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Sur d’autres sites (6065)

  • How we can open /dev/video0 or any v4l2 node with ffmpeg for capture raw frames and encode it in jpeg format ?

    19 mars 2016, par satinder

    I am new in video domain . I am working now on ffmpeg , I use ffmpeg command line but there is very big issue and challenge for use ffmpeg in my own c code .So I read some tutorials like dranger.com etc . But I am not able to capture v4l2 or my laptop /dev/video0 node . I want capture raw video stream and overlay it with some text and then compress it in jpeg format . I have a little idea and that is in following code that code is working for ant .mp4 format or encoded file but not work on /dev/video0 node format . so please any one help me . Thanks in advance !!

    please see following code snapshot that is a tutorial1.c from dranger.com :

    #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);
    
  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;
    

    
  if(argc &lt; 2) {
    
    printf("Please provide a movie file\n");
    
    return -1;
    
  }
    
  // Register all formats and codecs
    
  av_register_all();
    

    
  // Open video file
    
  if(avformat_open_input(&amp;pFormatCtx, argv[1], NULL, NULL)!=0)
    
    return -1; // Couldn't open file
    

    
  // Retrieve stream information
    
  if(avformat_find_stream_info(pFormatCtx, NULL)&lt;0)
    
    return -1; // Couldn't find stream information
    

    
  // Dump information about file onto standard error
    
  av_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==AVMEDIA_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_open2(pCodecCtx, pCodec, &amp;optionsDict)&lt;0)
    
    return -1; // Could not open codec
    

    
  // Allocate video frame
    
  pFrame=av_frame_alloc();
    

    
  // Allocate an AVFrame structure
    
  pFrameRGB=av_frame_alloc();
    
  if(pFrameRGB==NULL)
    
    return -1;
    

    
  // Determine required buffer size and allocate buffer
    
  numBytes=avpicture_get_size(AV_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,
    
        AV_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, AV_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;
    
}

  • Python and FFMPEG video streaming not displaying via HTML5

    18 mars 2016, par arussell

    I’m trying to write a python script to serve a video over HTTP and display it via HTML5 video tag, I’m using FFMPEG to serve the video over HTTP and receiving the the video via sockets in Python. FFMPEG seems to be sending the video and my Python script is receiving it but for some reason I’m not able to display it in my web browser nor getting any visible error in my script.

    Any help will be highly appreciated.

    This is the FFMPEG line I’m using to send the video to HTTP

    FFMPEG -re -i video_file.webm -c:v libx264 -c:a copy -f h264 http://127.0.0.1:8081

    Here is my Python code

    import socket   #for sockets handling
    
import time     #for time functions
    
import sys
    

    
hostIP = '127.0.0.1'
    
SourcePort = 8081 #FFMPEG
    
PlayerPort = 8082 #Internet Browser
    

    
def gen_headers():
    
     # determine response code
    
     h = ''
    
     h = 'HTTP/1.1 200 OK\n'
    
     # write further headers
    
     current_date = time.strftime("%a, %d %b %Y %H:%M:%S", time.localtime())
    
     h += 'Date: ' + current_date +'\n'
    
     h += 'Content-Type: video/mp4\n\n'
    
     return h
    

    
def start_server():
    
    socketFFMPEG = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    
    # this is for easy starting/killing the app
    
    socketFFMPEG.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    
    print('Socket created')
    

    
    try:
    
        socketFFMPEG.bind((hostIP, SourcePort))
    
        print('Socket bind complete')
    
    except socket.error as msg:
    
        print('Bind failed. Error : ' + str(sys.exc_info()))
    
        sys.exit()
    

    
    #Start listening on socketFFMPEG
    
    socketFFMPEG.listen(10)
    
    print('Socket now listening. Waiting for video source from FFMPEG on port', SourcePort)
    

    
    conn, addr = socketFFMPEG.accept()
    
    ip, port = str(addr[0]), str(addr[1])
    
    print('Accepting connection from ' + ip + ':' + port)
    

    
    socketPlayer = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    
    socketPlayer.bind((hostIP, PlayerPort))
    
    socketPlayer.listen(1) #listen just 1 petition
    
    print('Waiting for Internet Browser')
    
    conn2, addr2 = socketPlayer.accept()
    
    conn2.sendall(gen_headers().encode())
    

    
    while True:
    
        try :
    
