I am trying to create a progress bar for FFmpeg, much like python's FFpb and got far enough that I can capture FFmpeg's output to variable and save the needed info in variables, but only after it ends.
This command saves each line outputted by FFmpeg into the $RedirectOutput variable as objects:
$RedirectOutput = ffmpeg.exe -y -v quiet -stats -hide_banner -hwaccel cuda -i 'input' -c:v hevc_nvenc -preset slow -crf 18 -an -t 300 'output' 2>&1
$RedirectOutput then becomes:
frame= 124 fps=0.0 q=14.0 size= 768kB time=00:00:04.03 bitrate=1559.9kbits/s speed=8.04x
frame= 480 fps=479 q=14.0 size= 3840kB time=00:00:15.90 bitrate=1978.5kbits/s speed=15.9x
frame= 865 fps=576 q=17.0 size= 7424kB time=00:00:28.73 bitrate=2116.6kbits/s speed=19.1x
frame= 1256 fps=627 q=17.0 size= 10496kB time=00:00:41.76 bitrate=2058.7kbits/s speed=20.9x
frame= 1698 fps=678 q=16.0 size= 14080kB time=00:00:56.50 bitrate=2041.5kbits/s speed=22.6x
frame= 2074 fps=691 q=16.0 size= 17152kB time=00:01:09.03 bitrate=2035.4kbits/s speed= 23x
frame= 2515 fps=718 q=16.0 size= 20992kB time=00:01:23.73 bitrate=2053.7kbits/s speed=23.9x
frame= 2972 fps=742 q=18.0 size= 25088kB time=00:01:38.96 bitrate=2076.7kbits/s speed=24.7x
frame= 3404 fps=755 q=18.0 size= 28928kB time=00:01:53.36 bitrate=2090.4kbits/s speed=25.2x
...
Here I save each piece of necessary information into their respective variables:
$videoFps = $RedirectOutput -replace "(frame=)(\s+)?(\d+)(.*)", "$3"
$videoFps = $RedirectOutput -replace "(.*)(fps=)(\d+)(.*)", "$3"
$videoSpeed = $RedirectOutput -replace "(.*)(speed=)(\d+.*)x", "$3"
$videoBitrate = $RedirectOutput -replace "(.*)(bitrate=)(\d+)(.*)", "$3"
Now that the arrays were created, I'd need to write these to the console periodically, in a formatted fashion (that I'll figure out eventually), as the FFmpeg conversion is running (instead of when it finished) and in a singular line, but I don't know how to proceed.
Do I save FFmpeg's output to a file instead of a variable and try to read from there? If so, how do I read it after each write? With a while loop?
Wouldn't that be a performance issue? I have to say, that isn't a great concern of mine, for now. Just want it to work.
… how do I read it after each write? With a ForEach-Object loop:
ffmpeg.exe -y -v quiet -stats -hide_banner -hwaccel cuda -i 'input' -c:v hevc_nvenc -preset slow -crf 18 -an -t 300 'output' 2>&1 |
ForEach-Object {
$lineData = [psCustomObject]@{
videoFrame = $_ -replace "(frame=)(\s+)?(\d+)(.*)", '$3'
videoFps = $_ -replace "(.*)(fps=)(\d+)(.*)", '$3'
videoSpeed = $_ -replace "(.*)(speed=\s*?)(\d+.*)x", '$3'
videoBitrate = $_ -replace "(.*)(bitrate=)(\d+)(.*)", '$3'
}
$lineData | Select-Object -Property video*
Write-Progress -Activity "ffmpeg in progress: Bitrate=$($lineData.videoBitrate), Fps=$($lineData.videoFps)" -CurrentOperation "" -PercentComplete $lineData.videoSpeed -Status "Frame $($lineData.videoFrame)"
}
Output (derived from given $RedirectOutput data, progressbar example omitted:):
D:\PShell\SO\61971642.ps1
videoFrame videoFps videoSpeed videoBitrate ---------- -------- ---------- ------------ 124 0 8.04 1559 480 479 15.9 1978 865 576 19.1 2116 1256 627 20.9 2058 1698 678 22.6 2041 …