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• Enable hardware (GPU) video decode acceleration with ffmpeg C API ?

  8 avril 2019, par MSD Paul

  I am using avcodec_decode_video2() to decode a particular video without enabling any GPU hardware support.

  While I tried to get the hardware decoder by name :

  mVideoCodec = avcodec_find_decoder_by_name("h264_dxva2");

  But its results mVideoCodec = NULL although while running ffmpeg from command prompt using dxva2 hwaccel, no error is being shown. Here I am giving the configuration output what I got from the command prompt. can anyone please tell me how can I enable hardware acceleration properly while using avcodec_decode_video2() API to decode the video in C.

  I am using a laptop with an NVIDIA GPU.

  Log from command prompt :

  C :\ffmpeg\bin>ffmpeg -hwaccel dxva2 -i 9.mp4 -r 60 -vsync 0 -f image2 image-%2d.png**
  configuration : —enable-gpl —enable-version3 —enable-sdl2 —enable-bzlib —enable-fontconfig —enable-gnutls —enable-iconv —enable-libass —enable-libbluray —enable-libfreetype —enable-libmp3lame —enable-libopenjpeg —enable-libopus —enable-libshine —enable-libsnappy —enable-libsoxr —enable-libtheora —enable-libtwolame —enable-libvpx —enable-libwavpack —enable-libwebp —enable-libx264 —enable-libx265 —enable-libxml2 —enable-libzimg —enable-lzma —enable-zlib —enable-gmp —enable-libvidstab —enable-libvorbis —enable-cuda —enable-cuvid —enable-d3d11va —enable-nvenc —enable-dxva2 —enable-avisynth —enable-libmfx

• How to send continuous stream of frames to server most efficiently

  27 avril 2019, par Duthopi

  I am trying to send frames from a local camera (raspberry pi camera, but could also be my laptop’s webcam) to a Google cloud instance, on which I am running AI processing of the frames.

  I am managing to send frames captured through opencv via http (i.e. tcp ??) and receiving them on a flask server. When the flask server is running locally I can get good fps (50+ fps for image size 640x480), however once I send the frames to a flask app on the google instance the fps drop drastically to 5fps.

  How I currently send frames :

  while True:
  
          frame = vs.read() #Separate thread, using cv2 to get the frame
  
  
  
          ret, jpeg = cv2.imencode('.jpg', frame)
  
          imgdata = jpeg.tobytes()
  
          response = requests.post(
  
              url='http://<ip address="address" of="of" google="google" instance="instance">:<port>',
  
              data= imgdata,
  
              headers={'content-type':'image/jpeg'},
  
              )
  
  </port></ip>

  I see two problems with this :
  1 - using tcp means I am slower than udp protocol, however udp is limited in byte size. Correct me if I am wrong, but it seems very complex to send truncated frames and put them back together on the server..
  2 - Even if I had udp working, there is no compression of frames, so I will never reach an efficient transfer

  I expect the answer to be something like using ffmpeg, but so far I only figured out how to stream frames on a local port with ffmpeg, I do not know if it is possible to send frames to a remote server.

  Any recommendations on the best way forward ?

• Can't upload .mkv video file to camtasia 2018

  11 juin 2019, par FunTech StudentsVideos

  Can’t Import .mkv video file to camtasia 2018 :

  I have made an intro for my Youtube Channel on Penzoid and then uploaded it to my laptop in .mkv file format, now it can’t be import to camtasia 2018 for rendering with the recorded video in camtasia...

  I used cloudconvert to convert my intro to .mp4 format but it give me the following error :

  ERROR Could not find tag for codec vp8 in stream #0, codec not currently supported in container
  . Last message repeated 1 times
  Last message repeated 1 times

  I also used .bat file with the following code but it didn’t help me :

  @echo off
  
  if not exist "fixed" mkdir fixed
  
  for %%f in ("*.mp4") do "C:\Users\Nadeem Ullah\Downloads\Compressed\ffmpeg-win64-static\bin\ffmpeg.exe" -i "%%f" -c:a copy -c:v copy "fixed\%%~nf.mp4"