Blackmagic Intensity Usage Notes

19 Nov 2021

Notes on using Blackmagic Intensity Pro. These notes are best I can figure out.

Standard Definition Output

As one of my intended outputs here is VHS, here is how I prep videos for output through Blackmagic Express. Blackmagic Express chooses it’s output based on the project resolution, so in order to gain access to composite and s-video output, the project needs to be in a SD settings.

625i50

Example to output 10 seconds of colour bars. In this case Blackmagic Express interprets the rate of 25 as 50i.

ffmpeg -f lavfi -i smptebars=duration=10:size=720x576:rate=25 smptebars.mp4

This produces the following video stream.

Video: h264 (High) (avc1 / 0x31637661), yuv420p, 720x576 [SAR 1:1 DAR 5:4], 6 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)

625p50

For 50p output use a rate of 50

ffmpeg -f lavfi -i smptebars=duration=10:size=720x576:rate=50 smptebars.mp4

This produces.

Video: h264 (High) (avc1 / 0x31637661), yuv420p, 720x576 [SAR 1:1 DAR 5:4], 11 kb/s, 50 fps, 50 tbr, 12800 tbn, 100 tbc (default)

SMPTE Bars

ffmpeg -re -f lavfi -i "smptebars=duration=10:rate=25:size=720x576" -f lavfi -i "sine=duration=10:frequency=1000:sample_rate=48000" -vf drawtext="text='earlyworm:timecode=01\:00\:00\:00':rate=25:x=(w-tw)/2:y=(h-lh)/2:fontsize=48:fontcolor=white:box=1:boxcolor=black" -c:v h264 -profile:v baseline -pix_fmt yuv420p -preset ultrafast -tune zerolatency -crf 28 -g 60 -c:a aac "smpte_bars_sd_25.mp4"

High Definition Output

This profiles an 30 second offline clip with the words “OFFLINE” against a green background.

ffmpeg -i offline.wav -f lavfi -i color=c=darkgreen:s=1920x1080:d=30 -vf "drawtext=fontfile=Quicksand:fontsize=100:shadowx=4:shadowy=4:fontcolor=white:x=(w-text_w)/2:y=(h-text_h-text_h)/2:text='OFFLINE', drawtext=fontfile=Public Sans:fontsize=50:shadowx=4:shadowy=4:fontcolor=white:x=(w-text_w)/2:y=(h+text_h)/2:text='debug'" -c:a aac -ar 48000 offline_hd.mp4