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• Appending Video Stream to Existing or New File Using FFmpeg

  10 septembre 2013, par petre

  I can record 320x240 5-fps h264-encoded grayscale stream from internal webcam of my laptop to avi file. Beside this function, i can manage to extract a grayscale jpeg file every 5 seconds.

  I do want to record from webcam to file cumulatively to the file. If file (output avi) exists, script should append stream to end of file. If file does not exist, script should create file and then write.

  My code (script) overwrites the existing file, not appends to the end of file.

  How can i achieve this functionality ?

  Here is my design :

  ffmpeg -f video4linux2 -i /dev/video0 -c:v libx264 -r 5 -s 320x240 -vf format=gray /home/aydu/Desktop/demo/cam0.avi -r 1/5 -vf format=gray -f image2 -updatefirst 1 /home/aydu/Desktop/demo/image.jpeg

• How to build ffmpeg in android app ?

  24 mars 2014, par Sandeep Tiwari

  After successfully build ffmpeg by bellow steps

    http://stackoverflow.com/questions/22471514/ffmpeg-build-output-is-not-showing
  
  
  
    Now I have copy include and all .a file into my JNI folder. and my Android.mk 
  
    file is as:-
  
  
  
  
  
  
  
        LOCAL_PATH := $(call my-dir)
  
  
  
          include $(CLEAR_VARS)
  
  
  
          LOCAL_MODULE    := ffmpegutils
  
         LOCAL_SRC_FILES := tutorial02.c
  
  
  
        LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
  
        LOCAL_LDLIBS := -L$(NDK_PLATFORMS_ROOT)/$(TARGET_PLATFORM)/arch-arm/usr/lib -L$(LOCAL_PATH) -lavformat -lavcodec  -lavfilter -lavutil -lswscale -llog -ljnigraphics -lz -ldl -lgcc
  
  
  
  include $(BUILD_SHARED_LIBRARY)

  but my project giving error as :-

       Description    Resource    Path    Location    Type
  
  make: *** [obj/local/armeabi/libffmpegutils.so] Error 1 MainActivity            C/C++ Problem
  
  undefined reference to 'ANativeWindow_unlockAndPost'    MainActivity        line 231, external location: /home/kiwitech/Documents/development/tools/ndk/android-ndk-r9d/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/ffmpegutils/tutorial02.o: in function decodeAndRender:jni/tutorial02.c   C/C++ Problem
  
  undefined reference to 'ANativeWindow_lock' MainActivity        line 222, external location: /home/kiwitech/Documents/development/tools/ndk/android-ndk-r9d/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/ffmpegutils/tutorial02.o: in function decodeAndRender:jni/tutorial02.c   C/C++ Problem
  
  undefined reference to 'ANativeWindow_release'  MainActivity        line 150, external location: /home/kiwitech/Documents/development/tools/ndk/android-ndk-r9d/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/ffmpegutils/tutorial02.o: in function naSetSurface:jni/tutorial02.c  C/C++ Problem
  
  undefined reference to 'ANativeWindow_setBuffersGeometry'   MainActivity        line 147, external location: /home/kiwitech/Documents/development/tools/ndk/android-ndk-r9d/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/ffmpegutils/tutorial02.o: in function naSetSurface:jni/tutorial02.c  C/C++ Problem
  
  undefined reference to 'ANativeWindow_fromSurface'  MainActivity        line 145, external location: /home/kiwitech/Documents/development/tools/ndk/android-ndk-r9d/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/ffmpegutils/tutorial02.o: in function naSetSurface:jni/tutorial02.c  C/C++ Problem

  please anyone help me.

• How to put a video inside a frame and record whole thing as a video ?

  7 octobre 2024, par crysis

  I have a video. I want to create a new video such that the video plays inside a frame similar to this screenshot. Loom recording does this. Most of the screen recorders do this.

  


  

  


  This screenshot is of the video. This is done in most of the screen recorders. Here is what I'm thinking

  


  

  • render video on a canvas with the background.

  


  • Play the video

  


  • Use mediarecorder API to record a new video.

  


  


  I don't have good understanding of frontend development. Is that how it is generally done or I need to use ffmpeg ? I would really appreciate any guidance here.