more informations on the smart-renderer

Sektionschef · Post by **Sektionschef** » Sun Jun 25, 2006 7:16 pm

Dear All
I have a camcorder that generates mpeg2 files. I use UV10 to edit these files. I understand that UV10's smart renderer can detect video material that is already of the same type of the final file format and prevents reencoding to avoid quality loss, right?
In my opinion this should also affect the rendering time, the more "matching video" I already have as the source material the shorter the overall rendering time, right?
Now how do I find the best settings for my projects?
My camcorder delivers mpeg2 files in 704X576 with a VBR of around 6Mbs.
Audio is 256kbs at 48Hz frame rate.
What parameters of my source material must match with what parameters of the "Create Video File" settings that smart-renderer prevents reencoding?
Is there a more detailed information available how the smart-renderer works and what parameters affect it's decission whether reencoding will be done or not?
Regards
Sektionschef

GuyL · Post by **GuyL** » Sun Jun 25, 2006 8:31 pm

When you create the file you can choose one of the templates or create your own options for the file. If the file being rendered (saved) matches your create file options and they are within the DVD specification then they won't be rendered.

THoff · Post by **THoff** » Sun Jun 25, 2006 9:26 pm

When you go to insert a video file from your camcorder into the Timeline, click the Info button in the File Open dialog to view the MPEG2 parameters as Videostudio sees them -- if you create a template using the same encoding method (CBR vs. VBR), bitrate, field order, and audio options, you should be able to avoid unnecessary rendering.

The only thing that would still need to be done is the audio/video multiplexing, which will be limited mostly by the speed of your disk drive(s).

Sektionschef · Post by **Sektionschef** » Mon Jun 26, 2006 12:07 pm

Many Thanks for your answers!!!
What about the bitrate?
If "variable" is selected in the options then does the bitrate value refer to the max. bitrate of the whole mpeg2 clip or to the mean bitrate?
Must the bitrate also exactly match or are there some tolerances because it is variable?(
I must check but I could think that different clips coming from my camcorder can have different variable bitrates depending on how many fast moves I have recorded.
Is there any other way in VS10 to find out whether reencoding was prevented by the smart-renderer except comparing the rendering times?
Regards
Sektionschef

GuyL · Post by **GuyL** » Mon Jun 26, 2006 12:55 pm

Sektionschef wrote:Many Thanks for your answers!!!
What about the bitrate?
If "variable" is selected in the options then does the bitrate value refer to the max. bitrate of the whole mpeg2 clip or to the mean bitrate?
Must the bitrate also exactly match or are there some tolerances because it is variable?(
I must check but I could think that different clips coming from my camcorder can have different variable bitrates depending on how many fast moves I have recorded.
Is there any other way in VS10 to find out whether reencoding was prevented by the smart-renderer except comparing the rendering times?
Regards
Sektionschef

The bitrate you see for variable is the max bitrate. The actual bitrate will vary depending on the requirements. Now, your MPEG file will already have a bitrate throughout if set to variable and smartrender will leave this alone except where edits occured and the file needed to be re-rendered. During the re-rendering process the bitrate required will be recalculated.

Trevor Andrew · Post by **Trevor Andrew** » Mon Jun 26, 2006 2:47 pm

Hi

By using Tools-Make Movie Manager you can create a template to match your captured video file.

Use the Add option and Browse for your captured file. Give it a name.

The template will be available from Share Create Video File.

I am not sure if you can burn a dvd using 704 x 576 frame size.

Can others on the forum clarify this, or does the frame have to be 720 X 576.

If you have to use 720 create the template as above then edit the frame size to 720 x 576.

By using a template that matches the video file rendering time will be reduced.

Check out Mpeg Rendering Times from the link below.

Trevor

Sektionschef · Post by **Sektionschef** » Mon Jun 26, 2006 5:33 pm

="GuyLThe bitrate you see for variable is the max bitrate. The actual bitrate will vary depending on the requirements. Now, your MPEG file will already have a bitrate throughout if set to variable and smartrender will leave this alone except where edits occured and the file needed to be re-rendered. During the re-rendering process the bitrate required will be recalculated.

