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• Delphi android, deploying AND dynamic loading (external) libraries

  13 décembre 2020, par coban

  I am trying to start creating an application to test FFmpeg libraries, kind of a mediaplayer application, for ANDROID using Delphi 10.3/10.4

  


  I am getting some (strange ?) behaviors on different machines and locations of the files on the phone/tablet.

  


  The very first question should be ; what folder is the right one to put (external) libraries for dynamic/static loading ?

  


  I tried 2 locations ; '.\assets\internal' -> 'files' folder of the app
and 'library\lib\armeabi-v7a' -> bin folder (if i'm right)

  


  behavior on mobile phone Android 8

  


  when I choose to place the (FFmpeg) libraries in the Files folder '.\assets\internal' and try to load the libraries, 3 of the 7 libraries succesfully loads, while the other does not. Every tiem the same libraries which fail and succeeds to load. The succesfully loading libraries are 'libavutil.so', 'swresample.so' and 'libswscale.so'.

  


  When I choose to place the libraries in the bin folder 'library\lib\armeabi-v7a', all libraries are succesfully loaded.

  


  behavior on tablet android 4.4.4

  


  When choosing to put the libraries in the 'Files' folder, exact the same behavior as "Android 8 phone".

  


  The strange thing is ; When I choos the bin folder, none of the libraries are being loaded ?

  


  I did not compile/build the (FFmpeg) libraries myself, I downloaded them.
I tried libraries from different places.
In every attempt I checked for the existance of the files.
I used 'loadlibrary' function, after some reading and suggestions on the internet I allso tried 'dlopen' function directly which looks like unnecessary to use it directly after all.
I was not able to debug using D10.4 and Android 4.4.4 tablet, because of the minsdk version. Using D10.3 I am able to try on both machines.

  


  Delphi10.3 'Android SDK 25.2.5 32bit', 'jdk1.8.0_60'

  


  Delphi10.4 'Android SDK 25.2.5 32bit', 'AdoptOpenJDK jdk-8.0.242.08-hotspot'

  


  Any idea why 3 of the libraries are able to load in case of they are in the 'Files' folder while all of them can be loaded when they are in the 'BIN' folder (android 8) ?
And why does nothing load by android 4.4.4 when the files are in the 'Bin' folder while 3 of them are able to be loaded when they are placed in the 'Files' Folder ?

  


  I've been using FFmpeg libraries for windows (allmost)without issues, my question should not be FFmpeg specific but Delphi+android+(external)libraries specific except if this behavior is FFmpeg specific.

  


  Both are Samsung machines,

  


  Android 4.4 tablet cpu (using 'syscheck' embarcadero recommends);

family = ARM
processor = ARMv7 processor rev 5(v7I)
CPU Cores = 4
neon supported  yes
armv7 (ARMv7 compatible architecture)  yes

Android 8 phone cpu

Family   ARM
processor   unknown
CPU Cores   8
Neon   yes
armv7 = Arm
armv7 (ARMv7 compatible architecture)   yes


  


  Edit

  


  Test on Android 10, redmi note 10 lite

  


  None of the library files are being loaded from the 'Files'->'.\assets\internal' folder. All library files are being succesfully loaded from the 'Bin'->'library\lib\armeabi-v7a' Folder.

  


  I'll need an reasonably explanation for this. It looks like Andrid specific behavior ?

  


  Edit 2

  


  One of the reasons seems like that some those FFmpeg libraries are loading other FFmpeg libraries, even if they are in the same directory, if they are outside the folder of the EXE file, or not in a (library) folder where the OS searches by default, they cannot find/load eachother.

  


  This looks like the explanation why some of them are able to load in the 'Files'->'.\assets\internal' folder.

  


• ffmpeg- is there any limitation on number of drawtext filter used in a single command ?

  31 mars 2017, par hack

  i have to write different text on a number of images. The final filter command is quite large (> 500 draw text filters in a single command). I am writing this to a text file and using filter_complex_script to read it.
  If the number of frames and filter is small, it is working fine, but for a configuration with large number of images and draw text filters, it fails. Error is :

  Cannot find a valid font for the family Sans
  
  Error initializing filter 'drawtext' with args 'enable=between(n,180,180):fontsize=28:fontfile=C\:/Windows/Fonts/Arial.ttf:fontcolor=0x000000:text=109.0:x=581:y=527-th'
  
  Error initializing complex filters.
  
  No such file or directory

• Overlay text on video with ffmpeg

  7 avril 2017, par ACIDSTEALTH

  I have some short mp4 video clips. Each one represents a response to a question or prompt. I would like to overlay the question/prompt text atop a grey semi-opaque banner. I need to be able to control the size, position, color, and opacity of the grey banner as well as the size, color, font family, justification, etc of the text that is overlaid atop it.

  I’ll prepend my question by stating that my experience with ffmpeg is limited to applying watermarks to videos via it’s Ruby wrapper streamio-ffmpeg. I know what I want to do is possible, I just don’t know where to begin. What I would like to know is how I can do this with ffmpeg. Specifically I am hoping for some sample code that I can learn from and adapt to my specific need, as well as how I can execute that code on a video within the context of a Rails app.