使用FFMPeg解码rtsp协议的视屏流,并使用openGL渲染,

1.之前有使用VLC解码但是不能满足需求,后来直接使用FFmpeg解码openGL渲染
2.使用FFMpeg解码这里解决了,解码后不能拿到视屏流多出显示的问题
3.解决了打开首帧视屏比较慢的问题,现在1-2内既能打开视屏
4.解决了找不到pps报警告的问题
5.多线程优化,解码的同时不影响UI的操作更新
解码显示可以转为图片贴图显示,和使用openGL渲染两种方式显示

使用前准备
1.首先编译FFMpeg源码,集成ios的库,添加到工程中并导入相应的库,编译集成FFmpeg

我将FFMpeg的解码代码封装在一个文件中,方便使用

首先展示转为图片显示的

#import "CQMovieView.h"
#import "OpenglView.h"
#define LERP(A,B,C) ((A)*(1.0-C)+(B)*C)

@interface CQMovieView ()

@property (nonatomic, copy) NSString *cruutenPath;
@property (nonatomic ,strong)NSMutableArray         *mutArray;
@property (nonatomic,strong)OpenglView *openglView;

@end

@implementation CQMovieView
{
    AVFormatContext             *pFormatCtx;
    AVCodecContext              *pCodecCtx;
    AVFrame                     *pFream;
    AVStream                    *stream;
    AVPacket                    *packet;
     int                        i,videoIndex;
    AVPicture                   picture;
    int                         videoStram;
    double                      fps;
    BOOL                        isReleaseResources;
    dispatch_queue_t            queue;
}

- (instancetype)initWithFrame:(CGRect)frame
{
    if (self = [super initWithFrame:frame]) {
        self.frame = frame;
        _mutArray = [NSMutableArray array];
        _isdecoder = YES;
    }
    return self;
}

- (void)replaceTheResources:(NSString *)moviePath{

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

-(void)Video:(NSString *)moviePath
{
    NSLog(@"%@",moviePath);

//    queue = dispatch_queue_create("label", DISPATCH_QUEUE_SERIAL);
    queue = dispatch_get_global_queue(0,DISPATCH_QUEUE_PRIORITY_DEFAULT);
//    queue = dispatch_queue_create("label", DISPATCH_QUEUE_CONCURRENT);
    self.cruutenPath = [moviePath copy];
    self.ImageView = [[UIImageView alloc]initWithFrame:self.bounds];
    [self addSubview:self.ImageView];
//    self.openglView = [[OpenglView alloc]initWithFrame:self.bounds];
//    [self addSubview:self.openglView];
//    [self.openglView setVideoSize:self.bounds.size.width height:self.bounds.size.height];
    NSLog(@"===%@",moviePath);
    assert(moviePath);
    dispatch_async(queue, ^{
        NSString *path = [moviePath stringByAppendingString:@"0200012000c8000f"];
        [self initializeResources:[path UTF8String]];
    });
}

- (void)initializeResources:(const char *)pathUrl{
//    dispatch_async(queue, ^{
        //初始化所有组件
    av_register_all();
    avcodec_register_all();
        //声明上下文
//        AVFormatContext    *pFormatCtx;
        //初始化上下文
    pFormatCtx = avformat_alloc_context();

    avformat_network_init();

        //dispatch_async(queue, ^{
        //获取文件路径
    const char * path = pathUrl;
        if (path == NULL) {
            printf("无法找到文件路径/n");
            return ;
        }

    //这里设置检测空间,解决打开视屏慢的问题
    AVDictionary *options = NULL;
    av_dict_set(&options, "rtsp_transport", "tcp", 0);
    pFormatCtx->probesize = 1000;
    pFormatCtx->max_analyze_duration2 = 0;//3 * AV_TIME_BASE;
    //声明解码器类型
    AVCodec    *pCodec;
    //查找解码器
    pCodec = avcodec_find_decoder(AV_CODEC_ID_H264);
//    int i,videoIndex;
    videoIndex = -1;
    pCodecCtx = avcodec_alloc_context3(pCodec);
    pCodecCtx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
    uint8_t *ut = malloc(32);
    pCodecCtx->extradata = ut;
    pCodecCtx->extradata_size = 32;
    //给extradata成员参数设置值,解决找不到pps报警告的问题
    //00 00 00 01
    pCodecCtx->extradata[0] = 0x00;
    pCodecCtx->extradata[1] = 0x00;
    pCodecCtx->extradata[2] = 0x00;
    pCodecCtx->extradata[3] = 0x01;

