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• FFMPEG corruption concat

  11 avril 2017, par Please Help

  When I run

  ffmpeg -f concat -i resizedvideolist.txt -c copy concatenated_time.mp4 2>&1

  it concatenates all the videos in the txt, but there is one video around halfway through that get glitched out. The audio just doesn’t play for that video, but then starts playing on the next video, so it has been delayed. Then somewhere the audio managed to catch up and gets back in sync. Seems like some major corruption going on here.

  I do not know how to fix this as the codec is the same as all the other vidoes, H.264, it is an mp4 like the others. The individual video file runs fine as it is, and it already is in the same timescale, because before this ffmpeg command, I ran

  ffmpeg -i ./tempDownloadedMemes/$videoFileName -filter_complex 'scale=1080:-1,pad=1080:1080:(ow-iw)/2:(oh-ih)/2:0x2F2F2F' -video_track_timescale 15360 ./resizedVideos/resized_videoFileName 2>&1

  To be honest I don’t even know what timescale is, but I read that it needs to be the same for it to work. I deleted the video from the list, tried this same command, and the problem was gone at the same time in the video that it would have appeared. It seems like it is something to do with that one file itself. Any known issues/workarounds on concat bugs ? This is very important to me. Thanks.

• FFmpeg recording audio from several sources

  4 avril 2017, par Valery Shevchuk

  everyone.
  I’m trying to use FFmpeg to record video and 3 audio sources and use it to generate 3 different video files - each file should contain the same video stream but the different audio stream. The problem is that I got audio sync issues. The first audio stream is synced perfectly, but the second one has 1 sec lag, and the third one has like 2 sec lag.

  I’ve made a few tests so far and it seems that root cause of the issue is initialization time of video/audio devices. So, one device is already recording something but the second is still being opened and so on. I’ve tried to change input devices order and after that audio streams still have the same issue BUT if before 2nd and 3rd audio streams were some time ahead of video, after reordering they became to lag after the audio (audio for the same event appears with some delay). So this test confirms my version about device initialization times.

  But the question still, why the first audio stream is synchronized properly, while other 2 are not. and also, how could I overcome this issues ? Any workarounds and ideas are highly appreciated.

  Here is FFmpeg command I’m using and it’s output.

  ffmpeg.exe -f dshow -video_size 1920x1080 -i video="Logitech HD Webcam
  C615" -f dshow -i audio="Microphone (HD Webcam C615)" -f dshow -i
  audio="Microphone Array (Realtek High Definition Audio)"
  -filter_complex "[1:a]volume=1[a1] ;[2:a]volume=1[a2]" -vf scale=h=1080:force_original_aspect_ratio=decrease -vcodec libx264
  -pix_fmt yuv420p -crf 23 -preset ultrafast -acodec aac -vbr 5 -threads 0 -map v:0 -map [a1] -map [a2] -f tee
  "[select=\’v,a:0\’]C :/Users/vshevchu/Desktop/123/111/111_jjj1.avi|
  [select=\’v,a:1\’]C :/Users/vshevchu/Desktop/123/111/111_jjj2.avi"

  OUTPUT

  PS. Actually, the issue is exactly the same when I’m not using "tee" muxer but writing all the audio streams to one container. So, "tee" isn’t a suspect.

• Solved : ffmpeg : How can a MOV with transparent background be created ?

  25 mars 2017, par Mat

  (Remark : the error sat, as usual, between back-rest and keyboard. Thanks, Mulvya !)

  Hi, specialists !

  I’m trying - with no success at all - to convert the green pixels of a background into transparent ones and output the result as clip with ffmpeg. N.b. I do not want to lay the clip over anything ; I’m not having a problem with that. What I want is a clip with transparent background for the OpenShot video editor (the chromakey filter of which doesn’t work satisfyingly).

  What I have tried (amongst a felt 1 zillion other things over the last 15 hrs.) was

  ffmpeg.exe -i in.mov -vf chromakey=0x008001:0.115:0.0 -c:v qtrle out.mov

  but the pixels simply would not be transparent. Seemingly, nothing happens. I reckon the filter is ok, because it works fine in a complex chain (overlaying a background image).

  The output of ffprompt -show_stream -show_format of out.mov is as follows :

  [STREAM]
  
  index=0
  
  codec_name=qtrle
  
  codec_long_name=QuickTime Animation (RLE) video
  
  profile=unknown
  
  codec_type=video
  
  codec_time_base=1/30
  
  codec_tag_string=rle
  
  codec_tag=0x20656c72
  
  width=1920
  
  height=1080
  
  coded_width=1920
  
  coded_height=1080
  
  has_b_frames=0
  
  sample_aspect_ratio=1:1
  
  display_aspect_ratio=16:9
  
  pix_fmt=bgra
  
  level=-99
  
  color_range=N/A
  
  color_space=unknown
  
  color_transfer=unknown
  
  color_primaries=unknown
  
  chroma_location=unspecified
  
  field_order=progressive
  
  timecode=N/A
  
  refs=1
  
  id=N/A
  
  r_frame_rate=30/1
  
  avg_frame_rate=30/1
  
  time_base=1/15360
  
  start_pts=0
  
  start_time=0.000000
  
  duration_ts=54789
  
  duration=3.566992
  
  bit_rate=822383192
  
  max_bit_rate=N/A
  
  bits_per_raw_sample=N/A
  
  nb_frames=107
  
  nb_read_frames=N/A
  
  nb_read_packets=N/A
  
  DISPOSITION:default=1
  
  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
  
  DISPOSITION:timed_thumbnails=0
  
  TAG:language=eng
  
  TAG:handler_name=DataHandler
  
  TAG:encoder=Lavc57.64.101 qtrle
  
  [/STREAM]
  
