Question

我希望在缩小尺寸处理后存储视频。目前我使用与输入视频相同的大小。我正在使用c ++打开CV。

Answer 1

如果您的目标是更改视频分辨率，请将resize()功能用于存储图像的矩阵：

Mat source, destination;
IplImage new_img;
int fps = 30;

// Apply resize
resize(source, destination, Size(640, 360), 1, 1, 1);

// Create writer
CvVideoWriter *new_writer = cvCreateVideoWriter("video.mp4",CV_FOURCC('M', 'P', '4', '2'), fps, destination.size(), 3);

new_img = destination.operator IplImage();  
// 1-if image written or 0 if failed
int ret = cvWriteFrame(new_writer, (const IplImage*)&new_img);
printf("Written?: %d\n", ret);

// And finally release writer
cvReleaseVideoWriter(&new_writer);

如果您的目标是减少磁盘上的视频大小，请尝试使用各种编解码器创建VideoWriter，例如：

CV_FOURCC('P','I','M','1')    = MPEG-1 codec

CV_FOURCC('M','J','P','G')    = motion-jpeg codec (does not work well)

CV_FOURCC('M', 'P', '4', '2') = MPEG-4.2 codec

CV_FOURCC('D', 'I', 'V', '3') = MPEG-4.3 codec

CV_FOURCC('D', 'I', 'V', 'X') = MPEG-4 codec

CV_FOURCC('U', '2', '6', '3') = H263 codec

CV_FOURCC('I', '2', '6', '3') = H263I codec

CV_FOURCC('F', 'L', 'V', '1') = FLV1 codec

使用视频编写器更改存储视频的大小？

1 个答案: