PE 14 Occasional Loss of Resolution in Output

[Ikrananka]

I have been editing and rendering a lot of 1080p60 footage and creating videos for YouTube.  Most of the time the results are perfect, however sometimes I find in the output rendered video (say around 1 in 10 times) there are occasional moments (~1 sec) where the resolution seems to drop and then recover, much in the same way as is seen when videos are streamed and there are bandwidth issues.

Does anyone know why this may be happening and how I might prevent it?

My output render settings are:

Format : H.264

Frame Size : 1920 x 1080 (same as original footage)

FPS : 60 (same as original footage)

Profile : High

Level : 5.1

Render at Maximum Depth : OFF

Bitrate Encoding : 2 Pass, VBR

Target Bitrate : 15 Mbps

Max Bitrate : 50 Mbps

Thanks in advance for any help.

[Steve Grisetti]

Are you saying that your source video is 1920x1080p60?

What model of camcorder is your video coming from? What is the video's file format (MOV, MP4, M2T)?

If you look under the Edit menu, what is listed on the General page under Project Settings?

[Ikrananka]

Yes, source video is 1920x1080p60.  This is computer screen captured footage using software called Bandicam.

Source format is MP4.

Project settings are:

DSLR, 60 fps

Frame Size : 1920 x 1080

Square Pixels

No Fields (Progressive Scan)

60 fps timecode

[Steve Grisetti]

Software-created video can have its own challenges.

Open one of your source video files in MediaInfo (a free download). In MediaInfo, set View to Text and copy and paste the report it generates to this forum.

[Ikrananka]

Here you go Steve, the output from MediaInfo for my source footage.  Please bear in mind that of the 60 videos I have created using the same workflow over the past year, I have only seen this problem happen once before.  Now it has happened with the past two videos.  The source video is perfect when played back.

General

Complete name                            : D:\bandicam 2018-01-30 09-20-06-355.mp4

Format                                   : MPEG-4

Format profile                           : Base Media

Codec ID                                 : isom (mp41)

File size                                : 13.7 GiB

Duration                                 : 5 min 55 s

Overall bit rate mode                    : Variable

Overall bit rate                         : 330 Mb/s

Encoded date                             : UTC 2018-01-30 16:20:06

Tagged date                              : UTC 2018-01-30 16:20:06

Writing application                      : BandiMp4Muxer 1.0

Video

ID                                       : 1

Format                                   : AVC

Format/Info                              : Advanced Video Codec

Format profile                           : Main@L4.2

Format settings                          : CABAC / 1 Ref Frames

Format settings, CABAC                   : Yes

Format settings, RefFrames               : 1 frame

Format settings, GOP                     : N=1

Codec ID                                 : avc1

Codec ID/Info                            : Advanced Video Coding

Duration                                 : 5 min 55 s

Bit rate                                 : 330 Mb/s

Width                                    : 1 920 pixels

Height                                   : 1 080 pixels

Display aspect ratio                     : 16:9

Frame rate mode                          : Constant

Frame rate                               : 60.000 FPS

Color space                              : YUV

Chroma subsampling                       : 4:2:0

Bit depth                                : 8 bits

Scan type                                : Progressive

Bits/(Pixel*Frame)                       : 2.652

Stream size                              : 13.7 GiB (100%)

Language                                 : English

Encoded date                             : UTC 2018-01-30 16:20:06

Tagged date                              : UTC 2018-01-30 16:20:06

Audio #1

ID                                       : 2

Format                                   : AAC

Format/Info                              : Advanced Audio Codec

Format profile                           : LC

Codec ID                                 : mp4a-40-2

Duration                                 : 5 min 55 s

Bit rate mode                            : Variable

Bit rate                                 : 192 kb/s

Maximum bit rate                         : 310 kb/s

Channel(s)                               : 2 channels

Channel positions                        : Front: L R

Sampling rate                            : 48.0 kHz

Frame rate                               : 46.875 FPS (1024 SPF)

Compression mode                         : Lossy

Stream size                              : 7.97 MiB (0%)

Language                                 : English

Encoded date                             : UTC 2018-01-30 16:20:06

Tagged date                              : UTC 2018-01-30 16:20:06

Audio #2

ID                                       : 3

Format                                   : AAC

Format/Info                              : Advanced Audio Codec

Format profile                           : LC

Codec ID                                 : mp4a-40-2

Duration                                 : 5 min 55 s

Duration_LastFrame                       : 1 ms

Bit rate mode                            : Variable

Bit rate                                 : 192 kb/s

Maximum bit rate                         : 292 kb/s

Channel(s)                               : 2 channels

Channel positions                        : Front: L R

Sampling rate                            : 48.0 kHz

Frame rate                               : 46.875 FPS (1024 SPF)

Compression mode                         : Lossy

Stream size                              : 8.28 MiB (0%)

Language                                 : English

Encoded date                             : UTC 2018-01-30 16:20:06

Tagged date                              : UTC 2018-01-30 16:20:06

[Steve Grisetti]

Is this recorded with OBS software?

