Blackmagic Forum

Most of my current work is creating virtual choirs - which means putting together a lot of videos submitted be people primarily taken with the cell phones, then scaling and cropping them to put them in a grid. I have been noticing some regular problems when trying to use some videos, particularly if they were shot in portrait mode instead of landscape, and if I have "used optimized media" turned on (and the media has been optomized). The problem is that when I try to change the position, the image shifts incorrectly... as in, if I scale to .333 (x & y, with the project settings set to "fill" the clip) and I want the center to be at x = -240 , the image on screen will show up closer to x= -720. If I have the transformation border turned on, it shows up in the correct place.

On the left is with optimized media turned on, on the right turned off



Here is the "MediaInfo" output for the clip in question:
General
Complete name : G:\Projects AV\Masterworks\Submissions\altos\PXL_20201205_202446608.mp4
Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42 (isom/mp42)
File size : 599 MiB
Duration : 3 min 46 s
Overall bit rate : 22.2 Mb/s
Encoded date : UTC 2020-12-05 20:28:33
Tagged date : UTC 2020-12-05 20:28:33
xyz : +40.3786-79.6635/

Video
ID : 3
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L5.1
Format settings : CABAC / 1 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 1 frame
Format settings, GOP : M=1, N=30
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 3 min 46 s
Bit rate : 22.0 Mb/s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Rotation : 270°
Frame rate mode : Variable
Frame rate : 30.000 FPS
Minimum frame rate : 24.006 FPS
Maximum frame rate : 40.395 FPS
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.353
Stream size : 593 MiB (99%)
Title : VideoHandle
Language : English
Encoded date : UTC 2020-12-05 20:28:33
Tagged date : UTC 2020-12-05 20:28:33
Color range : Full
Color primaries : BT.601 PAL
Transfer characteristics : BT.709
transfer_characteristics_Original : BT.601
Matrix coefficients : BT.601
Codec configuration box : avcC

Audio
ID : 2
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 3 min 45 s
Bit rate mode : Constant
Bit rate : 192 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 5.17 MiB (1%)
Title : SoundHandle
Language : English
Encoded date : UTC 2020-12-05 20:28:33
Tagged date : UTC 2020-12-05 20:28:33

Other
Type : meta
Duration : 3 min 46 s
Bit rate mode : Variable