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• Cannot use pydub.AudioSegment on audio files downloaded by youtube-dl library

  26 octobre 2018, par Han M

  After I download a audio clip from a youtube link by the youtube-dl library, I cannot use pydub.AudioSegment to slice the audio file. The following is the information about my code.

  import youtube_dl
  
  options = {
  
          'format': 'bestaudio/best',
  
          'extractaudio': True,  # only keep the audio
  
          'audio-format': "wav",  # convert to wav
  
          'outtmpl': whole_path,  # name the file the ID of the video
  
          'noplaylist': True,  # only download single song, not playlist
  
          'audioquality': 1
  
  }
  
  with youtube_dl.YoutubeDL(options) as ydl:
  
      print('url is:', web_url)
  
      ydl.download([web_url])
  
  
  
  from pydub import AudioSegment
  
  audio_data = AudioSegment.from_wav(path_to_downloaded_file)

  Then, I got an error as follows first on Mac and second on Linux :

  b'avconv version 12.3, Copyright (c) 2000-2018 the Libav developers\n  built on Jul 26 2018 18:08:50 with Apple LLVM version 9.1.0 (clang-902.0.39.2)\n/Users/***/random17560390.wav: Invalid data found when processing input\n'
  
  
  
  b'ffmpeg version 2.8.15-0ubuntu0.16.04.1 Copyright (c) 2000-2018 the FFmpeg developers\n  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.10) 20160609\n  configuration: --prefix=/usr --e
  
  xtra-version=0ubuntu0.16.04.1 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-
  
  shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-li
  
  bbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmod
  
  plug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-li
  
  bspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --e
  
  nable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 --enable-libopencv\n  libavutil      54. 31.100 / 54.
  
   31.100\n  libavcodec     56. 60.100 / 56. 60.100\n  libavformat    56. 40.101 / 56. 40.101\n  libavdevice    56.  4.100 / 56.  4.100\n  libavfilter     5. 40.101 /  5. 40.101\n  libavresa
  
  mple   2.  1.  0 /  2.  1.  0\n  libswscale      3.  1.101 /  3.  1.101\n  libswresample   1.  2.101 /  1.  2.101\n  libpostproc    53.  3.100 / 53.  3.100\n[wav @ 0x20854c0] invalid start
  
   code [0][0][0][28] in RIFF header\n/home/users/test_download/random10485395.wav: Invalid data found when processing input\n'

  I think the problem might be about the encoding on the downloaded files by youtube-dl. I can use pydub.AudioSegment on other normal .wav files. After checking the details of the downloaded file by youtube-dl, I found the following feature :

  Stream #0:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 125 kb/s (default)

  It is different from other normal .wav files, which have the following :

  Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, 2 channels, s16, 1411 kb/s

• Losing frames when clipping videos with ffmpeg

  9 décembre 2018, par Mark C

  I seem to be losing frames when I clip videos up with ffmpeg.

  Here are the steps I take :

  [Get the Frame number to cut on] -> [turn the frame number into hh:mm:ss.ms format] -> [Run ffmpeg process]

  Here is the code :

  import subprocess
  
  
  
  def frames_to_timecode(frame,frameRate):
  
      '''
  
      Convert frame into a timecode HH:MM:SS.MS
  
      frame = The frame to convert into a time code
  
      frameRate = the frame rate of the video
  
      '''
  
      #convert frames into seconds
  
      seconds = frame / frameRate
  
  
  
      #generate the time code
  
      timeCode = '{h:02d}:{m:02d}:{s:02f}'.format(
  
      h=int(seconds/3600),
  
      m=int(seconds/60%60),
  
      s=seconds%60)
  
  
  
      return timeCode
  
  
  
  frameRate = 24.0
  
  
  
  inputVideo = r"C:\Users\aquamen\Videos\vlc-record-2018-10-23-17h11m11s-SEQ-0200_animatic_v4_20180827_short.mp4"
  
  outputVideo = r"C:\Users\aquamen\Videos\ffmpeg_test_clip001.mp4"
  
  ffmpeg = r"C:\ffmpeg\ffmpeg-20181028-e95987f-win64-static\bin\ffmpeg.exe" 
  
  
  
  endFrame = frames_to_timecode(29,frameRate)
  
  startFrame = frames_to_timecode(10,frameRate)
  
  
  
  subprocess.call([ffmpeg,'-i',inputVideo,'-ss',startFrame,'-to',endFrame,outputVideo])

  Here is a image of the original video and the clipped video with the time codes showing a frame was lost in process. The time code should show 00:01:18:10 instead its 00:01:18:11.

