Recherche avancée

Sur d’autres sites (6941)

• Issue with Asynchronous Video Processing and New Window Creation in Windows Forms Application

  2 août 2023, par sadra hoseini

  I have a Windows Forms application that uses FFmpeg for video processing tasks. In this application, I have a textBox2_TextChanged event handler that performs some video processing tasks based on user input.

  


  However, I noticed that when textBox2_TextChanged is called, the UI becomes unresponsive, and it seems like another window is being created but doesn't show up. I suspect that this issue is related to threading.

  


  Here's a simplified version of the problematic code :

  


  // Relevant code snippet:
private async void textBox2_TextChanged(object sender, EventArgs e)
{
    if (listBox1.Items.Count > 0 && int.TryParse(textBox2.Text, out int itemvalue) && int.TryParse(textBox1.Text, out int ratio))
    {
        await Task.Run(() =>
        {
            // Video processing code using FFmpeg (e.g., creating thumbnails).
            // This code seems to cause the UI to freeze and prevent new windows from showing up.
        });
    }
}


  


  Expected Behavior :

  


  When a user enters a valid input in textBox2, the video processing tasks should be executed in the background without freezing the UI. The application should remain responsive, and any new windows, including message boxes or progress dialogs, should show up as expected.

  


  Actual Behavior :

  


  When a user enters a valid input in textBox2, the video processing tasks appear to be running, but the UI becomes unresponsive, and new windows, such as message boxes, do not show up as expected. This makes it challenging to display any progress or error messages to the user during video processing.

  


  Steps to Reproduce :

  


  Open the Windows Forms application.
Add some video files to the list (listBox1) and provide valid input in textBox2.
Observe the UI behavior and any new windows that should be displayed, such as progress dialogs or message boxes.
Additional Notes :

  


  I am using Visual Studio [version] for development.
The application uses FFmpeg for video processing tasks, and I've verified that FFmpeg is functioning correctly.
I've also tried using proper error handling to catch any exceptions, but no exceptions are thrown during the video processing tasks.
Any help or suggestions on how to resolve this issue and enable new window creation during video processing would be greatly appreciated. Thank you !

  


• Using ffmpeg in Powershell

  27 avril 2016, par Matthew Goode

  Can’t find much information on this, as I believe it’s a pretty noobish problem and there aren’t really any tutorials on it. Can anyone explain how I can use ffmpeg in a powershell script ? I downloaded ffmpeg and I have the path to ffmpeg.exe. Shouldn’t I be able to do something like this ?

  "C:\path\ffmpeg.exe" -i stuff.mp3 stuff.wav

  It returns an error message along the lines of -i not being a recognized parameter. Am I missing something pretty basic here ? Thanks for any help. I’m trying to convert some audio files between .wav, .mp3. and .flac, and if anyone has any better suggestions than ffmpeg then please let me know.

• gcc : Undefined Reference Error

  26 octobre 2024, par jamie_y

  I would like to use a function 'ff_load_image' defined in ffmpeg/libavfilter/lavfutils.h.

  



  program.c

  



  #include "../ffmpeg/libavfilter/lavfutils.h"

int main ()
{
  uint8_t* data;

  int linesize, width, height, log_ctx;

  int i = ff_load_image(&data, &linesize, &width, &height, AV_PIX_FMT_RGB24, "blue.jpg", &log_ctx);
}


  



  Running

  



  gcc -I$HOME/ffmpeg/include program.c -L$HOME/ffmpeg/lib -lavfilter -lavcodec -lavutil


  



  gives undefined reference errors.

  



