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• How to make FuncAnimation animations faster ?

  12 juin 2021, par Zenitsu

  The code I have written is for a Lorrenz Attractor in Python. It shows how a number of random points evolves according to lorrenz equtions and falls into the lorrenz attractor. I did get satisfactory results when I ran the code, but ran into problems while saving the animation as a gif or mp4 file. Python and my text editor started crashing when I tried saving them. I want to know if the code could be simplified or maybe made more effective in some way. Thankyou for helping !!

  


  # Importing all the necessary modules

import matplotlib.pyplot as pl
from mpl_toolkits.mplot3d import Axes3D
from matplotlib.animation import FuncAnimation
import matplotlib.animation as animation
import matplotlib.cm as cm
import numpy as np

#Writer = animation.writers['ffmpeg']
#writer = Writer(fps=15, metadata=dict(artist='Me'), bitrate=1800)

fig = pl.figure(figsize=(35,35))
ax = pl.axes(projection="3d") 
fig.set_facecolor('black')
ax.set_facecolor('black') 
ax.w_xaxis.pane.fill = False
ax.w_yaxis.pane.fill = False
ax.w_zaxis.pane.fill = False
ax.get_proj = lambda: np.dot(Axes3D.get_proj(ax), np.diag([2, 2, 2, 1.3]))
ax.grid(False)
ax.set_axis_off()

# B has the values of sigma, rho and beta used in the lorrenz equations
B =[10,28,8/3]
# t is the dt time element
t = 0.001
# The number of points 
num_points = 20

# These three list will store all the x, y and z position of all the points
X_data = []
Y_data = []
Z_data = []

for i in range(0,num_points,1):
        x_data = []
        y_data = []
        z_data = []
        x , y , z = np.random.uniform(-25,25),np.random.uniform(-25,30),np.random.uniform(0,60)
        for i in np.arange(0,10,t):

                dx = B[0]*(y-x)*t
                dy = (x*(B[1] - z)-y)*t
                dz = (x*y-B[2]*z)*t

                x+=dx
                y+=dy
                z+=dz

                x_data.append(x)
                y_data.append(y)
                z_data.append(z)
        X_data.append(x_data)
        Y_data.append(y_data)
        Z_data.append(z_data)

color = cm.rainbow(np.linspace(0,1,num_points))

def animate(i):
        pl.cla()

        for j in range(0,num_points,1):
                ax.set_axis_off()
                ax.plot3D(X_data[j][2*i:10*i],Y_data[j][2*i:10*i],Z_data[j][2*i:10*i],linewidth=0.5,color=color[j])
                ax.plot3D(X_data[j][10*i],Y_data[j][10*i],Z_data[j][10*i],marker=".",color=color[j],markersize=3)
                ax.set_xlim([-30,30])
                ax.set_ylim([-30,30])
                ax.set_zlim([0,60])

        ax.view_init(0,i/2) 

ani = FuncAnimation(fig,animate,repeat=False,interval=100,frames=600)

# Commented out the bottom part so that i can see it before saving

#ani.save('Lorrenz_Attractor.mp4', writer=writer)

#writer = animation.PillowWriter(fps=10)  
#ani.save("Lorrenz_Attractor.gif", writer=writer)

pl.show()


  


• Open VideoStream using OpenCV 4.5.1 works on Windows but fails on Docker python:3.9.2-slim-buster for specific IP cam

  18 mai 2021, par Qua285

  I have 2 ip cameras - one of Hikvision and another of Provision ISR. Both use Onvif and work on VLC.
I've written a simple python script to record images every 5 sec from their video stream.
On Windows 10, using VSCode they both work as expected. Once deployed to a Docker container, my script works as expected with the Hikvision but fails with the Provision ISR - it doesn't open the stream.

