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• FFMpeg access AVFoundation usb subdevice camera on OSX Mojave

  20 août 2020, par Retiarius

  I Have a dual USB camera for VR : two cameras, one usb connection. On linux, this appears in /dev/video0 and /dev/video1 and I can capture using ffmpeg -i /dev/video0

  



  On Mojave, I can see both devices in the USB hub :

  



  USB 2.0 Hub:

Product ID: 0x0101
Vendor ID:  0x1a40  (TERMINUS TECHNOLOGY INC.)
Version:    1.11
Speed:  Up to 480Mb/sec
Location ID:    0x14200000 / 8
Current Available (mA): 500
Current Required (mA):  100
Extra Operating Current (mA):   0

    Stereo Vision 2:

    Product ID: 0x9901
    Vendor ID:  0x0ac8  (Z-Star Microelectronics Corporation)
    Version:    27.02
    Serial Number:  SN0099
    Speed:  Up to 480Mb/sec
    Manufacturer:   SHENZHEN RERVISION TECHNOLOGY
    Location ID:    0x14220000 / 10
    Current Available (mA): 500
    Current Required (mA):  500
    Extra Operating Current (mA):   0

    Stereo Vision 2:

    Product ID: 0x9902
    Vendor ID:  0x0ac8  (Z-Star Microelectronics Corporation)
    Version:    27.02
    Serial Number:  SN0100
    Speed:  Up to 480Mb/sec
    Manufacturer:   SHENZHEN RERVISION TECHNOLOGY
    Location ID:    0x14210000 / 9
    Current Available (mA): 500
    Current Required (mA):  500
    Extra Operating Current (mA):   0


  



  But when I list devices, I can see only one [0] :

  



  ffmpeg -f avfoundation -list_devices true -i ""
    [AVFoundation input device @ 0x7fae5b501a80] AVFoundation video devices:
    [AVFoundation input device @ 0x7fae5b501a80] [0] Stereo Vision 2
    [AVFoundation input device @ 0x7fae5b501a80] [1] FaceTime HD Camera
    [AVFoundation input device @ 0x7fae5b501a80] [2] Capture screen 0


  



  capturing from this device captures from one of the cameras.

  



  How can I get ffmpeg to detect the second usb device as well ?

  


• Running a py script in the Cloud

  12 janvier 2018, par Anay Bose

  I’m new to Google’s cloud & Virtual Machine(VM) instances, and I need some clarifications on a couple of points. I have a python script ; it imports a long range of functions. I need to run those functions in parallel. I’m using multiprocessing and Process, not threads. These functions are basically image and media processors, and they use many other tools like FFMPEG, imagemagick and Avisynth in addition to a wide range of python modules, including moviepy. Now, I would like to run some 50 functions in parallel assigning a CPU for each process. Images, media and avi files are stored in seperate folders. I’m on Windows7 Core-i7 machine. So, need cloud computing power.

  Now, my question can I run such a python script/app in the cloud that requires a very complicated file system and non-python tools i.e. ffmpeg, avisynth and avi files ?

  Can Google VMs emulate my local machine and empower me with more cores and memory to run such a program ? if not, then what are my options ? Is their any tutorials that I can follow ? I need your suggestions. I have given below an example script and some codes to help facilitate your understanding about my situation.

  from __future__ import unicode_literals
  
  import youtube_dl
  
  import os
  
  import time
  
  import sys
  
  reload(sys)  
  
  sys.setdefaultencoding('utf-8')
  
  from multiprocessing import Process
  
  from utils import *
  
  
  
  from clip31 import VIDEO31
  
  from clip32 import VIDEO32
  
  from clip189 import VIDEO189
  
  from clip16 import VIDEO16
  
  from clip39 import VIDEO39
  
  
  
  
  
  if __name__== '__main__':
  
  
  
      # 1. CALLING A FUNCTION
  
      folder = "bodyforce3\\16"
  
      serial = "16"
  
      images = get_filepaths("../16")
  
      videos = get_filepaths("12__media")
  
      pngs = get_filepaths("../pngs")
  
  
  
      Process(target=VIDEO192, args=(folder, serial, color1, color2, color3, images, videos)).start()
  
  
  
  
  
      # 2. CALLING A FUNCTION
  
      folder = "bodyforce3\\20"
  
      serial = "20"
  
      images = get_filepaths("../20")
  
      videos = get_filepaths("18__media")
  
  
  
      Process(target=VIDEO32, args=(folder, serial, color1, color2, color3, images, videos)).start()
  
  
  
  
  
      # 3. CALLING A FUNCTION
  
      folder = "bodyforce3\\14"
  
      serial = "14"
  
      images = get_filepaths("../14")
  
      videos = get_filepaths("16__media")
  
  
  
      Process(target=VIDEO91, args=(folder, serial, color1, color2, color3, images, videos)).start()

  I copy avi files in functions like this :

  src = "clip50_files"
  
  src_files = os.listdir(src)
  
  for file_name in src_files:
  
      full_file_name = os.path.join(src, file_name)
  
      if (os.path.isfile(full_file_name)):
  
          shutil.copy(full_file_name, folder)

  I call ffmpeg commands like this, and they are included within py functions.

