Playback Video Quality Improves When Using the Increase Speed/Rate Button in MPC-HC with madVR

I was recently watching a Blu-Ray REMUX in MPC-HC with madVR and I used the increase speed/rate button for the first time to skip a scene and noticed the overall picture quality was substantially better when played 2x or 4x the normal playback speed. The image was sharper and the colours were more vibrant than the regular playback speed. Now obviously I'm not a superhuman.. yet, so watching movies at 2/4 times the regular speed isn't happening. My questions are, is there a reason for this increase in video quality when "fast forwarding"? Is it possible to tweak my settings to achieve this increased video quality? Am I just stupid and the answer is very obvious? lol. Any help would be appreciated. Thanks in advance.

Codec Tweak Tool | Log file | Generated at 2019-04-17 03:19:40

#####  System Information  #####

OS:           Windows 7 Home Premium (6.01.7601) (x64)
CPU name:     Intel(R) Core(TM) i5-3570K CPU @ 3.40GHz
CPU speed:    3392 MHz (4t)
Memory:       16320 MB
Screen size:  1920x1080 (32bits) (60Hz)
Video card:   NVIDIA GeForce GTX 970
             VendorID: 10de, DeviceID: 13c2
Video mem:    4096 MB
Video driver: nvd3dumx.dll (Version 25.21.14.1967) (3-17-2019) (NV 419.67)
Audio device: Realtek High Definition Audio
             VendorID: 10ec, DeviceID: 0887, SubSys: 10438445
Audio driver: RTKVHD64.sys (Version 6.0.1.8186) (6-14-2017)

#####  K-Lite Codec Pack  #####

KLCP version: 14.8.8
KLCP type:    standard

Speaker conf: 2.0

MPC renderer: madVR
MPC subs:     ISR
MPC audio:    System Default

#####  Decoder Settings #####

LAV Video:
H264=CUVID HEVC=1 VP9=1 VC1=1 MPEG2=1 MPEG4=1 WMV3=0

LAV Audio:
MP3=1 AC3=1 DTS=1 DTSHD=1 EAC3=1 TRUEHD=1 AAC=1 Vorbis=1 LPCM=1 WMA=0

#####  DirectShow Filters (32-bit)  #####

(A total of 73 filters, 0 shown, 73 hidden)

#####  DirectShow Filters (64-bit)  #####

(A total of 74 filters, 0 shown, 74 hidden)

#####  ICM Class Manager (32-bit)  #####

(A total of 2 filters, 0 shown, 2 hidden)

#####  ICM Class Manager (64-bit)  #####

(A total of 2 filters, 0 shown, 2 hidden)

#####  Default source filters (32-bit)  #####

.video  {B98D13E7-55DB-4385-A33D-09FD1BA26338}  LAV Splitter Source

(A total of 54 default source filters, 1 shown, 53 hidden)

#####  Default source filters (64-bit)  #####

.video  {B98D13E7-55DB-4385-A33D-09FD1BA26338}  LAV Splitter Source

(A total of 54 default source filters, 1 shown, 53 hidden)

#####  ACM and VFW Codecs (32-bit)  #####

(A total of 14 codecs, 0 shown, 14 hidden)

#####  ACM and VFW Codecs (64-bit)  #####

(A total of 13 codecs, 0 shown, 13 hidden)

Playback speed should normally not have any effect on quality.

Is this a HDR video? Since you mentioned the colors are more vivid I think the problem might be related to the HDR conversion.

Press Ctrl+J during playback to display rendering details. Compare this in both situations. Easiest is probably to make two screenshots. If you see any differences, then please add them here, so I can forward them to the developer of Madvr.

Once I have more details, I may have a workaround for you.

Thank you for getting back to me so quickly. To answer your question, no, it is not a HDR video. I have tried both your recommendations. With the two screenshots, I have not noticed any differences between the two images and with the "Ctrl+J/display rendering details" I'm not exactly sure what differences I should be looking for. If you have any tips or workarounds to offer, I'm willing to try anything. Thanks again! look forward to hearing from you.

I included the screenshots with the display rendering details just in case you wanted to take a look. First image is the Fast Playback and the second is the Normal Playback speed.

It is probably because of smooth motion. That improves motion smoothness at the cost of a bit of sharpness. The amount of frames it blends depends on the framerate.

You could try with smooth motion turned off.
Or enable one of the sharpen filters in the Processing section of Madvr settings.

I've tweaked some settings under Processing > Image Enhancements and it hasn't changed much in the picture quality. I also tried to disable Smooth Motion and switch between the three available options for it but unfortunately I'm still not getting the same video quality I see when I fast forward a movie. After taking a better look at the differences between normal playback speed and fast playback, the best way I can describe the difference between the speeds is normal playback has a very grainy and blurred look compared to fast forwarding where it is very sharp, almost like watching a 4K video on a 4K TV. To be clear, it's not a 4K video as I mentioned before and I'm playing the Blu-Ray REMUX on a 1080p TV. I don't want to take up too much of your time but if you have any other tips or recommendations, I'll try anything. Even if there's a madVR/MPC-HC settings guide based or close to my PC specs, I'll give that a shot. Thanks again for your time.

Test if the same thing happens with EVR Custom as video renderer.
Also test with hardware decoding disabled.

Switching the video renderer seems to have the same result but with slightly decreased video enhancement with EVR Custom enabled compared to when madVR is activated. I also tried disabling hardware decoding to see if anything would change but no luck there either.

I have no logical explanation for this behavior. Maybe it is just a perceived visual improvement due to the higher framerate.

Or your monitor/TV is somehow doing some different internal processing.