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• Undefined reference, using FFMpeg-library (AvCodec) on Ubuntu, 64-bits system

  5 mai 2012, par Anders Branderud

  I am running the example code of the latest FFMpeg-library.
  I have inserted the example code into the file videofecencoder.c :

  /*
  
  * copyright (c) 2001 Fabrice Bellard
  
  *
  
  * This file is part of Libav.
  
  *
  
  * Libav is free software; you can redistribute it and/or
  
  * modify it under the terms of the GNU Lesser General Public
  
  * License as published by the Free Software Foundation; either
  
  * version 2.1 of the License, or (at your option) any later version.
  
  *
  
  * Libav is distributed in the hope that it will be useful,
  
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  
  * Lesser General Public License for more details.
  
  *
  
  * You should have received a copy of the GNU Lesser General Public
  
  * License along with Libav; if not, write to the Free Software
  
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  
  */
  
  #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
  
  
  
  
  
  #include 
  
  #include 
  
  #include 
  
  
  
  #ifdef HAVE_AV_CONFIG_H
  
  #undef HAVE_AV_CONFIG_H
  
  #endif
  
  
  
  #include "libavutil/imgutils.h"
  
  #include "libavutil/opt.h"
  
  #include "libavcodec/avcodec.h"
  
  #include "libavutil/mathematics.h"
  
  #include "libavutil/samplefmt.h"
  
  
  
  #define INBUF_SIZE 4096
  
  #define AUDIO_INBUF_SIZE 20480
  
  #define AUDIO_REFILL_THRESH 4096
  
  
  
  /*
  
  * Video encoding example
  
  */
  
  static void video_encode_example(const char *filename, int codec_id)
  
  {
  
     AVCodec *codec;
  
     AVCodecContext *c= NULL;
  
     int i, out_size, size, x, y, outbuf_size;
  
     FILE *f;
  
     AVFrame *picture;
  
     uint8_t *outbuf;
  
     int nrOfFramesPerSecond  =25;
  
     int nrOfSeconds =1;
  
  
  
  
  
     printf("Video encoding\n");
  
  
  
     /* find the mpeg1 video encoder */
  
     codec = avcodec_find_encoder((CodecID) codec_id);
  
     if (!codec) {
  
         fprintf(stderr, "codec not found\n");
  
         exit(1);
  
     }
  
  
  
     c = avcodec_alloc_context3(codec);
  
     picture= avcodec_alloc_frame();
  
  
  
     /* put sample parameters */
  
     c->bit_rate = 400000;
  
     /* resolution must be a multiple of two */
  
     c->width = 352;
  
     c->height = 288;
  
     /* frames per second */
  
     c->time_base= (AVRational){1,25};
  
     c->gop_size = 10; /* emit one intra frame every ten frames */
  
     c->max_b_frames=1;
  
     c->pix_fmt = PIX_FMT_YUV420P;
  
  
  
     if(codec_id == CODEC_ID_H264)
  
         av_opt_set(c->priv_data, "preset", "slow", 0);
  
  
  
     /* open it */
  
     if (avcodec_open2(c, codec, NULL) < 0) {
  
         fprintf(stderr, "could not open codec\n");
  
         exit(1);
  
     }
  
  
  
     f = fopen(filename, "wb");
  
     if (!f) {
  
         fprintf(stderr, "could not open %s\n", filename);
  
         exit(1);
  
     }
  
  
  
     /* alloc image and output buffer */
  
     outbuf_size = 100000;
  
     outbuf = (uint8_t*) malloc(outbuf_size);
  
  
  
     /* the image can be allocated by any means and av_image_alloc() is
  
      * just the most convenient way if av_malloc() is to be used */
  
     av_image_alloc(picture->data, picture->linesize,
  
                    c->width, c->height, c->pix_fmt, 1);
  
  
  
     /* encode 1 second of video */
  
     int nrOfFramesTotal = nrOfFramesPerSecond * nrOfSeconds;
  
  
  
     /* encode 1 second of video */
  
     for(i=0;i < nrOfFramesTotal; i++) {
  
         fflush(stdout);
  
         /* prepare a dummy image */
  
         /* Y */
  
         for(y=0;yheight;y++) {
  
             for(x=0;xwidth;x++) {
  
                 picture->data[0][y * picture->linesize[0] + x] = x + y + i * 3;
  
             }
  
         }
  
  
  
         /* Cb and Cr */
  
         for(y=0;yheight/2;y++) {
  
             for(x=0;xwidth/2;x++) {
  
                 picture->data[1][y * picture->linesize[1] + x] = 128 + y + i * 2;
  
                 picture->data[2][y * picture->linesize[2] + x] = 64 + x + i * 5;
  
             }
  
         }
  
  
  
         /* encode the image */
  
         out_size = avcodec_encode_video(c, outbuf, outbuf_size, picture);
  
         printf("encoding frame %3d (size=%5d)\n", i, out_size);
  
         fwrite(outbuf, 1, out_size, f);
  
     }
  
  
  
     /* get the delayed frames */
  
     for(; out_size; i++) {
  
         fflush(stdout);
  
  
  
         out_size = avcodec_encode_video(c, outbuf, outbuf_size, NULL);
  
         printf("write frame %3d (size=%5d)\n", i, out_size);
  
         fwrite(outbuf, 1, out_size, f);
  
     }
  
  
  
     /* add sequence end code to have a real mpeg file */
  
     outbuf[0] = 0x00;
  
     outbuf[1] = 0x00;
  
     outbuf[2] = 0x01;
  
     outbuf[3] = 0xb7;
  
     fwrite(outbuf, 1, 4, f);
  
     fclose(f);
  
     free(outbuf);
  
  
  
     avcodec_close(c);
  
     av_free(c);
  
     av_free(picture->data[0]);
  
     av_free(picture);
  
     printf("\n");
  
  }
  
  
  
  int main(int argc, char **argv)
  
  {
  
     const char *filename;
  
  
  
     /* register all the codecs */
  
     avcodec_register_all();
  
  
  
     if (argc <= 1) {
  
  
  
         video_encode_example("/grb_1.mpg", CODEC_ID_MPEG1VIDEO);
  
     } else {
  
         filename = argv[1];
  
     }
  
  
  
  
  
     return 0;
  
  }

  When I run gcc videofecencoder.cc -lavcodec I get the following error messages :

  /tmp/ccJg8IDy.o: In function `video_encode_example(char const*, int)':
  
  videofecencoder.cc:(.text+0x35): undefined reference to `avcodec_find_encoder(CodecID)'
  
  videofecencoder.cc:(.text+0x74): undefined reference to `avcodec_alloc_context3(AVCodec*)'
  
  videofecencoder.cc:(.text+0x7d): undefined reference to `avcodec_alloc_frame()'
  
  videofecencoder.cc:(.text+0x113): undefined reference to `av_opt_set(void*, char const*, char const*, int)'
  
  videofecencoder.cc:(.text+0x12b): undefined reference to `avcodec_open2(AVCodecContext*, AVCodec*, AVDictionary**)'
  
  videofecencoder.cc:(.text+0x1f0): undefined reference to `av_image_alloc(unsigned char**, int*, int, int, PixelFormat, int)'
  
  videofecencoder.cc:(.text+0x35c): undefined reference to `avcodec_encode_video(AVCodecContext*, unsigned char*, int, AVFrame const*)'
  
  videofecencoder.cc:(.text+0x3cf): undefined reference to `avcodec_encode_video(AVCodecContext*, unsigned char*, int, AVFrame const*)'
  
  videofecencoder.cc:(.text+0x47c): undefined reference to `avcodec_close(AVCodecContext*)'
  
  videofecencoder.cc:(.text+0x488): undefined reference to `av_free(void*)'
  
  videofecencoder.cc:(.text+0x497): undefined reference to `av_free(void*)'
  
  videofecencoder.cc:(.text+0x4a3): undefined reference to `av_free(void*)'
  
  /tmp/ccJg8IDy.o: In function `main':
  
  videofecencoder.cc:(.text+0x4c3): undefined reference to `avcodec_register_all()'
  
  collect2: ld returnerade avslutningsstatus 1

  The command nm libavcodec.a | grep avcodec_find results in :

  00000000000008e0 T avcodec_find_best_pix_fmt
  
  0000000000000740 T avcodec_find_best_pix_fmt2
  
                   U avcodec_find_encoder
  
  0000000000002ca0 T avcodec_find_decoder
  
  0000000000002cf0 T avcodec_find_decoder_by_name
  
  0000000000002bd0 T avcodec_find_encoder
  
  0000000000002c30 T avcodec_find_encoder_by_name

  I also have another similar error with another library :
  Undefined reference despite linking in OpenFEC-library

  My system : Ubuntu 11, 64-bits machine

  My next step is to try to compile it on VirtualBox with Ubuntu 32 bits (running on a Windows-OS).

• Does ReplayGain work on Opus audio files, too, and how do I apply it ?

  8 mars 2023, par finefoot

  


  ReplayGain is a proposed technical standard published by David Robinson in 2001 to measure and normalize the perceived loudness of audio in computer audio formats such as MP3 and Ogg Vorbis.

  


  


  Does ReplayGain work on audio files encoded with Opus, too ? And what's a command-line solution to apply it ?

  


• Problems video playing in some android devices (version 4+) but not in others

  5 juin 2014, par anquegi

  following the settings for video in android developers, http://developer.android.com/guide/appendix/media-formats.html I encoded a video using ffmpeg like this :

  ffmpeg -i gravityTrailer.mp4 -y -f mp4 -vcodec libx264 -profile:v baseline -acodec aac    -strict -2  -profile:a aac_low -b:v 500k -ar 44100 -b:a 128k -ac 2 -r 30 -s 480x360  output_hq.mp4

  which corresponds on sd highquality in table 2 from android developers (link above).

  Then i put this video in a server and use the class android.media.MediaPlayer to reproduce it from that URL like this

  https://cloudapp.somedomain.com/bmftvideos/output_hq.mp4

  The problem is that the video is played on android version 4+

  you can see the video on :
  LG G2,
  Sony xperia S

  you cannot see the video on :
  Samsung galaxy S4,
  BQ (spanish) aquaris 4.5

  And I don not know why

  this is the ffmpeg output :

  ffmpeg version 1.2.6 Copyright (c) 2000-2014 the FFmpeg developers
  
    built on Mar  5 2014 08:21:01 with gcc 4.8.2 (GCC) 20131212 (Red Hat 4.8.2-7)
  
    configuration: --prefix=/usr --bindir=/usr/bin --datadir=/usr/share/ffmpeg --incdir=/usr/include/ffmpeg --libdir=/usr/lib64 --mandir=/usr/share/man --arch=x86_64 --optflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic' --enable-bzlib --disable-crystalhd --enable-frei0r --enable-gnutls --enable-libass --enable-libcelt --enable-libdc1394 --disable-indev=jack --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-openal --enable-libopencv --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libv4l2 --enable-libvpx --enable-libx264 --enable-libxvid --enable-x11grab --enable-avfilter --enable-avresample --enable-postproc --enable-pthreads --disable-static --enable-shared --enable-gpl --disable-debug --disable-stripping --shlibdir=/usr/lib64 --enable-runtime-cpudetect
  
    libavutil      52. 18.100 / 52. 18.100
  
    libavcodec     54. 92.100 / 54. 92.100
  
    libavformat    54. 63.104 / 54. 63.104
  
    libavdevice    54.  3.103 / 54.  3.103
  
    libavfilter     3. 42.103 /  3. 42.103
  
    libswscale      2.  2.100 /  2.  2.100
  
    libswresample   0. 17.102 /  0. 17.102
  
    libpostproc    52.  2.100 / 52.  2.100
  
  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x14e5ba0] stream 0, timescale not set
  
  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x14e5ba0] max_analyze_duration 5000000 reached at 5013333 microseconds
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'gravityTrailer.mp4':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: mp42isomavc1
  
      creation_time   : 2013-12-01 03:59:56
  
      genre           : Trailer
  
      artist          : Warner Bros.
  
      title           : Gravity - 2K Trailer
  
      encoder         : HandBrake 0.9.9 2013051800
  
      date            : 2013
  
    Duration: 00:02:27.07, start: 0.000000, bitrate: 20296 kb/s
  
      Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 2048x858, 20149 kb/s, 23.98 fps, 23.98 tbr, 90k tbn, 47.95 tbc
  
      Metadata:
  
        creation_time   : 2013-12-01 03:59:56
  
      Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 153 kb/s
  
      Metadata:
  
        creation_time   : 2013-12-01 03:59:56
  
      Stream #0:2: Video: mjpeg, yuvj420p, 102x150 [SAR 72:72 DAR 17:25], 90k tbr, 90k tbn, 90k tbc
  
  [libx264 @ 0x1667680] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
  
  [libx264 @ 0x1667680] profile Constrained Baseline, level 3.0
  
  [libx264 @ 0x1667680] 264 - core 130 r2282 1db4621 - H.264/MPEG-4 AVC codec - Copyleft 2003-2013 - http://www.videolan.org/x264.html - options: cabac=0 ref=3 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=abr mbtree=1 bitrate=500 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
  
  Output #0, mp4, to 'output_hq.mp4':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: mp42isomavc1
  
      date            : 2013
  
      genre           : Trailer
  
      artist          : Warner Bros.
  
      title           : Gravity - 2K Trailer
  
      encoder         : Lavf54.63.104
  
      Stream #0:0(und): Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 480x360, q=-1--1, 500 kb/s, 15360 tbn, 30 tbc
  
      Metadata:
  
        creation_time   : 2013-12-01 03:59:56
  
      Stream #0:1(eng): Audio: aac ([64][0][0][0] / 0x0040), 44100 Hz, stereo, fltp, 128 kb/s
  
      Metadata:
  
        creation_time   : 2013-12-01 03:59:56
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 -> libx264)
  
    Stream #0:1 -> #0:1 (aac -> aac)
  
  Press [q] to stop, [?] for help
  
  frame= 4410 fps= 65 q=-1.0 Lsize=   11154kB time=00:02:27.07 bitrate= 621.3kbits/s dup=885 drop=0    
  
  video:9062kB audio:1969kB subtitle:0 global headers:0kB muxing overhead 1.115392%
  
  [libx264 @ 0x1667680] frame I:186   Avg QP:28.41  size:  4446
  
  [libx264 @ 0x1667680] frame P:4224  Avg QP:29.20  size:  2001
  
  [libx264 @ 0x1667680] mb I  I16..4: 75.5%  0.0% 24.5%
  
  [libx264 @ 0x1667680] mb P  I16..4:  7.5%  0.0%  3.6%  P16..4: 23.1%  6.2%  1.8%  0.0%  0.0%    skip:57.7%
  
  [libx264 @ 0x1667680] final ratefactor: 27.96
  
  [libx264 @ 0x1667680] coded y,uvDC,uvAC intra: 24.0% 31.9% 8.6% inter: 7.4% 7.6% 0.6%
  
  [libx264 @ 0x1667680] i16 v,h,dc,p: 58% 15% 13% 14%
  
  [libx264 @ 0x1667680] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 28%  9% 27%  7%  6%  8%  5%  7%  3%
  
  [libx264 @ 0x1667680] i8c dc,h,v,p: 80%  7% 12%  2%
  
  [libx264 @ 0x1667680] ref P L0: 84.7%  9.4%  5.9%
  
  [libx264 @ 0x1667680] kb/s:504.98

  ---