    //67 42 80 1e
    pCodecCtx->extradata[4] = 0x67;
    pCodecCtx->extradata[5] = 0x42;
    pCodecCtx->extradata[6] = 0x80;
    pCodecCtx->extradata[7] = 0x1e;

    //88 8b 40 50
    pCodecCtx->extradata[8] = 0x88;
    pCodecCtx->extradata[9] = 0x8b;
    pCodecCtx->extradata[10] = 0x40;
    pCodecCtx->extradata[11] = 0x50;

    //1e d0 80 00
    pCodecCtx->extradata[12] = 0x1e;
    pCodecCtx->extradata[13] = 0xd0;
    pCodecCtx->extradata[14] = 0x80;
    pCodecCtx->extradata[15] = 0x00;

    //03 84 00 00
    pCodecCtx->extradata[16] = 0x03;
    pCodecCtx->extradata[17] = 0x84;
    pCodecCtx->extradata[18] = 0x00;
    pCodecCtx->extradata[19] = 0x00;

    //af c8 02 00
    pCodecCtx->extradata[20] = 0xaf;
    pCodecCtx->extradata[21] = 0xc8;
    pCodecCtx->extradata[22] = 0x02;
    pCodecCtx->extradata[23] = 0x00;

    //00 00 00 01
    pCodecCtx->extradata[24] = 0x00;
    pCodecCtx->extradata[25] = 0x00;
    pCodecCtx->extradata[26] = 0x00;
    pCodecCtx->extradata[27] = 0x01;

    //68 ce 38 80
    pCodecCtx->extradata[28] = 0x68;
    pCodecCtx->extradata[29] = 0xce;
    pCodecCtx->extradata[30] = 0x38;
    pCodecCtx->extradata[31] = 0x80;
        //打开视频流
    if(avformat_open_input(&pFormatCtx,path,NULL,&options)!=0){
            NSLog(@"不能打开流");
            return ;
        }

        //查看视频流信息
        if(avformat_find_stream_info(pFormatCtx,&options)<0){
            NSLog(@"不能成功查看视频流信息");
            return ;
        }
        //       });

        //对上下文中的视频流进行遍历
    for (i = 0; i<pFormatCtx->nb_streams; i++) {
            //找到视频流信息后跳出循环 && pFormatCtx->streams[i]->codecpar->codec_type==AVMEDIA_TYPE_VIDEO
        if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO ){
            videoIndex=i;
            break;
        }
    }

        //若videoIndex还为初值那么说明没有找到视频流
    if(videoIndex==-1){
            NSLog(@"没有找到视频流");
        return ;
    }
        //声明编码器上下文结构体
        //这里新版本不再使用AVCodecContext这个结构体了,具体原因我也不太清楚,好像是pFormatCtx->streams过于臃肿
//        AVCodecContext    * pCodecCtx;

    if (pCodec == NULL) {

        NSLog(@"解码器没找到");
        return;
    }

        //打开解码器
    if(avcodec_open2(pCodecCtx, pCodec,NULL)<0){
        NSLog(@"解码器打开失败");
        return;
    }

    //解码后的数据
    //        AVFrame *pFream,*pFreamYUV;

    pFream = av_frame_alloc();

    //        pFreamYUV = av_frame_alloc();

    uint8_t *out_buffer;

        //开辟空间
        packet = (AVPacket *)av_malloc(sizeof(AVPacket));
        /*******************************输出信息*********************************************/
        NSLog(@"--------------- File Informatin ----------------");
        //打印视频信息,av_dump_format()是一个手工调试的函数,能使我们看到pFormatCtx->streams里面有什么内容
        av_dump_format(pFormatCtx, 0, path, 0);
        NSLog(@"-------------------------------------------------");
        //主要用来对图像进行变化,这里是为了缩放,把黑边裁去
        struct SwsContext * img_convert_ctx;
        /**
         该函数包含以下参数:
         srcW:源图像的宽
         srcH:源图像的高
         srcFormat:源图像的像素格式
         dstW:目标图像的宽
         dstH:目标图像的高
         dstFormat:目标图像的像素格式
         flags:设定图像拉伸使用的算法
         成功执行的话返回生成的SwsContext,否则返回NULL。
         //         */
        //        img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt,
        //                                         pCodecCtx->width, pCodecCtx->height, AV_PIX_FMT_RGB24, SWS_BICUBIC, NULL, NULL, NULL);
//    free(audioBuffer);

