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• Capture JPEG frame from avi file using ffmpeg library. How to open captured files ?

  30 novembre 2013, par ios198

  This is the code I found from the ffmpeg tutorial website :

  #include <libavcodec></libavcodec>avcodec.h>
  
  #include <libavformat></libavformat>avformat.h>
  
  #include <libswscale></libswscale>swscale.h>
  
  #include 
  
  void SaveFrame(AVFrame *pFrame, int width, int height, int iFrame) {
  
    FILE *pFile;
  
    char szFilename[32];
  
    int  y;
  
  
  
    // Open file
  
    sprintf(szFilename, "frame%d.ppm", iFrame); // szFilenam = frame4.ppm
  
    pFile=fopen(szFilename, "wb");
  
    if (pFile == NULL) {
  
     return;
  
      } 
  
     //Write header
  
    fprintf(pFile, "P6\n%d %d\n255\n", width, height);
  
  
  
    // Write pixel data
  
    for(y=0; ydata[0]+y*pFrame->linesize[0], 1, width*3, pFile);
  
  
  
    // Close file
  
    fclose(pFile);
  
  }
  
  
  
  int main(int argc, char **argv[])
  
  {
  
      AVFormatContext *pFormatCtx = NULL;
  
      int             i, videoStream;
  
      AVCodecContext  *pCodecCtx = NULL;
  
      AVCodec         *pCodec = NULL;
  
      AVFrame         *pFrame = NULL; 
  
      AVFrame         *pFrameRGB = NULL;
  
      AVPacket        packet;
  
      int             frameFinished;
  
      int             numBytes;
  
      uint8_t         *buffer = NULL;
  
  
  
      AVDictionary    *optionsDict = NULL;
  
      struct SwsContext      *sws_ctx = NULL;
  
  
  
  
  
      // Register all formats and codecs
  
      av_register_all();
  
  
  
      // Open video file
  
      if(avformat_open_input(&amp;pFormatCtx, "/root/dhquan/AVI/turning_pages.avi", NULL, NULL)!=0)
  
          return -1; // couldn&#39;t open file
  
  
  
      // Retrieve stream information
  
      if(avformat_find_stream_info(pFormatCtx,NULL)&lt;0)
  
          return -1; // couldn&#39;t find stream information
  
                     // This function populates pFormatCtx->streams with the proper 
  
  
  
      // dump information about file onto standard error
  
      av_dump_format(pFormatCtx, 0, "/root/dhquan/AVI/turning_pages.avi", 0);
  
  
  
      // Find the first video stream
  
      videoStream = -1;
  
      for(i=0;inb_streams;i++)
  
          if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO){
  
              videoStream=i;
  
              break;
  
          }
  
          if(videoStream==-1)
  
              return -1; // didn&#39;t find a video stream
  
  
  
      // Get a pointer to the codec context for the video stream
  
          pCodecCtx= pFormatCtx->streams[videoStream]->codec;
  
  
  
      // Find the decoder for the video stream
  
          pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
  
          if(pCodec==NULL){
  
              fprintf(stderr,"Unsupported codec!\n");
  
              return -1;
  
          }
  
  
  
      // Open Codec
  
          if(avcodec_open2(pCodecCtx, pCodec, &amp;optionsDict)&lt;0)
  
              return -1; // Could not open codec
  
  
  
      // Allocate video frame
  
          pFrame = avcodec_alloc_frame();
  
  
  
      // Allocate an AVFrame structure
  
           pFrameRGB=avcodec_alloc_frame();
  
          if(pFrameRGB==NULL)
  
              return -1;
  
      // Determine required buffer size and allocate buffer
  
           numBytes=avpicture_get_size(PIX_FMT_RGB24, pCodecCtx->width,
  
                    pCodecCtx->height);
  
           buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
  
  
  
           sws_ctx =
  
           sws_getContext
  
      (
  
          pCodecCtx->width,
  
          pCodecCtx->height,
  
          pCodecCtx->pix_fmt,
  
          pCodecCtx->width,
  
          pCodecCtx->height,
  
          PIX_FMT_RGB24,
  
          SWS_BILINEAR,
  
          NULL,
  
          NULL,
  
          NULL
  
      );
  
  
  
    // Assign appropriate parts of buffer to image planes in pFrameRGB
  
    // Note that pFrameRGB is an AVFrame, but AVFrame is a superset
  
    // of AVPicture
  
    avpicture_fill((AVPicture *)pFrameRGB, buffer, PIX_FMT_RGB24,
  
           pCodecCtx->width, pCodecCtx->height);
  
  
  
    // Read frames and save first five frames to disk
  
    i=0;
  
    while(av_read_frame(pFormatCtx, &amp;packet)>=0) {
  
      // Is this a packet from the video stream?
  
