VS ProX4 AVCHD video blotchy during motion on DVD

[Wilson]

Another Newbie joins the digital video age. I've split my questions into separate (3) threads so that people didn't have to suffer through content they're not interested in. Here's a brief run down on where I'm at and what I'm trying to do.

I'm about half-way through my 30day trial of VS Pro X4, and starting to feel a little more comfortable with the software, but a few things are still puzzling me. Granted I've only scratched the surface of the SW capabilities so far.

I took the plunge and got a new Panasonic HDC-TM90K HD video recorder to replace my old 8mm analog Sony. I've only had the opportunity to use it several times, so far so good.

The Panasonic camera comes with HD Writer AE 3.0 software. Pretty rudimentary compared to VS Pro X4; does the basics, trimming, titles, transitions etc. Not bad, it works, but definitely not as sophisticated as VS Pro X4. However I need software that can capture the 8mm tapes I'm converting, which the Panasonic SW cannot, really don't want to learn/use two software packages so hence trying to focus on VS Pro X4. See thread http://forum.corel.com/EN/viewtopic.php?f=1&t=41255 for my question re: mpeg compression.

Using the Panny HD Writer SW I was able to capture and burn AVCHD DVD's from the Panny camera SW without issue, not too difficult considering this is my firt time doing all this stuff. AVCHD DVD's play just fine on my Sony Blu-Ray.

I tried capturing the same video content from the Panny camera with VS Pro X4 and could not. VS Pro X4 is stating there is no camera attached. I believe the Panny SW is hijacking the USB connection first and hence is controlling the connection to the camera. I tried looking for some services that the Panny SW has running and closed the auto-run of the Panny SW, but still no luck. I haven't tried uninstalling the Panny SW, that's next.

I was however able to import the files from the Panny camcorder using the import function in VS Pro X4 by selecting the files I wanted. Maybe that's the way I should be doing it anyhow? Imported files are the exact same size as the files imported in the Panny HD Writer AE 3.0 SW.

Was able to make a simple little video by adding a title, couple of transitions between clips etc, couple of chapter
markers. All went fairly well. Then did "Share > Create Disc", used the default (only) disc template that came in the
VS Pro X4 SW trial, selected AVCHD and burn disc, no issues, until I went to play the disc in my Sony Blu-Ray. Once the action in the video picked up and there was significant motion in the video the video started to break up, don't know the technical name for it, digital artifacts maybe? It doesn't look like the deinterlacing examples I've seen, which appear to be unaligned thin lines, this is more blotchy, like blocks of data not being filled in. Anyhow tried a couple of discs same problem, tried making a regular .mpeg2 file same issue.

So then I tried it again and selected 2 pass conversion, this time it worked, which is good, but does that need to be
done anytime your burning HD content to a AVCHD DVD? Maybe the Panny SW is doing that anyhow, it's just not stated anywhere as an option.

Thanks,

Dan

[Black Lab]

I was however able to import the files from the Panny camcorder using the import function in VS Pro X4 by selecting the files I wanted. Maybe that's the way I should be doing it anyhow?

It's always best to capture with the software that came with the hardware.

[Ken Berry]

... But if 'capturing' using VS, it is indeed the import function you use 'anyhow'!

The blocky 'digital artifacts' you describe are called pixellation. They can be caused by using the wrong field order. X4 sets Upper Field First as the default, and this matches your original AVCHD field order which is always Upper Field First, so it shouldn't be that which is causing it -- though you might just want to cross check...

The only other thing I can think of which can cause pixellation of AVCHD is using too low a bitrate and/or using SmartRender during the production phase. AVCHD uses Variable Bitrate, but if you select a lower maximum bitrate than your original video, pixellation can occur. I think your camcorder can film using the highest quality setting under the international AVCHD standard, which is currently 24 Mbps. So selecting an AVCHD output which does not match that in X4 will cause loss of quality -- and pixellation -- in the resulting video.

Your camera is also one of the new breed which can film in true 50 (PAL) or 60 (NTSC) frames per second progressive mode at 1920 x 1080. To put it bluntly, X4 cannot handle that properly, and this too would account for pixellation and possibly jerky movement. Moreover, the international standard has not yet been changed to reflect this frame rate, only extending to 1280 x 720 true progressive made. And that represents a significant quality hit from what your camera is capable of. By the way, Panasonic and Sony are trend leaders in AVCHD video, and are ahead of the pack -- and international standards -- in this regard.

So if you are going to use X4 with your camera, you are possible going to have to consider using one of its lesser quality settings which may use interlaced 25/30 fps which is what most AVCHD cameras currently are capable of.

There are a couple of threads on this forum discussing at length the question of true progressive camera output and editing: see for example http://forum.corel.com/EN/viewtopic.php ... 29#p213629 You will see from that that it is possible to output video using such a frame rate, though not in AVCHD format as such. Moreover, the jury is still out. Some of us, including myself, can see no artifacts or doubling up of frames using the recommended workflow(s) in that thread. But others have been unable to get it to work to their satisfaction.

