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• FFmpeg : undefined references to av_frame_alloc()

  6 août 2014, par dontrythisathome

  I want to get into FFmpeg developing and i started following these samples tutorial here : here

  I started with the first tutorial - tutorial01.c - but i run into this problem ’undefined references to av_frame_alloc()’.

  I’m on Ubuntu 12.04 LTS.

  This is my program :

  /* 
  
   * File:   main.c
  
   * Author: dontrythisathome
  
   *
  
   * Created on 3 giugno 2014, 23.02
  
   */
  
  
  
  #include 
  
  #include <libavcodec></libavcodec>avcodec.h>
  
  #include <libavformat></libavformat>avformat.h>
  
  #include <libavutil></libavutil>frame.h>
  
  #include <libswscale></libswscale>swscale.h>
  
  /*
  
   *
  
   */
  
  void SaveFrame(AVFrame *pFrame, int width, int height, int iFrame)
  
      {
  
          FILE   *pFile;
  
          char  szFilename[32];
  
          int       y;
  
  
  
          //Apre il file
  
          sprintf(szFilename, "frame%d.ppm", iFrame);
  
          pFile=fopen(szFilename, "wb");
  
          if(pFile==NULL)
  
          {return; }
  
  
  
          //Scrive l'intestazione del file ( Larghezza x Altezza su video)
  
          fprintf(pFile, "P6\n%d %d\n255\n", width, height);
  
  
  
          //Scrive i data pixel
  
          for(y=0; ydata[0]+y*pFrame->linesize[0], 1, width*3, pFile);
  
          }
  
  
  
          //Chiude il file
  
          fclose(pFile);
  
        }
  
  /*
  
   * 
  
   */
  
  /*Main Function*/
  
  int main(int argc, char *argv[])
  
  {
  
      AVFormatContext *pFormatCtx;
  
      int                                     i, videoStreamIdx;
  
      AVCodecContext   *pCodecCtx;
  
      AVCodec                      *pCodec;
  
      AVFrame                      *pFrame;
  
      AVFrame                      *pFrameRGB;
  
      AVPacket                     packet;
  
      int                                     frameFinished;
  
      int                                     numBytes;
  
      uint8_t                           *buffer;
  
      static struct SwsContext  *img_convert_ctx;
  
  
  
      if(argc &lt; 2){
  
          printf("Inserisci un file video\n");
  
          return -1;
  
      }
  
  
  
      //Registra tutti i formati e i codec
  
      av_register_all();
  
  
  
      //Apre il file video
  
      if(avformat_open_input(&amp;pFormatCtx, argv[1], NULL, NULL) != 0)
  
      {return -1;} //Impossibile aprire il file
  
  
  
      //Recupera le informazioni dello stream
  
      if(avformat_find_stream_info(pFormatCtx, NULL) &lt; 0)
  
      {return -1;} // Couldn't find stream information
  
  
  
      //Versa le informazioni del file sullo standard error
  
      av_dump_format(pFormatCtx, 0, argv[1], 0);
  
  
  
      //Trova il primo stream video
  
      videoStreamIdx=-1;
  
      for(i=0; inb_streams; i++)
  
      {
  
          if(pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
  
          { videoStreamIdx=i;
  
              break;}
  
      }
  
  
  
      if(videoStreamIdx==-1)
  
          return -1; // Impossibile trovare lo stream video
  
  
  
      // Punta al contenuto del codec per lo stream video
  
      pCodecCtx = pFormatCtx->streams[videoStreamIdx]->codec;
  
  
  
      // Trova il decoder per lo stream video
  
      pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
  
      if(pCodec==NULL)
  
      {
  
          fprintf(stderr, "Codec Non Supportato!\n");
  
          return -1; //Impossibile trovare il codec
  
      }
  
  
  
      //Apre il codec
  
      if(avcodec_open2(pCodecCtx, pCodec, NULL) &lt; 0)
  
      {return -1;} //Impossibile aprire il codec
  
  
  
      //Alloca il frame video
  
      pFrame = av_frame_alloc();
  
  
  
      //Alloca una struct AVFrame
  
      pFrameRGB = av_frame_alloc();
  
      if(pFrameRGB==NULL)
  
      {return -1;}
  
  
  
      //Determina la grandezza necessaria per il buffer e lo alloca
  
      numBytes = avpicture_get_size(PIX_FMT_RGB24,
  
                                                                              pCodecCtx->width,
  
                                                                              pCodecCtx->height);
  
  
  
      buffer = (uint8_t *) av_malloc(numBytes*sizeof(uint8_t));
  
  
  
      //Assegna le parti appropriate del buffer sulla superficie dell'immagine in pFrameRGB
  
      //Tenere presente che pFrameRGB è un AVFrame, ma AVFrame è una superset di AVPicture
  
      avpicture_fill((AVPicture *)pFrameRGB, buffer, PIX_FMT_RGB24, pCodecCtx->width, pCodecCtx->height);
  
  
  
      int w = pCodecCtx->width;
  
      int h = pCodecCtx->height;
  
      img_convert_ctx = sws_getContext(w, h, pCodecCtx->pix_fmt,
  
                                                                                         w, h, PIX_FMT_RGB24,
  
                                                                                          SWS_LANCZOS, NULL, NULL, NULL);
  
  
  
      //Legge i frame e salva i primi 5 frame su disco
  
     i=0;
  
     while((av_read_frame(pFormatCtx, &amp;packet)>=0) &amp;&amp; (i&lt;5))
  
     {
  
         //Questo è il packet dello stream video?
  
         if(packet.stream_index==videoStreamIdx)
  
         {
  
             //Decodifica il frame video
  
             avcodec_decode_video2(pCodecCtx, pFrame, &amp;frameFinished, &amp;packet);
  
  
  
             //Si è riusiciti ad ottenere il frame video?
  
             if(frameFinished)
  
             {
  
                 i++;
  
                 sws_scale(img_convert_ctx, (const uint8_t * const *)pFrame->data,
  
                                          pFrame->linesize, 0, pCodecCtx->height,
  
                                          pFrameRGB->data, pFrameRGB->linesize);
  
                 SaveFrame(pFrameRGB, pCodecCtx->width, pCodecCtx->height, i);
  
             }
  
         }
  
  
  
         //Libera il pacchetto che era allocato da av_read_frame
  
         av_free_packet(&amp;packet);
  
     }
  
  
  
     //Libera l'immagine RGB
  
     av_free(buffer);
  
     av_free(pFrameRGB);
  
  
  
     //Libera il frame YUV
  
     av_free(pFrame);
  
  
  
     //Chiude il codec
  
     avcodec_close(pCodecCtx);
  
  
  
     //Chiude il file video
  
     avformat_close_input(&amp;pFormatCtx);
  
  
  
     /*FINE PROGRAMMA*/ 
  
  
  
      return 0;
  
  }

  This is the build output :

  "/usr/bin/make" -f nbproject/Makefile-Debug.mk QMAKE= SUBPROJECTS= .build-conf
  
  make[1]: ingresso nella directory "/home/dontrythisathome/Programmazione/C-C++/SimpleMediaPlayerForAndroid"
  
  "/usr/bin/make"  -f nbproject/Makefile-Debug.mk dist/Debug/GNU-Linux-x86/simplemediaplayerforandroid
  
  make[2]: ingresso nella directory "/home/dontrythisathome/Programmazione/C-C++/SimpleMediaPlayerForAndroid"
  
  mkdir -p dist/Debug/GNU-Linux-x86
  
  gcc     -o dist/Debug/GNU-Linux-x86/simplemediaplayerforandroid build/Debug/GNU-Linux-x86/main.o -L/usr/lib/x86_64-linux-gnu -lavformat -lavcodec -lavutil -lswscale -lz -lbz2
  
  build/Debug/GNU-Linux-x86/main.o: In function `main':
  
  /home/dontrythisathome/Programmazione/C-C++/SimpleMediaPlayerForAndroid/main.c:105: undefined reference to `av_frame_alloc'
  
  /home/dontrythisathome/Programmazione/C-C++/SimpleMediaPlayerForAndroid/main.c:108: undefined reference to `av_frame_alloc'
  
  collect2: ld returned 1 exit status
  
  make[2]: *** [dist/Debug/GNU-Linux-x86/simplemediaplayerforandroid] Errore 1
  
  make[2]: uscita dalla directory "/home/dontrythisathome/Programmazione/C-C++/SimpleMediaPlayerForAndroid"
  
  make[1]: *** [.build-conf] Errore 2
  
  make[1]: uscita dalla directory "/home/dontrythisathome/Programmazione/C-C++/SimpleMediaPlayerForAndroid"
  
  make: *** [.build-impl] Errore 2
  
  
  
  BUILD FAILED (exit value 2, total time: 143ms)

  I also linked the correct library path and headers path because there is no error with that.

  But when i try to build the program from the terminal with these commands :

  gcc -o prog1 /home/dontrythisathome/Programmazione/C-C++/SimpleMediaPlayerForAndroid/main.c -lavformat -lavcodec -lavutil -lswscale -lz -lbz2

  And the output is different :

  /home/dontrythisathome/Programmazione/C-C++/SimpleMediaPlayerForAndroid/main.c:11:29: fatal error: libavutil/frame.h: File o directory non esistente
  
  compilation terminated.

