Can't get SmartRender to work when editting MPEGs

[Underscore]

I've been trialing VS10+ for the last week. I will predominantly be using it for editting DV footage - and it seems OK for that. However, I would also like to use it to archive a few recordings made from DVB-T. However, try as I might, VS always reencodes the MPG, which is not what I want at all.

I have a Topfield PVR5800t, which allows me to upload the recordings onto a PC. I can then use ProjectX and PVAStrumento to convert (without reencoding) into a DVD-compatible MPG. I have used the trial of another DVD authoring package to produce a DVD from these files before - one which deosn't support reencoding of MPG at all - and it worked fine so I know that the files produced are good.

However, with VS, I've tried the following:

• Insert the clip into the timeline
• Clicked 'Yes' to change project properties to match the clip
• Trimmed the clip and turned on fade in and fade out
• Added 3 seconds of black, front and back
• Create a video file using SmartRender

However, it appears to alway reencode the file. If I export the trimmed clip, it does about 1% every 4 seconds. Creating a video file takes about 1min per % - irrespective of whether I use the project properties, the first video clip properties or various custom settings trying to match, or deliberately not matching, the video.

Am I missing something?

FYI, the video is 16:9, PAL with 256kbps MP2 audio.

_

[sjj1805]

Its the editing that prevents it from smart rendering.
If you have a clip with no editing at all then it simply passes through unchanged.

Try splitting your clips up into separate scenes and only edit the scenes that need modification such as fade to black, titles and so on. this way only the changes scens will be rendered, the remainder will be 'smart rendered.'

[Trevor Andrew]

Hi Underscore

Just to expand on Steve's comments.

However, with VS, I've tried the following:
• Insert the clip into the timeline ( I assume the main video timeline) (the top one)

• Clicked 'Yes' to change project properties to match the clip (now select Details to view the video properties)
(Highlight them and copy and paste the properties What are they? Post the properties.

• Trimmed the clip and turned on fade in and fade out
( For the video track--this fade in is the audio fade)

• Added 3 seconds of black, front and back
• Create a video file using SmartRender
(Share--Create Video File-same as First Video Clip, you can view the properties again in the preceding window--
this should render to a new file using the same properties.)

Now do another edit to the project—Maybe add a title to the start.

Share Create Video File, Same as first video clip.
Now watch Smart Render do its thing. Render should be relatively quick only fully rendering the changes.

Hope this Helps
Trevor

[Underscore]

Its the editing that prevents it from smart rendering.
If you have a clip with no editing at all then it simply passes through unchanged.

Try splitting your clips up into separate scenes and only edit the scenes that need modification such as fade to black, titles and so on. this way only the changes scens will be rendered, the remainder will be 'smart rendered.'

Ah, so you are saying that the (audio) fade in and fade out are what is causing the problem? If I split the clip a second in and fade in the audio in that first section, it won't reencode the bulk of the clip? That makes sense, I guess - I didn't realise that SmartRender turned rendering on or off for the whole clip only - probably because the trial version hasn't installed the help files on my machine so I'm having to work by guesswork and this forum.

I'll give it a go over the weekend and report back on Monday.

Cheers,

_

[Underscore]

Comments inserted below in green:

Just to expand on Steve's comments.

However, with VS, I've tried the following:
• Insert the clip into the timeline ( I assume the main video timeline) (the top one)
Exactly

• Clicked 'Yes' to change project properties to match the clip (now select Details to view the video properties)
(Highlight them and copy and paste the properties What are they? Post the properties.
If I still have problems, I will but I remember the format being PAL DVD, res 720x576, aspect being 16:9, VBR max ~5500kbps

• Trimmed the clip and turned on fade in and fade out
( For the video track--this fade in is the audio fade)
Yes, my trim points had black in the video so it was only the audio that I faded in and out

• Added 3 seconds of black, front and back
• Create a video file using SmartRender
(Share--Create Video File-same as First Video Clip, you can view the properties again in the preceding window--
this should render to a new file using the same properties.)

Now do another edit to the project—Maybe add a title to the start.

Share Create Video File, Same as first video clip.
Now watch Smart Render do its thing. Render should be relatively quick only fully rendering the changes.
I'll play a little more over the weekend and, hopefully, get it working - I think that I understand it all a little more now, at least

Hope this Helps
Trevor

Thanks for your help,

_

[Trevor Andrew]

Its the editing that prevents it from smart rendering.
If you have a clip with no editing at all then it simply passes through unchanged.

