使用libVLC打开mp4并在OpenCV中播放C++

Question

我想播放使用libVLC和OpenCV从IP摄像头（H264-codec）获得的视频文件，因此我从this post获取了代码，然后在VS中创建项目2010，并将我的mp4文件放入项目文件夹（“5.mp4”）。当我开始它 - 我得到这个错误：

main error: open of `5.mp4' failed

main error: Your input can't be opened

main error: VLC is unable to open the MRL '5.mp4'. Check the log for details.

这里是我的代码：

#include <vlc/vlc.h> 
#include <opencv2/opencv.hpp> 
#include <opencv2/highgui/highgui.hpp> 
#include <stdio.h> 

using namespace cv; 
using namespace std; 

struct VideoDataStruct { 
    int param; 
}; 

int done = 0; 
libvlc_media_player_t *mp; 
unsigned int videoBufferSize = 0; 
uint8_t *videoBuffer = 0; 

void cbVideoPrerender(void *p_video_data, uint8_t **pp_pixel_buffer, int size) { 
// Locking 
    if (size > videoBufferSize || !videoBuffer) 
    { 
    printf("Reallocate raw video buffer\n"); 
    free(videoBuffer); 
    videoBuffer = (uint8_t *) malloc(size); 
    videoBufferSize = size; 
    } 

    *pp_pixel_buffer = videoBuffer; 
} 

void cbVideoPostrender(void *p_video_data, uint8_t *p_pixel_buffer, int width, int height, int pixel_pitch, int size, int64_t pts) { 
    // Unlocking 
    //CloseHandle(hMutex); 
} 

static void handleEvent(const libvlc_event_t* pEvt, void* pUserData) { 
    libvlc_time_t time; 
    switch(pEvt->type) 
    { 
     case libvlc_MediaPlayerTimeChanged: 
      time = libvlc_media_player_get_time(mp); 
      printf("MediaPlayerTimeChanged %lld ms\n", (long long)time); 
      break; 
     case libvlc_MediaPlayerEndReached: 
      printf ("MediaPlayerEndReached\n"); 
      done = 1; 
     break; 
     default: 
      printf("%s\n", libvlc_event_type_name(pEvt->type)); 
    } 
} 

int main(int argc, char* argv[]) { 

// VLC pointers 
libvlc_instance_t *inst; 
libvlc_media_t *m; 
void *pUserData = 0; 
VideoDataStruct dataStruct; 

// VLC options 
char smem_options[1000]; 
// RV24 
sprintf(smem_options 
    , "#transcode{vcodec=RV24}:smem{" 
    "video-prerender-callback=%lld," 
    "video-postrender-callback=%lld," 
    "video-data=%lld," 
    "no-time-sync}," 
    , (long long int)(intptr_t)(void*)&cbVideoPrerender 
    , (long long int)(intptr_t)(void*)&cbVideoPostrender 
    , (long long int)(intptr_t)(void*)&dataStruct 
); 

const char * const vlc_args[] = { 
      "-I", "dummy",   // Don't use any interface 
      "--ignore-config",  // Don't use VLC's config 
      "--extraintf=logger",  // Log anything 
      "--verbose=1",   // Be verbose 
      "--sout", smem_options // Stream to memory 
      }; 

// We launch VLC 
inst = libvlc_new(sizeof(vlc_args)/sizeof(vlc_args[0]), vlc_args); 

/* Create a new item */ 
m = libvlc_media_new_location(inst, "5.mp4"); 

/* Create a media player playing environement */ 
mp = libvlc_media_player_new_from_media (m); 

libvlc_event_manager_t* eventManager = libvlc_media_player_event_manager(mp); 
libvlc_event_attach(eventManager, libvlc_MediaPlayerTimeChanged, handleEvent, pUserData); 
libvlc_event_attach(eventManager, libvlc_MediaPlayerEndReached, handleEvent, pUserData); 
libvlc_event_attach(eventManager, libvlc_MediaPlayerPositionChanged, handleEvent, pUserData); 

libvlc_video_set_format(mp, "RV24", 1280, 720, 1280* 3); 

/* play the media_player */ 
libvlc_media_player_play (mp); 

while(1) 
{ 
    if(videoBuffer)   // Check for invalid input 
    { 
     // CV_8UC3 = 8 bits, 3 chanels 
     Mat img = Mat(Size(1280, 720), CV_8UC3, videoBuffer); 
     // cvtColor(img, img, CV_RGB2BGR); 
     namedWindow("Display window", WINDOW_AUTOSIZE); // Create a window for display. 
     imshow("Display window", img);  // Show our image inside it. 
    } 
} 
libvlc_release (inst); 
} 

我猜，这很容易解决，但我便无法找到在互联网的任何信息。我也尝试把它放到“C：\ 5.mp4”中，但我得到了同样的错误。谢谢你的帮助。

编辑： 好了，我修复了这个问题，我需要把文件：///“5.mp4”之前，现在我的视频播放，但它看起来像这样：

EDIT02 好了，用“* .AVI”一切看起来都不错，所以我想这个文件的问题 - 我记录了它FROP IP摄像头，使用VLC，并保存成* .MP4

Answer 1

好，所以我发现了这个问题，我在视频分辨率上犯了一个错误，原始分辨率是2560x1536，所以当我把libvlc_video_set_format(mp,2560,1536,2560 *3);我的照片看起来很好，所以在我把它传递给OpenCV后，我可以调整它。