  program.c: In function \u2018main\u2019:
program.c:9: warning: passing argument 1 of \u2018ff_load_image\u2019 from incompatible pointer type
../ffmpeg/libavfilter/lavfutils.h:39: note: expected \u2018uint8_t **\u2019 but argument is of type \u2018uint8_t *\u2019
program.c:9: warning: passing argument 2 of \u2018ff_load_image\u2019 makes pointer from integer without a cast
../ffmpeg/libavfilter/lavfutils.h:39: note: expected \u2018int *\u2019 but argument is of type \u2018int\u2019
program.c:9: warning: passing argument 3 of \u2018ff_load_image\u2019 makes pointer from integer without a cast
../ffmpeg/libavfilter/lavfutils.h:39: note: expected \u2018int *\u2019 but argument is of type \u2018int\u2019
program.c:9: warning: passing argument 4 of \u2018ff_load_image\u2019 makes pointer from integer without a cast
../ffmpeg/libavfilter/lavfutils.h:39: note: expected \u2018int *\u2019 but argument is of type \u2018int\u2019
program.c:9: warning: passing argument 5 of \u2018ff_load_image\u2019 makes pointer from integer without a cast
../ffmpeg/libavfilter/lavfutils.h:39: note: expected \u2018enum AVPixelFormat *\u2019 but argument is of type \u2018int\u2019
program.c:9: warning: passing argument 7 of \u2018ff_load_image\u2019 makes pointer from integer without a cast
../ffmpeg/libavfilter/lavfutils.h:39: note: expected \u2018void *\u2019 but argument is of type \u2018int\u2019
/home/jamiey/ffmpeg/lib/libavfilter.a(lavfutils.o): In function `ff_load_image':
/home/jamiey/ffmpeg/libavfilter/lavfutils.c:38: undefined reference to `av_register_all'
/home/jamiey/ffmpeg/libavfilter/lavfutils.c:40: undefined reference to `av_find_input_format'
/home/jamiey/ffmpeg/libavfilter/lavfutils.c:41: undefined reference to `avformat_open_input'
/home/jamiey/ffmpeg/libavfilter/lavfutils.c:66: undefined reference to `av_read_frame'
/home/jamiey/ffmpeg/libavfilter/lavfutils.c:92: undefined reference to `avformat_close_input'
/home/jamiey/ffmpeg/libavfilter/lavfutils.c:92: undefined reference to `avformat_close_input'
/home/jamiey/ffmpeg/libavfilter/lavfutils.c:92: undefined reference to `avformat_close_input'
/home/jamiey/ffmpeg/lib/libavcodec.a(frame_thread_encoder.o): In function `ff_frame_thread_encoder_free':
/home/jamiey/ffmpeg/libavcodec/frame_thread_encoder.c:225: undefined reference to `pthread_join'
/home/jamiey/ffmpeg/lib/libavcodec.a(frame_thread_encoder.o): In function `ff_frame_thread_encoder_init':
/home/jamiey/ffmpeg/libavcodec/frame_thread_encoder.c:200: undefined reference to `pthread_create'
/home/jamiey/ffmpeg/lib/libavcodec.a(pthread_frame.o): In function `ff_frame_thread_free':
/home/jamiey/ffmpeg/libavcodec/pthread_frame.c:575: undefined reference to `pthread_join'
/home/jamiey/ffmpeg/lib/libavcodec.a(pthread_frame.o): In function `ff_frame_thread_init':
/home/jamiey/ffmpeg/libavcodec/pthread_frame.c:705: undefined reference to `pthread_create'
/home/jamiey/ffmpeg/lib/libavcodec.a(pthread_slice.o): In function `ff_slice_thread_init':
/home/jamiey/ffmpeg/libavcodec/pthread_slice.c:220: undefined reference to `pthread_create'
/home/jamiey/ffmpeg/lib/libavcodec.a(pthread_slice.o): In function `ff_slice_thread_free':
/home/jamiey/ffmpeg/libavcodec/pthread_slice.c:118: undefined reference to `pthread_join'
/home/jamiey/ffmpeg/lib/libavutil.a(rational.o): In function `av_d2q':
/home/jamiey/ffmpeg/libavutil/rational.c:115: undefined reference to `log'
/home/jamiey/ffmpeg/libavutil/rational.c:118: undefined reference to `floor'
/home/jamiey/ffmpeg/lib/libavutil.a(eval.o): In function `eval_expr':
/home/jamiey/ffmpeg/libavutil/eval.c:183: undefined reference to `trunc'
/home/jamiey/ffmpeg/libavutil/eval.c:182: undefined reference to `ceil'
/home/jamiey/ffmpeg/libavutil/eval.c:181: undefined reference to `floor'
/home/jamiey/ffmpeg/libavutil/eval.c:241: undefined reference to `pow'
/home/jamiey/ffmpeg/libavutil/eval.c:177: undefined reference to `exp'
/home/jamiey/ffmpeg/libavutil/eval.c:176: undefined reference to `exp'
/home/jamiey/ffmpeg/libavutil/eval.c:287: undefined reference to `pow'
/home/jamiey/ffmpeg/libavutil/eval.c:278: undefined reference to `floor'
/home/jamiey/ffmpeg/lib/libavutil.a(eval.o): In function `av_strtod':
/home/jamiey/ffmpeg/libavutil/eval.c:112: undefined reference to `pow'
/home/jamiey/ffmpeg/libavutil/eval.c:103: undefined reference to `pow'
/home/jamiey/ffmpeg/libavutil/eval.c:109: undefined reference to `pow'
/home/jamiey/ffmpeg/lib/libavutil.a(eval.o): In function `parse_primary':
/home/jamiey/ffmpeg/libavutil/eval.c:394: undefined reference to `sinh'
/home/jamiey/ffmpeg/libavutil/eval.c:395: undefined reference to `cosh'
/home/jamiey/ffmpeg/libavutil/eval.c:396: undefined reference to `tanh'
/home/jamiey/ffmpeg/libavutil/eval.c:397: undefined reference to `sin'
/home/jamiey/ffmpeg/libavutil/eval.c:398: undefined reference to `cos'
/home/jamiey/ffmpeg/libavutil/eval.c:399: undefined reference to `tan'
/home/jamiey/ffmpeg/libavutil/eval.c:400: undefined reference to `atan'
/home/jamiey/ffmpeg/libavutil/eval.c:401: undefined reference to `asin'
/home/jamiey/ffmpeg/libavutil/eval.c:402: undefined reference to `acos'
/home/jamiey/ffmpeg/libavutil/eval.c:403: undefined reference to `exp'
/home/jamiey/ffmpeg/libavutil/eval.c:404: undefined reference to `log'
/home/jamiey/ffmpeg/libavutil/eval.c:405: undefined reference to `fabs'
collect2: ld returned 1 exit status


  



  However, I was successful in running functions in other library, such as the ones in "ffmpeg/libavcodec/avcodec.h". Why is this happening to "ffmpeg/libavfilter/lavfutils.h" ?