Recherche avancée

Sur d’autres sites (6311)

• Fix comment : Enhanced AC-3 in mov is defined in ETSI TS 102 366.

  22 octobre 2011, par Carl Eugen Hoyos

  Fix comment : Enhanced AC-3 in mov is defined in ETSI TS 102 366.

• OpenCV reading from live camera creates a short video that moves quickly

  17 novembre 2022, par user19019404

  I am reading in a live vide stream from a CCTV camera. The camera is set to 5 fps, another is set to 25fps and another to 30fps. Irrespective of the FPS that the camera is set, I can record 5 minutes but end up with a 30 second recorded clip where everyone is running around the scene.

  


  My code is the 'typical' read in video and write video code that you would find online such as (code below simplified for readability) :

  


  import cv2

video = cv2.VideoCapture(live RTSP address of camera)

if (video.isOpened() == False):
    print("Error reading video file")
else:
    frame_width = video.get(cv2.CAP_PROP_FRAME_WIDTH)
    frame_height = video.get(cv2.CAP_PROP_FRAME_HEIGHT)
    frame_fps = video.get(cv2.CAP_PROP_FPS)
    size = (frame_width, frame_height)
    result = cv2.VideoWriter('filename.avi',cv2.VideoWriter_fourcc(*'MJPG'),frame_fps , size)

    while(True):
        ret, frame = video.read()
        if ret == True:
            result.write(frame)
            cv2.imshow('Frame', frame)
        if cv2.waitKey(1) & 0xFF == ord('s'):
            break
        else:
            break
    video.release()
    result.release()
    cv2.destroyAllWindows()
print("The video was successfully saved with new fps")


  


  I have tried playing with the FPS by reading in the FPS from the live camera and using the same FPS in the video write, but all that results is a video that is a fraction of the real time and with people zooming around the scene. So watching a 5 minute smooth video results in a 20 second recorded video with everyone zooming around.

  


  Is this something that I need to fix in the writing of the video or do I need a second pass with ffmpeg to readjust the video ?

  


  Much appreciated

  


  Update, corrected the code above and :
When printing the frames read and the frame written the numbers are the same, showing that each frame that is read is being written (so I am not losing frames along the way thereby writing half the amount of frames).

  


• Video moves sideways when captured raw from camera and piped into ffplay

  21 septembre 2018, par peetonn

  I’m trying to capture video from the camera using ffmpeg (macOS 10.12) and pipe it for preview into ffplay using rawvideo and -v copy options :

  ffmpeg -f avfoundation -pixel_format 0rgb -framerate 25 -video_size 1280x720 -i "0" -map 0:v -c copy -f rawvideo - | ffplay -f rawvideo -video_size 1280x720 -pixel_format 0rgb -i -

  Video captures just fine, however, it constantly moves sideways (see screenshot attached). What might the issue here ?

  

  UPDATE Full ffmpeg log output :

  $ ffmpeg -f avfoundation -pixel_format 0rgb -framerate 25 -video_size 1280x720 -i "0" -map 0:v -c copy -f rawvideo - | ffplay -f rawvideo -video_size 1280x720 -pixel_format 0rgb -i -
  
  ffmpeg version 4.0.2ffplay version 4.0.2 Copyright © 2003-2018 the FFmpeg developers Copyright © 2000-2018 the FFmpeg developers
  
  
  
    built with Apple LLVM version 9.0.0 (clang-900.0.39.2)
  
    built with Apple LLVM version 9.0.0 (clang-900.0.39.2)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/4.0.2 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-ffplay --enable-libfontconfig --enable-libfreetype --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --enable-videotoolbox --disable-lzma
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/4.0.2 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-ffplay --enable-libfontconfig --enable-libfreetype --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --enable-videotoolbox --disable-lzma
  
