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AVCHD Format Discussion
Inexpensive High Definition H.264 encoding to DVD, Hard Disc or SD Card.


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Old September 29th, 2008, 04:43 PM   #1
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Video Bitrate: AVCHD raw clips vs. rendered files

I am creating 1920x1080 AVCHD discs on standard DVD+R from AVCHD files (AVC H.264) rendered in Corel Pro X2 from Sony SR-11 1920x1080 clips (I'm not using Smart Render in Pro X2 because it causes audio-video sync problems, so Pro X2 is re-rendering the clips when it creates the AVCHD file).

I checked the raw clips from the camera and the bit rate is almost always close to 16 Mbps, which is the rate associated with the SR-11.

When I create AVCHD files from these clips in Pro X2, I set the bit rate to 16 Mbps in the settings for file rendering. However, the resulting AVCHD file (and the discs burned from that file) shows the bit rate varying between 7 and 11 Mbps. Yet the video looks good on my 1920x1080 LCD TV when played from my Blu-ray player.

Is this normal that rendered files and discs have a much lower bit rate than the native clips out of the camcorder even though I set the bit rate to be the same as the SR-11 produces (16 Mbps)?
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Old September 30th, 2008, 12:20 PM   #2
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Dale,

You might consider posting this on the Ulead / Corel support forum. There are a lot of very knowledgable Video Studio users there.

Your experience differs from mine when using VS Pro X2. I do not encounter lip sync issues and therefore use Smart Render, with resulting output exactly the same as input.

As you may have discovered, there are 3 sets of parameters which need to be carefully matched, the Project Properties, the Disk Template properties, and the video clip properties. Unless all 3 are the same, problems will arise.

A common mistake is to allow the Project Properties to stay as their default rather than being set up for AVCHD, leaving the resulting timeline in a form which forces re-rendering when the disk is burned. You might want to first check this out.

I really am not an expert on this program, and hope to get you started with a solution, but I really do encourage you to take advantage of their support forum. I have benefited a lot from the people there and their experience with this program.

Larry
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Old September 30th, 2008, 01:20 PM   #3
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I just got X2 trial installed and trying to figure out how to change Project Properties to AVCHD. It gives me only two options: either MPEG or Microsoft AVI, both standard defenition. How to configure this program so the Project Settings would match my original file properties H.264 1920x1080i 17Mbs?
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Old September 30th, 2008, 01:33 PM   #4
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Originally Posted by Stas Bobkov View Post
I just got X2 trial installed and trying to figure out how to change Project Properties to AVCHD. It gives me only two options: either MPEG or Microsoft AVI, both standard defenition. How to configure this program so the Project Settings would match my original file properties H.264 1920x1080i 17Mbs?
I also only find AVI and MPEG as the choices in the Project Properties. However, there is an edit button at the bottom of that dialog. When you click it, there are some other options, but none of them are AVCHD. According to the help file, the Project Properties determine the quality of the playback in the preview window.
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Old September 30th, 2008, 01:52 PM   #5
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I thought that the preview quality is determined by the Smart Proxy settings.
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Old September 30th, 2008, 01:53 PM   #6
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Dale,

You might consider posting this on the Ulead / Corel support forum. There are a lot of very knowledgable Video Studio users there.

Your experience differs from mine when using VS Pro X2. I do not encounter lip sync issues and therefore use Smart Render, with resulting output exactly the same as input.

Larry
Thanks, Larry. I posted in the ulead forum a while back about the sync problem and the suggestion was to turn off Smart Render, which did solve the problem. I have also just posted the bit rate question and am awaiting replies.

Interesting that you don't get lip sync problems with AVCHD even though you use Smart Render. Mine problem occurs if I burn an AVCHD disc directly from the timeline/project, or if I create an AVCHD file with Smart Render on, and then burn the file to an AVCHD disc with Pro X2's Create Disc. I am carefull to match the properties of the clip to the rendering properties. When I play the file created by Pro X2, it is in sync - regardless of whether I used Smart Render or not. But a AVCHD disc created from a file that was smart rendered is out of sync. Even though the Create Disc step doesn't re-render the file, the disc ends up out of sync. I suspect the video/audio multiplexing step of the burn process.

The only way I have not had lip sync problems with AVCHD discs is to create an AVCHD file with Smart Render off and then burn that file to disc (with Pro X2's Burn Disc).

I can burn standard-def DVD's directly from the timeline/project and the lip sync is fine. I only get the problem with AVCHD discs.

Which camcorder do your AVCHD clips come from? Mine are from a Sony SR-11. I have wondered if there is something proprietary about Sony's clips that Pro X2's Smart Render feature is not able to handle correctly.
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Old September 30th, 2008, 02:00 PM   #7
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Originally Posted by Stas Bobkov View Post
I thought that the preview quality is determined by the Smart Proxy settings.
Now that you mention it, although the Help file says Project Properties determine the quality of the preview, Smart Proxy seems to be the main determinant of the playback quality.

If I turn Smart Proxy off, the preview looks high-definition, which makes me think it is playing the raw AVHCD clip (and the preview playback is choppy as you might expect with AVCHD). With Smart Proxy on, the preview is obviously lower quality (as expected) and it plays back smoothly.

So now I am not sure how to interpret the Help file regarding how the Project Properties are used.
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Old September 30th, 2008, 03:55 PM   #8
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Preview quality vs project rendering settings

Quote:
Originally Posted by Dale McClelland View Post
Now that you mention it, although the Help file says Project Properties determine the quality of the preview, Smart Proxy seems to be the main determinant of the playback quality.

