Recherche avancée

Sur d’autres sites (5261)

• Compiling FFmpeg lib and add it to NDK sources on Windows8

  28 septembre 2014, par Dalvik

  I’ve seen some articles about how to compile and uses FFmpeg for Android.

  Thess are good examplea - example1 and example2

  Unfortunately, non off them, or others I found helped me. In those two examples a build_android.sh is created and configure the FFmpeg’s configuraion file and call to make. Every time when I’m running the script I’m getting the following error :

  c:\android\development\android-ndk-r9\sources\ffmpeg>sh build_android.sh
  
  c:/android/development/android-ndk-r9/toolchains/arm-linux-androideabi-4.8/prebu
  
  ilt/windows-x86_64/arm-linux-androideabi/bin/bin/arm-linux-androideabi-gcc is un
  
  
  
  able to create an executable file.
  
  C compiler test failed.
  
  
  
  If you think configure made a mistake, make sure you are using the latest
  
  version from Git.  If the latest version fails, report the problem to the
  
  ffmpeg-user@ffmpeg.org mailing list or IRC #ffmpeg on irc.freenode.net.
  
  Include the log file "config.log" produced by configure as this will help
  
  solving the problem.
  
  Makefile:2: config.mak: No such file or directory
  
  Makefile:49: /common.mak: No such file or directory
  
  Makefile:92: /libavutil/Makefile: No such file or directory
  
  Makefile:92: /library.mak: No such file or directory
  
  Makefile:169: /doc/Makefile: No such file or directory
  
  Makefile:170: /tests/Makefile: No such file or directory
  
  make: *** No rule to make target `/tests/Makefile'.  Stop.
  
  Makefile:2: config.mak: No such file or directory

  If someone encountered and solved this issue it’ll be much appreciated !

  After trying the suggested script I ran into a new problem that I couldn’t solved, this is the output of the script :

  .... Enabled components list....

  In the end of the list I got the following :

  Enabled indevs :
  dv1394 v4l2i
  fbdev

  Enabled outdevs :
  fbdev v4l2

  License : LGPL version 2.1 or later
  Creating config.mak, config.h, and doc/config.texi...

  WARNING : C :/android/development/android-ndk-r9/toolchains/arm-linux-androideabi-
  4.8/prebuilt/windows-x86_64/bin/arm-linux-androideabi-pkg-config not found, libr
  ary detection may fail.
  make : * No rule to make target libavfilter/libavfilter.so', needed byall-ye
  s’. Stop.
  make : * No rule to make target install-libavfilter-shared', needed byinstal
  l-libs-yes’. Stop.

• Android encode video with ffmpeg while it is still recording

  30 décembre 2016, par Andreas Pabst

  I want to develop an android aplication which allows me to continuously record a video and upload parts of the video to a server without stopping the recording.
  It is crucial for the application that I can record up to 60 min without stopping the video.

  Initial approach

  Application consits of two parts :

  1. MediaRecorder which records a video continuously from the camera.
  2. Cutter/Copy - Part : While the video is recorded I have to take out certain segments and send them to a server.
     This part was implemented using http://ffmpeg4android.netcompss.com/
     libffmpeg.so. I used their VideoKit Wrapper which allows me to directly run ffmpeg with any params I need.

  My Problem

  I tried the ffmpeg command with the params

  ffmpeg -ss 00:00:03 -i  -t 00:00:05 -vcodec copy -acodec copy  

  which worked great for me as long as Android’s MediaRecorder finished recording.

  When I execute the same command, while the MediaRecorder is recording the file, ffmpeg exits with the error message "Operation not permitted".

  • I think that the error message doesn’t mean that android prevents the access to the file. I think that ffmpeg needs the "moov-atoms" to find the proper position in the video.

  For that reason I thought of other approaches (which don’t need the moov-atom) :

  1. Create a rtsp stream with android and access the rtsp stream later. The problem is that to my knowledge android SDK doesn’t support the recording to a rtsp stream.
  2. Maybe it is possible to access the camera directly with ffmpeg (/dev/video0 seems to be a video device ?!)
  3. I read about webm as an alternative for streaming, maybe android can record webm streams ?!

  TLDR : Too long didn’t read :

  I want to access a video file with ffmpeg (libffmpeg.so) while it is recording. Fffmpeg exits with the error message "Operation not permitted"

  Goal :

  My goal is to record a video (and audio) and take parts of the video while it is still recording and upload them to the server.

  Maybe you can help me solve the probelm or you have other ideas on how to approach my problem.

  Thanks a lot in advance.

• Expanding media capabilities of Win Embedded CE 6.0

  1er décembre 2014, par Simo Erkinheimo

  I have an embedded device with WinCE 6.0 as OS. The manufacturer provides an IDE for 3rd party development to it. The IDE pretty much allows nothing else than

  • .NET 3.5 Compact Framework scripting that’s invoked from various events from the main application
  • Adding files to the device.

  The included mediaplayer seems to be using DirectShow and the OS has media codec only for mpeg-1 encoded video playback. My goal is to to be able to play media encoded with some other codecs as well inside that main application.

  I’ve already managed to use DirectShowNETCF (DirectShow wrapper for .NET Compact Framework) and successfully playback mpeg-1 encoded video.

  I’m totally new with this stuff and I have tons of (stupid) questions. I’ll try to narrow them down :

  • The OS is based on WinCE, but as far as I’ve understood, it’s actually always some customized version of it (via Platform Builder). Only "correct way" of developing anything for it afterwards is to use the SDK the manufacturer usually provides. Right ? In my case, the SDK is extremely limited and tightly integrated into IDE as noted above. However, .NET CF 3.5 is capable for interop so its possible to call native libraries -as long as they are compiled for correct platform.

  • Compiled code is pretty much just instructions for the processor (assembler code) and the compiler chooses the correct instructions based on the target processor setting. Also there’s the PE-header that defines under which platform the program is meant to be run. If I target my "helloworld.exe" (does nothing but returns specific exit code) to x86 and compile it with VC, should it work ?

  • If the PE-header is in fact the problem, is it possible to setup for WINCE without the SDK ? Do I REALLY need the whole SDK for creating a simple executable that uses only base types ? I’m using VS2010, which doesn’t even support smart device dev anymore and I’d hate to downgrade just for testing purposes.

  • Above questions are prequel to my actual idea : Porting ffmpeg/ffdshow for WinCE. This actually already exists, but not targeted nor built for Intel Atom. Comments ?

  • If the native implementation is not possible and I would end up implementing some specific codec with C#...well that would probably be quite a massive task. But having to choose C# over native, could I run into problems with codec performance ? I mean.. is C# THAT much slower ?

  Thank you.