Avi to avi in Vegas Pro, without any quality loss (smart rendering)

Dana wrote on 10/7/2019, 10:41 AM

Hi everyone,

I'd need the opinion of real professionals here on vegascreativesoftware to be absolutely sure that I am doing everything right.

The content of my PAL MiniDV cassettes is saved in external hard drives. Friends want me to send them some original footage, not only to watch but to also edit it. I need to cut out some parts first, and join the remaining parts. No effects or fades applied. No modification of the content. Only simple cuts. I want the original quality of the avi files to stay intact after the render.

DV avi should render with no re-encoding because each frame is coded independently. So logically I should be able to smart render the video files (to trim them without re-encoding the bulk of the file) and thus keep the initial quality.

I'm running Sony Vegas Pro 14 (64) on a Windows 7 laptop. I set my project video settings to "match this media". To render the final trimmed project I use the Video for Windows (*.avi) template. During rendering a black screen says No Recompression Required. It means smart rendering is initiated. Does it also mean that the rendered trimmed file will be of the exact same quality as the large original one, that there will be no loss of quality at all? Please confirm. I need to be sure I'm doing everything right, before starting to trim more videos (and spending more nights on it).

Some more questions.

–1. If I disable smart resampling (on the timeline and in project properties), will it have any influence on the quality of the rendered file?

–2. In project properties, the resolution quality should be set to good or best? Deinterlace method: blend fields or interpolate fields?

–3. Do changes in project properties have any importance whatsoever in the present case (i.e. avi to avi)?

–4. Should I customize the Video for Windows (*.avi) render template, or should I leave everything as it is, eg. "interleave every 0,250 seconds", etc?

–5. Some people say SolveigMM Video Splitter is better than Vegas Pro, as far as keeping the original quality of trimmed files. Is it really so?

Thanks a lot! And have a great day.

Comments

Marco. wrote on 10/7/2019, 11:04 AM

Your settings are fine and if "No Recompression Required" is displayed on your preview, real smart rendering of video takes place without any video quality loss. The video stream will be copied then.

Dana wrote on 10/7/2019, 11:34 AM

Hi Marco, and many thanks for your quick answer. :)

So to be 100% sure: I don't need to worry about the project properties at all, right? I just keep the default settings, i.e. smart resample on, blend fields, "good" rendering quality of both video & audio... etc. Neither do I need to worry about the Video for Windows .avi template settings. Super!

Back to my trimming now. Have a great day!

fr0sty wrote on 10/7/2019, 11:54 AM

It shouldn't matter, but I always set render quality to best, and make sure your project settings match the settings of the media you are putting into it. If Vegas says it is not recompressing, that means it is indeed copying the raw frame into a new DV AVI file without touching it, but the above advice is always good to use in any project, not just DV projects that you intend to be lossless. You want to make sure Vegas is doing the fewest number of conversions possible along the way from input files to rendered output file. Vegas will ask you if you want to set project settings to match your media when you add media to a new project, use that. Also, only use resample when necessary, when using mixed frame rate media.

Dana wrote on 10/7/2019, 1:30 PM

Hi Fr0sty, thanks a lot for your message.

Hmmm... so my hesitation about the "good/best" resolution quality was actually not so silly. I will do as you say, and choose "best". I will also disable the default smart resampling. One never knows. I definitely want to make sure Vegas is doing the fewest number of conversions. As for the deinterlace method, what would you do; would you keep the default "blend" fields?

I will render one of the videos in several different ways, and see if MediaInfo shows me some differences.

Sylk wrote on 10/7/2019, 7:10 PM

Your settings are fine and if "No Recompression Required" is displayed on your preview, real smart rendering of video takes place without any video quality loss. The video stream will be copied then.

Maybe i'm stupid or blind but i don't see such thing in VP17.

EricLNZ wrote on 10/7/2019, 9:31 PM

It will just happen with the appropriate video format but I suspect VP will only "not compress" dv-avi.

