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• Trouble getting video stream from Bebop 2 (python, open cv and ffmpeg)

  20 décembre 2018, par Seb A

  I’m currently working with the Bebop 2 drone from parrot and I would like to get the video stream from the bebop and to use the frame I get. To control the bebop I’m using this library : https://github.com/amymcgovern/pyparrot.

  First I’ve tried to use opencv by opening the sdp file used by the bebop to stream the video with this code :

  capture = cv2.VideoCapture('./bebop.sdp')
  
  
  
      while True :
  
          rt,img = capture.read()
  
          cv2.imshow("cam",img)
  
          cv2.waitKey(10)

  here is the content of the sdp file :

  c=IN IP4 192.168.42.1
  
  m=video 55004 RTP/AVP 96
  
  a=rtpmap:96 H264/90000

  but I got this error

  [rtp @ 0000020b890b3300] Protocol 'rtp' not on whitelist 'file,crypto'!
  
  warning: Error opening file (/build/opencv/modules/videoio/src/cap_ffmpeg_impl.hpp:808)
  
  warning: ./bebop.sdp (/build/opencv/modules/videoio/src/cap_ffmpeg_impl.hpp:809)
  
  False
  
  OpenCV Error: Assertion failed (size.width>0 && size.height>0) in cv::imshow, file C:\projects\opencv-python\opencv\modules\highgui\src\window.cpp, line 331
  
  Traceback (most recent call last):
  
   File "pilotage.py", line 109, in <module>
  
     _main_(args)
  
   File "pilotage.py", line 56, in main
  
     cv2.imshow('drone view',im)
  
  cv2.error: C:\projects\opencv-python\opencv\modules\highgui\src\window.cpp:331: error: (-215) size.width>0 &amp;&amp; size.height>0 in function cv::imshow
  
  </module>

  I’ve seen that this is due to the ffmpeg command used by opencv that does not include the option -protocol_whitelist
  So I tried to get the image directly with ffmpeg by using this command

  "ffmpeg -protocol_whitelist \"file,rtp,udp\"  -i  ./bebop.sdp -r 30 -b:v 800k image_%03d.png &"

  But the images I got were awful and useless.
  Like this one :
  

  So I tried different options to improve the quality but I can’t get it to work.
  Thanks for your help.

  I’m on windows 10 and using latest python version

• ffmpeg : Cannot open libx265 encoder. Error initializing output stream 0:0 — Error while opening encoder for output stream #0:0

  16 mai 2018, par bnge

  Sorry for my bad English. I am trying to use ffmpeg to convert some image to heic format. Most of them were succeeded, but some large jpeg (seems only jpeg, png will be okay) files not.

  How can I improve my command to compatible all my images, so I can convert them automatically ?

  ➜  ~ ffmpeg -i sample.jpg -crf 12 -preset placebo -pix_fmt yuv420p -f hevc bitstream.265
  
  ffmpeg version 4.0 Copyright (c) 2000-2018 the FFmpeg developers
  
    built with Apple LLVM version 9.1.0 (clang-902.0.39.1)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/4.0 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-libmp3lame --enable-libx264 --enable-libx265 --enable-libxvid --enable-opencl --enable-videotoolbox --disable-lzma
  
    libavutil      56. 14.100 / 56. 14.100
  
    libavcodec     58. 18.100 / 58. 18.100
  
    libavformat    58. 12.100 / 58. 12.100
  
    libavdevice    58.  3.100 / 58.  3.100
  
    libavfilter     7. 16.100 /  7. 16.100
  
    libavresample   4.  0.  0 /  4.  0.  0
  
    libswscale      5.  1.100 /  5.  1.100
  
    libswresample   3.  1.100 /  3.  1.100
  
    libpostproc    55.  1.100 / 55.  1.100
  
  Input #0, image2, from 'sample.jpg':
  
    Duration: 00:00:00.04, start: 0.000000, bitrate: 5226869 kb/s
  
      Stream #0:0: Video: mjpeg, yuvj444p(pc, bt470bg/unknown/unknown), 13333x4200, 25 tbr, 25 tbn, 25 tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (mjpeg (native) -> hevc (libx265))
  
  Press [q] to stop, [?] for help
  
  [swscaler @ 0x7fd2e3006000] deprecated pixel format used, make sure you did set range correctly
  
  x265 [info]: HEVC encoder version 2.7
  
  x265 [info]: build info [Mac OS X][clang 9.0.0][64 bit] 8bit+10bit+12bit
  
  x265 [info]: using cpu capabilities: MMX2 SSE2Fast LZCNT SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
  
  x265 [error]: Picture width must be an integer multiple of the specified chroma subsampling
  
  [libx265 @ 0x7fd2e2802a00] Cannot open libx265 encoder.
  
  Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
  
  Conversion failed!

• not able to open image generated by ffmpeg

  26 avril 2018, par user3745870

  I am trying to get images from the video stream using ffmpeg in python and I need the raw bytes to do further things. I am trying to store the raw bytes in image file so if my file opens then I can confirm that the raw bytes I have got are correct.

  import subprocess as sp
  
  
  
  def getImages(self):
  
    cmd = ['ffmpeg',
  
             '-ss', 2,
  
             '-i', url,
  
             '-t', 2,
  
             '-f', 'image2pipe',
  
             '-s', '420x360',
  
             '-pix_fmt', 'rgb24',
  
             '-vcodec', 'rawvideo',
  
             '-vf', 'fps=fps=1', '-']
  
    pipe = sp.Popen(cmd, stdout = sp.PIPE, bufsize=10**8)
  
    raw = pipe.stdout.read(420*360)
  
    file = open('image.jpg','wb')
  
    file.write(raw)

  I see a file image.jpg but I cannot open it. Is there anything wrong I am doing here ? I am sizing the image to be 420*360 bytes so I am assuming that the first 420*360 bytes are belong to the first frame.

  Thanks in advance !