            #receive data from client FFMPEG
    
            input_from_FFMPEG = conn.recv(1024) 
    
            #send data to internet browser
    
            conn2.sendall(input_from_FFMPEG)
    
        except socket.error:
    
            print('Error data :' + str(input_from_FFMPEG))
    
            print('send Error : ' + str(sys.exc_info()))
    
            conn2.close()
    
            sys.exit()
    

    
    socketFFMPEG.close()
    

    
start_server()  

    I’m getting the error 10053 "An established connection was aborted by the software in your host machine" when loading the following "byte" type data

    \x00\x00\x00\x01A\x9b\x1dI\xe1\x0f&amp;S\x02\xbf\xb1\x82j3{qz\x85\xca\\\xb2\xb7\xc5\xdfi\x92y\x0c{\xb0\xde\xd1\x96j\xccE\xa3G\x87\x84Z\x0191\xba\x8a3\x8e\xe2lfX\x82\xd4*N\x8a\x9f\xa9\xc9\xfb\x13\xfc_]D\x0f\x9e\x1c"\x0fN\xceu\t\x17n\xbe\x95\xd1\x10Wj\xf5t\x90\xa8\x1am\xf7!d\x82py\n\x10\xf5\x9b{\xd9\xf8\x8e^\xc7\xb3o+\x0eQX\xb3\x17B?\xb8\x1c\xecP\xa0\xf10\xc7\xc8\x8d\xf1P\xd3\xdf\xd0\xd5\x13ah+bM\x9c\xbe\xca\xb4\x9a?\xac\xb9\x0fao\xf3\xed\x9c\xe4^\x10\x079t\xf4\x0f\xce\xbe*\xd4w\x1f\x1a\x02\xbd\xed\xe9\x16\x8a\x98\xe0\x1d\xc4\xde5\xa8\xf0\x88\xb4\x07=\xe2w\xc3Q\xc1\x99K7\xff\x01`(\xb3sN\x88\x18\xfd7\xd4\x07\xab\x95\xf95\x05\xcd\xd6,!=\xfb\xc4\xc8\xbf\xad\x96\x83\xc0\x9b%\xdds\x92s\xc0lN\xdd\x14\xba\xbd\x04L\xb1\x08\xec[~tB~`\r\xbe\xa9\xbe\xa4r`\xa3\x98\x19z\xa9\xe9\xd3jK>(\xd5\x8c\x9eY~\xa8\x9f\x86\x90\x148R\xfd&lt;\xb2\xdaUy\xa8\xb5\xba\x1d\xd1\xf6\xa6N\xb0#\x08Xo\xa6\x1c \xbaB\x8cbp\x1c\r\xa1\xa4"\x06\xd8\xe5\x85[\x89\x8a\xcba\xa3\xcc\xe0C\x946\xad6\x08\x90\r&amp;\xcb\x13\xa6\xfbG\xc5\x85I&lt;\x96\xcb\x89}\xcb\xda\xa5\x02\xbcB\xb9\x93\x938\x89\x1c\x92\xb3\x83\xfe\xa7\xf6\xa8\x1f\xdf\xa8\xef\xd55\xb6\xbf>#\xba\xd7\x8e\xd2z\xc2\xca\xf9\xdd2\xdd\x96\xb6\xf8\xc3\xc1\x0f/D\x05\xd3?