
        CMTime time = CMTimeMake(thumbnailImageTime, 60);//CMTimeMakeWithSeconds(0.0, 600);
        NSError *error = nil;
        CMTime actualTime;
        CGImageRef image = [assetGen copyCGImageAtTime:time actualTime:&actualTime error:&error];
        UIImage *videoImage = [[UIImage alloc] initWithCGImage:image];
        CGImageRelease(image);
        
        
        
        
        dispatch_async(dispatch_get_main_queue(), ^{
            SDImageCache * cache =  [SDImageCache sharedImageCache];
            [cache storeImage:videoImage forKey:videoURL.absoluteString toDisk:YES completion:nil];
            [self setImage:videoImage];
        });
        
    });
    
}
@end