Try splitting your clips up into separate scenes and only edit the scenes that need modification such as fade to black, titles and so on. this way only the changes scens will be rendered, the remainder will be 'smart rendered.'

Ah, so you are saying that the (audio) fade in and fade out are what is causing the problem? If I split the clip a second in and fade in the audio in that first section, it won't reencode the bulk of the clip? That makes sense, I guess - I didn't realise that SmartRender turned rendering on or off for the whole clip only - probably because the trial version hasn't installed the help files on my machine so I'm having to work by guesswork and this forum.

I'll give it a go over the weekend and report back on Monday.

Cheers,

_

Hi

Yes I think that is what Steve is saying.

I would cut the clip a little longer than 1 second, say 10. Then add the colour and transitions. No need for transitions at the cut.

Rendering should be faster.

You don’t indicate how long your clip is, or how long render is taking.
Nor the exact properties of the clip.

Trevor

[Underscore]

I would cut the clip a little longer than 1 second, say 10. Then add the colour and transitions. No need for transitions at the cut.

Rendering should be faster.

You don’t indicate how long your clip is, or how long render is taking.
Nor the exact properties of the clip.

Trevor

Actually, I didn't have a transition - it was a straight cut - but I take your point.

The clip is a couple of minutes under 1.5 hours. When saving the trimmed clip (i.e. the recording has 3 minutes padding on the front and 6 minutes on the end, which I removed in VS), each % takes about 4 seconds. When rendering each percent takes around a minute. I was expecting SmartRender to merely copy the uneditted parts of the clip - so ~4 seconds per % - but it is obviously not quite that smart!

I'll post full details of the clip if I still have problems once I've tried what Steve suggests...

Thanks for your help,

_

[jchunter]

Underscore,

When you clicked Fade In and Fade out, I assume that these were the buttons at the top of the Video Tab (within the Edit tab). These only affect sound on the clip and do not prevent smart rendering (as Trevor said earlier).

Smart rendering is NOT prevented by light editing such as cuts, insertions, adding still photos, transitions, music, etc. The uncut video frames pass through to the output video file unaltered. Only the cut/join video juctions, the stills, transitions, and the sound track are fully rendered. The net effect is that creating a video file with smart render enabled goes a lot faster.

However, smart rendering usually can't be preformed on clips that have a globally acting video filter, say, that alters the color balance but the rest of the project can be smart rendered.

Smart rendering is generally not possible, when transcoding one video format into another, which generally requires the video to be decompressed and then recompressed with a different algorithm.

Therefore, if you are not able to smart smart render, at least one of your properties, set up for Create Video, does not match the input file. Something like Field Order, Frame size, datarate, etc. is different.

[DVDDoug]

DVB-T.... VS always reencodes the MPG, which is not what I want... I can then use ProjectX and PVAStrumento to convert (without reencoding) into a DVD-compatible MPG. I have used the trial of another DVD authoring package to produce a DVD from these files before - one which deosn't support reencoding of MPG at all - and it worked fine...

Are you sure about that? As far as I know, digital broadcast uses bitrates and resolutions that are not DVD compliant. In that case, it must be re-coded.

[Underscore]

DVB-T.... VS always reencodes the MPG, which is not what I want... I can then use ProjectX and PVAStrumento to convert (without reencoding) into a DVD-compatible MPG. I have used the trial of another DVD authoring package to produce a DVD from these files before - one which deosn't support reencoding of MPG at all - and it worked fine...

Are you sure about that? As far as I know, digital broadcast uses bitrates and resolutions that are not DVD compliant. In that case, it must be re-coded.

That's what PVAStrumento does - it converts from program stream to transport stream (I think that's the right way round) - so that (GOP permitting) you then have a DVD compliant MPEG file.

Anyway, thanks all for your help - especially Steve. I placed a cut a few seconds into the clip and added the fade in to this short section - the SmartRender then did exactly what I was expecting - rendered the first few seconds and then copied the rest. My one concern is that I'm not sure that the audio sync is still good but I only looked at it in the preview window so I'll wait until I've burnt it to DVD before passing final judgement.

Thanks again,

_

EDIT: I've just re-read your comment. In the UK, most (though not, I think, all) broadcasts are at 720x576 and average between 2 and 4 Mbps. GOPs are typically suitable for DVD, though some (notably Film4) do sometimes use large GOPs (~40) which are not. However, the clip that I'm working on is DVD compliant.

[Underscore]

As an update, I burned the editted MPEG to a DVD last night and the lip-sync is fine. As a result, I've now ordered the full version of VS10+. Thanks again for all your help.

_