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• ffmpeg detects a videofile path when it does not exist

  17 novembre 2020, par Nejc Kejzar

  this is boggling my mind. I am using ffmpeg to compress videos within the following python script :

  


  import re
import os

kage = 'MH5'
year = '2020'
month = '11'
day = '10'

# Set output dir; create it if it doesn't exist yet
downsampled_video_dir = home_data_dir + f'piCamera/downsampled_videos/{kage}/{year}/{month}/{day}/'
Path(downsampled_video_dir).mkdir(parents=True, exist_ok=True)
    
for i, video in enumerate(videos):
        # Set ffmpeg video compression terminal command and output directory for downsampled videos
        video_name = re.findall('\d+_\d+.mp4', video)[0]
        ds_output = downsampled_video_dir + video_name
        compress_command = f"ffmpeg -i {video} -vf scale={video_res[0]}:-2 {ds_output}"
        
        # Run ffmpeg video compression
        os.system(compress_command)


  


  videos is a list of full video paths of the videos that I wish to compress, and ds_output is a full path of where to write the compressed video. video_res[0] contains the desired height of the video with the following -2 automatically calculating the width so that the aspect ratio is preserved.

  


  For some reason when running this, ffmpeg detects some of the videos in the output directory as already existing and asks if I wish to overwrite them. The videos of course aren't there yet, so when I pass y, ffmpeg complains that no such file exists. Here is an example output for one of the problematic videos :

  


  ffmpeg -y -i '/home/piCamera/MH4/2020/11/10/20201110_085451.mp4' -vf scale=400:300  '/home/piCamera/downsampled_videos/MH4/2020/11/10/20201110_085451.mp4'
ffmpeg version 4.2.4-1ubuntu0.1 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/home/piCamera/MH4/2020/11/10/20201110_085451.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.20.100
  Duration: 00:03:58.84, start: 0.000000, bitrate: 1190 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 960x720, 1190 kb/s, 5 fps, 5 tbr, 10240 tbn, 20480 tbc (default)
    Metadata:
      handler_name    : VideoHandler
/home/piCamera/downsampled_videos/MH4/2020/11/10/20201110_085451.mp4: No such file or directory


  


  This happens with about 3 videos out of 53, the rest run normally. I've tried restarting the terminal, deleted the whole created downsampled_video_dir and run again, but no matter how many times I restart, the same videos are the problem. The only thing that appears to help is if I change the output directory name. Any ideas of why this strange error is happening ?

  


  This is being run on Ubuntu20 with python3.7.9 in a Jupyter Notebook.

  


  Many, many thanks for all the insights !

  


• swscale/rgb2xyz : add explicit width parameter

  7 octobre 2024, par Niklas Haas

  swscale/rgb2xyz : add explicit width parameter
  This fixes an 11-year-old bug in the rgb2xyz functions, when used with a
  
  negative stride. The current loop bounds turned it into a no-op.
  Additionally, this increases performance on highly cropped images, whose
  
  stride may be substantially higher than the effective width.
  Sponsored-by : Sovereign Tech Fund
  
  Signed-off-by : Niklas Haas <git@haasn.dev>
  

  • [DH] libswscale/swscale.c
  • [DH] tests/ref/fate/filter-pixfmts-vflip

• avformat/avienc : add muxer option "write_channel_mask"

  10 septembre 2015, par Tobias Rapp

  avformat/avienc : add muxer option "write_channel_mask"
  Allow writing an empty channel mask into the wave format header. Useful
  
  if the input file contains an unknown channel layout.
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavformat/avienc.c
  • [DH] libavformat/riff.h
  • [DH] libavformat/riffenc.c