That isom (mp41) codec appears to be causing a lot of editors problems.

You can try converting it to a more standard MP4 using Handbrake and see if that makes a difference.

[Ikrananka]

https://forums.adobe.com/people/Steve+Grisetti  wrote

Is this recorded with OBS software?

That isom (mp41) codec appears to be causing a lot of editors problems.

You can try converting it to a more standard MP4 using Handbrake and see if that makes a difference.

No, it's recorded with Bandicam software (https://www.bandicam.com/).

Interesting, I wasn't aware that the codec was causing problems.  Can you provide any links to discussions/articles about this?

Won't using Handbrake to convert it to a more "standard" MP4 format result in a loss of quality?

Could this be an issue with my PC? e.g. CPU maxing out, or hard disks not responding quickly enough to request from Elements?  BTW, my source and rendered output are both onto a pair of HDD drives that are setup in Windows as a single Dynamic drive - could this be a contributing factor?

[Steve Grisetti]

You will not see a difference in quality at all if you convert the file using Handbrake.

My tutorial shows you how. Just set your frame rate to 60 rather than the 30 suggested in my tut.

Handbrake - YouTube

[Ikrananka]

Thanks Steve.  Now, before I started diving down the rabbit hole of adding another time consuming step to my video creation workflow (Handbrake), I decided to do some more testing with different render settings.

After a lot of trial and error, I found that increasing the Target Bitrate of my PE Export Settings from 15 Mbps to 18 Mbps started to eliminate those occasional visual blurring/artifacts.  I thought 18 Mbps would do it, but then applied this to a longer video and the problem still occurred, but less frequently.  So, I just tried a test with the Target Bitrate set to 20 Mbps and the occasional blurriness has gone (at least in my 20 minute test video).  Although this leads to a larger file size, it is still perfectly acceptable to me.  So, this is all very promising.

I'm going to do some more testing, part of which will involve looking into whether to use CBR instead of VBR (based on this discussion : https://forums.adobe.com/thread/2420931) and if I should have "Render at Maximum Depth" turned on or off.  What are your thoughts on these settings?

[Bill Sprague]

The best advice I have I think came from Steve a long time back.  It is that your output will be best if you try to match your source as closely as possible.  Your mediainfo says the source is  330 Mbps!

[Ikrananka]

whsprague  wrote

The best advice I have I think came from Steve a long time back.  It is that your output will be best if you try to match your source as closely as possible.  Your mediainfo says the source is  330 Mbps!

My thought when setting up Bandicam was to generate as high a quality source as possible.  My concern being that Premiere Elements encoding would be lossy and therefore the better the quality input I provided the better the "lossy" output would be.  Is this thinking flawed seeing as I will only ever be using this source footage to produce videos for YouTube with a maximum bitrate of say 20 to 30 Mbps?  Am I better trying to get Bandicam to generate source footage with a 20 to 30 Mbps bitrate to "match the output as closely as possible"?

Bandicam has a "quality" setting that I can experiment with.  My current value is 100% and I'm guessing that reducing this will reduce the recorded bitrate.  I'll look into that.

[Ikrananka]

So, I completed a long series of tests with Bandicam's "Quality" setting recording exactly the same game footage and these are the results:

Quality (%)	Bitrate (Mbps)	Relative File Size (%)	Notes
100	460	100	Perfect
90	379	82	Negligible loss of quality
80	309	67	Negligible loss of quality
70	243	53	Very slight loss of quality
60	188	41	Artefacts barely evident
50	138	30	Artefacts slightly evident
40	100	22	Artefacts more evident
30	71	15	Major loss of visual quality
20	69	15	Major loss of visual quality
10	69	15	Major loss of visual quality

What surprised me was that dropping the Quality setting to 80% had negligible impact on visual quality but dropped the bitrate and file size by 33%.  In fact, I believe that Bandicam's presets are all set to the 80% setting.  On rendering the test files in PE 14 with the same output settings (25 Mbps VBR 2-pass) the rendering time between the 100% and 80% was 10% less.  So, dropping the Bandicam quality setting not only reduces file size but also reduces the PE render time.

Based on these tests I record all of my future footage with Bandicam's quality set to 80%.

Going back to my original issue, reducing the source Mbps (e.g. Bandicam quality = 80%) seems to give PE less overhead and more chance to render the output without these occasional losses of resolution.  What I now need to do is to do a lot more rendering tests with longer videos to confirm this is the case and what render setting work best.