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• Unmapping memory-mapped images that are created during processing

  23 avril 2013, par user2309283

  I have a pretty big issue, although I only have the symptoms, and a theory on the cause.

  I have a C++ application under Windows 7x64 that uses system calls to FFMPEG 0.7.13 to extract frames from videos. When running, the parent application maintains a nice, predicable memory footprint in memory profilers (task manager, RAMMap) of about 2MB. I can see the individual calls to FFMPEG also come and go without incident. The trouble is, after about 100 calls to FFMPEG, and 70,000+ PNGs created (no one directory has more than 1500 pngs), the Windows memory page size raises gradually from about 2.5GB to over 7.0GB, and the system is brought to its knees. The sum of the processes for all users is no where near the reported Memory Page amount.

  I thought it might be Windows Search indexing related, so I turned off the indexing for the output directories in question using SetFileAttributes() and FILE_ATTRIBUTE_NOT_CONTENT_INDEXED, and while it seems to be working as advertised, it does not seem to combat the issue at hand. My current running theory is that all of these extracted PNGs are either fully or partially memory mapped, by FFMPEG or something else. I can also see the output PNGs under the RAMMap Physical Pages tab as standby mapped files.

  Question :
   Is there enough information here to possibly diagnose the exact problem ?
   Do I have a way to combat this issue ?

  Thanks in advance...

• FFMPEG Take 1 second clips each video file from a directory of files, and until total playtime reached

  3 février 2021, par Matthew

  I'm working on a music art video project for a song.

  


  I have a directory that contains approximately 400 individual videos

  


  

  • varying lengths (as short as 3 seconds and as long as 31 minutes)

  


  • varying file types (mp4 and webm)

  


  • varying resolutions/framerates/bitrates

  


  


  The output video should consist of :

  


  

  • 1 second chunks of each video

  


  • in round-robin fashion

  


  • until all videos are played fully or the output total video length reaches a certain limit (example, 20 minutes).

  


  • Output video should be 1280×720 at 24fps, with no preference to bitrate.

  


  • Videos that are larger should be scaled down and letterboxed (vertically or horizontally).

  


  • Audio is not important at all. The video can be silent. I can overlay audio separately.

  


  


  I do not want to loop short videos. In the example below, you can see that, for top-left-view-take-1.mp4, each 'clip' that's taken is incrementally further into the video. In other words, it shouldn't take the same 1 second clip from the beginning. The goal is to get further in to each individual video as the output video progresses.

  


  For example, say my directory contains files such as the following (and, for the example here, we'll say that this is all files in the directory) :

  


  overhead-view-take-1.mp4 (3 seconds, for the sake of the question)
top-right-view-take-1.mp4 (3 seconds, for the sake of the question)
top-right-view-take-2.mp4 (5 seconds, for the sake of the question)
outside-kaleidoscope-1.mp4
yellow-kaleidoscope-1.mp4
red-kaleidoscope-1.mp4
brake-lights-slow-1.mp4
soft-city-lights.webm


  


  Assume anything that isn't marked with a video duration is at least 5 seconds long.

  


  Based on the above files & times, here would be the order and time code of each clip during the first 30 seconds of the output video :

  


  Based on each video's total duration, the output video should include 1 second clips from all videos in the directory.

  


  





  


  


  


  


  


  



  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  Output time	Clip time	Clip file
  00:00-00:01	00:00-00:01	overhead-view-take-1.mp4
  00:01-00:02	00:00-00:01	top-right-view-take-1.mp4
  00:02-00:03	00:00-00:01	top-right-view-take-2.mp4
  00:03-00:04	00:00-00:01	outside-kaleidoscope-1.mp4
  00:04-00:05	00:00-00:01	yellow-kaleidoscope-1.mp4
  00:05-00:06	00:00-00:01	red-kaleidoscope-1.mp4
  00:06-00:07	00:00-00:01	brake-lights-slow-1.mp4
  00:07-00:08	00:00-00:01	soft-city-lights.webm
  00:08-00:09	00:01-00:02	overhead-view-take-1.mp4
  00:09-00:10	00:01-00:02	top-right-view-take-1.mp4
  00:10-00:11	00:01-00:02	top-right-view-take-2.mp4
  00:11-00:12	00:01-00:02	outside-kaleidoscope-1.mp4
  00:12-00:13	00:01-00:02	yellow-kaleidoscope-1.mp4
  00:13-00:14	00:01-00:02	red-kaleidoscope-1.mp4
  00:14-00:15	00:01-00:02	brake-lights-slow-1.mp4
  00:15-00:16	00:01-00:02	soft-city-lights.webm
  00:16-00:17	00:02-00:03	overhead-view-take-1.mp4
  00:17-00:18	00:02-00:03	top-right-view-take-1.mp4
  00:18-00:19	00:02-00:03	top-right-view-take-2.mp4
  00:19-00:20	00:02-00:03	outside-kaleidoscope-1.mp4
  00:20-00:21	00:02-00:03	yellow-kaleidoscope-1.mp4
  00:21-00:22	00:02-00:03	red-kaleidoscope-1.mp4
  00:22-00:23	00:02-00:03	brake-lights-slow-1.mp4
  00:23-00:24	00:02-00:03	soft-city-lights.webm