  


  Running python -c "import cv2; print(cv2.getBuildInformation())" on windows (venv 3.9.2) and on docker machine bring slightly different results but it's beyond my understanding to take something out of it...
Here is the Windows one :

  


  General configuration for OpenCV 4.5.1 =====================================
  Version control:               4.5.1

  Platform:
    Timestamp:                   2021-01-02T14:30:58Z
    Host:                        Windows 6.3.9600 AMD64
    CMake:                       3.18.4
    CMake generator:             Visual Studio 14 2015 Win64
    CMake build tool:            C:/Program Files (x86)/MSBuild/14.0/bin/MSBuild.exe
    MSVC:                        1900

  CPU/HW features:
    Baseline:                    SSE SSE2 SSE3
      requested:                 SSE3
    Dispatched code generation:  SSE4_1 SSE4_2 FP16 AVX AVX2
      requested:                 SSE4_1 SSE4_2 AVX FP16 AVX2 AVX512_SKX
      SSE4_1 (15 files):         + SSSE3 SSE4_1
      SSE4_2 (1 files):          + SSSE3 SSE4_1 POPCNT SSE4_2
      FP16 (0 files):            + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 AVX
      AVX (4 files):             + SSSE3 SSE4_1 POPCNT SSE4_2 AVX
      AVX2 (29 files):           + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 FMA3 AVX AVX2

  C/C++:
    Built as dynamic libs?:      NO
    C++ standard:                11
    C++ Compiler:                C:/Program Files (x86)/Microsoft Visual Studio 14.0/VC/bin/x86_amd64/cl.exe  (ver 19.0.24241.7)
    C++ flags (Release):         /DWIN32 /D_WINDOWS /W4 /GR  /D _CRT_SECURE_NO_DEPRECATE /D _CRT_NONSTDC_NO_DEPRECATE /D _SCL_SECURE_NO_WARNINGS /Gy /bigobj /Oi  /fp:precise     /EHa /wd4127 /wd4251 /wd4324 /wd4275 /wd4512 /wd4589 
/MP  /MT /O2 /Ob2 /DNDEBUG
    C++ flags (Debug):           /DWIN32 /D_WINDOWS /W4 /GR  /D _CRT_SECURE_NO_DEPRECATE /D _CRT_NONSTDC_NO_DEPRECATE /D _SCL_SECURE_NO_WARNINGS /Gy /bigobj /Oi  /fp:precise     /EHa /wd4127 /wd4251 /wd4324 /wd4275 /wd4512 /wd4589 
/MP  /MTd /Zi /Ob0 /Od /RTC1
    C Compiler:                  C:/Program Files (x86)/Microsoft Visual Studio 14.0/VC/bin/x86_amd64/cl.exe
    C flags (Release):           /DWIN32 /D_WINDOWS /W3  /D _CRT_SECURE_NO_DEPRECATE /D _CRT_NONSTDC_NO_DEPRECATE /D _SCL_SECURE_NO_WARNINGS /Gy /bigobj /Oi  /fp:precise     /MP   /MT /O2 /Ob2 /DNDEBUG
    C flags (Debug):             /DWIN32 /D_WINDOWS /W3  /D _CRT_SECURE_NO_DEPRECATE /D _CRT_NONSTDC_NO_DEPRECATE /D _SCL_SECURE_NO_WARNINGS /Gy /bigobj /Oi  /fp:precise     /MP /MTd /Zi /Ob0 /Od /RTC1
    Linker flags (Release):      /machine:x64  /NODEFAULTLIB:atlthunk.lib /INCREMENTAL:NO  /NODEFAULTLIB:libcmtd.lib /NODEFAULTLIB:libcpmtd.lib /NODEFAULTLIB:msvcrtd.lib
    Linker flags (Debug):        /machine:x64  /NODEFAULTLIB:atlthunk.lib /debug /INCREMENTAL  /NODEFAULTLIB:libcmt.lib /NODEFAULTLIB:libcpmt.lib /NODEFAULTLIB:msvcrt.lib
    ccache:                      NO
    Precompiled headers:         YES
    Extra dependencies:          ade wsock32 comctl32 gdi32 ole32 setupapi ws2_32
    3rdparty dependencies:       ittnotify libprotobuf zlib libjpeg-turbo libwebp libpng libtiff libopenjp2 IlmImf quirc ippiw ippicv