    free(ut);
        //解码序号
        int got_picture_ptr = 0;
        //循环读取每一帧
        while (_isdecoder) {
            if ( av_read_frame(pFormatCtx, packet)>=0) {
            //若为视频流信息
            if (packet->stream_index == videoIndex) {
                //解码一帧数据,输入一个压缩编码的结构体AVPacket,输出一个解码后的结构体AVFrame。
                int ret = avcodec_decode_video2(pCodecCtx, pFream, &got_picture_ptr, packet);
                //                  ret1 = avcodec_decode_audio4(pCodecCtx, frames, &got_frame, packet);
                //当解码失败
//                if (ret < 0) {
//                    NSLog(@"解码失败");
//                    return;
//                }
                //                if (got_frame) {
                //                    swr_convert(swrCtx, &audioBuffer, 2 * 44100, frames->data, frames->nb_samples);
                //                    NSData *data = [NSData dataWithBytes:fp_pcm length:pFream->height*pFream->width*3/2];
                //                    [player playWithData:data];
                //                }

                /*
                 char *yuvdata = malloc(pFream->height*pFream->width*3/2);
                 int i;
                 for (i = 0; i < pFream->height; i++) {
                 memcpy(yuvdata + i * pFream->width,
                 pFream->data[0] + i * pFream->linesize[0], pFream->width);
                 }
                 for (i = 0; i < pFream->height / 2; i++) {
                 memcpy(yuvdata + pFream->height*pFream->width + i * pFream->width / 2,
                 pFream->data[1] + i * pFream->linesize[1], pFream->width / 2);
                 }
                 for (i = 0; i < pFream->height / 2; i++) {
                 memcpy(yuvdata + pFream->height*pFream->width*5/4 + i * pFream->width / 2,
                 pFream->data[2] + i * pFream->linesize[2], pFream->width / 2);
                 }
                 [self.openglView displayYUV420pData:yuvdata width:pFream->width height:pFream->height];

                 free(yuvdata);
                 */
                avpicture_free(&picture);
                avpicture_alloc(&picture, AV_PIX_FMT_RGB24, pCodecCtx->width, pCodecCtx->height);
                struct SwsContext *imgConverCtx = sws_getContext(pFream->width,
                                                                 pFream->height,
                                                                 AV_PIX_FMT_YUV420P,
                                                                 pCodecCtx->width,
                                                                 pCodecCtx->height,
                                                                 AV_PIX_FMT_RGB24,
                                                                 SWS_FAST_BILINEAR,
                                                                 NULL,
                                                                 NULL,
                                                                 NULL);
                if(imgConverCtx == nil){
                    return ;
                }
                sws_scale(imgConverCtx,
                          pFream->data,
                          pFream->linesize,
                          0,
                          pFream->height,
                          picture.data,
                          picture.linesize);
                sws_freeContext(imgConverCtx);
                CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault;
                CFDataRef   data = CFDataCreate(kCFAllocatorDefault, picture.data[0], picture.linesize[0] * pCodecCtx->height);
                CGDataProviderRef provider = CGDataProviderCreateWithCFData(data);
                CGColorSpaceRef   colorSpace = CGColorSpaceCreateDeviceRGB();
                CGImageRef  cgImage = CGImageCreate(pCodecCtx->width, pCodecCtx->height, 8, 24, picture.linesize[0], colorSpace, bitmapInfo, provider, NULL, NO, kCGRenderingIntentDefault);
                UIImage *image = [UIImage imageWithCGImage:cgImage];
                CGImageRelease(cgImage);
                CGColorSpaceRelease(colorSpace);
                CGDataProviderRelease(provider);
                CFRelease(data);
                dispatch_async(dispatch_get_main_queue(),^{
//                    self.ImageView.image = image; //在本view中显示
//                    [[NSNotificationCenter defaultCenter]postNotificationName:self.cruutenPath object:image]; //将数据传出,可以在多个地方显示同意画面,不需多次解码而显示同意画面
                });
            }

