opencv mat与avframe互转

原文：http://answers.opencv.org/question/36948/cvmat-to-avframe/

cv::Mat avframe_to_cvmat(AVFrame *frame)
{
        AVFrame dst;
        cv::Mat m;

        memset(&dst, 0, sizeof(dst));

        int w = frame->width, h = frame->height;
        m = cv::Mat(h, w, CV_8UC3);
        dst.data[0] = (uint8_t *)m.data;
        avpicture_fill( (AVPicture *)&dst, dst.data[0], PIX_FMT_BGR24, w, h);

        struct SwsContext *convert_ctx=NULL;
        enum PixelFormat src_pixfmt = (enum PixelFormat)frame->format;
        enum PixelFormat dst_pixfmt = PIX_FMT_BGR24;
        convert_ctx = sws_getContext(w, h, src_pixfmt, w, h, dst_pixfmt,
                        SWS_FAST_BILINEAR, NULL, NULL, NULL);
        sws_scale(convert_ctx, frame->data, frame->linesize, 0, h,
                        dst.data, dst.linesize);
        sws_freeContext(convert_ctx);

        return m;
}
AVFrame cvmat_to_avframe(cv::Mat* frame)
{
        AVFrame dst;
        cv::Size frameSize = frame->size();
        AVCodec *encoder = avcodec_find_encoder(AV_CODEC_ID_H264);
        AVFormatContext* outContainer = avformat_alloc_context();
        AVStream *outStream = avformat_new_stream(outContainer, encoder);
        avcodec_get_context_defaults3(outStream->codec, encoder);

        outStream->codec->pix_fmt = AV_PIX_FMT_YUV420P;
        outStream->codec->width = frame->cols;
        outStream->codec->height = frame->rows;
        avpicture_fill((AVPicture*)&dst, frame->data, PIX_FMT_BGR24, outStream->codec->width, outStream->codec->height);
        dst.width = frameSize.width;
        dst.height = frameSize.height;
        SaveFrame(&dst,dst.width,dst.height,0);
        return dst;
}