ghosting

dkf343

Newbie Joined: Mar 22, 2021 00:54 Messages: 3 Offline

Solved by

Mar 22, 2021 12:28

Hi all,

First off, I'm new here, and relatively new to video editing -- I got started to help my daughter with an art project. My question isn't about PowerDirector per se, but it's the tool I have, and hope someone more knowledgeable here can point me in a helpful direction.

I'm trying to use PowerDirector 365 to enhance an MP4 clip from my home security camera, and am running into surprising weirdness. Static portions of the scene come through as expected, but I notice that a person moving in the scene is bizarrely distorted. In some frames, the face is ghosted, and smears over several frames. In others, there appear to be compression artifacts, as the face is garbled as I've come to expect in low-quality JPGs. In other frames, the person becomes semi-invisible, as I can see my car through the person, and the head even disappears (!) for several frames, even though it's visible in the reflection in the car window. I don't know enough about recording technology or compression, etc. to even hazard a guess what might be causing these effects, and although I'd like to hope that they're fixable, I don't know if it's possible. I've tried to do a little research, and read descriptions of what appear to be similar effects elsewhere as being the result of frame blending, interlacing, mismatched frame rates, and compression artifacts, but I haven't actually seen video with the combination (or the invisibility / missing head) I'm seeing here. Of course, it's possible that this has been discussed at length and I just can't find anything because I'm using the wrong terms.

Has anyone seen such effects in video? Are these easily explained? Even better, is there anything I can try that has a chance of fixing them? Thanks.

Cheers,
Daniel

StevenG

Contributor Joined: Jan 14, 2014 14:04 Messages: 513 Offline

Mar 22, 2021 14:01

Well, the first thing to be aware of is that security video isn't designed to be edited. It's designed to be archived or used as an aid to security. For that reason, its format is designed to fit the most data in the smallest space. It may made up of codecs that maximize compression and variable frame rates and bit rates.

Editable video -- from a camcorder or phone, for instance -- is designed to be a balance of quality and size.

If you'd like we can crack open your video and see what it's made of. Then we can give you more specific advice -- or advise you to convert the video before editing it.

If you'd like us to do that, open one of your videos in the free download MediaInfo. In MediaInfo, set View to Text and then copy the complete text report and paste it to this forum.

dkf343

Newbie Joined: Mar 22, 2021 00:54 Messages: 3 Offline

Mar 22, 2021 14:41

Quote Well, the first thing to be aware of is that security video isn't designed to be edited. It's designed to be archived or used as an aid to security. For that reason, its format is designed to fit the most data in the smallest space. It may made up of codecs that maximize compression and variable frame rates and bit rates.

Editable video -- from a camcorder or phone, for instance -- is designed to be a balance of quality and size.

If you'd like we can crack open your video and see what it's made of. Then we can give you more specific advice -- or advise you to convert the video before editing it.

If you'd like us to do that, open one of your videos in the free download MediaInfo. In MediaInfo, set View to Text and then copy the complete text report and paste it to this forum.

I appreciate the offer! Here's the report:

Format : MPEG-4
Format profile : Base Media
Codec ID : isom (isom)
File size : 7.04 MiB
Duration : 2 min 2 s
Overall bit rate mode : Variable
Overall bit rate : 483 kb/s
Encoded date : UTC 2021-03-20 01:22:37
Tagged date : UTC 2021-03-20 01:22:37
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L4.1
Format settings : CABAC / 2 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 2 frames
Format settings, GOP : M=3, N=60
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 2 min 2 s
Source duration : 2 min 2 s
Bit rate mode : Variable
Bit rate : 465 kb/s
Maximum bit rate : 1 016 kb/s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Variable
Frame rate : 14.967 FPS
Minimum frame rate : 7.463 FPS
Maximum frame rate : 16 000.000 FPS
Original frame rate : 15.000 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.015
Stream size : 6.77 MiB (96%)
Source stream size : 6.77 MiB (96%)
Tagged date : UTC 2021-03-20 01:22:38
Color range : Full
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Codec configuration box : avcC
Audio
ID : 2
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 2 min 2 s
Source duration : 2 min 2 s
Source_Duration_LastFrame : -8 ms
Bit rate mode : Variable
Bit rate : 16.0 kb/s
Maximum bit rate : 19.3 kb/s
Channel(s) : 1 channel
Channel layout : C
Sampling rate : 16.0 kHz
Frame rate : 15.625 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 239 KiB (3%)
Source stream size : 239 KiB (3%)
Default : Yes
Alternate group : 1
Tagged date : UTC 2021-03-20 01:22:38
Text
ID : 3
Format : Timed Text
Muxing mode : sbtl
Codec ID : tx3g
Duration : 2 min 2 s
Bit rate mode : Constant
Bit rate : 208 b/s
Stream size : 3.10 KiB (0%)
Title : *subtitles.ttxt:hdlr=sbtl:lang=en:group=2:layer=1@GPAC0.5.2-DEV-revVersion: 0.5.2-426-gc5ad4e4+dfsg5-3+deb9u1
Default : Yes
Forced : No
Alternate group : 2
Encoded date : UTC 2021-03-20 01:22:38
Tagged date : UTC 2021-03-20 01:22:38

KCwho

Administrator Joined: May 02, 2014 03:14 Messages: 11 Offline

Mar 23, 2021 05:31

The video bitrate is very low. It could make the video looks like broken or has moasic on it. That is probably the ghost you mentioned. Try recode your video in higher bitrate but the video file size will grow significantly.

BarryTheCrab

Senior Contributor Location: USA Joined: Nov 06, 2008 22:18 Messages: 6240 Offline

Mar 23, 2021 06:02

Quote The video bitrate is very low. It could make the video looks like broken or has moasic on it. That is probably the ghost you mentioned. Try recode your video in higher bitrate but the video file size will grow significantly.

You can't make something from nothing. Increasing the bit rate will only bloat the file size.

This message was edited 1 time. Last update was at Mar 23. 2021 09:52

StevenG

Contributor Joined: Jan 14, 2014 14:04 Messages: 513 Offline

Mar 23, 2021 07:33

Though it might be worth trying a conversion with Handbrake to a more standard MP4. While technically you can't create frames or bit rate, it may create a file that you can at least edit in PowerDirector.

Here's how to do it right.

dkf343

Newbie Joined: Mar 22, 2021 00:54 Messages: 3 Offline

Mar 23, 2021 11:52

Thanks for the suggestion. I followed the instructions, but don't see any real differences between the original and the more standard version. PowerDirector didn't seem to have any issues editing the original one, at least with pan, zoom, lighting, etc., and the standard version still has those bizarre artifacts I described. Anything else I could try?
Cheers,
Daniel

tomasc

Senior Contributor Joined: Aug 25, 2011 12:33 Messages: 6464 Offline

Mar 23, 2021 12:51

The posted video mediainfo shows a variable frame rate from 7 to 16 fps. With such slow exposure especially at night you can get the motion blur or ghosting. See this from a knowledge base: https://support.swann.com/s/article/j7Ia06KJfA#:~:text=In%20a%20security%20context,%20motion%20blur%20can%20cause,minimal%20lighting,%20which%20requires%20a%20longer%20exposure%20time. . You may want to make changes to the camera settings as suggested in the article or use a better camera.