  ###########################
  
  #### FFMPEG OPERATIONS ####
  
  ###########################
  
  
  
  print "Starting FFMPEG operations ..."
  
  
  
  if os.path.isfile(os.path.join(folder, "bounce-(3).avi")):
  
      os.remove(os.path.join(folder, "bounce-(3).avi"))
  
  
  
  
  
  infile = folder + "/bounce-(3).avs"
  
  outfile = folder + "/bounce-(3).avi"
  
  codec = "rawvideo"
  
  pix_fmt = "bgra"
  
  
  
  try:
  
      subprocess.call(["ffmpeg",
  
                       "-i" ,infile, 
  
                       "-c:v" ,codec, 
  
                       "-pix_fmt", pix_fmt, 
  
                       outfile],
  
                      stdout=open(os.devnull, 'w'), 
  
                      stderr=subprocess.STDOUT)
  
  except subprocess.CalledProcessError as e:   
  
      #except subprocess.CalledProcessError as e:
  
      sys.exit(e.output)
  
  except OSError as e:
  
      sys.exit(e.strerror)
  
  
  
  
  
  print "FFMPEG operations ended"

• converting video with avconv while capturing

  31 mai 2017, par Oliver

  I am successfully capturing a video stream with that device :
  Easycap DC60

  But I need to run the following commands in serial :

  First that :

  sudo killall -9 somagic-both

  sudo killall -9 somagic-capture

  sudo somagic-init

  sudo somagic-both -n 1>.video 2>.audio

  [CTRL+C]

  Then that :

  avconv

  -f rawvideo -pix_fmt uyvy422 -r 30 -s:v 720x480 -i .video

  -f s16le -sample_rate 24000 -ac 2 -i .audio -strict experimental

  -vcodec mpeg4 -vtag xvid -qscale:v 7

  -vf yadif -s:v 720x540

  video.avi

  The problem is that when I try to run them together in a row (with "&" at the end of "sudo somagic-both -n 1>.video 2>.audio") I get that error :

  ffmpeg version 2.8.11-0ubuntu0.16.04.1 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.4) 20160609
  
    configuration: --prefix=/usr --extra-version=0ubuntu0.16.04.1 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 --enable-libopencv
  
    libavutil      54. 31.100 / 54. 31.100
  
    libavcodec     56. 60.100 / 56. 60.100
  
    libavformat    56. 40.101 / 56. 40.101
  
    libavdevice    56.  4.100 / 56.  4.100
  
    libavfilter     5. 40.101 /  5. 40.101
  
    libavresample   2.  1.  0 /  2.  1.  0
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  2.101 /  1.  2.101
  
    libpostproc    53.  3.100 / 53.  3.100
  
  Input #0, rawvideo, from '.video':
  
    Duration: N/A, bitrate: 165888 kb/s
  
      Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 720x480, 165888 kb/s, 30 tbr, 30 tbn, 30 tbc
  
  [s16le @ 0x24d7480] Estimating duration from bitrate, this may be inaccurate
  
  Guessed Channel Layout for  Input Stream #1.0 : stereo
  
  Input #1, s16le, from '.audio':
  
    Duration: 00:00:00.71, bitrate: 767 kb/s
  
      Stream #1:0: Audio: pcm_s16le, 24000 Hz, 2 channels, s16, 768 kb/s
  
  File 'video.avi' already exists. Overwrite ? [y/N] y
  
  Output #0, avi, to 'video.avi':
  
    Metadata:
  
      ISFT            : Lavf56.40.101
  
      Stream #0:0: Video: mpeg4 (xvid / 0x64697678), yuv420p, 720x540, q=2-31, 200 kb/s, 30 fps, 30 tbn, 30 tbc
  
      Metadata:
  
        encoder         : Lavc56.60.100 mpeg4
  
      Stream #0:1: Audio: mp3 (libmp3lame) (U[0][0][0] / 0x0055), 24000 Hz, stereo, s16p
  
      Metadata:
  
        encoder         : Lavc56.60.100 libmp3lame
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (rawvideo (native) -> mpeg4 (native))
  
    Stream #1:0 -> #0:1 (pcm_s16le (native) -> mp3 (libmp3lame))
  
  Press [q] to stop, [?] for help
  
  Multiple frames in a packet from stream 0
  
  [pcm_s16le @ 0x24f33c0] Invalid PCM packet, data has size 2 but at least a size of 4 was expected
  
  Error while decoding stream #1:0: Invalid data found when processing input
  
  frame=    0 fps=0.0 q=0.0 Lsize=      38kB time=00:00:03.19 bitrate=  98.0kbits/s    
  
  video:0kB audio:25kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 50.802467%

  I think it happens because it is converting more quickly than it is capturing. I tried to use the solution given here
  without success.

  Anyone ever faced that situation before ?