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• ffmpeg playback problems when concatenating 2 gif of same type into 1 file without re-encoding [closed]

  15 juin 2022, par kite

  I see this information here, but it didn't help :
https://stackoverflow.com/a/11175851/11361179

  


  Given 2 gif files 1.gif 2.gif of same type, I want to merge them into a single .gif file and stream without re-encode. Following the instructions here https://trac.ffmpeg.org/wiki/Concatenate : I make a list in windows called mylist with the names, then I concatenate using the below. The file created only runs correctly in ffplay though, anywhere else it will simply repeat the first 1.gif over and over and not play the other.

  


  (for %i in (*.gif) do @echo file '%i') > mylist.txt
ffmpeg -f concat -i mylist.txt -c copy output.gif


  


  I downloaded the newest version of ffmpeg and it didn't change anything. I also tried : ffmpeg -i "concat:input1|input2" -codec copy output.mkv. No change. I need the output to play properly in programs other than ffplay.

  


  The file generated is of the same length as 1.gif rather than the combined, and seeking has issues in ffplay, so there seems to be an issue with the output not having the right metadata for proper playback. All 3 files are the exact same in ffprobe except their bitrate value, as they should be since both gif were taken in same program with same settings of same length....with the exception that the third gif should be the combined length which it isn't. Removing -c copy and re-encoding works but generates a gif 50x the size of horrid quality.

  


• Problem while building libffmpeg.so from ffmpeg sources (undefined symbol : avcodec_version)

  10 octobre 2023, par serggt1

  I'm trying to build libffmpeg.so shared library from sources on Linux. Sources are here FFmpeg.git.

  


  I run

  


  ./configure
make -j4

gcc -shared \
    libavcodec/libavcodec.a \
    libavdevice/libavdevice.a \
    libavfilter/libavfilter.a \
    libavformat/libavformat.a \
    libavutil/libavutil.a \
    libswresample/libswresample.a \
    libswscale/libswscale.a \
    -o libffmpeg.so


  


  The problem is the resulting libffmpeg.so is only 15 KB and says

  


  dlsym fail : /opt/yandex/browser/libffmpeg.so: undefined symbol: avcodec_version


  


  What do I wrong and how to link the library in correct way ?

  


  UPD :

  


  Now trying with this :

  


  ./configure --enable-pic --disable-programs  --enable-gpl --enable-version3 --enable-nonfree

make -j4

ld \
    -rpath-link=/usr/lib \
    -L/usr/lib \
    -L/lib \
    --library=c --library=m --library=z --library=dl --library=log \
    -soname libffmpeg.so -shared -nostdlib -Bsymbolic --whole-archive --no-undefined \
    libavcodec/libavcodec.a \
    libavdevice/libavdevice.a \
    libavfilter/libavfilter.a \
    libavformat/libavformat.a \
    libavutil/libavutil.a \
    libswresample/libswresample.a \
    libswscale/libswscale.a \
    -o libffmpeg.so


  


  Error is ld: cannot find -lc: No such file or directory

  


• Building optional libraries into FFmpeg on OS X 10.9.4

  30 août 2014, par user3539778

  I’m not managing FFmpeg configure to find installed libopencore or other
  external libraries. The code below includes research so far to solve it. These external libraries are installed in /usr/local/ . The configure for these libraries was

  --enable-shared \
  
  --enable-static \
  
  --disable-dependency-tracking \
  
  --disable-libtool-lock

  My FFmpeg configure is

  ./configure --prefix=/usr/local \
  
  --shlibdir=/usr/local/lib \
  
  --extra-cflags=-I/usr/local/include \
  
  --disable-avdevice \
  
  --disable-avfilter \
  
  --disable-bzlib \
  
  --disable-debug \
  
  --disable-doc \
  
  --disable-iconv \
  
  --disable-postproc \
  
  --disable-programs \
  
  --disable-swresample \
  
  --disable-swscale \
  
  --disable-static \
  
  --disable-zlib \
  
  --enable-shared \
  
  --enable-gpl \
  
  --enable-version3 \
  
  --enable-libopencore-amrnb \
  
  --enable-libopencore-amrwb \
  
  --enable-libopus \
  
  --enable-libspeex \
  
  --enable-libvo-aacenc \
  
  --enable-libvo-amrwbenc

  End of config.log shows

  ffconf.YCeYsFXo /var/folders/c0/8p18hd453p3_433cf9_595b40000gn/
  
  T//ffconf.Nnm5uT0x.o     -lopencore-amrnb -lm -pthread
  
  clang: warning: argument unused during compilation: '-pthread'
  
  ld: library not found for -lopencore-amrnb
  
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  
  ERROR: libopencore_amrnb not found

  I can build FFmpeg fine with no external libraries.