FFmpeg saturates memory + CPU usage drops to 0% during very basic conversion of PNG files to MP4 video

Question

I have this Python function that runs ffmpeg with minimal options from the Windows command line:

def run_ffmpeg(frames_path, ffmpeg_path=notebook_directory):
    '''
    This function runs ffmpeg.exe to convert PNG image files into a MP4 video.
    
    Parameters
    ----------
    frames_path : string
        Absolute path to the PNG files
    ffmpeg_path : string
        Absolute path to the FFmpeg executable (ffmpeg.exe)
    '''
    
    from subprocess import check_call
    
    
    check_call(
        [
            os.path.join(ffmpeg_path, 'ffmpeg'),
            '-y',    # Overwrite output files without asking
            '-report',    # Write logfile to current working directory
            '-framerate', '60',    # Input frame rate
            '-i', os.path.join(frames_path, 'frame%05d.png'),    # Path to input frames
            os.path.join(frames_path, 'video.mp4')    # Path to store output video
        ]
    )

When running it from a Jupyter notebook over 2500 PNG files (RGBA, ca. 600-700 kB each, 9000 x 13934 pixels), CPU usage briefly peaks to 100% before dropping to 0%, while memory usage quickly saturates to 100% and stays there, slowing the system down almost to a freeze, so I need to terminate ffmpeg from the task manager:

Screenshot

The generated video file has a size of only 48 bytes and contains just a black frame when viewed in the VLC player.

This is the ffmpeg log output:

ffmpeg started on 2022-08-05 at 17:17:55
Report written to "ffmpeg-20220805-171755.log"
Log level: 48
Command line:
"C:\\Users\\Username\\Desktop\\folder\\ffmpeg" -y -report -framerate 60 -i "C:\\Users\\Username\\Desktop\\e\\frame%05d.png" "C:\\Users\\Username\\Desktop\\e\\video.mp4"
ffmpeg version 2022-07-14-git-882aac99d2-full_build-www.gyan.dev Copyright (c) 2000-2022 the FFmpeg developers
  built with gcc 12.1.0 (Rev2, Built by MSYS2 project)
  configuration: --enable-gpl --enable-version3 --enable-static --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-bzlib --enable-lzma --enable-libsnappy --enable-zlib --enable-librist --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-sdl2 --enable-libdav1d --enable-libdavs2 --enable-libuavs3d --enable-libzvbi --enable-librav1e --enable-libsvtav1 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs2 --enable-libxvid --enable-libaom --enable-libjxl --enable-libopenjpeg --enable-libvpx --enable-mediafoundation --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-liblensfun --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-libshaderc --enable-vulkan --enable-libplacebo --ena  libavutil      57. 29.100 / 57. 29.100
  libavcodec     59. 38.100 / 59. 38.100
  libavformat    59. 28.100 / 59. 28.100
  libavdevice    59.  8.100 / 59.  8.100
  libavfilter     8. 45.100 /  8. 45.100
  libswscale      6.  8.100 /  6.  8.100
  libswresample   4.  8.100 /  4.  8.100
  libpostproc    56.  7.100 / 56.  7.100
Splitting the commandline.
Reading option '-y' ... matched as option 'y' (overwrite output files) with argument '1'.
Reading option '-report' ... matched as option 'report' (generate a report) with argument '1'.
Reading option '-framerate' ... matched as AVOption 'framerate' with argument '60'.
Reading option '-i' ... matched as input url with argument 'C:\Users\Username\Desktop\e\frame%05d.png'.
Reading option 'C:\Users\Username\Desktop\e\video.mp4' ... matched as output url.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option y (overwrite output files) with argument 1.
Applying option report (generate a report) with argument 1.
Successfully parsed a group of options.
Parsing a group of options: input url C:\Users\Username\Desktop\e\frame%05d.png.
Successfully parsed a group of options.
Opening an input file: C:\Users\Username\Desktop\e\frame%05d.png.
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00000.png' for reading
[file @ 0000000000425680] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000042d800] Statistics: 668318 bytes read, 0 seeks
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00001.png' for reading
[file @ 000000000042dac0] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000042d6c0] Statistics: 668371 bytes read, 0 seeks
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00002.png' for reading
[file @ 000000000042d6c0] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000042dac0] Statistics: 669177 bytes read, 0 seeks
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00003.png' for reading
[file @ 000000000042dac0] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 0000000000437a40] Statistics: 684594 bytes read, 0 seeks
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00004.png' for reading
[file @ 0000000000437a40] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 0000000000437c00] Statistics: 703014 bytes read, 0 seeks
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00005.png' for reading
[file @ 0000000000437c00] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 0000000000437d00] Statistics: 721604 bytes read, 0 seeks
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00006.png' for reading
[file @ 0000000000437cc0] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 0000000000437f40] Statistics: 739761 bytes read, 0 seeks
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00007.png' for reading
[file @ 0000000000437f40] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 0000000000438040] Statistics: 757327 bytes read, 0 seeks
[image2 @ 000000000041ff80] Probe buffer size limit of 5000000 bytes reached
Input #0, image2, from 'C:\Users\Username\Desktop\e\frame%05d.png':
  Duration: 00:00:41.67, start: 0.000000, bitrate: N/A
  Stream #0:0, 8, 1/60: Video: png, rgba(pc), 9000x13934 [SAR 29528:29528 DAR 4500:6967], 60 fps, 60 tbr, 60 tbn
Successfully opened the file.
Parsing a group of options: output url C:\Users\Username\Desktop\e\video.mp4.
Successfully parsed a group of options.
Opening an output file: C:\Users\Username\Desktop\e\video.mp4.
[file @ 000000002081e3c0] Setting default whitelist 'file,crypto,data'
Successfully opened the file.
detected 12 logical cores
Stream mapping:
  Stream #0:0 -> #0:0 (png (native) -> h264 (libx264))
Press [q] to stop, [?] for help
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00008.png' for reading
[file @ 00000000024ad980] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 00000000004379c0] Statistics: 767857 bytes read, 0 seeks
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00009.png' for reading
[file @ 000000000042d600] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 00000000004379c0] Statistics: 774848 bytes read, 0 seeks
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00010.png' for reading
[file @ 00000000004379c0] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000042da00] Statistics: 787178 bytes read, 0 seeks
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00011.png' for reading
[file @ 00000000004379c0] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000042da00] Statistics: 797084 bytes read, 0 seeks
