通过帧视频德codeR库结构简单 [英] Simple frame by frame video decoder library

问题描述

我在寻找一个简单的C / C ++的lib，允许提取视频的第一帧作为UCHAR数组。并有一个简单的fonction进入下一个。

I'm looking for a simple c/c++ lib that would allow to extract the first frame of a video as a uchar array. And have a simple fonction to access the next one.

我知道的ffmpeg但它requiere用包之类的东西玩，我很惊讶，没有一个地方在网络上我能找到一个lib，允许这样的：

I know of FFMPEG but it requiere to play with packet and things like that, and i'm surprised that nowhere on the net i can find a lib that allow something like :

视频V = openVideo（路径）;
UCHAR *数据= v.getFrame（）;
v.nextFrame（）;

Video v = openVideo("path"); uchar* data = v.getFrame(); v.nextFrame();

我只需要提取视频帧使用它作为纹理...无需后或任何重新编码...

I just need to extract frames of a video to use it as a texture...no need for reencoding after or anything...

当然东西会比读尽可能最格式将是巨大的，在东西libav codeC内置例如，P

of course something that would read the most format than possible would be great, something built upon libavcodec for example ;p

和我使用Windows 7

And i'm using Windows 7

谢谢！

推荐答案

下面是用OpenCV的一个例子：

Here's an example with OpenCV:

#include <cv.h>
#include <highgui.h>

int
main(int argc, char **argv)
{       
    cv::VideoCapture capture(argv[1]);
    if (capture.grab())
    {   
        cv::Mat_<char> frame;
        capture.retrieve(frame);
        //
        // Convert to your byte array here
        //
    }    
    return 0;
}

这是未经测试，但我拆解它从一些现有的工作code，所以它不应该带你长得到它的工作。

It's untested, but I cannibalized it from some existing working code, so it shouldn't take you long to get it working.

的 CV :: Mat_＆LT; unsigned char型＆GT; 本质上是一个字节数组。如果您真的需要的东西，这是明确键入无符号字符* ，那么你可以MALLOC适当大小的空间，并采用了矩阵迭代

The cv::Mat_<unsigned char> is essentially a byte array. If you really need something that's explicitly of type unsigned char *, then you can malloc space of the appropriate size and iterate over the matrix using

您可以转换 CV ::垫来使用像素位置（一个字节数组 CV ::垫_ ::在（））或迭代器（ CV ::垫_ ::开始（）和朋友）。

You can convert a cv::Mat to a byte array using pixel positions(cv::Mat_::at()) or iterators (cv::Mat_::begin() and friends).

有很多原因，很少库暴露图像数据作为一个简单的指针，如：

There are many reasons why libraries rarely expose image data as a simple pointer, such as:

• 这意味着整个图像必须占用一个连续内存空间。这是一个大问题，大的图片的时候


• 它要求提交的数据的某一排序（像素与非平面？ - 是将RGB平面存储穿插或分开），并降低了灵活性


• 取消引用指针是错误（缓冲区溢出等）的原因。

• It implies the entire image must occupy a contiguous space in memory. This is a big deal when dealing with large images
• It requires committing a certain ordering of the data (pixel vs non-planar -- are the RGB planes stored interspersed or separately?) and reduces flexibility
• Dereferencing pointers is a cause for bugs (buffer overruns, etc).

所以，如果你希望你的指针，你必须做一些工作吧。

So if you want your pointer, you have to do a bit of work for it.

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