\x18\xb1\x85T\x08\xcd\xfc\xc7p\xba\x0c\x93\xcdY\xf3 !4\x13\xaen\x82\x10[\x07I>\xe4\xc3\xb7\xca\xee\x93\r\xc3\xe1>\xe9\xd6\x9a\xbeLQ\x93\x86n\xadb\x13\xcas\xc0\xdeh\x1a\x9f\x00Dp\x94fv\xb7\xd9\xba\x93\x0c\xd1H2\x0e\xa2]`\xf2Q{+o\x80\xf0\x8a\x11"\x94u\x9b1\xc3\xdaV\xd9\x9e\xc6\xf7?\x18\xd9\xfbs\xf3\x07\xc6\x91\x83\x19\'\x13\xe4o\xa9S\x1cP\xa4w\xbc\xe36\xb9k\xc3\xaa":~`\xe7\x18\xe8\x9bu\n\x16\xf3\x89\xe2k\x07\x08\xf6\x8c\x98\x98\xbd\x8f*\x11\xe7\xa1\nj1\'\xe2=\x7f\xdf\x16\xc8\xf6\xec\xe1\xe6G\xd1\x1b\xeb\xc0\xd4\xf7\xc3c\xc7v\xc3\xf8\xa5\xac\x89\xdd4\x90i\t\x98\xfe\xfcx\xad{[\xf4\x92\x16^O\xf2\xc2]\xec\xa7\xe9Gu\\dF\xa6\xa7\xd3k?\xba\xedY\xba\x85\'\x1a\xa6.(\xcfB\x82tN\xdc\xad\xe6\xfcM\x01:\x0b\x14\x070\xf4\x99l2C\x92\x9c\x13h\x82\xf6w\xc4$5\xe1~\x11T~\xc9\x8f\xaeUAI%\xa6\x12(\x9c\x17\x9d*\xcc9\xee\xb7\xb8w \x92\x9a\x1cD\xfd\xd8wi7rt\xd8\x93\xbd7\x83\xf1\xe3\xbd\x92\x81\xe0\xfel\xfa\\\x9c\xebM\xf3m`p\xb9\xe2\x13Kd\xe08\xcc\x15\x96[G\xda`\x8cD\xa7\xf1\xd3\xc8T\xcf\xb1)\xa5E$\x91\x94{\x88&amp;\xac\xc1\x92\xd5E\xa98\xd2\x89\xd1?\xd7\x9c\xdc\xbb!\x18\xc1\xa1m\xba*L\xab\xa0\xff\xd8\xee\xbbH\xe3\xa2\xe4\x9d=9\x05\xb4\x9bm\xe7\xc6J\xd9\xc3\xb1\xe9b*jB`4t\x9fv\xe8\xc4F\x9c`\xd0\x03\xd8\x12}\x8b\xb3$A\x9c\xdc;\x81@)rH\xf1\x18\xe1\xba\x0c4\x06\xe9xa\x94\xdd\xde\xa8&amp;\xef)\xd7F\x94F\xa7j\xd3\x13O\xe03\xc9\xc9\xf2\x15\x1a\x9bsy\x16\x83H\xb4\x9e\xee\xc9M\xe7\xf4x \xa5\x9c^\xb9m\xeee\x03=_\x11\xda^l\xfe\xba\xa4\x98mjW\xf0\xa9\xc4\x11g\xd9C\xf7K.\x8c\xab3~n%\x7f\xc0p\xc8\xb1\xd6\x8d\xe5E\xb1\xc1\xe3(~\x9e\x9c\x91.\xdc\x08\xfb\xa0\xbe\x98y$U\xdeH\x08\xb2z,yX\xfaqx\xfe\xb0\xa9\xb4Q\xf2P\x95d\xc8\x88\r\xc3\x1dr\x88\xba\xc8\x990`(\x08m\x19\xebi\xf8\x11\xc6g\xd6\xc4\x12C\xad~\xe1$2\x01Hmg\xdb\x920\x18\xcc\xc0K\x04~\x1e\xeb\xd9>\x81F*I\x99\xe4\x00\xa3\xc4,U\x89\xdf\x843\xa3\xfb\xea\xc9d\x05\xeb]