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00012.png' for reading
[file @ 0000000000437a80] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000042da00] Statistics: 802870 bytes read, 0 seeks
[graph 0 input from stream 0:0 @ 00000000208bf800] Setting 'video_size' to value '9000x13934'
[graph 0 input from stream 0:0 @ 00000000208bf800] Setting 'pix_fmt' to value '26'
[graph 0 input from stream 0:0 @ 00000000208bf800] Setting 'time_base' to value '1/60'
[graph 0 input from stream 0:0 @ 00000000208bf800] Setting 'pixel_aspect' to value '29528/29528'
[graph 0 input from stream 0:0 @ 00000000208bf800] Setting 'frame_rate' to value '60/1'
[graph 0 input from stream 0:0 @ 00000000208bf800] w:9000 h:13934 pixfmt:rgba tb:1/60 fr:60/1 sar:29528/29528
[format @ 00000000025ef840] Setting 'pix_fmts' to value 'yuv420p|yuvj420p|yuv422p|yuvj422p|yuv444p|yuvj444p|nv12|nv16|nv21|yuv420p10le|yuv422p10le|yuv444p10le|nv20le|gray|gray10le'
[auto_scale_0 @ 00000000025efe40] w:iw h:ih flags:'' interl:0
[format @ 00000000025ef840] auto-inserting filter 'auto_scale_0' between the filter 'Parsed_null_0' and the filter 'format'
[AVFilterGraph @ 000000000042da00] query_formats: 4 queried, 3 merged, 1 already done, 0 delayed
[auto_scale_0 @ 00000000025efe40] picking yuv444p out of 13 ref:rgba alpha:1
[auto_scale_0 @ 00000000025efe40] w:9000 h:13934 fmt:rgba sar:29528/29528 -> w:9000 h:13934 fmt:yuv444p sar:1/1 flags:0x0
[auto_scale_0 @ 00000000025efe40] w:9000 h:13934 fmt:rgba sar:29528/29528 -> w:9000 h:13934 fmt:yuv444p sar:1/1 flags:0x0
[auto_scale_0 @ 00000000025efe40] w:9000 h:13934 fmt:rgba sar:29528/29528 -> w:9000 h:13934 fmt:yuv444p sar:1/1 flags:0x0
[auto_scale_0 @ 00000000025efe40] w:9000 h:13934 fmt:rgba sar:29528/29528 -> w:9000 h:13934 fmt:yuv444p sar:1/1 flags:0x0
[libx264 @ 000000002081d280] using mv_range_thread = 376
[libx264 @ 000000002081d280] using SAR=1/1
[libx264 @ 000000002081d280] frame MB size (563x871) > level limit (139264)
[libx264 @ 000000002081d280] DPB size (4 frames, 1961492 mbs) > level limit (1 frames, 696320 mbs)
[libx264 @ 000000002081d280] MB rate (29422380) > level limit (16711680)
[libx264 @ 000000002081d280] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
[libx264 @ 000000002081d280] profile High 4:4:4 Predictive, level 6.2, 4:4:4, 8-bit
[libx264 @ 000000002081d280] 264 - core 164 r3095 baee400 - H.264/MPEG-4 AVC codec - Copyleft 2003-2022 - 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=18 lookahead_threads=3 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=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'C:\Users\Username\Desktop\e\video.mp4':
  Metadata:
    encoder         : Lavf59.28.100
  Stream #0:0, 0, 1/15360: Video: h264 (avc1 / 0x31637661), yuv444p(tv, progressive), 9000x13934 [SAR 1:1 DAR 4500:6967], q=2-31, 60 fps, 15360 tbn
    Metadata:
      encoder         : Lavc59.38.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
Clipping frame in rate conversion by 0.000008
frame=    1 fps=0.8 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00013.png' for reading
[file @ 000000000a6a2180] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000b38de80] Statistics: 810395 bytes read, 0 seeks
frame=    2 fps=0.8 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00014.png' for reading
[file @ 000000001ec86c80] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000b38de80] Statistics: 818213 bytes read, 0 seeks
cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00015.png' for reading
[file @ 000000001ec86c80] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000b38de80] Statistics: 817936 bytes read, 0 seeks
frame=    4 fps=1.2 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00016.png' for reading
[file @ 000000001ec86c80] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000b38de80] Statistics: 817014 bytes read, 0 seeks
cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00017.png' for reading
[file @ 000000001ec86c80] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000b38de80] Statistics: 828088 bytes read, 0 seeks
frame=    6 fps=1.5 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00018.png' for reading
[file @ 000000001ec86c80] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000b38de80] Statistics: 831007 bytes read, 0 seeks
cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00019.png' for reading
[file @ 000000001ec86c80] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000b38de80] Statistics: 845203 bytes read, 0 seeks
frame=    8 fps=1.7 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00020.png' for reading
[file @ 000000001ec86c80] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000b38de80] Statistics: 851548 bytes read, 0 seeks
cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00021.png' for reading
[file @ 000000001ec86c80] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000b38de80] Statistics: 847629 bytes read, 0 seeks
frame=   10 fps=1.8 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00022.png' for reading
[file @ 000000001ec86c80] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000b38de80] Statistics: 860169 bytes read, 0 seeks
frame=   11 fps=1.4 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00023.png' for reading
[file @ 000000001ec86c80] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000b38de80] Statistics: 857243 bytes read, 0 seeks
frame=   12 fps=1.2 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[image2 @ 000000000041ff80] Opening 'C:\Users\Username\Desktop\e\frame00024.png' for reading
[file @ 000000001ec86c80] Setting default whitelist 'file,crypto,data'
[AVIOContext @ 000000000b38de80] Statistics: 835155 bytes read, 0 seeks