If I turn Smart Proxy off, the preview looks high-definition, which makes me think it is playing the raw AVHCD clip (and the preview playback is choppy as you might expect with AVCHD). With Smart Proxy on, the preview is obviously lower quality (as expected) and it plays back smoothly.

So now I am not sure how to interpret the Help file regarding how the Project Properties are used.
I think the preview quality and the rendering are two unconnected issues, though I don't class myself as a VideoStudio pro by any means.

Preview without Smart Proxy should play the video back as best it can using the native codecs that apply to the clip itself being played. Preview with Smart Proxy is definitely playing back a low-quality version of the video in order to get increased smoothness and frame rate. Each frame is less detailed and accurate than the real video, but in a format that requires less horsepower to get a good smooth frame rate.

The project setting for rendering doesn't seem to have any inherent relation to the preview playback - at least it doesn't make sense that it should until you start to process a clip so heavily that it effectively has to render just to play your edits. With Smart Proxy on, even this presumably is faked somewhat instead of truly calculated.

What I have found for rendering is that if my clips are all in the same format, the easiest thing to do on the Share side is to specify that the rendering settings should match those of the first clip. I used to faithfully copy my HDV settings between projects by loading a project with the right settings but no clips. Then I'd rename it and save it, and then would use the new empty project. Once I switched to an AVCHD camcorder, I just left the project settings alone (the rendering ones) and always selected "same as first clip". The SW then figures that all out and renders based on what it found. I don't seem to need to intervene.

/ Tom
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Old September 30th, 2008, 04:42 PM   #9
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Dale, Tom, and Stas,

Select the Project Properties menu item, hit the Edit button, choose the Compression tab, select from the Media Type drop down menu the choice MPEG2, enter a high bitrate (I use 20,000), go to the General Tab, select 1920 by 1080 resolution and lower field first, click OK and confirm that the Video properties match AVCHD video (1920 by 1080, 29,97 fps, LFF). The audio properties will NOT match your camcorder or mine, since there is no project property settimg at these resolutions for Digital Dolby. This does NOT appear to effect the Smart Render or the burned disk however.

The above are my settings for the Canon HF100 and I have not seen lip sync errors. I should mention that I have never made a 1 hour+ continuous AVCHD file as you apparently have, so it certainly is possible that a slight offset in audio and video could be invisible on my shorter clips but would show up on extremely long (1 hour+) uninterrupted clips such as you have referred to. My camera may also form the .mts file differently during acquisition.

Also, I never use the internal capture feature of the program, but instead bring all of the raw .mts files (the video clips) directly off the SD card with a card reader and then import them into the timeline directly. This may somehow effect how the program handles the file.

Once again, I am not an expert on this program, use it occasionally, and think the best answers will come from the support forum. Hope this is of some help however.

Larry
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Old September 30th, 2008, 05:08 PM   #10
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Dale, Tom, and Stas,

Select the Project Properties menu item, hit the Edit button, choose the Compression tab, select from the Media Type drop down menu the choice MPEG2, enter a high bitrate (I use 20,000), go to the General Tab, select 1920 by 1080 resolution and lower field first, click OK and confirm that the Video properties match AVCHD video (1920 by 1080, 29,97 fps, LFF).

Larry
Larry, you mentioned "Lower Field First" in the settings. Maybe that is the cause of my sync problem. I thought AVCHD was Upper Field First. I'll try Smart Rendering with Lower Field First. I'm not sure whether field order affects sync, but will try it and find out. Thanks.
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Old September 30th, 2008, 05:51 PM   #11
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Thanks Larry.
I had the same question: why LFF if the original canon files have UFF?

Actually, changing the Project Settings didnt affect the output file (judging by the file size). The size of the rendered file is slightly bigger the the source one (less the 1%) no matter what Project Settings are.
Can this be explained by the differences between the original MTS container and the output MPG one?
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Old September 30th, 2008, 08:05 PM   #12
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Dale and Stas,

My mistake. It is UFF for AVCHD. Sorry!

Larry
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Old October 1st, 2008, 12:57 AM   #13
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One more question about X2 Pro:
When drag and drop a clip into an Overlay Track it looks like one attribute has already been applied to that track permanently by default. It's a sort of "moving path" or PiP like video effect that I'm having a hard time to get rig of. And you can see a little icon on the timeline (two perpendicular arrows) whenever there is a clip on the overlay track.
I was wondering if there is a way to delete all attributes from a particular clip or track.
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Old October 1st, 2008, 07:53 AM   #14
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Originally Posted by Stas Bobkov View Post
One more question about X2 Pro:
When drag and drop a clip into an Overlay Track it looks like one attribute has already been applied to that track permanently by default. It's a sort of "moving path" or PiP like video effect that I'm having a hard time to get rig of. And you can see a little icon on the timeline (two perpendicular arrows) whenever there is a clip on the overlay track.
I was wondering if there is a way to delete all attributes from a particular clip or track.
Stas,

My interpretation of this little icon is that any video which has been designated for placement in the Overlay track is, by very definition, a "picture in picture" which can be moved and re-sized. I do not believe there is any other way for an Overlay video clip to exist except in this fashion.
The little icon is added to clips which are placed in the Overlay track merely to indicate that they are PIP. This attribute can't be removed since the clip will always have this property.The icon arrows imply that the clip can be moved and resized.


Once again, this is just my personal interpretation, and I would very much like to hear if anyone else has a different description or suggestion.

Larry
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Old October 1st, 2008, 11:30 AM   #15
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Hi Larry.
This is how I understend it too. I wouldn't have a problem with that if the program had more then one video track. I need at list two normal video tracks (three is better) to do my B-roll and work with overlapping audio etc. I checked the Track Manager - how come they have SEVEN!!! overlay tracks, each with PiP and only one video track. Or, maybe I'm missing something...
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