[Wilson]

Ok thanks Ken. Still learning as I'm going here, so I'll need to do a little research on the points you mention.

Still curious why the 2 pass conversion corrected the problem though when creating the AVCHD DVD. If I can figure out a way to post some screen shots of what I'm seeing I will.

I had the Panny camera set at the Medium (default) recording quality. Panny uses some lame name as HG mode, which means nothing other than it's later in the alphabet than HA mode. I haven't yet tried the full 1080P/60 mode yet. In order to reap the full benefit of that I would need a Blu-Ray burner and/or have to play the videos directly from the camcorder to my TV via a HDMI cable. Might be o.k. to quickly review a file after recording it, but you can't store many 1080P/60 videos on the camcorder.

I primarily bought it for the slightly larger image sensor, the external mic input and the optical image stabilization features as well as being HD. The medium HG mode looks great on every AVCHD DVD I've created so far.

Here's some details on the file differences from Windows Explorer between a HG mode file (Default) and one step higher at HA Mode. As I said above haven't even tried the highest 1080P/60 mode yet.

HG mode 12632 kbps
HA mode 16377 kbps

Thanks for your help.

Dan

[Ken Berry]

Ah... So no problem yet with the full 60 fps mode...

As for the properties of your videos, it will gives us here on this forum a better idea if you used the Properties read-out from VS itself. Just right click on one of the files, either in the VS timeline or library windows. I suspect that those bitrate readings you gave were the average ones, rather than the maximum ones. I would suspect that the maximum bitrates would probably be 16000 or 18000 for HG and 18 or even 24 for the HA mode. As for why you might get pixellation withg HG mode, when you output the edited file, do you first go to Share > Create Video File > AVCHD? If so, which output do you select?

As for why you get good quality output using two pass encode, that is the nature of the beast. The first pass is used to calculate the optimum quality settings for that particularly video, and the second pass applies them. Commercial videos use many-pass encodes, which is one of the reasons that they are such good quality. But one pass encode just applies the quality analysis on the fly in one go.

[mitchell65]

Hi Dan

If I can figure out a way to post some screen shots of what I'm seeing I will.

As you have Windows 7 you can use the Snipping Tool to select your screenshot and save it to a PNG. Then in the message box of this Forum at the bottom click on "Full Editor". At the bottom of that window click "Choose File" and then "Add file" You will then be able to click the "In Line" box. That will put your file in the message box between attachment tags. If you want to move the image within your message just cut the entry and paste it elsewhere. Then use the Preview to see if it is where you want it.

[Wilson]

Ok, sorry it's been awhile since I've been able to get back to this. Here's some file properties by right clicking the files in VSPx4.

Raw AVCHD video file from camera
File Format: NTSC HDMV
File Size: 36084 KB
Duration: 23.524 seconds
Video type: H.264 Video, Upper Field First
Total frames: 705 frames
Attributes: 24bits, 1920 x 1080, 16:9
Frame rate: 29.970 frames /sec
Data rate: Variable bit rate (Max. 16800 kbps)


Finished project of several clips outputted to an mpg file;
File format: MPEG-2 (Transport stream)
File Size: 349,998 KB
Duration 108.842
Video type: MPEG-2 Video, Upper Field First
Total frames: 3,262 frames
Attributes: 24bits, 1440 x 1080, 16:9
Frame rate: 29.970 frames/sec
Data rate: 25000 kbps

Note playback within VSPx4 looks fine.

I was able to use the snipping tool and save a couple of .PNG examples to my harddrive, but I cannot locate the "Full Editor" option you mention? I've searched high and low, tried the "Upload attachement" tab, but nothing ever appeared. It's either right in front of my face and I'm just completely missing it, or it's well hidden via some other option I haven't found yet. All I did was click the "PostReply" button and was brought to this editor, I cannot find any other "Full Editor" option?

thanks

[Ken Berry]

For uploading your screen shots, see the image below. (I too am not sure what mitchell65 is referring to when he talks about a 'full editor'...! )

As for the file properties you posted above, I am slightly confused as to why you converted your already high quality, high definition AVCHD (mpeg-4) to high definition HDV (mpeg-2) format. If your intention is to burn a DVD, then you need to convert the AVCHD (or HDV) to standard definition mpeg-2 which has a frame size of 720 x 480 and a bitrate usually of 8000 kbps.

[Wilson]

What I did when creating the AVCHD DVD is just select AVCHD from the "Create Disc" menu option. That puts the .mt2s files onto the DVD for playing on my Blu-Ray player. I also was experminting with creating just a plain vanilla DVD disc so that I could give the disc to the folks I was recording it for who don't have a Blu-Ray player. That's when I noticed the problem. After that I also tried outputting the project to a .mpeg file first so that I could try a raw copy of the .mpeg to a DVD to see if that made a difference.

Ok, so let me try this picture attachment thing again. This is playing the DVD mpeg file from the DVD via Windows Media Player;