  OpenCV modules:
    To be built:                 calib3d core dnn features2d flann gapi highgui imgcodecs imgproc ml objdetect photo python3 stitching video videoio
    Disabled:                    world
    Disabled by dependency:      -
    Unavailable:                 java python2 ts
    Applications:                -
    Documentation:               NO
    Non-free algorithms:         NO

  Windows RT support:            NO

  GUI:
    Win32 UI:                    YES
    VTK support:                 NO

  Media I/O:
    ZLib:                        build (ver 1.2.11)
    JPEG:                        build-libjpeg-turbo (ver 2.0.6-62)
    WEBP:                        build (ver encoder: 0x020f)
    PNG:                         build (ver 1.6.37)
    TIFF:                        build (ver 42 - 4.0.10)
    JPEG 2000:                   build (ver 2.3.1)
    OpenEXR:                     build (ver 2.3.0)
    HDR:                         YES
    SUNRASTER:                   YES
    PXM:                         YES
    PFM:                         YES

  Video I/O:
    DC1394:                      NO
    FFMPEG:                      YES (prebuilt binaries)
      avcodec:                   YES (58.91.100)
      avformat:                  YES (58.45.100)
      avutil:                    YES (56.51.100)
      swscale:                   YES (5.7.100)
      avresample:                YES (4.0.0)
    GStreamer:                   NO
    DirectShow:                  YES
    Media Foundation:            YES
      DXVA:                      NO

  Parallel framework:            Concurrency

  Trace:                         YES (with Intel ITT)

  Other third-party libraries:
    Intel IPP:                   2020.0.0 Gold [2020.0.0]
           at:                   C:/Users/appveyor/AppData/Local/Temp/1/pip-req-build-wvn_it83/_skbuild/win-amd64-3.9/cmake-build/3rdparty/ippicv/ippicv_win/icv
    Intel IPP IW:                sources (2020.0.0)
              at:                C:/Users/appveyor/AppData/Local/Temp/1/pip-req-build-wvn_it83/_skbuild/win-amd64-3.9/cmake-build/3rdparty/ippicv/ippicv_win/iw
    Lapack:                      NO
    Eigen:                       NO
    Custom HAL:                  NO
    Protobuf:                    build (3.5.1)

  OpenCL:                        YES (NVD3D11)
    Include path:                C:/Users/appveyor/AppData/Local/Temp/1/pip-req-build-wvn_it83/opencv/3rdparty/include/opencl/1.2
    Link libraries:              Dynamic load

  Python 3:
    Interpreter:                 C:/Python39-x64/python.exe (ver 3.9)
    Libraries:                   C:/Python39-x64/libs/python39.lib (ver 3.9.0)
    numpy:                       C:/Users/appveyor/AppData/Local/Temp/1/pip-build-env-sk7r7w_5/overlay/Lib/site-packages/numpy/core/include (ver 1.19.3)
    install path:                python

  Python (for build):            C:/Python27-x64/python.exe

  Java:
    ant:                         NO
    JNI:                         C:/Program Files/Java/jdk1.8.0/include C:/Program Files/Java/jdk1.8.0/include/win32 C:/Program Files/Java/jdk1.8.0/include
    Java wrappers:               NO
    Java tests:                  NO

  Install to:                    C:/Users/appveyor/AppData/Local/Temp/1/pip-req-build-wvn_it83/_skbuild/win-amd64-3.9/cmake-install
-----------------------------------------------------------------


  


  this is the Docker one (python:3.9.2-slim-buster) :

  


  General configuration for OpenCV 4.5.1 =====================================
  Version control:               4.5.1-dirty

  Platform:
    Timestamp:                   2021-01-02T13:04:10Z
    Host:                        Linux 4.15.0-1077-gcp x86_64
    CMake:                       3.18.4
    CMake generator:             Unix Makefiles
    CMake build tool:            /bin/gmake
    Configuration:               Release

