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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 Re-muxing .MKV to MP4\MV4 while retaining Dolby Digital Plus [closed]

  30 décembre 2020, par David F

  I would be grateful if anyone could help me out here. I'm remuxing a large number of video files from .MKV to .MP4\M4V so they play on the Apple platform (including the TV App) without any issues. It has been a bit of a learning curve, but I’m so close now. It's important NOT to convert, but to remux.

  


  I have achieved the ability to remux 4K HDR with Dolby Digital Plus in a .MKV to 4K HDR with Dolby Digtial 5.1. MP4. The issue is retaining the Dolby Digital Plus. This contains the ATMOS information for object based sound.

  


  The media players on Apple reports Dolby Digital Plus for the .MKV and Dolby Digital 5.1 for .MP4

  


  I'm using FFMPEG with the following command :-

  


  ffmpeg -i original.mkv -c:v copy -c:a eac3 -tag:v hvc1 output.mp4

  


  Output from MediaInfo (note .MKV contains only 1 video and 1 audio track)

  


  Audio -----Original.mkv

  


  

  • ID : 2

  


  • Format : E-AC-3 JOC

  


  • Format/Info : Enhanced AC-3 with Joint
Object Coding

  


  • Commercial name : Dolby Digital Plus with Dolby
Atmos

  


  • Codec ID : **A_**EAC3

  


  • Duration : 51 min 51 s

  


  • Bit rate mode : Constant

  


  


  Audio ----- Remuxed .mp4

  


  

  • ID : 2

  


  • Format : E-AC-3

  


  • Format/Info : Enhanced AC-3

  


  • Commercial name : Dolby Digital Plus

  


  • Codec ID : ec-3

  


  • Duration : 51 min 51 s

  


  • Bit rate mode : Constant

  


  


  The remux operation finished in about 1 minute for a 8Gb 4k video file, so we I know there is no reencoding. My theory is the stream is still a E-AC-3 with Joint Object Control, but its marked as a E-AC-3.

  


  I can see that .mp4 can take E-AC-3 Joint Object Control (JOC) with the demo files from Dolby labs.

  


  I've also remuxed an MKV to MKV and able to see the same result. The JOC markings have been removed with FFMPEG

  


  My ask is, does anyone have any knowledge of how to remux and keep Enhanced AC-3 with Joint Object Control with FFMPEG. Does FFMPEG support this ?

  


  Or know if just editing the Format, Format/Info, and Code ID is enough and the sound information in my .MP4\M4V is E-AC-3 JOC. If so can I just edit the media info, if so how ?

  


  I know Dolby Labs to allow free remuxing of Dolby Digital Plus/ Atmos with sample code and information they have uploaded onto Github for developers. I just wonder if FFMPEG supports it

  


  Thanks in advanced.

  


  David

  


• How to make a batch file wait for all processes of another call to finish before continuing

  1er juillet 2020, par Roman Stadler

  The idea of this script is to take a (lecture) video, split it into smaller pieces, remove the silence for each one, and merge them back together, for increased performance, since the silence-removing script does not scale that well for larger videos.

  


  The 3 batch scripts below work perfectly when started manually after eachother, but when trying to launch them from a single .bat file, I can't prevent them from starting at the same time, which creates errors at the merging stage.

  


  These are the 3 batch files :

  


  

  1. split.bat

  


  2. startall.bat

  


  3. merge.bat

  


  


  Split.bat creates 10 minute long segments, afterwards, startall.bat starts one Video-Remove-Silence task for every segment. At the end, merge.bat creates one single mp4 file with all the segments.

  


  split.bat does the following :

  


  ffmpeg -i in.mp4 -c copy -map 0 -segment_time 00:10:00 -f segment out%%03d.mp4
exit


  


  startall.bat :

  


  start start000.bat
start start001.bat
start start002.bat
start start003.bat
...


  


  The start000.bat call looks like this :

  


  python video-remove-silence out000.mp4 --linear 0.0005
exit


  


  And merge.bat :

  


  :: Create File List
for %%i in (*_result.mp4) do echo file '%%i'>> mylist.txt
:: Concatenate Files
ffmpeg -f concat -safe 0 -i mylist.txt -c copy shortened.mp4

del "C:\Users\Roman\Desktop\download\mylist.txt"
del "C:\Users\Roman\Desktop\download\out*.mp4"
exit


  


  When trying either call, or start /wait, errors occur due to simultaneous execution :

  


  START /wait split.bat
START /wait startall2.bat
START /wait merge.bat


  


  So basically my question is, how can I call these 3 scripts and prevent merge.bat from starting, until all processes inside startall.bat have finished ?