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• How to get first 16 fames from a video using ffmpeg ?

  5 mai 2021, par SRI VINOD PALACHARLA

  I have a video mp4 file(5 seconds duration), it has 125 frames. I need to extract first 16 continuous frames into a folder. Can you please put the code for extracting first 16 frames ?

  


  I tried -

  


  cmd = 'ffmpeg -i {} -frames:v 16 {}/%d.png'.format('/content/drive/MyDrive/MTP/train/X/X0.mp4', '/content/drive/MyDrive/MTP/sample') 
subprocess.call(cmd, shell = True)


  


  and it worked.

  


• make video from image file using ffmpeg

  4 août 2014, par Roylisto Putra Pradana

  i have 64 images sequence and i want to make a video using that images.

  you can download the images here

  i use ffmpeg in ubuntu.
  here’s my command

  ffmpeg -r 60 -f image2 -s 1360x768 -i "/home/roylisto/Documents/Tugas Akhir/JAva version/UAVSystem/UAVSystem/tmp/result%d.png" -vcodec libx264 -crf 20 "/home/roylisto/Documents/Tugas Akhir/JAva version/UAVSystem/UAVSystem/render/test.mp4"

  it works but only 39 images has generated to a video. My question is why ffmpeg not render all images in that folder into a video, what is my mistake and how to solve it ?

  Output Command :

      ffmpeg version 2.2.git-73d820e Copyright (c) 2000-2014 the FFmpeg developers
  
    built on Jun 16 2014 10:08:12 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
  
    configuration: --extra-libs=-ldl --prefix=/opt/ffmpeg --enable-avresample --disable-debug --enable-nonfree --enable-gpl --enable-version3 --enable-x11grab --enable-libpulse --enable-libx264 --enable-libfdk-aac --enable-libvorbis --enable-libmp3lame --enable-libopus --enable-libvpx --enable-libspeex --enable-libass --enable-avisynth --enable-libsoxr
  
    libavutil      52. 89.100 / 52. 89.100
  
    libavcodec     55. 66.101 / 55. 66.101
  
    libavformat    55. 43.100 / 55. 43.100
  
    libavdevice    55. 13.101 / 55. 13.101
  
    libavfilter     4.  8.100 /  4.  8.100
  
    libavresample   1.  3.  0 /  1.  3.  0
  
    libswscale      2.  6.100 /  2.  6.100
  
    libswresample   0. 19.100 /  0. 19.100
  
    libpostproc    52.  3.100 / 52.  3.100
  
  Input #0, image2, from '/home/roylisto/Documents/Tugas Akhir/JAva version/UAVSystem/UAVSystem/tmp/result%d.png':
  
    Duration: 00:00:00.62, start: 0.000000, bitrate: N/A
  
      Stream #0:0: Video: png, rgb24, 320x240, 60 fps, 60 tbr, 60 tbn, 60 tbc
  
  No pixel format specified, yuv444p for H.264 encoding chosen.
  
  Use -pix_fmt yuv420p for compatibility with outdated media players.
  
  [libx264 @ 0x2bccce0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.1 Cache64
  
  [libx264 @ 0x2bccce0] profile High 4:4:4 Predictive, level 2.1, 4:4:4 8-bit
  
  [libx264 @ 0x2bccce0] 264 - core 142 r2431 ac76440 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - 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=4 threads=3 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=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=20.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
  
  Output #0, mp4, to '/home/roylisto/Documents/Tugas Akhir/JAva version/UAVSystem/UAVSystem/render/test.mp4':
  
    Metadata:
  
      encoder         : Lavf55.43.100
  
      Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv444p, 320x240, q=-1--1, 60 fps, 15360 tbn, 60 tbc
  
      Metadata:
  
        encoder         : Lavc55.66.101 libx264
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (png (native) -> h264 (libx264))
  