  • How to extract grayscale image from a video with ffmpeg-library ?

    9 mars 2016, par user1587451

    I’v compiled and tested this tutorial from here which works just fine. After I tried to edit the tutorial to read/convert frames into grayscale. I just changed pFrameRGB to pFrameGray, PIX_FMT_RGB24 to PIX_FMT_GRAY16 and to save just the 200th frame. It compiles and run but the image don’t show the expected. What’s wrong ?

    The image :
    image

    The edited code :

    #include <libavcodec></libavcodec>avcodec.h>
    
#include <libavformat></libavformat>avformat.h>
    
#include <libswscale></libswscale>swscale.h>
    

    
#include 
    

    
// compatibility with newer API
    
#if LIBAVCODEC_VERSION_INT &lt; AV_VERSION_INT(55,28,1)
    
#define av_frame_alloc avcodec_alloc_frame
    
#define av_frame_free avcodec_free_frame
    
#endif
    

    
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[]) {
    
  // Initalizing these to NULL prevents segfaults!
    
  AVFormatContext   *pFormatCtx = NULL;
    
  int               i, videoStream;
    
  AVCodecContext    *pCodecCtxOrig = NULL;
    
  AVCodecContext    *pCodecCtx = NULL;
    
  AVCodec           *pCodec = NULL;
    
  AVFrame           *pFrame = NULL;
    
  AVFrame           *pFrameGRAY = NULL;
    
  AVPacket          packet;
    
  int               frameFinished;
    
  int               numBytes;
    
  uint8_t           *buffer = NULL;
    
  struct SwsContext *sws_ctx = NULL;
    

    
  if(argc &lt; 2) {
    
    printf("Please provide a movie file\n");
    
    return -1;
    
  }
    
  // Register all formats and codecs
    
  av_register_all();
    

    
  // Open video file
    
  if(avformat_open_input(&amp;pFormatCtx, argv[1], NULL, NULL)!=0)
    
    return -1; // Couldn't open file
    

    
  // Retrieve stream information
    
  if(avformat_find_stream_info(pFormatCtx, NULL)&lt;0)
    
    return -1; // Couldn't find stream information
    

    
  // Dump information about file onto standard error
    
  av_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==AVMEDIA_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
    
  pCodecCtxOrig=pFormatCtx->streams[videoStream]->codec;
    
  // Find the decoder for the video stream
    
  pCodec=avcodec_find_decoder(pCodecCtxOrig->codec_id);
    
  if(pCodec==NULL) {
    
    fprintf(stderr, "Unsupported codec!\n");
    
    return -1; // Codec not found
    
  }
    
  // Copy context
    
  pCodecCtx = avcodec_alloc_context3(pCodec);
    
  if(avcodec_copy_context(pCodecCtx, pCodecCtxOrig) != 0) {
    
    fprintf(stderr, "Couldn't copy codec context");
    
    return -1; // Error copying codec context
    
  }
    

    
  // Open codec
    
  if(avcodec_open2(pCodecCtx, pCodec, NULL)&lt;0)
    
    return -1; // Could not open codec
    

    
  // Allocate video frame
    
  pFrame=av_frame_alloc();
    

    
  // Allocate an AVFrame structure
    
  pFrameGRAY=av_frame_alloc();
    
  if(pFrameGRAY==NULL)
    
    return -1;
    

    
  // Determine required buffer size and allocate buffer
    
  numBytes=avpicture_get_size(PIX_FMT_GRAY16, pCodecCtx->width,
    
                  pCodecCtx->height);
    
  buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
    

    
  // Assign appropriate parts of buffer to image planes in pFrameGRAY
    
  // Note that pFrameGRAY is an AVFrame, but AVFrame is a superset
    
  // of AVPicture
    
  avpicture_fill((AVPicture *)pFrameGRAY, buffer, PIX_FMT_GRAY16,
    
         pCodecCtx->width, pCodecCtx->height);
    

    
  // initialize SWS context for software scaling
    
  sws_ctx = sws_getContext(pCodecCtx->width,
    
               pCodecCtx->height,
    
               pCodecCtx->pix_fmt,
    
               pCodecCtx->width,
    
               pCodecCtx->height,
    
               PIX_FMT_GRAY16,
    
               SWS_BILINEAR,
    
               NULL,
    
               NULL,
    
               NULL
    
               );
    

    
  // 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 GRAY
    
    sws_scale(sws_ctx, (uint8_t const * const *)pFrame->data,
    
          pFrame->linesize, 0, pCodecCtx->height,
    
          pFrameGRAY->data, pFrameGRAY->linesize);
    

    
    // Save the frame to disk
    
    if(++i==200)
    
      SaveFrame(pFrameGRAY, pCodecCtx->width, pCodecCtx->height, 
    
            i);
    
      }
    
    }
    

    
    // Free the packet that was allocated by av_read_frame
    
    av_free_packet(&amp;packet);
    
  }
    

    
  // Free the GRAY image
    
  av_free(buffer);
    
  av_frame_free(&amp;pFrameGRAY);
    

    
  // Free the YUV frame
    
  av_frame_free(&amp;pFrame);
    

    
  // Close the codecs
    
  avcodec_close(pCodecCtx);
    
  avcodec_close(pCodecCtxOrig);
    

    
  // Close the video file
    
  avformat_close_input(&amp;pFormatCtx);
    

    
  return 0;
    
}

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