      if(packet.stream_index==videoStream) {
  
        // Decode video frame
  
        avcodec_decode_video2(pCodecCtx, pFrame, &amp;frameFinished, 
  
                 &amp;packet);
  
  
  
        // Did we get a video frame?
  
        if(frameFinished) {
  
      // Convert the image from its native format to RGB
  
          sws_scale
  
          (
  
              sws_ctx,
  
              (uint8_t const * const *)pFrame->data,
  
              pFrame->linesize,
  
              0,
  
              pCodecCtx->height,
  
              pFrameRGB->data,
  
              pFrameRGB->linesize
  
          );
  
  
  
      // Save the frame to disk
  
      if(++i&lt;=5)
  
        SaveFrame(pFrameRGB, pCodecCtx->width, pCodecCtx->height, 
  
              i);
  
        }
  
      }
  
  
  
      // Free the packet that was allocated by av_read_frame
  
      av_free_packet(&amp;packet);
  
    }
  
  
  
    // Free the RGB image
  
    av_free(buffer);
  
    av_free(pFrameRGB);
  
  
  
    // Free the YUV frame
  
    av_free(pFrame);
  
  
  
    // Close the codec
  
    avcodec_close(pCodecCtx);
  
  
  
    // Close the video file
  
    avformat_close_input(&amp;pFormatCtx);
  
  
  
    return 0;
  
    //getch();
  
  }

  In line :
  sprintf(szFilename, "frame%d.ppm", iFrame) ;

  I changed into frame%d.jpg. It creates .jpg file in my folder. But I can't read it. How to open this file ? Please help me.

• python Instagram API doesnt work

  9 avril 2017, par sdgm

  I was looking for a c++-Instagram API but there was not any complete project. Now,I am using python-Instagram API. whenever I execute my code, too many errors occur. this is my code :

  from InstagramAPI import InstagramAPI
  
  
  
  InstagramAPI = InstagramAPI("no_ideaw", "xs*************#")
  
  InstagramAPI.login()
  
  InstagramAPI.removeProfilePicture()

  Then, these are the errors :

      Traceback (most recent call last):
  
    File "tester.py", line 1, in <module>
  
      from InstagramAPI import InstagramAPI
  
    File "/home/muhammad/Downloads/Instagram-API-python-master/InstagramAPI.py", line 25, in <module>
  
      from moviepy.editor import VideoFileClip
  
    File "/home/muhammad/.local/lib/python2.7/site-packages/moviepy/editor.py", line 22, in <module>
  
      from .video.io.VideoFileClip import VideoFileClip
  
    File "/home/muhammad/.local/lib/python2.7/site-packages/moviepy/video/io/VideoFileClip.py", line 3, in <module>
  
      from moviepy.video.VideoClip import VideoClip
  
    File "/home/muhammad/.local/lib/python2.7/site-packages/moviepy/video/VideoClip.py", line 20, in <module>
  
      from .io.ffmpeg_writer import ffmpeg_write_image, ffmpeg_write_video
  
    File "/home/muhammad/.local/lib/python2.7/site-packages/moviepy/video/io/ffmpeg_writer.py", line 15, in <module>
  
      from moviepy.config import get_setting
  
    File "/home/muhammad/.local/lib/python2.7/site-packages/moviepy/config.py", line 38, in <module>
  
      FFMPEG_BINARY = get_exe()
  
    File "/home/muhammad/.local/lib/python2.7/site-packages/imageio/plugins/ffmpeg.py", line 86, in get_exe
  
      raise NeedDownloadError('Need ffmpeg exe. '
  
  imageio.core.fetching.NeedDownloadError: Need ffmpeg exe. You can download it by calling:
  
    imageio.plugins.ffmpeg.download()
  
  </module></module></module></module></module></module></module>

  I tried to install

  imageio.plugins.ffmpeg.download()

  but nothing happened. what is wrong with my python code ?

• fatal error : libavcodec/avcodec.h no such file or directory compilation terminated

  23 avril 2019, par user1625271

  I’m trying to execute tutorial01.c using gcc and I have the gcc and tutorial01.c in the same folder along with libavcodec and libavformat and its associated files it gives me this error

  fatal error : libavcodec/avcodec.h no such file or directory compilation terminated

  when I run gcc -o tutorial01 tutorial01.c -lavformat -lavcodec -lz through the terminal in ubuntu 12.04

  the code is

  #include  libavcodec/avcodec.h
  
  #include libavformat/avformat.h
  
  #include stdio.h
  
  
  
  void SaveFrame(AVFrame *pFrame, int width, int height, int iFrame)
  
   {
  
    FILE *pFile;
  
    char szFilename[32];
  
    int  y;
  
  
  
    // Open file
  
    sprintf(szFilename, "frame%d.ppm", iFrame);
  
    pFile=fopen(szFilename, "wb");
  
    if(pFile==NULL)
  
      return;
  
