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• avfilter/af_astats : fix msvc compile error

  29 avril 2019, par Matthias Troffaes

  avfilter/af_astats : fix msvc compile error
  MSVC requires an explicit cast from void * to void when applying the
  
  ternary conditional operator to switch between methods that return
  
  void.
  

  • [DH] libavfilter/af_astats.c

• Popen ffmpeg process hang if run in shell and leaves a defunct process if run in background

  12 janvier 2023, par dr__noob

  I have a script that runs the FFmpeg command. When I run the command in the background using the & operator it runs fine but leaves a zombie process. And when I remove the operator the process hangs and goes into the pipe_wait state.

  


  The code used to execute the FFmpeg command

  


  def run_cmd(cmd:str,
            check:bool=False,       
            capture:bool=False,
            timeout:float=None,
            ) -> tuple[int,bytearray,bytearray]:
    import  subprocess

    stdout_data,stderr_data = (bytearray(),bytearray()) if capture else (None,None)
    try:
        sp = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, )
        while any(data:=(sp.stdout.readline(),sp.stderr.readline())):
            out,err = data
            if out: stdout_data += out
            if err: stderr_data += err
        sp.communicate(timeout=timeout)
        return sp.returncode,stdout_data,stderr_data
    except subprocess.CalledProcessError as e:
        print("Called process error")
        raise e
    except subprocess.TimeoutExpired as e:
        sp.kill()
        print(f"{sp.pid} killed")
        if check:
            raise e
    except PermissionError as e:
        print("Permission error")
        if check:
            raise e


  


  The command which is causing the issue is

  


  nice -n 10 ffmpeg -loglevel verbose -hide_banner -y -threads 0 -i "/dev/shm/480TEST-1999963.dfw.480_1673030704/SBS_Plus_Test_Feed.480TEST-1999963.480.eng.p.intermediate.mp4" -map 0:v:0? -q:v 1 -f rawvideo -pix_fmt "yuv420p" -an ./SBS_Plus_Test_Feed.480TEST-1999963.480.eng.p_fifo_video.yuv -map 0:a:0? -q:a 1 -ac 2 -af "aresample=async=1:first_pts=0" -vn ./SBS_Plus_Test_Feed.480TEST-1999963.480.eng.p_fifo_audio.wav > "./SBS_Plus_Test_Feed.480TEST-1999963.480.eng.p.ffmpeg.demux.log" 2>&1 &


  


  However, other FFmpeg commands are running fine without the last &. But this command will block if I remove the &. If I keep it as it is, the process will later become a zombie(defunct). Can it be because it is actually a nice -n 10 causing the issue ?

  


  Example of a command running fine

  


  ffmpeg -loglevel verbose -hide_banner -y -threads 0 -i "./SBS_Plus_Test_Feed.480TEST-1999963.480.eng.p.ts" -r "59.94" -s:v "1280"x"720" -pix_fmt "yuv420p" -vcodec libx264 -x264-params qp="30" -af "aresample=async=1:first_pts=0" -crf 0 -q:a 1 -vf yadif=1 ./SBS_Plus_Test_Feed.480TEST-1999963.480.eng.p.intermediate.mp4 > "./p.intermediate.mp4.intermediate.ffmpeg.log" 2>&1


  


  Till now I have tried other options like -nostdin and null suggested in ffmpeg hangs when run in background

  


  Is there any other way run this without creating a zombie ?

  


• libFLAC/fixed.c : Fix undefined behaviour

  28 août 2015, par Erik de Castro Lopo

  libFLAC/fixed.c : Fix undefined behaviour
  Left shift if a negative integer such that the sign bit is affected is
  
  (according to the C spec) undefined behaviour and the residual
  
  calculations using the shift operator were hitting this.
  Fortunately these same calculations using plain multiplication do not
  
  invoke UB and according to benchmarking (on x86_64 linux) have the same
  
  performance as the bit shift version.
  

  • [DH] src/libFLAC/fixed.c