Many Thanks agin for your answer.
Does this mean that the bitrate does not need to match in case variable bitrate is used? For example, if I put 2 clips onto the timeline, one has a max. bitrate of 6Mbs, the other has max. bitrate of 5Mbs, but all other parameters match to the project settings, does it mean that the smart-renderer will not reencode?
Regards
Sektionschef

GuyL · Post by **GuyL** » Mon Jun 26, 2006 7:39 pm

Sektionschef wrote:
="GuyLThe bitrate you see for variable is the max bitrate. The actual bitrate will vary depending on the requirements. Now, your MPEG file will already have a bitrate throughout if set to variable and smartrender will leave this alone except where edits occured and the file needed to be re-rendered. During the re-rendering process the bitrate required will be recalculated.
Many Thanks agin for your answer.
Does this mean that the bitrate does not need to match in case variable bitrate is used? For example, if I put 2 clips onto the timeline, one has a max. bitrate of 6Mbs, the other has max. bitrate of 5Mbs, but all other parameters match to the project settings, does it mean that the smart-renderer will not reencode?
Regards
Sektionschef

I believe the max needs to match. However, I have never tested the theory. I haven't edited in MPEG for a couple of years now. Anyone else know for sure?

Sektionschef · Post by **Sektionschef** » Mon Jun 26, 2006 8:24 pm

I did some tests now and could see the following:
I have put 3 mpeg2 clips from my camcorder onto the timeline.
No transitions, no effects no titles added. The mpeg2 files have audio inside. VS10 reports that they have a max. bitrate of 9558kbps.
Using the tool "bitrate viewer" I learned that this bitrate is the nominal bitrate, not the max. bitrate and it also reports that the max. bitrate is about 5245kbps. This sounds plausible for me because I use the camcorder in SP mode and according to the manual it should use a max. bitrate of about 6000kbps.
If ANY of the parameters in VS10 do not match exactly to those VS10 reports from the clip then the rendering time is about 2.5 minutes(total clip time is about 2Minutes). However, if ALL parameters do exactly match(including the nominal bitrate) then the rendering takes about 5 seconds(!). To reach these 5seconds it is also very important to disable "two pass encode". If I specify a bitrate of 9557 instead of 9558 then the rendering time goes up to 2.5Minutes. So it must match exactly.
Unfortunately I found a strange behaviour which seems to be a bug in VS10:
All tests from above were made using "custom settings" so I didn't use a template yet. If I create a template with EXACTLY the same parameters from my previous test I also get a rendering time of about 2.5Minutes.
Or, with other words, I could never reach the rendering time of 5seconds using a template. I only could reach it via custom settings(but used identical settings, checked several times).
Regards
Sektionschef

GuyL · Post by **GuyL** » Mon Jun 26, 2006 8:44 pm

Sektionschef wrote:I did some tests now and could see the following:
I have put 3 mpeg2 clips from my camcorder onto the timeline.
No transitions, no effects no titles added. The mpeg2 files have audio inside. VS10 reports that they have a max. bitrate of 9558kbps.
Using the tool "bitrate viewer" I learned that this bitrate is the nominal bitrate, not the max. bitrate and it also reports that the max. bitrate is about 5245kbps. This sounds plausible for me because I use the camcorder in SP mode and according to the manual it should use a max. bitrate of about 6000kbps.
If ANY of the parameters in VS10 do not match exactly to those VS10 reports from the clip then the rendering time is about 2.5 minutes(total clip time is about 2Minutes). However, if ALL parameters do exactly match(including the nominal bitrate) then the rendering takes about 5 seconds(!). To reach these 5seconds it is also very important to disable "two pass encode". If I specify a bitrate of 9557 instead of 9558 then the rendering time goes up to 2.5Minutes. So it must match exactly.
Unfortunately I found a strange behaviour which seems to be a bug in VS10:
All tests from above were made using "custom settings" so I didn't use a template yet. If I create a template with EXACTLY the same parameters from my previous test I also get a rendering time of about 2.5Minutes.
Or, with other words, I could never reach the rendering time of 5seconds using a template. I only could reach it via custom settings(but used identical settings, checked several times).
Regards
Sektionschef

Awesome find, Sektionschef. Thank you for sharing with us.