  [STREAM]
  
  index=1
  
  codec_name=aac
  
  codec_long_name=AAC (Advanced Audio Coding)
  
  profile=LC
  
  codec_type=audio
  
  codec_time_base=1/44100
  
  codec_tag_string=mp4a
  
  codec_tag=0x6134706d
  
  sample_fmt=fltp
  
  sample_rate=44100
  
  channels=2
  
  channel_layout=stereo
  
  bits_per_sample=0
  
  id=N/A
  
  r_frame_rate=0/0
  
  avg_frame_rate=0/0
  
  time_base=1/44100
  
  start_pts=926
  
  start_time=0.020998
  
  duration_ts=157481
  
  duration=3.570998
  
  bit_rate=132103
  
  max_bit_rate=132103
  
  bits_per_raw_sample=N/A
  
  nb_frames=153
  
  nb_read_frames=N/A
  
  nb_read_packets=N/A
  
  DISPOSITION:default=1
  
  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
  
  DISPOSITION:timed_thumbnails=0
  
  TAG:language=eng
  
  TAG:handler_name=DataHandler
  
  [/STREAM]
  
  [FORMAT]
  
  filename=out.mov
  
  nb_streams=2
  
  nb_programs=0
  
  format_name=mov,mp4,m4a,3gp,3g2,mj2
  
  format_long_name=QuickTime / MOV
  
  start_time=0.000000
  
  duration=3.567000
  
  size=366708874
  
  bit_rate=822447712
  
  probe_score=100
  
  TAG:major_brand=qt
  
  TAG:minor_version=512
  
  TAG:compatible_brands=qt
  
  TAG:encoder=Lavf57.56.101
  
  [/FORMAT]

  I have a "sample" clip which shows the behaviour I want, with the following stream and information :

  [STREAM]
  
  index=0
  
  codec_name=qtrle
  
  codec_long_name=QuickTime Animation (RLE) video
  
  profile=unknown
  
  codec_type=video
  
  codec_time_base=1/24
  
  codec_tag_string=rle
  
  codec_tag=0x20656c72
  
  width=1920
  
  height=1080
  
  coded_width=1920
  
  coded_height=1080
  
  has_b_frames=0
  
  sample_aspect_ratio=0:1
  
  display_aspect_ratio=0:1
  
  pix_fmt=bgra
  
  level=-99
  
  color_range=N/A
  
  color_space=unknown
  
  color_transfer=unknown
  
  color_primaries=unknown
  
  chroma_location=unspecified
  
  field_order=progressive
  
  timecode=N/A
  
  refs=1
  
  id=N/A
  
  r_frame_rate=24/1
  
  avg_frame_rate=24/1
  
  time_base=1/12288
  
  start_pts=0
  
  start_time=0.000000
  
  duration_ts=74760
  
  duration=6.083984
  
  bit_rate=49226848
  
  max_bit_rate=N/A
  
  bits_per_raw_sample=N/A
  
  nb_frames=146
  
  nb_read_frames=N/A
  
  nb_read_packets=N/A
  
  DISPOSITION:default=1
  
  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
  
  DISPOSITION:timed_thumbnails=0
  
  TAG:language=eng
  
  TAG:handler_name=DataHandler
  
  TAG:encoder=Lavc57.24.102 qtrle
  
  [/STREAM]
  
  [STREAM]
  
  index=1
  
  codec_name=aac
  
  codec_long_name=AAC (Advanced Audio Coding)
  
  profile=LC
  
  codec_type=audio
  
  codec_time_base=1/48000
  
  codec_tag_string=mp4a
  
  codec_tag=0x6134706d
  
  sample_fmt=fltp
  
  sample_rate=48000
  
  channels=2
  
  channel_layout=stereo
  
  bits_per_sample=0
  
  id=N/A
  
  r_frame_rate=0/0
  
  avg_frame_rate=0/0
  
  time_base=1/48000
  
  start_pts=0
  
  start_time=0.000000
  
  duration_ts=293856
  
  duration=6.122000
  
  bit_rate=53537
  
  max_bit_rate=128000
  
  bits_per_raw_sample=N/A
  
  nb_frames=288
  
  nb_read_frames=N/A
  
  nb_read_packets=N/A
  
  DISPOSITION:default=1
  
  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
  
  DISPOSITION:timed_thumbnails=0
  
  TAG:language=eng
  
  TAG:handler_name=DataHandler
  
  [/STREAM]
  
  [FORMAT]
  
  filename=templateOK.mov
  
  nb_streams=2
  
  nb_programs=0
  
  format_name=mov,mp4,m4a,3gp,3g2,mj2
  
  format_long_name=QuickTime / MOV
  
  start_time=0.000000
  
  duration=6.144000
  
  size=37478506
  
  bit_rate=48800138
  
  probe_score=100
  
  TAG:major_brand=qt
  
  TAG:minor_version=512
  
  TAG:compatible_brands=qt
  
  TAG:encoder=Lavf57.25.100
  
  [/FORMAT]

  and I simply am not able to spot the relevant difference.

  Any suggestions would be highly appreciated !

  Cheers,

  Mat

  The input, output and the working template can be found here.

  (The security issue you might see when clicking the link comes from the server certificate being self-signed. You can accept a temporal exception. Btw : The ridiculous file size of the output file will be the next nut to crack. Probably s.t. about compression.)