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• how to improve edge interpolation of rotation in moviepy

  15 juillet 2021, par OneWorld

  I tried changing the interpolation method of rotation from 'bilinear' to 'bicubic' in the below, but it didn't seem to improve the edge interpolation. (it still looks a little bit jagged)

  


  I was wondering what I need to do to improve this ?

  


  import moviepy.editor as mped
import sys
import numpy as np

bgrd_width = 200
bgrd_height = 200
sunset = mped.ImageClip("sunset200x100.jpg", duration=1).set_position((1, 1))
bgrd = mped.ColorClip(size=(bgrd_width, bgrd_height), color=np.array([200, 200, 200]).astype(np.uint8), duration=3).set_position((0, 0))

angle = 56
interpolation = 'bicubic'

rotated_sunset = sunset.add_mask().rotate(angle, unit='deg', expand=True, resample=interpolation).set_duration(3)
stacked_clips = mped.CompositeVideoClip([bgrd, rotated_sunset], size=[bgrd_width, bgrd_height])

stacked_clips.write_videofile(f'sunset_rotated_{angle}_{interpolation}.mp4', fps=5)



  


  See attached comparison image of bilinear and bicubic interpolation.


  


  Adding to this, I have seen now that the inside of the image does improve in quality with cubic, compared with nearest neighbour.

  


  

  


  The reason for the smooth inside, and jagged asset edge is because there's no pixel to sample from outside the boundary of the image, when interpolation is applied.

  


  I wrote some moviepy code, which adds a black margin (which actually turns transparent) and mask and then rotates. With bicubic interpolation it creates course, black lines, with a strange blend. However, with bilinear interpolation, the lines are much less apparent.

  


  # Add margin, add mask, rotate with interpolation of transparent 2 pixel border.
original_clip = mped.ImageClip("sunset200x100.jpg")
opaque_color = np.array([255, 255, 255]).astype(np.uint8)
margin_color = np.array([0, 0, 0]).astype(np.uint8)
margin_added_clip = original_clip.margin(2, color=margin_color)  # adds 2 pixel black border.
color_mask = mped.ColorClip(size=(original_clip.size), color=opaque_color).margin(2, color=margin_color)
mask = color_mask.to_mask()  # converts to grayscale with values between 0 and 1
masked_clip = margin_added_clip.set_mask(mask)  # adds the float mask to the clip
rotated_sunset = masked_clip.rotate(56, unit='deg', expand=True, resample="bicubic")
rotated_sunset.save_frame("sunset_rotated_56_degrees_moviepy_with_2px_mask.png")  # uses imageio to save the frame.


  


  

  


  However,

  


  If you switch from bicubic to bilinear, it looks a lot better :-

  


  

  


• png_parser : Fix parsing on big endian

  18 décembre 2013, par Martin Storsjö

  png_parser : Fix parsing on big endian
  Since pc.state is populated by shifting in from the end of the
  
  32 bit word, the content within pc.state is already in native endian
  
  and should not be read with the AV_RL,B functions.
  This was already done correctly for state64 above.
  This fixes the fate-corepng test on big endian.
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DH] libavcodec/png_parser.c

• avcodec/binkaudio : Remove AV_CODEC_CAP_DELAY

  11 octobre 2021, par Andreas Rheinhardt

  avcodec/binkaudio : Remove AV_CODEC_CAP_DELAY
  This decoder may output multiple AVFrames for every AVPacket
  
  passed to it, but after it has returned AVERROR(EAGAIN),
  
  it is completely drained and there is no reason to flush it
  
  at the end with a NULL packet. Furthermore, there is also no
  
  delay in the common sense of the word.
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] libavcodec/binkaudio.c