Export size huge considering new versions vs old versions

considering the following custom export preset:

movflags=+faststart
preset=fast
f=mp4
acodec=aac
channels=2
ar=48000
ab=128k
vcodec=h264_vaapi
qscale=5
g=25
bf=2
vprofile=main
width=2560
height=1440
aspect=1.77778
progressive=1
top_field_first=2
deinterlace_method=yadif
rescale=hyper
frame_rate_num=50000000
frame_rate_den=1000000
threads=7

newer versions produce vastly larger files
(e.g. Shotcut-190914.glibc2.14-x86_64.AppImage
Vs Shotcut-181223.glibc2.14-x86_64.AppImage )

$ ls -lrt --block-size=M -rt
-rw-r--r-- 1 user user  2667M Sep 24 11:56  2019-09-22_flightlog.v18.mp4
-rw-r--r-- 1 user user 16693M Sep 24 12:06  2019-09-22_flightlog_v19.mp4

2019-09-24_14-10

This started sometime among the las few releases but don’t know which was the first to be as such.

This is probably due to the frame rate from preset bug fix I mentioned here:

Look at your two output files and compare their frame rate and resolution.
Also, you are using VAAPI, which is going to be quite dependent on whatever ffmpeg and the driver decides to do with qscale. In particular, FFmpeg dropped or broke support for qscale in VAAPI when we upgraded to v4.2. We now use vglobal_quality with a different numeric range. You will need to adjust the preset accordingly.

1 Like

Thank you.
what is the vglobal equivalent/estimate of 90% in prior version?

i’m okay with encoding in another way if recommended. my video are “action” / motion oriented.

historically, after uploading my videos, i re-encoded them for archiving as crf=18 / veryslow. Can i encode(export) directly from shotcut with crf=18 with some method? if so, how,… what would be the preset to initialize with?

thank you

i found this: About to give up on Shotcut
i.e. crf=18 is about 64% vglobal.

and as i played with vglobal, those values corresponded.
therfore, i think i will be testing 65% and preset=slow for my action cam footage.