    libavutil      56. 14.100 / 56. 14.100
  
    libavutil      56. 14.100 / 56. 14.100
  
    libavcodec     58. 18.100 / 58. 18.100
  
    libavformat    58. 12.100 / 58. 12.100
  
    libavcodec     58. 18.100 / 58. 18.100
  
    libavdevice    58.  3.100 / 58.  3.100
  
    libavformat    58. 12.100 / 58. 12.100
  
    libavfilter     7. 16.100 /  7. 16.100
  
    libavdevice    58.  3.100 / 58.  3.100
  
    libavresample   4.  0.  0 /  4.  0.  0
  
    libavfilter     7. 16.100 /  7. 16.100
  
    libswscale      5.  1.100 /  5.  1.100
  
    libswresample   3.  1.100 /  3.  1.100
  
    libavresample   4.  0.  0 /  4.  0.  0
  
    libpostproc    55.  1.100 / 55.  1.100
  
    libswscale      5.  1.100 /  5.  1.100
  
    libswresample   3.  1.100 /  3.  1.100
  
    libpostproc    55.  1.100 / 55.  1.100
  
  2018-09-20 09:33:28.013 ffmpeg[45781:16452887] Error loading /Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn:  dlopen(/Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn, 262): no suitable image found.  Did find:
  
      /Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn: mach-o, but wrong architecture
  
      /Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn: mach-o, but wrong architecture
  
  2018-09-20 09:33:28.013 ffmpeg[45781:16452887] Cannot find function pointer New_SHP_PlugIn for factory 834FC054-C1CC-11D6-BD01-00039315CD46 in CFBundle/CFPlugIn 0x7fe63b506d00 Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin> (bundle, not loaded)
  
  2018-09-20 09:33:28.069 ffplay[45782:16452888] Error loading /Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn:  dlopen(/Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn, 262): no suitable image found.  Did find:
  
      /Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn: mach-o, but wrong architecture
  
      /Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn: mach-o, but wrong architecture
  
  2018-09-20 09:33:28.069 ffplay[45782:16452888] Cannot find function pointer New_SHP_PlugIn for factory 834FC054-C1CC-11D6-BD01-00039315CD46 in CFBundle/CFPlugIn 0x7f93f3c13020 Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin> (bundle, not loaded)
  
  [avfoundation @ 0x7fe63c000000] Stream #0: not enough frames to estimate rate; consider increasing probesize
  
  Input #0, avfoundation, from '0':
  
    Duration: N/A, start: 1054.178167, bitrate: N/A
  
      Stream #0:0: Video: rawvideo ([0]RGB / 0x42475200), 0rgb, 1280x720, 1000k tbr, 1000k tbn, 1000k tbc
  
  Output #0, rawvideo, to 'pipe:':   0KB vq=    0KB sq=    0B f=0/0   
  
    Metadata:
  
      encoder         : Lavf58.12.100
  
      Stream #0:0: Video: rawvideo ([0]RGB / 0x42475200), 0rgb, 1280x720, q=2-31, 1000k tbr, 1000k tbn, 1000k tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 ©
  
  Press [q] to stop, [?] for help
  
  Input #0, rawvideo, from 'pipe:':
  
    Duration: N/A, start: 0.000000, bitrate: 737280 kb/s
  
      Stream #0:0: Video: rawvideo ([0]RGB / 0x42475200), 0rgb, 1280x720, 737280 kb/s, 25 tbr, 25 tbn, 25 tbc
  
  frame=   16 fps=0.0 q=-1.0 size=   57600kB time=00:00:00.60 bitrate=786437.5kbits/s speed=1.frame=   29 fps= 28 q=-1.0 size=  104401kB time=00:00:01.12 bitrate=763617.4kbits/s speed=1.frame=   42 fps= 27 q=-1.0 size=  151201kB time=00:00:01.64 bitrate=755268.5kbits/s speed=1.frame=   55 fps= 26 q=-1.0 size=  198002kB time=00:00:02.16 bitrate=750939.5kbits/s speed=1.frame=   68 fps= 26 q=-1.0 size=  244802kB time=00:00:02.68 bitrate=748290.4kbits/s speed=1.av_interleaved_write_frame(): Broken pipe=    0KB sq=    0B f=0/0   
  
  Error writing trailer of pipe:: Broken pipe
  
  frame=   69 fps= 26 q=-1.0 Lsize=  247650kB time=00:00:02.72 bitrate=745863.6kbits/s speed=1.01x    
  
  video:248402kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
  
  Exiting normally, received signal 2.