  CPU/HW features:
    Baseline:                    SSE SSE2 SSE3
      requested:                 SSE3
    Dispatched code generation:  SSE4_1 SSE4_2 FP16 AVX AVX2 AVX512_SKX
      requested:                 SSE4_1 SSE4_2 AVX FP16 AVX2 AVX512_SKX
      SSE4_1 (15 files):         + SSSE3 SSE4_1
      SSE4_2 (1 files):          + SSSE3 SSE4_1 POPCNT SSE4_2
      FP16 (0 files):            + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 AVX
      AVX (4 files):             + SSSE3 SSE4_1 POPCNT SSE4_2 AVX
      AVX2 (29 files):           + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 FMA3 AVX AVX2
      AVX512_SKX (4 files):      + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 FMA3 AVX AVX2 AVX_512F AVX512_COMMON AVX512_SKX

  C/C++:
    Built as dynamic libs?:      NO
    C++ standard:                11
    C++ Compiler:                /usr/lib/ccache/compilers/c++  (ver 9.3.1)
    C++ flags (Release):         -Wl,-strip-all   -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wuninitialized -Wsuggest-override -Wno-delete-non-virtual-dtor -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections  -msse -msse2 -msse3 -fvisibility=hidden -fvisibility-inlines-hidden -O3 -DNDEBUG  -DNDEBUG
    C++ flags (Debug):           -Wl,-strip-all   -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wuninitialized -Wsuggest-override -Wno-delete-non-virtual-dtor -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections  -msse -msse2 -msse3 -fvisibility=hidden -fvisibility-inlines-hidden -g  -O0 -DDEBUG -D_DEBUG
    C Compiler:                  /usr/lib/ccache/compilers/cc
    C flags (Release):           -Wl,-strip-all   -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wuninitialized -Wno-comment -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections  -msse -msse2 -msse3 -fvisibility=hidden -O3 -DNDEBUG  -DNDEBUG
    C flags (Debug):             -Wl,-strip-all   -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wuninitialized -Wno-comment -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections  -msse -msse2 -msse3 -fvisibility=hidden -g  -O0 -DDEBUG -D_DEBUG
    Linker flags (Release):      -Wl,--exclude-libs,libippicv.a -Wl,--exclude-libs,libippiw.a -L/root/ffmpeg_build/lib  -Wl,--gc-sections -Wl,--as-needed
    Linker flags (Debug):        -Wl,--exclude-libs,libippicv.a -Wl,--exclude-libs,libippiw.a -L/root/ffmpeg_build/lib  -Wl,--gc-sections -Wl,--as-needed
    ccache:                      YES
    Precompiled headers:         NO
    Extra dependencies:          ade Qt5::Core Qt5::Gui Qt5::Widgets Qt5::Test Qt5::Concurrent /lib64/libpng.so /lib64/libz.so dl m pthread rt
    3rdparty dependencies:       ittnotify libprotobuf libjpeg-turbo libwebp libtiff libopenjp2 IlmImf quirc ippiw ippicv

  OpenCV modules:
    To be built:                 calib3d core dnn features2d flann gapi highgui imgcodecs imgproc ml objdetect photo python3 stitching video videoio
    Disabled:                    world
    Disabled by dependency:      -
    Unavailable:                 java python2 ts
    Applications:                -
    Documentation:               NO
    Non-free algorithms:         NO

  GUI:
    QT:                          YES (ver 5.15.0)
      QT OpenGL support:         NO
    GTK+:                        NO
    VTK support:                 NO

  Media I/O:
    ZLib:                        /lib64/libz.so (ver 1.2.7)
    JPEG:                        libjpeg-turbo (ver 2.0.6-62)
    WEBP:                        build (ver encoder: 0x020f)
    PNG:                         /lib64/libpng.so (ver 1.5.13)
    TIFF:                        build (ver 42 - 4.0.10)
    JPEG 2000:                   build (ver 2.3.1)
    OpenEXR:                     build (ver 2.3.0)
    HDR:                         YES
    SUNRASTER:                   YES
    PXM:                         YES
    PFM:                         YES

