公司最近專案不是很忙,就將之前弄東西整理了一下,解碼直播流使用FFMPeg,
之前做的一個專案是智慧家居的控制系統,加監控,這個監控有多個攝像頭,每一個都要顯示出來,並將預覽的畫面在不同的位置顯示出來,達到同步的效果,之前使用的VLC解碼顯示的,但是太多預覽源的話,每一個都要解碼一次,一個是耗費效能,另一個是每次拖拽到一個控制器上就預覽一個解碼一次,顯然這種方式,不符合要求,

理想狀態是,一個源直解碼一次,同一個源在不同的地方顯示多次的話,是直接拿資料渲染,
下面是是我的做成的效果

由於錄屏軟體的限制,不能操作,這三個畫面顯示的是解碼一次,顯示在不同的地方………就是我只解碼了一路流將資料顯示在多個不同的位置

這是我在別人的基礎上進行執行緒優化的,借鑑了別人的程式碼,我將程式碼封裝在一個類中,呼叫很簡單 最後面有原始碼檔案下載連線


@implementation CQMovieView
{
    AVFormatContext             *FormatCtx;
    AVCodecContext              *codecCtx;
    AVFrame                     *avframe;
    AVStream                    *stream;
    AVPacket                    packet;
    AVPicture                   picture;

    int
 
                         videoStram;
    double                      fps;
    BOOL                        isReleaseResources;
    dispatch_queue_t            queue;
    UIImageView                 *imageView;

}

- (instancetype)initWithFrame:(CGRect)frame
{
    if (self = [super initWithFrame:frame]) {
        self
 
.frame = frame;
    }
    return self;
}

-(void)Video:(NSString *)moviePath
{
    queue = dispatch_queue_create("LABEL", DISPATCH_QUEUE_SERIAL);

    self.cruutenPath = [moviePath copy];

    imageView = [[UIImageView alloc]initWithFrame:self.bounds];

    [self addSubview:imageView];


    dispatch_async(queue, ^{
        [self initializeResources:[moviePath UTF8String]];
    });

}

-(void)displayNextFrame:(NSTimer *)timer {

    NSTimeInterval startTime = [NSDate timeIntervalSinceReferenceDate];
    //    self.TimerLabel.text = [NSString stringWithFormat:@"%f s",video.currentTime];

    if (![self stepFrame]) {
        [timer invalidate];

        return;
    }
    imageView.image = self.currentImage;
    //    _ImageSubView.image = video.currentImage;

    float frameTime = 1.0 / ([NSDate timeIntervalSinceReferenceDate] - startTime);
    if (_lastFrameTime < 0) {

        _lastFrameTime = frameTime;
    } else {
        _lastFrameTime = LERP(frameTime, _lastFrameTime, 0.8);
    }


}

- (BOOL)initializeResources:(const char *)filePath {

    isReleaseResources = NO;
    AVCodec *pCodec;
    //註冊所有解碼器
    avcodec_register_all();
    av_register_all();
    avformat_network_init();

    //開啟視屏檔案
    if (avformat_open_input(&FormatCtx, filePath, NULL, NULL) != 0) {
        NSLog(@"開啟檔案失敗");

    }

    //檢查資料流
    if (avformat_find_stream_info(FormatCtx, NULL) < 0) {
        NSLog(@"檢查資料流失敗");
    }

    //根據資料流,找到第一個視屏流
    if ((videoStram = av_find_best_stream(FormatCtx, AVMEDIA_TYPE_VIDEO, -1, -1, &pCodec, 0)) < 0) {
        NSLog(@"沒有找到第一個視屏流");
        //           goto initError;

    }

    //獲取視屏流的編解碼上下文的指標
    stream = FormatCtx->streams[videoStram];
    codecCtx = stream->codec;
#if DEBUG
    //列印視屏流的詳細資訊
    av_dump_format(FormatCtx, videoStram, filePath,  0);
#endif
    if (stream->avg_frame_rate.den && stream->avg_frame_rate.num) {
        fps = av_q2d(stream->avg_frame_rate);
    }else{fps = 30;}
    //查詢解碼器
    pCodec = avcodec_find_decoder(codecCtx->codec_id);
    if (pCodec == NULL) {
        NSLog(@"沒有找到解碼器");

    }
    //開啟解碼器
    if (avcodec_open2(codecCtx, pCodec, NULL) < 0) {
        NSLog(@"開啟解碼器失敗");
        //           goto initError;
    }

