Newest 'ffmpeg' Questions - Stack Overflow

http://stackoverflow.com/questions/tagged/ffmpeg

Les articles publiés sur le site

  • Get frame type for specific frame using ffmpeg

    1er juin 2016, par Damnesia

    I need to get the frame type (I/B/P) of a specific frame number for an x264 encoded movie.

    How do I do this using ffmpeg/ffprobe? I'm open to other solutions as well.

  • How to Extract Timestamps and Corresponding Screenshots from .MTS File ?

    1er juin 2016, par broyang

    I have a .MTS file, and I want to output its timestamps every n milliseconds. I have to match each timestamp with its corresponding screenshot of the video.

    I tried using avchd2srt to output each timestamp, but it outputs a .srt file. I'm trying to output the timestamps in a .txt file, and the pictures in jpeg format. Does anyone have suggestions on what to do?

  • FFmpeg - Finally compiled. Now what ?

    1er juin 2016, par Gopgop

    OK So here is my story:

    I am creating an app that requires me to take a couple images and a video and merge them together. At first I had no idea what to use, never heard of ffmpeg or ndk.. After around 5 days of battling NDK, switching to Ubuntu and going crazy with ndk-build commands I finally got FFmpeg to compile using the dolphin-player example. Now that I can run ffmpeg on my computer and android device I have no idea what to do next.

    Here are the main questions I have:

    • To use FFmpeg, I saw that I need to use some sort of commands. First off what are these commands, where do I run them?

    • Second of all, Are the commands all I need? By that I mean can i just run my application normally, somewhere in it execute the commands in some way and it will do the rest for me? or do I need some sort of element in the code, for example VideoEncoder instance or something..

    • Third of all, I saw people using NDK to use FFmpeg, Do I have to? Or is it optional? I would like to avoid using C if possible as I don't know it at all..

    • OPTIONAL: Last but not least, Is this the best way of handling what I need to do in my application? If so, can someone guide me in a brief manner of how to use FFmpeg to accomplish said task (mention commands or anything like this)..

    I know it's a wall of text but every question is important to me!

    Thank you very much stackoverflow community!

  • C++ : Combine 4 YV12 images to a single image (4 quadrants). FFMPEG ?

    1er juin 2016, par Paul Knopf

    I have 4 YV12 buffers that I need to combine to a single buffer (4 quadrants).

    I could manually write a bunch of memcpy stuff with offsets, but I fear performance issues.

    Is there an FFMPEG method that I can use to achieve this?

    AVFrame* topLeft = ...
AVFrame* topRight = ...
AVFrame* bottomLeft = ...
AVFrame* bottomRight = ...
AVFrame* destination = ... // topLeft-size + topRight->size + bottomLeft->size + bottomRight ->size

    Maybe there is a method with a similar signature here?

    void blend_image(AVFrame* src, AVFrame dest, int x, int y);

    Then...

    blend_image(topLeft, destination, 0, 0);
blend_image(topRight, destination, 1920, 0);
blend_image(bottomLeft, destination, 0, 1080);
blend_image(bottomRight, destination, 1920, 1080);

    Any guidance would be greatly appreciated.

  • I can't seem to install opencv2.4.13 for Python3.4 on Mac El Capitan

    1er juin 2016, par ThatProgrammerDude

    This has been driving me nuts. I have been working on this non stop for a week. I have looked at many tutorials online they did not help.

    I have tried so much I don't even remember what I tried. I can say the last thing I tried though.. which is this video https://www.youtube.com/watch?v=U49CVY8yOxw.

    So I download opencv2.4.13, create the build folder, open cmake, configure, generate and then go to terminal and type in make.

    I get this:

    Richie's Macbook Air:build Richie$ make
[  2%] Built target zlib
[  6%] Built target libtiff
[ 10%] Built target libjpeg
[ 14%] Built target libjasper
[ 16%] Built target libpng
[ 23%] Built target IlmImf
[ 26%] Built target opencv_core
[ 31%] Built target opencv_imgproc
[ 32%] Built target opencv_video
[ 32%] Built target opencv_flann
[ 32%] Building CXX object modules/highgui/CMakeFiles/opencv_highgui.dir/src/cap_ffmpeg.cpp.o
In file included from /Users/Richie/Downloads/opencv-2.4.13/modules/highgui/src/cap_ffmpeg.cpp:45:
/Users/Richie/Downloads/opencv-2.4.13/modules/highgui/src/cap_ffmpeg_impl.hpp:71:6: error: 
      "libswscale is necessary to build the newer OpenCV ffmpeg wrapper"
    #error "libswscale is necessary to build the newer OpenCV ffmpeg wrapper"
     ^
/Users/Richie/Downloads/opencv-2.4.13/modules/highgui/src/cap_ffmpeg_impl.hpp:481:9: error: 
      use of undeclared identifier 'sws_freeContext'
        sws_freeContext(img_convert_ctx);
        ^
/Users/Richie/Downloads/opencv-2.4.13/modules/highgui/src/cap_ffmpeg_impl.hpp:965:17: error: 
      use of undeclared identifier 'SWS_BICUBIC'
                SWS_BICUBIC,
                ^
/Users/Richie/Downloads/opencv-2.4.13/modules/highgui/src/cap_ffmpeg_impl.hpp:998:5: error: 
      use of undeclared identifier 'sws_scale'
    sws_scale(
    ^
/Users/Richie/Downloads/opencv-2.4.13/modules/highgui/src/cap_ffmpeg_impl.hpp:1639:46: error: 
      use of undeclared identifier 'SWS_BICUBIC'
                                             SWS_BICUBIC,
                                             ^
/Users/Richie/Downloads/opencv-2.4.13/modules/highgui/src/cap_ffmpeg_impl.hpp:1645:14: error: 
      use of undeclared identifier 'sws_scale'
        if ( sws_scale(img_convert_ctx, input_picture->data,
             ^
/Users/Richie/Downloads/opencv-2.4.13/modules/highgui/src/cap_ffmpeg_impl.hpp:1693:9: error: 
      use of undeclared identifier 'sws_freeContext'
        sws_freeContext(img_convert_ctx);
        ^
/Users/Richie/Downloads/opencv-2.4.13/modules/highgui/src/cap_ffmpeg_impl.hpp:2290:9: warning: 
      ignoring return value of function declared with warn_unused_result
      attribute [-Wunused-result]
        avformat_write_header(oc_, NULL);
        ^~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~
1 warning and 7 errors generated.
make[2]: *** [modules/highgui/CMakeFiles/opencv_highgui.dir/src/cap_ffmpeg.cpp.o] Error 1
make[1]: *** [modules/highgui/CMakeFiles/opencv_highgui.dir/all] Error 2
make: *** [all] Error 2
Richie's Macbook Air:build Richie$

    From what I can see, it says

    "libswscale is necessary to build the newer OpenCV ffmpeg wrapper"

    I have tried googling though to no avail, does anyone know?

    EDIT: I do have ffmpeg installed... (brew).

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