Recherche avancée

Sur d’autres sites (5297)

• using ffmpeg headers with a c program

  15 avril 2014, par orpgol

  i'm trying to learn ffmpeg from drangers guide (for school), i have a mac so the first thing i did was to use Macports and get ffmpeg and sdl...

  now when i'm tried to compile drangers code, the compiler didnt recognize the headers...
  so i used -I on gnu when compiling, and also gave the "whole/path/name..." to the headers,
  but i always get an error on some header missing...

  below i will put the code with my corrections.

  i also tried including all the headers that i get an error about but there is always another header the compiler can't find

  i tried both gnu (on console) and on xcode.

  // tutorial01.c
  
  // Code based on a tutorial by Martin Bohme (boehme@inb.uni-luebeckREMOVETHIS.de)
  
  // Tested on Gentoo, CVS version 5/01/07 compiled with GCC 4.1.1
  
  
  
  // A small sample program that shows how to use libavformat and libavcodec to
  
  // read video from a file.
  
  //
  
  // Use
  
  //
  
  // gcc -o tutorial01 tutorial01.c -lavformat -lavcodec -lz
  
  //
  
  // to build (assuming libavformat and libavcodec are correctly installed
  
  // your system).
  
  //
  
  // Run using
  
  //
  
  // tutorial01 myvideofile.mpg
  
  //
  
  // to write the first five frames from "myvideofile.mpg" to disk in PPM
  
  // format.
  
  
  
  #include "/opt/local/include/libavcodec/avcodec.h"
  
  #include "/opt/local/include/libavformat/avformat.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;
  
    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;
  
  }

• getting video duration with ffmpeg, php function

  17 novembre 2014, par keithp

  I have FFMpeg installed and I know it’s functional, but i’m trying to get the duration time from a flv video through PHP but when I use this code :

  function mbmGetFLVDuration($file)

  /*  
  
  * Determine video duration with ffmpeg   
  
  * ffmpeg should be installed on your server.  
  
  */  
  
  
  
  //$time = 00:00:00.000 format   
  
  $ffmpeg = "../ffmpeg/ffmpeg";
  
  
  
  $time =  exec("$ffmpeg -i $file 2>&1 | grep 'Duration' | cut -d ' ' -f 4 | sed s/,//");   
  
  
  
  $duration = explode(":",$time);   
  
  $duration_in_seconds = $duration[0]*3600 + $duration[1]*60+ round($duration[2]);   
  
  
  
  return $duration_in_seconds;   

  and :

  $duration = mbmGetFLVDuration(’http://www.videoaddsite.com/videos/intro.flv’) ;
  echo $duration ;

  I get an output of 220. THe video is 3:40. Can any help me on what i’m doing wrong, or if there’s something else I can use ?

• Grab (all) audio samples with ffmpeg, C/C++ [closed]

  28 août 2020, par nji9

  For further analysis I need to access/ collect all samples of
audio files with ffmpeg.
There are lot of code examples around, but all of them are either out-of-date
(using deprecated or non-existing ffmpeg API),
or are buggy (multiple frames in packets etc), or are incomplete...

  


  So, could some of the profs please present a simple working code ?

  


  In : Just filename, Out : Just error code, Within : Determine properties and access audio samples.

  


  Would probably be of great help not only for me ;-)

  


  Thankyou in advance.