  

  

• ffpmeg drops last frame when compressing from MP4 to MP4 (libx264)

  28 octobre 2018, par Usoboi

  So, I’m using this code to compress my *mp4 file. I need to get lower quality and decrease bitrate :

  ffmpeg -i input.mp4 -c:v libx264 output.mp4

  The problem is : the last frame of footage is dropped after ffmpeg compression.
  Screenshot is here : screenshot_ffmpeg_drop frame

  I tried to use full preferences I need, but the problem is the same.

  ffmpeg -i input.mp4 -c:v libx264 -vf scale=1280:720 -preset fast -crf 29 -r 25 -c:a copy output.mp4

  logfile during ffmpeg encoding :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from ’\input.mp4’ :
  Metadata :
  major_brand : mp42
  minor_version : 0
  compatible_brands : mp42mp41
  creation_time : 2018-10-28T11:06:03.000000Z
  Duration : 00:00:12.76, start : 0.000000, bitrate : 5374 kb/s
  Stream #0:0(eng) : Video : h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 5368 kb/s, 25 fps, 25 tbr, 50k tbn, 50 tbc (default)
  Metadata :
  creation_time : 2018-10-28T11:06:03.000000Z
  handler_name : Alias Data Handler
  encoder : AVC Coding

  Stream mapping : Stream #0:0 -> #0:0 (h264 (native) -> h264
  (libx264)) Press [q] to stop, [?] for help [libx264 @
  000002fae8b50780] using SAR=1/1 [libx264 @ 000002fae8b50780] using cpu
  capabilities : MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2 [libx264 @
  000002fae8b50780] profile High, level 3.1 [libx264 @ 000002fae8b50780]
  264 - core 155 r2901 7d0ff22 - H.264/MPEG-4 AVC codec - Copyleft
  2003-2018 - http://www.videolan.org/x264.html - options : cabac=1 ref=2
  deblock=1:0:0 analyse=0x3:0x113 me=hex subme=6 psy=1 psy_rd=1.00:0.00
  mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0
  deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12
  lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0
  bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1
  b_bias=0 direct=1 weightb=1 open_gop=0 weightp=1 keyint=250
  keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=30 rc=crf
  mbtree=1 crf=29.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40
  aq=1:1.00 Output #0, mp4, to ’\output.mp4’ : Metadata :
  major_brand : mp42
  minor_version : 0
  compatible_brands : mp42mp41
  encoder : Lavf58.17.100
  Stream #0:0(eng) : Video : h264 (libx264) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=-1—1, 25 fps, 12800 tbn, 25
  tbc (default)
  Metadata :
  creation_time : 2018-10-28T11:06:03.000000Z
  handler_name : Alias Data Handler
  encoder : Lavc58.19.104 libx264
  Side data :
  cpb : bitrate max/min/avg : 0/0/0 buffer size : 0 vbv_delay : -1

  frame= 318 fps=127 q=-1.0 Lsize= 855kB time=00:00:12.60 bitrate=
  556.0kbits/s speed=5.05x video:851kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead : 0.534683% [libx264 @
  0000015d5cef0500] frame I:2 Avg QP:26.18 size : 67800 [libx264 @
  0000015d5cef0500] frame P:80 Avg QP:27.93 size : 5439 [libx264 @
  0000015d5cef0500] frame B:236 Avg QP:32.44 size : 1269 [libx264 @
  0000015d5cef0500] consecutive B-frames : 0.9% 0.0% 0.9% 98.1%
  [libx264 @ 0000015d5cef0500] mb I I16..4 : 10.6% 62.5% 26.8% [libx264
  @ 0000015d5cef0500] mb P I16..4 : 0.5% 1.0% 0.2% P16..4 : 36.1%
  5.1% 3.6% 0.0% 0.0% skip:53.6% [libx264 @ 0000015d5cef0500] mb B I16..4 : 0.6% 0.5% 0.0% B16..8 : 22.2% 0.6% 0.0% direct : 2.0%
  skip:74.2% L0:44.9% L1:54.5% BI : 0.6% [libx264 @ 0000015d5cef0500]
  8x8 transform intra:55.0% inter:86.2% [libx264 @ 0000015d5cef0500]
  coded y,uvDC,uvAC intra : 48.1% 54.9% 27.0% inter : 3.2% 5.2% 0.2%
  [libx264 @ 0000015d5cef0500] i16 v,h,dc,p : 19% 56% 10% 15% [libx264 @
  0000015d5cef0500] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu : 19% 25% 18% 5% 6%
  5% 8% 5% 8% [libx264 @ 0000015d5cef0500] i4
  v,h,dc,ddl,ddr,vr,hd,vl,hu : 27% 24% 9% 5% 8% 7% 9% 5% 7%
  [libx264 @ 0000015d5cef0500] i8c dc,h,v,p : 60% 20% 15% 4% [libx264 @
  0000015d5cef0500] Weighted P-Frames : Y:0.0% UV:0.0% [libx264 @
  0000015d5cef0500] ref P L0 : 67.7% 32.3% [libx264 @ 0000015d5cef0500]
  ref B L0 : 80.4% 19.6% [libx264 @ 0000015d5cef0500] ref B L1 : 92.1%
  7.9% [libx264 @ 0000015d5cef0500] kb/s:547.35