            //销毁packet
            av_free_packet(packet);
            avpicture_free(&picture);

        }
        //销毁
//                sws_freeContext(img_convert_ctx);
        av_frame_free(&pFreamYUV);
//
//        av_frame_free(&pFream);
//
//        avcodec_close(pCodecCtx);
//
//        avformat_close_input(&pFormatCtx);
//    });
        }
}

//暂停
- (void)pause{
    _isdecoder = NO;
}

//播放
-(void)play{
    _isdecoder = YES;
}


- (void)releaseResources {
    NSLog(@"释放资源");
    //    SJLogFunc
    isReleaseResources = YES;
    // 释放RGB
    av_packet_unref(&packet);
    // 释放frame
//    av_packet_unref(&packet);
    // 释放YUV frame
    if (pFream) {
        av_free(pFream);
    }
    //     关闭解码器
    if (pCodecCtx != nil){
        avcodec_close(pCodecCtx);
    }
    // 关闭文件
    if (pFormatCtx) avformat_close_input(&pFormatCtx);
    avformat_network_deinit();
}
- (void)dealloc
{
    [[NSNotificationCenter defaultCenter]removeObserver:self];
    [self releaseResources];
}
@end

下面展示使用openGL渲染的代码

#import "CQMovieView.h"
#import "OpenglView.h"
#define LERP(A,B,C) ((A)*(1.0-C)+(B)*C)

@interface CQMovieView ()

@property (nonatomic, copy) NSString *cruutenPath;
@property (nonatomic ,strong)NSMutableArray         *mutArray;
@property (nonatomic,strong)OpenglView *openglView;

@end

@implementation CQMovieView
{
    AVFormatContext             *pFormatCtx;
    AVCodecContext              *pCodecCtx;
    AVFrame                     *pFream;
    AVStream                    *stream;
    AVPacket                    *packet;
     int                        i,videoIndex;
    AVPicture                   picture;
    int                         videoStram;
    double                      fps;
    BOOL                        isReleaseResources;
    dispatch_queue_t            queue;
}

- (instancetype)initWithFrame:(CGRect)frame
{
    if (self = [super initWithFrame:frame]) {
        self.frame = frame;
        _mutArray = [NSMutableArray array];
        _isdecoder = YES;
    }
    return self;
}

- (void)replaceTheResources:(NSString *)moviePath{

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

-(void)Video:(NSString *)moviePath
{
    NSLog(@"%@",moviePath);

//    queue = dispatch_queue_create("label", DISPATCH_QUEUE_SERIAL);
    queue = dispatch_get_global_queue(0,DISPATCH_QUEUE_PRIORITY_DEFAULT);
//    queue = dispatch_queue_create("label", DISPATCH_QUEUE_CONCURRENT);
    self.cruutenPath = [moviePath copy];
    self.ImageView = [[UIImageView alloc]initWithFrame:self.bounds];
    [self addSubview:self.ImageView];
    self.openglView = [[OpenglView alloc]initWithFrame:self.bounds];
    [self addSubview:self.openglView];
    [self.openglView setVideoSize:self.bounds.size.width height:self.bounds.size.height];
    NSLog(@"===%@",moviePath);
    assert(moviePath);
    dispatch_async(queue, ^{
        NSString *path = [moviePath stringByAppendingString:@"0200012000c8000f"];
        [self initializeResources:[path UTF8String]];
    });
}

- (void)initializeResources:(const char *)pathUrl{
//    dispatch_async(queue, ^{
        //初始化所有组件
    av_register_all();
    avcodec_register_all();
        //声明上下文
//        AVFormatContext    *pFormatCtx;
        //初始化上下文
    pFormatCtx = avformat_alloc_context();

    avformat_network_init();

        //dispatch_async(queue, ^{
        //获取文件路径
    const char * path = pathUrl;
        if (path == NULL) {
            printf("无法找到文件路径/n");
            return ;
        }