    //分配視屏幀
    avframe = av_frame_alloc();
    _outputWidth = codecCtx->width;
    _outputHeight = codecCtx->height;

    dispatch_async(dispatch_get_main_queue(), ^{
        [self seekTime:0.0];
        [NSTimer scheduledTimerWithTimeInterval: 1 / fps
                                         target:self
                                       selector:@selector(displayNextFrame:)
                                       userInfo:nil
                                        repeats:YES];
    });

    return YES;


    return NO;



}
- (void)seekTime:(double)seconds {

    AVRational timeBase = FormatCtx->streams[videoStram]->time_base;
    int64_t targetFrame = (int64_t)((double)timeBase.den / timeBase.num *seconds);
    avformat_seek_file(FormatCtx, videoStram, 0, targetFrame, targetFrame, AVSEEK_FLAG_FRAME);
    avcodec_flush_buffers(codecCtx);
}


- (BOOL)stepFrame
{
    int frameFinished = 0;
    while (!frameFinished && av_read_frame(FormatCtx, &packet) >= 0) {
        if (packet.stream_index == videoStram) {
            avcodec_decode_video2(codecCtx, avframe, &frameFinished, &packet);


        }
    }

    if (frameFinished == 0 && isReleaseResources == NO) {
        [self releaseResources];
    }
    return frameFinished != 0;
}

- (void)replaceTheResources:(NSString *)moviePath {
    if (!isReleaseResources) {
        [self releaseResources];
    }
    self.cruutenPath = [moviePath copy];

    [self initializeResources:[moviePath UTF8String]];


}

-(void)redialPaly
{
    [self initializeResources:[self.cruutenPath UTF8String]];
}
#pragma mark  重寫屬性訪問方法
-(void)setOutputWidth:(int)newValue {
    if (_outputWidth == newValue)return;
    _outputWidth = newValue;
}

-(void)setOutputHeight:(int)newValue {
    if (_outputHeight == newValue) return;
    _outputHeight = newValue;
}

-(UIImage *)currentImage {
    if (!avframe->data[0]) return nil;
    return [self imageFromAVPicture];

    return nil;
}

-(double)duration {
    return (double)FormatCtx->duration / AV_TIME_BASE;
}

- (double)currentTime {
    AVRational timeBase = FormatCtx->streams[videoStram]->time_base;
    return packet.pts * (double)timeBase.num / timeBase.den;
}

- (int)sourceWidth {
    return codecCtx->width;
}
- (int)sourceHeight {
    return codecCtx->height;
}

- (double)fps {
    return fps;
}

#pragma mark - 內部方法
- (UIImage *)imageFromAVPicture
{
    avpicture_free(&picture);
    avpicture_alloc(&picture, AV_PIX_FMT_RGB24, _outputWidth, _outputHeight);
    struct SwsContext *imgConverCtx = sws_getContext(avframe->width,
                                                     avframe->height,
                                                     AV_PIX_FMT_YUV420P,
                                                     _outputWidth,
                                                     _outputHeight,
                                                     AV_PIX_FMT_RGB24,
                                                     SWS_FAST_BILINEAR,
                                                     NULL,
                                                     NULL,
                                                     NULL);
    if(imgConverCtx == nil)return nil;
    sws_scale(imgConverCtx,
              avframe->data,
              avframe->linesize,
              0,
              avframe->height,
              picture.data,
              picture.linesize);
    sws_freeContext(imgConverCtx);
    CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault;
    CFDataRef   data = CFDataCreate(kCFAllocatorDefault, picture.data[0], picture.linesize[0] * _outputHeight);
    CGDataProviderRef provider = CGDataProviderCreateWithCFData(data);
    CGColorSpaceRef   colorSpace = CGColorSpaceCreateDeviceRGB();
    CGImageRef  cgImage = CGImageCreate(_outputWidth, _outputHeight, 8, 24, picture.linesize[0], colorSpace, bitmapInfo, provider, NULL, NO, kCGRenderingIntentDefault);
    UIImage *image = [UIImage imageWithCGImage:cgImage];
    CGImageRelease(cgImage);
    CGColorSpaceRelease(colorSpace);
    CGDataProviderRelease(provider);
    CFRelease(data);   
    return image;
}


#pragma mark --------------------------
#pragma mark - 釋放資源
- (void)releaseResources {
    NSLog(@"釋放資源");
    //    SJLogFunc
    isReleaseResources = YES;
    // 釋放RGB
    avpicture_free(&picture);
    // 釋放frame
    av_packet_unref(&packet);
    // 釋放YUV frame
    av_free(avframe);
    // 關閉解碼器
    if (codecCtx) avcodec_close(codecCtx);
    // 關閉檔案
    if (FormatCtx) avformat_close_input(&FormatCtx);
    avformat_network_deinit();
}

這是檔案的詳細程式碼資源下載 程式碼檔案下載