  
  
    // Write header
  
    fprintf(pFile, "P6\n%d %d\n255\n", width, height);
  
    // Write pixel data
  
    for(y=0; ydata[0]+y*pFrame->linesize[0], 1, width*3, pFile);
  
  
  
    // Close file
  
    fclose(pFile);
  
  }
  
  
  
  int main(int argc, char *argv[])
  
   {
  
    AVFormatContext *pFormatCtx;
  
    int             i, videoStream;
  
    AVCodecContext  *pCodecCtx;
  
    AVCodec         *pCodec;
  
    AVFrame         *pFrame; 
  
    AVFrame         *pFrameRGB;
  
    AVPacket        packet;
  
    int             frameFinished;
  
    int             numBytes;
  
    uint8_t         *buffer;
  
  
  
    if(argc < 2) 
  
    {
  
      printf("Please provide a movie file\n");
  
      return -1;
  
    }
  
  
  
    // Register all formats and codecs
  
    av_register_all();
  
    // Open video file
  
    if(av_open_input_file(&pFormatCtx, argv[1], NULL, 0, NULL)!=0)
  
      return -1; // Couldn't open file
  
  
  
    // Retrieve stream information
  
    if(av_find_stream_info(pFormatCtx)<0)
  
      return -1; // Couldn't find stream information
  
  
  
    // Dump information about file onto standard error
  
    dump_format(pFormatCtx, 0, argv[1], 0);
  
    // Find the first video stream
  
    videoStream=-1;
  
    for(i=0; inb_streams; i++)
  
      if(pFormatCtx->streams[i]->codec->codec_type==CODEC_TYPE_VIDEO)
  
      {
  
        videoStream=i;
  
        break;
  
      }
  
    if(videoStream==-1)
  
      return -1; // Didn't find a video stream
  
  
  
    // Get a pointer to the codec context for the video stream
  
    pCodecCtx=pFormatCtx->streams[videoStream]->codec;
  
    // Find the decoder for the video stream
  
    pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
  
    if(pCodec==NULL) 
  
    {
  
      fprintf(stderr, "Unsupported codec!\n");
  
      return -1; // Codec not found
  
    }
  
  
  
    // Open codec
  
    if(avcodec_open(pCodecCtx, pCodec)<0)
  
      return -1; // Could not open codec
  
  
  
    // Allocate video frame
  
    pFrame=avcodec_alloc_frame();
  
  
  
    // Allocate an AVFrame structure
  
    pFrameRGB=avcodec_alloc_frame();
  
  
  
    if(pFrameRGB==NULL)
  
      return -1;
  
  
  
    // Determine required buffer size and allocate buffer              
  
   numBytes=avpicture_get_size(PIX_FMT_RGB24, pCodecCtx->width,
  
                    pCodecCtx->height);
  
  
  
    buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
  
  
  
    // Assign appropriate parts of buffer to image planes in pFrameRGB
  
    // Note that pFrameRGB is an AVFrame, but AVFrame is a superset
  
    // of AVPicture
  
    avpicture_fill((AVPicture *)pFrameRGB, buffer, PIX_FMT_RGB24,
  
           pCodecCtx->width, pCodecCtx->height);
  
  
  
    // Read frames and save first five frames to disk
  
    i=0;
  
    while(av_read_frame(pFormatCtx, &packet)>=0)
  
   {
  
      // Is this a packet from the video stream?
  
      if(packet.stream_index==videoStream) 
  
      {
  
        // Decode video frame
  
        avcodec_decode_video(pCodecCtx, pFrame, &frameFinished, 
  
                 packet.data, packet.size);
  
  
  
        // Did we get a video frame?
  
        if(frameFinished) 
  
        {
  
          // Convert the image from its native format to RGB
  
  
  
  
  
  
  
  
  
      img_convert((AVPicture *)pFrameRGB, PIX_FMT_RGB24, 
  
                      (AVPicture*)pFrame, pCodecCtx->pix_fmt, pCodecCtx->width, 
  
                      pCodecCtx->height);
  
  
  
  
  
  
  
  
  
      // Save the frame to disk
  
  
  
      if(++i<=5)
  
    SaveFrame(pFrameRGB, pCodecCtx->width, pCodecCtx->height, 
  
              i);
  
        }
  
     }
  
  
  
      // Free the packet that was allocated by av_read_frame
  
      av_free_packet(&packet);
  
    }
  
  
  
    // Free the RGB image
  
    av_free(buffer);
  
    av_free(pFrameRGB);
  
  
  
    // Free the YUV frame
  
    av_free(pFrame);
  
  
  
   // Close the codec
  
    avcodec_close(pCodecCtx);
  
  
  
  
  
    // Close the video file
  
    av_close_input_file(pFormatCtx);
  
  
  
  
  
    return 0;
  
  
  
  }