    AVDictionary *options = NULL;
    av_dict_set(&options, "rtsp_transport", "tcp", 0);
    pFormatCtx->probesize = 1000;
    pFormatCtx->max_analyze_duration2 = 0;//3 * AV_TIME_BASE;
    //声明解码器类型
    AVCodec    *pCodec;
    //查找解码器
    pCodec = avcodec_find_decoder(AV_CODEC_ID_H264);
//    int i,videoIndex;
    videoIndex = -1;
    pCodecCtx = avcodec_alloc_context3(pCodec);
    pCodecCtx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
    uint8_t *ut = malloc(32);
    pCodecCtx->extradata = ut;
    pCodecCtx->extradata_size = 32;
    //给extradata成员参数设置值
    //00 00 00 01
    pCodecCtx->extradata[0] = 0x00;
    pCodecCtx->extradata[1] = 0x00;
    pCodecCtx->extradata[2] = 0x00;
    pCodecCtx->extradata[3] = 0x01;

    //67 42 80 1e
    pCodecCtx->extradata[4] = 0x67;
    pCodecCtx->extradata[5] = 0x42;
    pCodecCtx->extradata[6] = 0x80;
    pCodecCtx->extradata[7] = 0x1e;

    //88 8b 40 50
    pCodecCtx->extradata[8] = 0x88;
    pCodecCtx->extradata[9] = 0x8b;
    pCodecCtx->extradata[10] = 0x40;
    pCodecCtx->extradata[11] = 0x50;

    //1e d0 80 00
    pCodecCtx->extradata[12] = 0x1e;
    pCodecCtx->extradata[13] = 0xd0;
    pCodecCtx->extradata[14] = 0x80;
    pCodecCtx->extradata[15] = 0x00;

    //03 84 00 00
    pCodecCtx->extradata[16] = 0x03;
    pCodecCtx->extradata[17] = 0x84;
    pCodecCtx->extradata[18] = 0x00;
    pCodecCtx->extradata[19] = 0x00;

    //af c8 02 00
    pCodecCtx->extradata[20] = 0xaf;
    pCodecCtx->extradata[21] = 0xc8;
    pCodecCtx->extradata[22] = 0x02;
    pCodecCtx->extradata[23] = 0x00;

    //00 00 00 01
    pCodecCtx->extradata[24] = 0x00;
    pCodecCtx->extradata[25] = 0x00;
    pCodecCtx->extradata[26] = 0x00;
    pCodecCtx->extradata[27] = 0x01;

    //68 ce 38 80
    pCodecCtx->extradata[28] = 0x68;
    pCodecCtx->extradata[29] = 0xce;
    pCodecCtx->extradata[30] = 0x38;
    pCodecCtx->extradata[31] = 0x80;
        //打开视频流
    if(avformat_open_input(&pFormatCtx,path,NULL,&options)!=0){
            NSLog(@"不能打开流");
            return ;
        }

        //查看视频流信息
        if(avformat_find_stream_info(pFormatCtx,&options)<0){
            NSLog(@"不能成功查看视频流信息");
            return ;
        }
        //       });

        //对上下文中的视频流进行遍历
    for (i = 0; i<pFormatCtx->nb_streams; i++) {
            //找到视频流信息后跳出循环 && pFormatCtx->streams[i]->codecpar->codec_type==AVMEDIA_TYPE_VIDEO
        if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO ){
            videoIndex=i;
            break;
        }
    }

        //若videoIndex还为初值那么说明没有找到视频流
    if(videoIndex==-1){
            NSLog(@"没有找到视频流");
        return ;
    }
        //声明编码器上下文结构体
        //这里新版本不再使用AVCodecContext这个结构体了,具体原因我也不太清楚,好像是pFormatCtx->streams过于臃肿
//        AVCodecContext    * pCodecCtx;

    if (pCodec == NULL) {

        NSLog(@"解码器没找到");
        return;
    }

        //打开解码器
    if(avcodec_open2(pCodecCtx, pCodec,NULL)<0){
        NSLog(@"解码器打开失败");
        return;
    }

    //解码后的数据
    //        AVFrame *pFream,*pFreamYUV;

    pFream = av_frame_alloc();

    //        pFreamYUV = av_frame_alloc();

    uint8_t *out_buffer;