  The output says that there is no file or directory existing.
  What is the problem ?

• Reduce HLS latency from +30 seconds

  4 juin 2014, par Rick

  Ubuntu 12.04

  nginx 1.2.4

  avconv -version

  avconv version 0.8.10-4:0.8.10-0ubuntu0.12.04.1, Copyright (c) 2000-2013 the Libav developers
  
    built on Feb  6 2014 20:56:59 with gcc 4.6.3
  
  avconv 0.8.10-4:0.8.10-0ubuntu0.12.04.1
  
  libavutil    51. 22. 2 / 51. 22. 2
  
  libavcodec   53. 35. 0 / 53. 35. 0
  
  libavformat  53. 21. 1 / 53. 21. 1
  
  libavdevice  53.  2. 0 / 53.  2. 0
  
  libavfilter   2. 15. 0 /  2. 15. 0
  
  libswscale    2.  1. 0 /  2.  1. 0
  
  libpostproc  52.  0. 0 / 52.  0. 0

  I’m using avconv and nginx to create an HLS stream but right now my latency is regularly well over 30 seconds. After much reading I am aware that HLS has built in latency and that 10s is expected and even preferred but 30s seems quite extreme.

  I’ve seen a lot of discussion on the nginx-rtmp google group, this thread in particular had a lot of suggestions. I have attempted to reduce solve my issue by reducing the hls_fragment and the hls_playlist_length but they haven’t had a significant effect.

  nginx.conf :

  #user  nobody;
  
  worker_processes  1;
  
  
  
  error_log  logs/error.log debug;
  
  
  
  events {
  
      worker_connections  1024;
  
  }
  
  
  
  http {
  
      include       mime.types;
  
      default_type  application/octet-stream;
  
  
  
      sendfile        on;
  
      keepalive_timeout  65;
  
  
  
      server {
  
          listen       8888;
  
          server_name  localhost;
  
  
  
          add_header 'Access-Control-Allow-Origin' "*";
  
  
  
          location /hls {
  
              types {
  
                  application/vnd.apple.mpegurl m3u8;
  
                  video/mp2t ts;
  
              }
  
              root /tmp;
  
          }
  
  
  
          # rtmp stat
  
          location /stat {
  
              rtmp_stat all;
  
              rtmp_stat_stylesheet stat.xsl;
  
          }
  
          location /stat.xsl {
  
              # you can move stat.xsl to a different location
  
              root /usr/build/nginx-rtmp-module;
  
          }
  
  
  
          # rtmp control
  
          location /control {
  
              rtmp_control all;
  
          }
  
  
  
          error_page   500 502 503 504  /50x.html;
  
          location = /50x.html {
  
              root   html;
  
          }
  
      }
  
  }
  
  
  
  rtmp {
  
      server {
  
          listen 1935;
  
          ping 30s;
  
          notify_method get;
  
  
  
          application myapp {
  
              live on;
  
  
  
              hls on;
  
              hls_path /tmp/hls;
  
              hls_base_url http://x.x.x.x:8888/hls/;
  
              hls_sync 2ms;
  
              hls_fragment 2s;
  
  
  
              #hls_variant _low BANDWIDTH=160000;
  
              #hls_variant _mid BANDWIDTH=320000;
  
              #hls_variant _hi BANDWIDTH=640000;
  
          }
  
      }
  
  }

  avconv command :

  avconv -r 30 -y -f image2pipe -codec:v mjpeg -i - -f flv -codec:v libx264 -profile:v baseline -preset ultrafast -tune zerolatency -an -f flv rtmp://127.0.0.1:1935/myapp/mystream

• Setting start date in gource

  5 juin 2014, par rfc1484

  I’m trying to run gource from a certain date, but it reports me a ’codec not found error’.

  This is the command without a start date :

  gource -1280x720 --seconds-per-day 1 --stop-at-end --hide filenames --hide files --git-branch master --camera-mode track --output-ppm-stream - | ffmpeg -y -b 3000k -r 25 -f image2pipe -vcodec ppm -i - test.mp4

  Which works fine and generates the .mp4 file as expected.

  This is the command with a start date :

  gource -1280x720 --start-date '2014-01-01' --seconds-per-day 1 --stop-at-end --hide filenames --hide files --git-branch master --camera-mode track --output-ppm-stream - | ffmpeg -y -b 3000k -r 25 -f image2pipe -vcodec ppm -i - test.mp4

  Which doesn’t work and generates the following error message :

  [image2pipe @ 0x78a600] Could not find codec parameters (Video : ppm)

  Any suggestions on how to fix this ?