  Press [q] to stop, [?] for help
  
  Input stream #0:0 frame changed from size:320x240 fmt:rgb24 to size:480x360 fmt:rgb24
  
  frame=   35 fps=0.0 q=-1.0 Lsize=      18kB time=00:00:00.55 bitrate= 264.7kbits/s dup=0 drop=2    
  
  video:17kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 7.355630%
  
  [libx264 @ 0x2bccce0] frame I:1     Avg QP:14.45  size:  1829
  
  [libx264 @ 0x2bccce0] frame P:12    Avg QP:20.02  size:   908
  
  [libx264 @ 0x2bccce0] frame B:22    Avg QP:24.15  size:   161
  
  [libx264 @ 0x2bccce0] consecutive B-frames: 14.3%  5.7%  0.0% 80.0%
  
  [libx264 @ 0x2bccce0] mb I  I16..4:  3.3% 84.3% 12.3%
  
  [libx264 @ 0x2bccce0] mb P  I16..4:  0.6%  2.9%  1.9%  P16..4:  7.6%  6.0%  2.8%  0.0%  0.0%    skip:78.3%
  
  [libx264 @ 0x2bccce0] mb B  I16..4:  0.0%  0.1%  0.0%  B16..8: 10.1%  3.2%  0.5%  direct: 0.3%  skip:85.8%  L0:36.3% L1:56.4% BI: 7.3%
  
  [libx264 @ 0x2bccce0] 8x8 transform intra:72.3% inter:49.0%
  
  [libx264 @ 0x2bccce0] coded y,u,v intra: 34.4% 16.0% 10.7% inter: 3.6% 0.5% 0.3%
  
  [libx264 @ 0x2bccce0] i16 v,h,dc,p: 76% 21%  3%  0%
  
  [libx264 @ 0x2bccce0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 14% 22% 50%  2%  2%  1%  5%  2%  3%
  
  [libx264 @ 0x2bccce0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu:  7% 30% 32%  2%  8%  3% 11%  3%  5%
  
  [libx264 @ 0x2bccce0] Weighted P-Frames: Y:0.0% UV:0.0%
  
  [libx264 @ 0x2bccce0] ref P L0: 64.9% 22.6%  9.7%  2.8%
  
  [libx264 @ 0x2bccce0] ref B L0: 86.1% 12.2%  1.7%
  
  [libx264 @ 0x2bccce0] ref B L1: 94.3%  5.7%
  
  [libx264 @ 0x2bccce0] kb/s:223.06

• Dreamcast Track Sizes

  1er mars 2015, par Multimedia Mike — Sega Dreamcast

  I’ve been playing around with Sega Dreamcast discs lately. Not playing the games on the DC discs, of course, just studying their structure. To review, the Sega Dreamcast game console used special optical discs named GD-ROMs, where the GD stands for “gigadisc”. They are capable of holding about 1 gigabyte of data.

  You know what’s weird about these discs ? Each one manages to actually store a gigabyte of data. Each disc has a CD portion and a GD portion. The CD portion occupies the first 45000 sectors and can be read in any standard CD drive. This area is divided between a brief data track and a brief (usually) audio track.

  The GD region starts at sector 45000. Sometimes, it’s just one humongous data track that consumes the entire GD region. More often, however, the data track is split between the first track and the last track in the region and there are 1 or more audio tracks in between. But the weird thing is, the GD region is always full. I made a study of it (click for a larger, interactive graph) :

  
  
  

  Some discs put special data or audio bonuses in the CD region for players to discover. But every disc manages to fill out the GD region. I checked up on a lot of those audio tracks that divide the GD data and they’re legitimate music tracks. So what’s the motivation ? Why would the data track be split in 2 pieces like that ?

  I eventually realized that I probably answered this question in this blog post from 4 years ago. The read speed from the outside of an optical disc is higher than the inside of the same disc. When I inspect the outer data tracks of some of these discs, sure enough, there seem to be timing-sensitive multimedia FMV files living on the outer stretches.

  One day, I’ll write a utility to take apart the split ISO-9660 filesystem offset from a weird sector.