        //开辟空间
        packet = (AVPacket *)av_malloc(sizeof(AVPacket));
        /*******************************输出信息*********************************************/
        NSLog(@"--------------- File Informatin ----------------");
        //打印视频信息,av_dump_format()是一个手工调试的函数,能使我们看到pFormatCtx->streams里面有什么内容
        av_dump_format(pFormatCtx, 0, path, 0);
        NSLog(@"-------------------------------------------------");
        //主要用来对图像进行变化,这里是为了缩放,把黑边裁去
        struct SwsContext * img_convert_ctx;
        /**
         该函数包含以下参数:
         srcW:源图像的宽
         srcH:源图像的高
         srcFormat:源图像的像素格式
         dstW:目标图像的宽
         dstH:目标图像的高
         dstFormat:目标图像的像素格式
         flags:设定图像拉伸使用的算法
         成功执行的话返回生成的SwsContext,否则返回NULL。
         //         */
        //        img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt,
        //                                         pCodecCtx->width, pCodecCtx->height, AV_PIX_FMT_RGB24, SWS_BICUBIC, NULL, NULL, NULL);
//    free(audioBuffer);

    free(ut);
        //解码序号
        int got_picture_ptr = 0;
         //循环读取每一帧
        while (av_read_frame(pFormatCtx, packet)>=0) {
            //若为视频流信息
            if (packet->stream_index == videoIndex) {
                //解码一帧数据,输入一个压缩编码的结构体AVPacket,输出一个解码后的结构体AVFrame。
                int ret = avcodec_decode_video2(pCodecCtx, pFream, &got_picture_ptr, packet);
//                  ret1 = avcodec_decode_audio4(pCodecCtx, frames, &got_frame, packet);
                //当解码失败
                if (ret < 0) {
                    NSLog(@"解码失败");
                    return;
                }
//                if (got_frame) {
//                    swr_convert(swrCtx, &audioBuffer, 2 * 44100, frames->data, frames->nb_samples);
//                    NSData *data = [NSData dataWithBytes:fp_pcm length:pFream->height*pFream->width*3/2];
//                    [player playWithData:data];
//                }
                    //开辟空间存放yuv
                char *yuvdata = malloc(pFream->height*pFream->width*3/2);
                    //下面三个for是对yuv数据查找拼接位置 y = u * 2  v,u= y/2  
                int i;
                for (i = 0; i < pFream->height; i++) {
                    memcpy(yuvdata + i * pFream->width,
                           pFream->data[0] + i * pFream->linesize[0], pFream->width);
                }
                for (i = 0; i < pFream->height / 2; i++) {
                    memcpy(yuvdata + pFream->height*pFream->width + i * pFream->width / 2,
                           pFream->data[1] + i * pFream->linesize[1], pFream->width / 2);
                }
                for (i = 0; i < pFream->height / 2; i++) {
                    memcpy(yuvdata + pFream->height*pFream->width*5/4 + i * pFream->width / 2,
                           pFream->data[2] + i * pFream->linesize[2], pFream->width / 2);
                }
                [self.openglView displayYUV420pData:yuvdata width:pFream->width height:pFream->height];
                NSLog(@"====开始获取流33333333=====%@",[NSDate date]);
                free(yuvdata);
            }

            //销毁packet
            av_free_packet(packet);
        }
//                sws_freeContext(img_convert_ctx);
        av_frame_free(&pFreamYUV);
//
//        av_frame_free(&pFream);
//
//        avcodec_close(pCodecCtx);
//
//        avformat_close_input(&pFormatCtx);
//    });
        }
}

//暂停
- (void)pause{
    _isdecoder = NO;
}

//播放
-(void)play{
    _isdecoder = YES;
}


- (void)releaseResources {
    NSLog(@"释放资源");
    //    SJLogFunc
    isReleaseResources = YES;
    // 释放RGB
    av_packet_unref(&packet);
    // 释放frame
//    av_packet_unref(&packet);
    // 释放YUV frame
    if (pFream) {
        av_free(pFream);
    }
    //     关闭解码器
    if (pCodecCtx != nil){
        avcodec_close(pCodecCtx);
    }
    // 关闭文件
    if (pFormatCtx) avformat_close_input(&pFormatCtx);
    avformat_network_deinit();
}
- (void)dealloc
{
    [[NSNotificationCenter defaultCenter]removeObserver:self];
    [self releaseResources];
}
@end