Edit - Correction as other streams can be smart rendered. This is from VMS16 Help Screen but I expect VP is similar.

Sylk wrote on 10/7/2019, 9:54 PM

It will just happen with the appropriate video format but I suspect VP will only "not compress" dv-avi.

Edit - Correction as other streams can be smart rendered. This is from VMS16 Help Screen but I expect VP is similar.

Thanks. Here's VP17 formats list.

No AVC, no HEVC... Only available for all the formats i never use...

Marco. wrote on 10/8/2019, 2:57 AM

Smart rendering of AVC or HEVC does make only limited sense due to its particular reference frame structure (including the IDR frames), though you could use Vegasaur or HOS for certain AVC smart render cases.

Sylk wrote on 10/8/2019, 5:07 AM

Same with "uncompressed" AVI files from Fraps :/

Marco. wrote on 10/8/2019, 5:21 AM

Fraps AVIs aren't uncompressed. Fraps uses a proprietary low compressing codec.

Sylk wrote on 10/8/2019, 5:36 AM

Real uncompressed AVI not supported either... Curious to know the argument of why.

Marco. wrote on 10/8/2019, 5:50 AM

This is strange, indeed. Smart rendering uncompressed YUV AVIs works fine, but same for RGB AVIs does not.

3POINT wrote on 10/8/2019, 6:19 AM

As far as I know, smartrendering of XDCAM doesn't work either, despite it's named in the smartrendering list in the helpfile. Smartrendering with Vegas is also not really fast, what you would normally expect when just copying data.

Setting the render/projectsettings from good to best has no influence on speed or quality when smart rendering is used. Smartrendering is a 1:1 copy of the original.

Marco. wrote on 10/8/2019, 6:40 AM

Smart render of XDCAM HD/EX MXF works fine here, only XDCAM EX MP4 doesn't.

Sylk wrote on 10/8/2019, 8:39 AM

This isn't worth the Direct Stream Copy from Vdub...

Dana wrote on 10/8/2019, 9:10 AM

Setting the render/projectsettings from good to best has no influence on speed or quality when smart rendering is used. Smartrendering is a 1:1 copy of the original.

Thank you, 3POINT. I have rendered one of the trimmed avi projects in three different ways, with random project properties settings... and indeed, MediaInfo shows identical descriptions for all the three rendered trimmed avi files:

However, when I compare the rendered trimmed videos to the original avi file, MediaInfo shows some differences... which makes me a bit confused. Would you have an explanation?

As far as rendering, the Vegas help screen says that in order to perform smart rendering "the width, height, frame rate, field order, profile, level, and bit rate of the source media, project settings, and rendering template must match". Are you absolutely sure there is no need to customize the rendering template (the Video for Windows avi)? I could for instance change the audio sample rate to 32,000 Hz and thus make it match the source media sample rate... Idk.

Marco. wrote on 10/8/2019, 9:43 AM

Yes, it's the audio stream which is re-rendered to a higher bitrate because of a higer sampling frequence. And that's fine. I'd leave the settings as they are (48 kHz for audio).

Dana wrote on 10/8/2019, 10:29 AM

Thanks, Marco.

3POINT wrote on 10/8/2019, 10:39 AM

Exactly, only the videopart was rendered "smart", not the audiopart, as Marco stated.

3POINT wrote on 10/8/2019, 10:40 AM

Smart render of XDCAM HD/EX MXF works fine here, only XDCAM EX MP4 doesn't.

I have only experience with XDCAM EX MP4.

theo-w wrote on 3/15/2020, 8:57 AM

Vegas Pro can't find AVI-files! What a **** program is this!

michael-harrison wrote on 3/15/2020, 11:17 AM

@theo-w start your own post and state an actual problem if you want help

theo-w wrote on 3/19/2020, 9:19 AM

Thanks Michael-Harrison - no problems more! Ennything is working now!