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• How to encode H.264 video using FFmpeg C API and then open the output with a media player ?

  4 avril 2016, par GummiB

  I’m trying to encode a H.264 video with the FFMPEG C API.
  I have successfully compiled and executed the decoding/encoding example provided by FFMPEG.

  The problem I’m facing is that the .mpg file (encoded with AV_CODEC_ID_MPEG1VIDEO) the example creates works. Windows creates a thumbnail and everything. On the other hand the .h264 (encoded with AV_CODEC_ID_H264) file does not. When I try to play the file in VLC the play/pause button just flickers, no thumbnail in windows, no nothing.

  During encoding libx264 reports the following :

  [libx264 @ 004b81a0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
  
  [libx264 @ 004b81a0] profile High, level 1.3
  
  [libx264 @ 004b81a0] frame I:3     Avg QP:26.79  size:  2116
  
  [libx264 @ 004b81a0] frame P:12    Avg QP:26.60  size:   789
  
  [libx264 @ 004b81a0] frame B:10    Avg QP:31.39  size:   499
  
  [libx264 @ 004b81a0] consecutive B-frames: 20.0% 80.0%
  
  [libx264 @ 004b81a0] mb I  I16..4: 78.3% 11.6% 10.1%
  
  [libx264 @ 004b81a0] mb P  I16..4: 77.4%  0.6%  0.1%  P16..4: 20.3%  0.7%  0.9%  0.0%  0.0%    skip: 0.0%
  
  [libx264 @ 004b81a0] mb B  I16..4:  0.0%  0.0%  0.0%  B16..8:  9.4%  0.2%  0.0%  direct:11.0%  skip:79.4%  L0:25.4% L1:35.4% BI:39.2%
  
  [libx264 @ 004b81a0] final ratefactor: 17.03
  
  [libx264 @ 004b81a0] 8x8 transform intra:3.4% inter:31.3%
  
  [libx264 @ 004b81a0] direct mvs  spatial:0.0% temporal:100.0%
  
  [libx264 @ 004b81a0] coded y,uvDC,uvAC intra: 4.4% 35.8% 1.6% inter: 1.3% 34.5% 9.5%
  
  [libx264 @ 004b81a0] i16 v,h,dc,p:  0%  0%  0% 100%
  
  [libx264 @ 004b81a0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu:  7% 20% 17% 49%  0%  0%  0%  1%  6%
  
  [libx264 @ 004b81a0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 14%  7% 18% 45%  2%  7%  2%  3%  2%
  
  [libx264 @ 004b81a0] i8c dc,h,v,p:  2%  6%  4% 88%
  
  [libx264 @ 004b81a0] Weighted P-Frames: Y:0.0% UV:0.0%
  
  [libx264 @ 004b81a0] ref P L0: 95.6%  1.6%  2.2%  0.5%  0.2%
  
  [libx264 @ 004b81a0] ref B L0: 67.5% 28.5%  3.2%  0.8%
  
  [libx264 @ 004b81a0] kb/s:166.45

  "ffprobe.exe test.h264 -show_streams" returns

  [STREAM]
  
  index=0
  
  codec_name=h264
  
  codec_long_name=H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
  
  profile=High
  
  codec_type=video
  
  codec_time_base=1/50
  
  codec_tag_string=[0][0][0][0]
  
  codec_tag=0x0000
  
  width=352
  
  height=288
  
  has_b_frames=1
  
  sample_aspect_ratio=0:1
  
  display_aspect_ratio=0:1
  
  pix_fmt=yuv420p
  
  level=13
  
  timecode=N/A
  
  id=N/A
  
  r_frame_rate=50/2
  
  avg_frame_rate=25/1
  
  time_base=1/1200000
  
  start_pts=N/A
  
  start_time=N/A
  
  duration_ts=N/A
  
  duration=N/A
  
  bit_rate=N/A
  
  nb_frames=N/A
  
  nb_read_frames=N/A
  
  nb_read_packets=N/A
  
  DISPOSITION:default=0
  
  DISPOSITION:dub=0
  
  DISPOSITION:original=0
  
  DISPOSITION:comment=0
  
  DISPOSITION:lyrics=0
  
  DISPOSITION:karaoke=0
  
  DISPOSITION:forced=0
  
  DISPOSITION:hearing_impaired=0
  
  DISPOSITION:visual_impaired=0
  
  DISPOSITION:clean_effects=0
  
  DISPOSITION:attached_pic=0
  
  [/STREAM]

  There you can see :

  start_time=N/A
  
  duration_ts=N/A
  
  duration=N/A

  I have tried countless changes to the AVCodecContext and multitude of parameters options to av_opt_set function. Still no luck getting a working H.264 video. I have even tried different builds of FFmpeg. No luck.

  I’m using the "FFmpeg git-0fb64da 32-bit Dev" build from Zeranoe and MinGw 4.7.2

• Can not open video in OpenCV and all solution on stacjoverflow is not working with me

  19 mai 2017, par Abeer Yosef

  I am trying to open video in openCV but it is not working i found solutions by adding full path i.e "D :/Folder1/Folder2/1.avi", converting video to .avi instead of mp4, copy the dll file from open cv to python folder after changing it is name by opencv version and windows 64 bit ffmpeg opencv_ffmpeg320_64.dll
  my opencv version 3.2.0
  windows 64
  python2.7 and Anaconda2

  I am beginner in Python and unfortunately nothing of the above solved my problem.

  below my code snappit

  import numpy as np

  import cv2

  cap = cv2.VideoCapture(’1.avi’)
  if cap.isOpened() :
  print "opend"
  else :
  print "not opend"

  while(cap.isOpened()) :
  ret, frame = cap.read()

  gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
  
  
  
  cv2.imshow('frame',gray)
  
  if cv2.waitKey(1) & 0xFF == ord('q'):
  
      break

  cap.release()
  cv2.destroyAllWindows()

• Cannot open video in OpenCV (Python)

  19 mai 2017, par Abeer Yosef

  I am trying to open video in openCV but it is not working i found solutions by adding full path i.e "D :/Folder1/Folder2/1.avi", converting video to .avi instead of mp4, copy the dll file from open cv to python folder after changing it is name by opencv version and windows 64 bit ffmpeg opencv_ffmpeg320_64.dll
  my opencv version 3.2.0
  windows 64
  python2.7 and Anaconda2

  I am beginner in Python and unfortunately nothing of the above solved my problem.

  below my code snippet :

  import numpy as np
  
  import cv2
  
  
  
  cap = cv2.VideoCapture('1.avi')
  
  if cap.isOpened():
  
      print "opend"
  
  else:
  
      print "not opend"
  
  
  
  while(cap.isOpened()):
  
      ret, frame = cap.read()
  
  
  
      gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
  
  
  
      cv2.imshow('frame',gray)
  
      if cv2.waitKey(1) & 0xFF == ord('q'):
  
          break
  
  
  
  cap.release()
  
  cv2.destroyAllWindows()