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• tensorflow 2, tfds.features.Video Usage for video decoding

  5 mars 2020, par Sandeep

  I am trying to decode a video in tensorflow 2 using tfds.features.Video , so that the output is a "tf.Tensor of type tf.uint8 and shape [num_frames, height, width, channels]" using following code :

  import numpy as np
  import pandas as pd
  import tensorflow as tf
  import tensorflow_datasets as tfds

  df_trains= pd.DataFrame()
  df_trains[’video_files’]= [’aa.mp4’]

  files_ds = tf.data.Dataset.from_tensor_slices(df_trains.video_files)
  video_class = tfds.features.Video(shape=(None, 1080, 1920,3), encoding_format=’png’, ffmpeg_extra_args=())
  a= video_class.decode_example(files_ds)

  However it generates following error :
  "AssertionError : Feature Video can only be decoded when defined as top-level feature, through info.features.decode_example()"

  I am unable to solve it, please help in this regard.

• Video play VLC player only in Android(Video Recording using FFmpeg)

  28 juillet 2017, par Astro

  I am trying to record video from url, its fine I can record video from my url but the problem is the recorded video only play VLC player, can’t play no other video players. I think it is the problem of video encoding. my url is http://192.168.1.1:8080/?action=stream . So I have getting mpeg encoded frames from this url. I used different ffmpeg command but these are not worked properly. These are the command I used.

  "ffmpeg -i "+URL+" -codec:v libx264 -c:a aac -movflags +faststart "+toFile;
  
  
  
  "ffmepg -i "+URL+" -acodec libfaac -ab 96k -vcodec libx264 -vpre slower -vpre main -level 21 -refs 2 -b 345k -bt 345k -threads 0 -s 640×360 "+toFile;

  So anyone knows how to fix these problem please help me...

• Overlay streaming video on another video with ffmpeg

  9 août 2017, par user3354787

  I am running a robot that uses fmpeg to send straming video to letsrobot.tv You can see my bot on the website called patton II. I want to overlay a video HUD on the stream.

  I have found a link explaining how to do this, however I do not know how to do it with a streaming video as input instead of a single image file.

  This is the command that is currently being used to stream the video :

  overlayCommand = '-vf dynoverlay=overlayfile=/home/pi/runmyrobot/images/hud.png:check_interval=500'
  
  videoCommandLine = '/usr/local/bin/ffmpeg -f v4l2 -framerate 25 -video_size 640x480 -i /dev/video%s %s -f mpegts -codec:v mpeg1video -s 640x480 -b:v %dk -bf 0 -muxdelay 0.001 %s http://%s:%s/hello/640/480/' % (deviceAnswer, rotationOption, args.kbps, overlayCommand, server, videoPort)
  
  audioCommandLine = '/usr/local/bin/ffmpeg -f alsa -ar 44100 -i hw:1 -ac 2 -f mpegts -codec:a mp2 -b:a 32k -muxdelay 0.001 http://%s:%s/hello/640/480/' % (server, audioPort)