https://www.youtube.com/channel/UCKf53MyUzPTWJViWc0BYbUg

https://www.youtube.com/user/JustAlexHalford

https://www.youtube.com/user/PocketSplit

I wonder if anyone else see such ongoing YouTube channel bombing rather as spam. Following the links above in one of the video I'm welcomed with a "How to monetize your YouTube video". Exactly what ria-s asked for.

@Marco.

must be something on your side. I don't end up at anything like you describe when following all three links

but it is anything but a qualified answer to the TO question.

@Marco.  ... Yes, that's what I got too. The 1st link is 10 tips for Vegas Pro; the 2nd link is how to monetize YT; and the 3rd is a short overview of Scrapyard Films services. Neither the 2nd or 3rd link provides any specific educational information about Vegas Pro, and none of the 3 address the OP's issue as has been pointed out by @walter-i.

"The video in the preview box jumps and the sound is not in harmony with the video."

Sounds to me like this is between the 'unfriendly media format' or PC spec not powerful enough. Yes, more info like Dexcon pointed out is necessary to assist further at the best.

Anyway, in easier answer, where this source video you are editing coming from? is it a camera (what type?), cellphone (what type?), screen recording?

@Marco. @Dexcon You guys don't spend much time on youtube. All three of those links go to prolific youtubers that produce video about and with vegas pro. The "monetization" link is the promo video that Alex has set up for his channel.
@walter-i. I suspect that @Sheriff-adeyemi stopped reading the OP at "I am a beginner"

 All three of those links go to prolific youtubers that produce video about and with vegas pro

@michael-harrison  ... that's fine that someone familiar with those YT sites recommends them, BUT wouldn't it have been way more helpful for the person who posted them to have gone to the trouble of posting a link to the specific tutorial that directly addresses the OP's issue, particularly if they are familiar with those YT sites.

Thank you all for trying to help. I appreciate it very much. I use a Canon camera EOS 1200D.

I did go to the FAQ's and did disable resample on the properties but the video is still not playing smoothly on the preview. The settings are: 1920 x 1080; 25 000p frame: 24734 display: 364 x 205 x 32. pixel = 8 bit. The previous videos that I edited played smoothly but the settings were: 640 x 480 x 32; 25 000p frame: 7342 dispaly: 273 x 205 x 32. pixel = 8 bit smart resample.

Thank you for the links to the tutorials, that will be helpful.

Hi Ria, thanks for providing more info... especially the camera type.

I try searching around for public sample and found one:

https://www.photographyblog.com/reviews/canon_eos_1200d_review/sample_images

Let me help providing media info of your video format:

General
Complete name                            : E:\TEST\Canon eos 1200D\canon_eos_1200d_01.mov
Format                                   : MPEG-4
Format profile                           : QuickTime
Codec ID                                 : qt   2007.09 (qt  /CAEP)
File size                                : 108 MiB
Duration                                 : 19 s 360 ms
Overall bit rate                         : 46.7 Mb/s
Encoded date                             : UTC 2014-04-01 15:48:03
Tagged date                              : UTC 2014-04-01 15:48:03

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Baseline@L5
Format settings                          : 1 Ref Frames
Format settings, CABAC                   : No
Format settings, Reference frames        : 1 frame
Format settings, GOP                     : M=1, N=12
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 19 s 360 ms
Bit rate                                 : 45.1 Mb/s
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Original height                          : 1 088 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 25.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.871
Stream size                              : 104 MiB (97%)
Language                                 : English
Encoded date                             : UTC 2014-04-01 15:48:03
Tagged date                              : UTC 2014-04-01 15:48:03
Color range                              : Full
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.601
Codec configuration box                  : avcC

Audio
ID                                       : 2
Format                                   : PCM
Format settings                          : Little / Signed
Codec ID                                 : sowt
Duration                                 : 19 s 360 ms
Bit rate mode                            : Constant
Bit rate                                 : 1 536 kb/s
Channel(s)                               : 2 channels
Channel layout                           : L R
Sampling rate                            : 48.0 kHz
Bit depth                                : 16 bits
Stream size                              : 3.54 MiB (3%)
Language                                 : English
Encoded date                             : UTC 2014-04-01 15:48:03
Tagged date                              : UTC 2014-04-01 15:48:03

What is your computer spec?

Hi

Desktop - 7TM344E

Intel (R) Core(TM) 17-2620m cpu @ 2.70 GHz

270 Ghz

Installed RAM 6,000 GB

64-bit operating system, x64-based processor

windows 10 Pro version 1903

Intel (R) Core(TM) 17-2620m cpu @ 2.70 GHz

270 Ghz

Then your problems are caused by the processor of your desktop, because that one is to weak to handle the program well.
4 cores are needed and the processor in your desktop has only 2.
Look at the minimal spec that are needed for this program

Thank you

As for the alternative way, hopefully this can help, will be using proxy.

Right click on your medias in Project Media tab> Create Video Proxy.

Try test one first, and see if this can help smoothing the playback. The Preview quality should be Preview (Full) in maximum.

If this work, this is your only way for now. Hope helps.

I used a way worse processor than that for 4K editing for years, using exactly what set described. Give it a try and you might be pleased with the results!

thanks for the patience, I can't get "create video proxy".

Right click on your medias in Project Media tab> Create Video Proxy.

Here's how to do it:

To check whether the video proxy has been made, look at the location of your media, and you should find *.sfvp0 . If these files already available, you cannot recreate proxy.