What is the problem?

By the way, the color model of the image files was confirmed by doing

from PIL import Image


img = Image.open('C:\\Users\\EPI-SMLM\\Desktop\\e\\frame00000.png')
img.mode
-------------------------------------------------------------------
C:\Program Files\Python38\lib\site-packages\PIL\Image.py:3035: DecompressionBombWarning: Image size (125406000 pixels) exceeds limit of 89478485 pixels, could be decompression bomb DOS attack.
  warnings.warn(

'RGBA'

The "decompression bomb warning" appears to be a false alarm/bug.

UPDATE: I can confirm that this happens even when there are only 50 image files, i.e. 50 x 700 kB = 35 MB in total size. ffmpeg still gobbles up all available memory (almost 60 GB of private bytes!!!).

And it also happens if ffmpeg is run from the command line.

This must be a bug!

Answer 1

I can confirm that this happens even when there are only 50 image files, i.e. 50 x 700 kB = 35 MB in total size. ffmpeg still gobbles up all available memory (almost 60 GB of private bytes!!!). [..] This must be a bug!

Let's calculate! When using RGB input, we use YUV444/RGB encoding using x264. This will use a frame queue of all 50 frames for rate control purposes, each 3 bytes/pixel, so total memory usage = 3x9000x14000x50=~19GB just for the images alone. Inside the RC (rate control; specifically, the lookahead queue), these images will have several chunks of per-block metadata associated with them like MVs and complexity graphs, so a multiplier of 3 is not so strange for this situation. 60GB? Sure, that's expected. In my local quick experiments, that's indeed what's happening (and it's easily prevented).

The problem is that you're encoding extremely high resolution images (9kx14k! Typical video res is 2k/HD = 2kx1k; 4k/UHD = 4kx2k is considered extremely high resolution, and almost nobody uses 8K = 8kx4k at this point) using a production encoder at production settings. What you probably want to do is one or more of the following:

• downscale images to yuv420p and lower resolution (e.g. 1000x1556 pixels or so: -vf scale=1000:-1, possibly combined with -pix_fmt yuv420p) - just -vf scale=1000:-1 makes it use 2.75GB memory for me
• use low-latency encoding (-tune zerolatency) to reduce number of frames in queue (this uses ~10GB memory for me at 9k*14k resolution).
• use a high-end server that is suitable for high-def video encoding, e.g. one with several 100s of GB of memory and several 10s of cores for CPU processing.

Answer 2

As a complement/addendum/update to the other answer provided: It appears that setting the profile to high444 instead of the default medium (just high doesn't work!) and increasing the H.264 level to the highest possible value 6.2 is successful in preventing memory leaks.

The problem seems to be a bug of ffmpeg, where reading in images with a resolution higher than the max. specified resolution of whatever H.264 level currently set will lead to an unbounded memory leak and possibly system freeze/crash.

Limiting the resolution using the scale filter to the max. specified value for the set H.264 level and/or increasing said level seems to solve the problem. I still get 100% CPU and RAM usage, but ffmpeg now pulls through and finishes with 0 status.

The output MP4 video resulting from a 10-20 GB/2000-3000 frames input of PNG image files has a size of only 2-3 MB.

check_call(
    [
        os.path.join(ffmpeg_path, 'ffmpeg'),
        '-y',    # Overwrite output files without asking
        '-report',    # Write logfile to current working directory
        '-framerate', '60',    # Input frame rate
        '-i', os.path.join(frames_path, 'frame%05d.png'),    # Path to input frames
        '-profile:v', 'high444',
        '-level:v', '6.2',
        '-bsf:v', 'h264_metadata=level=6.2',
        #'-vf', 'scale=4096:-1',    # Scale width or height down to max. 4096x2304 while keeping aspect ratio (H.264 level 5.2)
        #'-vf', 'scale=-1:2304',    # Scale width or height down to max. 4096x2304 while keeping aspect ratio (H.264 level 5.2)
        #'-vf', 'scale=8192:-1',    # Scale width or height down to max. 4096x2304 while keeping aspect ratio (H.264 level 6.2)
        '-vf', 'scale=-1:4320',    # Scale width or height down to max. 4096x2304 while keeping aspect ratio (H.264 level 6.2)
        os.path.join(frames_path, 'video.mp4')    # Path to store output video
    ]
)