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• How do I actually use ffmpeg on Android ?

  14 mars 2021, par slhck

  I have a very basic question regarding Android and ffmpeg. I obtained ffmpeg from http://bambuser.com/opensource and was able to compile it for ARM.

  



  The results are the binaries (ffmpeg) as well as several libsomething.so files.

  



  My question is : Is this enough to decode videos ? How do I actually use ffmpeg then ?

  



  To load the library I have :

  



  static {
    System.load("/data/data/com.package/lib/libavcodec.so");
 }


  



  It loads fine. But what then ?

  



  _{
More explanation : I saw other projects where people had their ffmpeg source in a JNI directory in the project. They also created some Android.mk files and some C code along with it. Would I need this as well ? Why would I create the .so files first and then copy the ffmpeg source code again ?
}

  



  _{
I know the NDK and how it should work but I've never seen an example of how one would actually call ffmpeg functions using it, because people seem to be hiding their implementations (which is sort of understandable) but not even giving useful pointers or examples.
}

  



  _{
Let's just say I wanted to decode a video file. Which kind of native methods would I need to implement ? How do I run the project ? Which data types need to be passed ? etc. There are certainly a few people here who have at least done that, I know this from searching for hours and hours.
}

  


• ffmpeg - invalid duration

  22 septembre 2016, par OmidAntiLong

  For a project I’m working on I have a small bash script that loops over an input csv file of timecodes, and uses ffmpeg to create screenshots of a given film at each timecode. The csv file is in the format hh:mm:ss,id - it looks like this (extract)

  00:00:08,1
  
  00:00:49,2
  
  00:01:30,3
  
  00:02:38,4
  
  00:03:46,5
  
  00:04:08,6
  
  00:04:26,7
  
  00:04:37,8
  
  00:04:49,9
  
  00:05:29,10
  
  00:05:52,11
  
  00:06:00,12
  
  00:06:44,13
  
  00:07:49,14
  
  00:08:32,15
  
  00:09:28,16
  
  00:10:17,17
  
  00:10:44,18
  
  00:11:48,19
  
  00:12:07,20

  I’ve used it without issue in the past, but today I’ve come to update some of the films and I’m getting a weird issue where ffmpeg is complaining that my input timecode is invalid, despite being in the right format.

  The new input csv files are the same format as the old ones, but it seems like every so often ffmpeg drops the hours from the hh:mm:ss timestamp. If I comment out the ffmpeg line, everything prints to the terminal as expected (but obviously I get no screenshots).

  This is my loop code :

  while read code a
  
  do
  
    echo $code
  
    f="$(printf "%03d" $i)"
  
  
  
    ffmpeg -loglevel error -y -ss $code -i $FILM -vframes 1 -q:v 2 $OUTPUT/$f.jpg
  
  
  
    ((i++))
  
  done < $INPUT

  I’ve tried all sorts, including padding the csv with extra 0s - which works until the hours tick over to 01.

  

  Does anyone have any ideas ? I’m scratching my head.

  Cheers

• linphone on windows building error

  21 novembre 2013, par chhameed

  i have downloaded the linphone for Android from Github.
  i have also followed all the instructions in readme file. the problem is that when i run ndk-build command it produce below error .

  Android NDK: ERROR:jni/..//submodules/externals/build/ffmpeg/Android.mk:avutil-linphone: LOCAL_SRC_FILES points to a missing file
  
  Android NDK: Check that jni/..//submodules/externals/build/ffmpeg/arm/libavutil/libavutil-linphone-arm.so exists  or that its path is correct
  
  /cygdrive/c/development/android-ndk-r9b/build/core/prebuilt-library.mk:45: *** Android NDK: Aborting    .  Stop.

  what this error mean ? & how can i resolve this? i already spent many hours to searchout this error but no success...
  my OS is window 7 & i used cygwin for commands.

  i have found same question on SO
  Android NDK error when using FFmpeg in Android ?

  it says Basically problem was with ffmpeg lib.I was not able to compile ffmpeg lib on Windows 7. I switched to Ubuntu & tried AppUnite & after spending so many hours it was working.

  is it not possible to build linphone on windows ???