  Video I/O:
    DC1394:                      NO
    FFMPEG:                      YES
      avcodec:                   YES (58.109.100)
      avformat:                  YES (58.61.100)
      avutil:                    YES (56.60.100)
      swscale:                   YES (5.8.100)
      avresample:                NO
    GStreamer:                   NO
    v4l/v4l2:                    YES (linux/videodev2.h)

  Parallel framework:            pthreads

  Trace:                         YES (with Intel ITT)

  Other third-party libraries:
    Intel IPP:                   2020.0.0 Gold [2020.0.0]
           at:                   /tmp/pip-req-build-ddpkm6fn/_skbuild/linux-x86_64-3.9/cmake-build/3rdparty/ippicv/ippicv_lnx/icv
    Intel IPP IW:                sources (2020.0.0)
              at:                /tmp/pip-req-build-ddpkm6fn/_skbuild/linux-x86_64-3.9/cmake-build/3rdparty/ippicv/ippicv_lnx/iw
    Lapack:                      NO
    Eigen:                       NO
    Custom HAL:                  NO
    Protobuf:                    build (3.5.1)

  OpenCL:                        YES (no extra features)
    Include path:                /tmp/pip-req-build-ddpkm6fn/opencv/3rdparty/include/opencl/1.2
    Link libraries:              Dynamic load

  Python 3:
    Interpreter:                 /opt/python/cp39-cp39/bin/python (ver 3.9)
    Libraries:                   libpython3.9.a (ver 3.9.0)
    numpy:                       /tmp/pip-build-env-jqrfyj0w/overlay/lib/python3.9/site-packages/numpy/core/include (ver 1.19.3)
    install path:                python

  Python (for build):            /bin/python2.7

  Java:
    ant:                         NO
    JNI:                         NO
    Java wrappers:               NO
    Java tests:                  NO

  Install to:                    /tmp/pip-req-build-ddpkm6fn/_skbuild/linux-x86_64-3.9/cmake-install
-----------------------------------------------------------------


  


  If relevant, the docker is installed on an Intel NUC with Ubuntu Desktop 20.04

  


  If relevant, this is the dockerfile I've used to build the image :

  


  FROM python:3.9.2-slim-buster as builder

# Keeps Python from generating .pyc files in the container
ENV PYTHONDONTWRITEBYTECODE=1
# Without this setting, Python never prints anything out.
ENV PYTHONUNBUFFERED=1

RUN pip install --upgrade pip
COPY ./Cam/requirements.txt .
RUN pip install -r requirements.txt
RUN apt-get update
RUN apt-get install ffmpeg libsm6 libxext6 -y

WORKDIR /app

FROM builder
COPY ./Cam .
CMD ["python", "camStreamer.py"]


  


  and last, this is the script code (simplified) :

  


  import os, logging, threading
from os.path import join
import sys, inspect, datetime, time
from pathlib import Path
import cv2
import imutils
from imutils.video import VideoStream

def StartRecording(showVideoWindow, interval, imagePath):
    key = None
    cam = VideoStream(os.getenv("CAM_RTSP")).start()
    counter = 0
    try:
        while True:
            ## 2 min retry to connect if frame is None
            if counter > 60/interval*2: break

            ts = time.time()
            ## Wait for [interval] seconds
            while ts + interval > time.time():
                continue
            print(f"Counter: {counter}, ts: {str(ts)}")

            frame = cam.read()
            if frame is None:
                counter += 1
                continue
            counter = 0

            print("frame is valid")
            if showVideoWindow:
                frame = imutils.resize(frame, width=1200)
                cv2.imshow('VIDEO', frame)

            imageName = f"{datetime.datetime.fromtimestamp(ts).strftime('%Y-%m-%dT%H_%M_%S')}.jpg"
            cv2.imwrite(join(imagePath, imageName), frame)
            print("saved image to disk")