  


  


  Now, the output video should include 1 second clips only from videos that still have time remaining. The videos that don't have any time remaining, such as overhead-view-take-1.mp4 and top-right-view-take-1.mp4, are not present here.

  


  





  


  


  


  


  


  



  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  Output time	Clip time	Clip file
  00:24-00:25	00:03-00:04	top-right-view-take-2.mp4
  00:25-00:26	00:03-00:04	outside-kaleidoscope-1.mp4
  00:26-00:27	00:03-00:04	yellow-kaleidoscope-1.mp4
  00:27-00:28	00:03-00:04	red-kaleidoscope-1.mp4
  00:28-00:29	00:03-00:04	brake-lights-slow-1.mp4
  00:29-00:30	00:03-00:04	soft-city-lights.webm

  


  


  What I've tried

  


  

  • I've read through the docs and cobbled together some code that produces output, but it only seems to work with images ; I can't get the same thing to work with videos (specifically the incremental chunks).

  


  • I've tried manipulating commands meant to `create a snapshot every x seconds/frames' but I've hit dead ends there.

  


  • I've also started trying to create a text file to run the input from. That's the point where I thought it would make sense to ask here.

  


  


  My main issue is picking off incremental chunks of individual videos, and playing those in sequence.

  


  Thoughts ?

  


  Environment details
I have access to Win, Mac, and Linux machines. So, that environment isn't as important to me. Here's ffmpeg's output :

  


  ffmpeg version 4.3.1-0york0~16.04 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.12) 20160609
  configuration: --prefix=/usr --extra-version='0york0~16.04' --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-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-librabbitmq --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --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-libzimg --enable-pocketsphinx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 51.100 / 56. 51.100
  libavcodec     58. 91.100 / 58. 91.100
  libavformat    58. 45.100 / 58. 45.100
  libavdevice    58. 10.100 / 58. 10.100
  libavfilter     7. 85.100 /  7. 85.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  7.100 /  5.  7.100
  libswresample   3.  7.100 /  3.  7.100
  libpostproc    55.  7.100 / 55.  7.100
Hyper fast Audio and Video encoder


  


• Python subprocess or os.system not working with ffmpeg

  13 février 2024, par confused

  I've been trying to get this darn programming run since last night and cannot seem to get anything to work. I want to first trim the video and then resize the video. I'm reading which video and what to give the final name from a text file, over 780 lines long, quite a few videos.

  


  Thus far with every idea under the sun I have tried, subprocess and os.system, I can't get anything more than error statements or right now all I get is no file creation of any kind. How the heck do I get this to work correctly ?

  


  import ffmpeg
import subprocess
import os

os.chdir('/home/Downloads/SRs/')
a = open('SRt.txt', 'r')
b = a.readlines()
a.close()
for c in range(0, len(b)-1):
    words = list(b[c].split(" "))
    d = len(words)
    e = words[d-1]
    f = b[c].replace(e, 'FR' + str(c) + '.mp4')
    words[d-1] = 'FR' + str(c) + '.mp4'
    print(f)
    subprocess.call(f, shell=True)
    subprocess.call([
        'ffmpeg',
        '-i',
        "'FR' + str(c) + '.mp4'",
        '-vf scale=320:240',
        words[d-1],
        ])


  


  Here are some examples of what the original file would look like :

  


   ffmpeg -i SR.mp4 -ss 00:00:00 -to 00:01:22 -c:v copy -a copy CPH.mp4
 ffmpeg -i SR.mp4 -ss 00:01:24 -to 00:02:58 -c:v copy -a copy CG.mp4
 ffmpeg -i SR.mp4 -ss 00:02:59 -to 00:05:41 -c:v copy -a copy CSGP.mp4


  


  Nothing fancy just separating video in its own individual segments and then resaving it before resizing it.

  


  I tried :

  


  z=subprocess.call(f, shell=True, stdout=subprocess.PIPE)
print(z)


  


  But all I get is '1'.

  


  When I changed it to :

  


  z=subprocess.call(f, shell=True, stderr=subprocess.PIPE)
print(z)


  


  All I get is '1'.

  


  Maybe I'm doing something wrong.