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• 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.

  

  

• ffmpeg for android, out of memory on decoding rotate mp4 file with openh264

  29 octobre 2018, par da que

  Version

  • ffmpeg : 4.0.2
  • openh264 : 1.8.0

  Problem

  I try to trim a .mp4 file which metadata info contains rotate info, but I failed with the error information.

  The file stream info :

    Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '1.mp4':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: isommp42
  
      creation_time   : 2018-10-09T09:40:53.000000Z
  
      location        : +39.8983+116.4145/
  
      location-eng    : +39.8983+116.4145/
  
      com.android.version: 6.0
  
    Duration: 00:00:10.56, start: 0.000000, bitrate: 8671 kb/s
  
      Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720, 8563 kb/s, SAR 1:1 DAR 16:9, 30.01 fps, 30 tbr, 90k tbn, 180k tbc (default)
  
      Metadata:
  
        rotate          : 180
  
        creation_time   : 2018-10-09T09:40:53.000000Z
  
        handler_name    : VideoHandle
  
      Side data:
  
        displaymatrix: rotation of -180.00 degrees
  
      Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
  
      Metadata:
  
        creation_time   : 2018-10-09T09:40:53.000000Z
  
        handler_name    : SoundHandle

  ffmpeg cmd

  ffmpeg -y -i 1.mp4 -threads 4 -b:v 2000k -vcodec libopenh264 -acodec copy -ss 0 -t 3 -f mp4 -movflags faststart -strict -2 ./output.mp4

  result

  Error reinitializing filters!
  
  Failed to inject frame into filter network: Out of memory
  
  Error while processing the decoded data for stream #0:0

  Then I found this answer : ffmpeg-for-android-out-of-memory, after i added -noautorotate command to my cmd, the video is trimmed successful.

  If I use -vcodec copy instead of -vcodec libopenh264, the result also is ok, I wonder if there is a bug when libopenh264 decode with ffmpeg’s autorotate function.

  I wipe the video’s rotate info from metadata with -metadata:s:v:0 command, the newly video can be trimmed successful with the origin cmd :(

• FFmpeg | subtitles with ass format

  26 octobre 2018, par Praveen Tamil

  I would like to generate subtitles with dynamic font

  [Script Info]
  
  ScriptType: v4.00+
  
  PlayResX: 1280
  
  PlayResY: 720
  
  Title: WoFox
  
  
  
  [V4+ Styles]
  
  Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
  
  Style: Default,Arial,30,&Hffffff,&Hffffff,&H0000FF,&H0000FF,0,0,0,0,100,100,5,0,3,1,0,3,10,10,10,1
  
  Style: Default1,/home/nodeuser8/tmp/CharmonmanRegular.ttf,40,&Hffffff,&Hffffff,&H0000FF,&H0000FF,0,0,0,0,100,100,5,0,3,1,0,3,10,10,10,1
  
  
  
  [Events]
  
  Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
  
  Dialogue: 0,00:00:00.0,00:00:03.0,Default,,0,0,0,,My first subtitle! Click this text to edit
  
  Dialogue: 0,00:00:00.0,00:00:03.0,Default1,,0,0,0,,This box shows the amount of text that fits into one caption. As you change the style of the captions, you can preview how

  And my ffmpeg code is

  ffmpeg -i ./tmp/source.mp4 -t 5 -filter_complex "ass=filename=./tmp/subtitles.ass" ./t mp/output.mp4 -y

  But I didn’t get out expected output.

  The Console is

  [Parsed_ass_0 @ 0x58680c0] Shaper: FriBidi 1.0.5 (SIMPLE)
  
  [Parsed_ass_0 @ 0x58680c0] Using font provider fontconfig
  
  [Parsed_ass_0 @ 0x58680c0] Added subtitle file: './tmp/subtitles.ass' (3 styles, 2 events)
  
  Stream mapping:
  
    Stream #0:0 (h264) -> ass (graph 0)
  
    ass (graph 0) -> Stream #0:0 (libx264)
  
    Stream #0:1 -> #0:1 (aac (native) -> aac (native))
  
  Press [q] to stop, [?] for help
  
  [Parsed_ass_0 @ 0x5cd4180] Shaper: FriBidi 1.0.5 (SIMPLE)
  
  [Parsed_ass_0 @ 0x5cd4180] Using font provider fontconfig
  
  [Parsed_ass_0 @ 0x5cd4180] Added subtitle file: './tmp/subtitles.ass' (3  styles, 2 events)
  
  [Parsed_ass_0 @ 0x5cd4180] fontselect: (Arial, 400, 0) -> /usr/share/fonts/liberation/LiberationSans-Regular.ttf, 0, LiberationSans
  
  [Parsed_ass_0 @ 0x5cd4180] fontselect: (/home/nodeuser8/tmp/CharmonmanRegular.ttf, 400, 0) -> /usr/share/fonts/dejavu/DejaVuSans.ttf, 0, DejaVuSans
  
  [libx264 @ 0x5869880] using SAR=1/1
  
  [libx264 @ 0x5869880] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
  
  [libx264 @ 0x5869880] profile High, level 3.1, 4:2:0, 8-bit
  
  [libx264 @ 0x5869880] 264 - core 157 r2935 545de2f - H.264/MPEG-4 AVC codec - Copyleft 2003-2018 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 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=6 lookahead_threads=1 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=2 keyint=250 keyint_min=15 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
  
   Output #0, mp4, to './tmp/output.mp4':

  Here I’m trying to load font from /home/nodeuser8/tmp/CharmonmanRegular.ttf but ffmpeg load font from /usr/share/fonts/dejavu/DejaVuSans.ttf.

  So how to load fontfile for ass subtitles ?