            key = cv2.waitKey(1) & 0xFF
            if key == ord('q') or key == ord('r'):
                break

    except Exception as e:
        exc_tb = sys.exc_info()[2]
        extra = ""
        print(f"{inspect.stack()[0][3]}: {e} (lineno: {exc_tb.tb_lineno}) {extra}")
    finally:
        if showVideoWindow: cv2.destroyAllWindows()
        cam.stop()
        return key


while True:
    log.warning(f"Starting {Name}")
    key = StartRecording(
                showVideoWindow=(Env.startswith("development") and os.getenv("SHOW_VIDEO") == "True"),
                interval=int(os.getenv("SAVE_IMAGE_INTERVAL")),
                imagePath=os.getenv('CAPTURE_FOLDER')
                )
    if key == ord('q'):
        break


  


  I apologize for the very long post. Hopefully someone can put me on the right direction...

  


• OpenCV 3.0.0 make error with FFMPEG

  14 octobre 2017, par Ujjwal Aryan

  I have been using OpenCV for a while. However I have recently changed my system to a cluster where I do not have any admin permission. The problem is like this :

  In my home folder, I installed FFMPEG (latest stable version available on ffmpeg site). I installed it in $HOME, and so in $HOME/lib there are the library files installed. For more information I compiled FFMPEG with following options :

  ./configure --prefix=$HOME --enable-shared --enable-pic

  I then downloaded the latest stable version of OpenCV 3.0.0 and configured it using ccmake. When I try to make -j8, it gives me the following error.

   Scanning dependencies of target opencv_videoio
  
  [ 63%] [ 63%] [ 63%] [ 63%] [ 63%] [ 63%] Building CXX object modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap.cpp.o
  
  Building CXX object modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap_mjpeg_decoder.cpp.o
  
  Building CXX object modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap_images.cpp.o
  
  Building CXX object modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap_v4l.cpp.o
  
  Building CXX object modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap_mjpeg_encoder.cpp.o
  
  Building CXX object modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap_ffmpeg.cpp.o
  
  In file included from /home/uujjwal/libraries/opencv-nogpu/opencv-3.0.0/modules/videoio/src/cap_ffmpeg.cpp:45:0:
  
  /home/uujjwal/libraries/opencv-nogpu/opencv-3.0.0/modules/videoio/src/cap_ffmpeg_impl.hpp:1546:71: error: use of enum 'AVCodecID' without previous declaration
  
  /home/uujjwal/libraries/opencv-nogpu/opencv-3.0.0/modules/videoio/src/cap_ffmpeg_impl.hpp:1556:83: error: use of enum 'AVCodecID' without previous declaration
  
  make[2]: *** [modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap_ffmpeg.cpp.o] Error 1
  
  make[2]: *** Waiting for unfinished jobs....

  However without ffmpeg support it works fine. However I need ffmpeg support due to the nature of my work.

  In trying to resolve the problem, I tried installing OpenCV 2.4.11 but it also gave this error. The latest GIT version does not give me this error but rather an error a part of which goes like this

  Linking CXX shared library ../../lib/libopencv_highgui.so /usr/bin/ld: /home/matheus/ffmpeg_build/lib/../lib/libavcodec.a(avpacket.o): relocation R_X86_64_32 against `.rodata.str1.1' can not be used

  I have pasted the above error from another unresolved question online and so the folder names are different but the relocation error is exactly the same.

  In trying to resolve the problem I searched and found the following link http://answers.opencv.org/question/12597/build-problems-for-opencv-241-with-ubuntu-1204-lts/

  However, one of the answers over there mentioned changing some lines in cap_ffmpeg_impl.hpp file. I tried doing that but either i am not able to do it correctly or something else is going wrong and it is not working. Exact line numbers and exact changes are not mentioned and so I am having difficulty changing things and being sure.

  I am using Fedora 19 (Schrodinger Cat) as the operating system I hope the details of my question are clear and I hope that the community would oblige me with a good response.

  Regards
  Ujjwal