degradation of HD quality ...

[joneisele]

I'm using VSX4 and a new Sony HD camcorder that records video in AVHCD format (Sony HDR-CX560). I have a short clip from the zoo where I pan one way and then back. I created a new VSX4 project and inserted just this clip onto the timeline, nothing else, no transitions, effects, etc.. I then created a video file using Share.Create Video File using Same as First Video Clip settings. I put both the original source file and created video file on a USB flash drive and walked it over to my PS3 and played them several times.

Both my wife and I can tell a difference. The produced file is not as smooth during the panning motion and doesn't look quite as defined. The difference is minor, but noticeable to a trained eye.

Does it make sense than creating a video file would result in quality loss? Perhaps my wife and I are dreaming. Is there a way to prevent the degradation?

Thanks,
Jon

[bstuartb]

You are right, see my post about the unwanted re-rendering problem. I don't think that Corel software folk understand the AVCHD format, either that or there is an industry problem and Corel might be decent enough to explain it to us. Your clips and my clips should not need to be re-rendered, according to all I have read about AVCHD (our camera's format)

Let's keep the pressure on Corel to wake up and fix it. they have been releasing software which does not do what it says on the packet.

[joneisele]

bstuartb - several questions:

1) Did you submit a defect report to support? Did they respond if so? One of the problems I have had since Corel bought the product is support responding with "reinstall" or "can't reproduce" and not really digging into matters.
2) Can you point me to some of the posts where you or others described this problem?
3) Even if they need to re-render, why is the output degraded so noticeably?
4) Are you still sticking with the product? I'm not sure what to do - I upgraded to HD for a reason and to use software that doesn't work right and loses quality is dissapointing to say the least. I have been using VS since 2000 back to version 4. Kind of sad really.

PS I studied the two clips I mentioned above furthre and found more obvious areas of degradation. Anyone else care to comment?

Thanks,
Jon

[Black Lab]

There are plenty of users on this forum who experience success with AVCHD. I'm sure some of them will comment on this thread.

[bstuartb]

To notice the poor (re-)rendering, you need a full HD 1080x1920 display or TV. And you need material that demonstrates it beyond doubt. I find that the reflections on a shiny car body, or soft close ups of a person's face are among the biggest giveaways. The original clips from my Panasonic SD700 look perfect, no artifacts, even as the camera is slowly panning. VS re-rendering turns them into images with nasty unstable blotches. Conversely, high contrast sharp edged stuff come out pretty well.

You'll see from my post that my real problem is when this nasty re-rendering has been successfully avoided, and the AVCHD Disk plays well to begin with but always falls over in the Bluray players.

[joneisele]

Let me add a bit more information following from bstuartb's prior comment. I have a relatively high end Samsung series 8000 3D LED-LCD TV, 55" that is full 1080P, a high end Yamaha AV receiver, and a PS3 for playback. The point being you need a big screen to be able to see the issues.

And to the point about the right clip, agreed, you have to choose a good test clip - note in my original post I mentioned one needs a "trained" eye. Where I noticed problems was during the panning - some trees, etc. in the background as the camera is moving experience some degradation, kind of like jutter. And then after the pan if you look at one of the faces in the middle of the video you can see noticeably poorer video quality. Beyond, I could just tell a difference. The original clip has a "soap opera" / smooth look and the AVCHD rendered version isn't as smooth, although my wife had more trouble identifying.

I will post a defect report to Corel and explain this isn't one for the first line support folks; and that I would happy to share the clip.

Stuartb: did you file a defect report? Any response?

Jeff: agreed, would be nice to hear from others.

[Ken Berry]

This comment only addresses the juddering during pans, and not the question of pixelation/blockiness. Pans in either AVCHD or HDV are almost always subject to some shimmering, which some people called juddering. It is the nature of the beast. If you look at professional movies shot in HD, there are not all that many panning shots (horizontal ones) and for those that exist, they are done very slowly and with not too much range. I realise you are reporting more problems than this one, but equally, I would not place too much reliance on panning judder as being indicative of a problem with VS...

[bstuartb]

Ken

You are right about panning but there is a serious problem. Of course panning leads to defects in any compression technology, but this problem is plain to see even without panning. I had talked about panning to emphasise just how good the clips were to start with. After VS Pro gets its hands on them, they are AWFUL. Is there a way for us to upload some examples to you, so that you can help us?? And speaking for myself I do NOT ask Corel to improve their rendering, just enable me to author an non-re-rendered AVCHD Disk that actually works. The cameras are producing wonderful AVCHD, I just want to add music.

Please, please help ! I have been through the Corel help process before and it takes a great deal of effort . I upgraded to VSPro4X because the help folk said that *AVCHD had been fixed".

Bill S-B (40 years of video and computer hardware & software engineering, still have good eyesight)

[joneisele]

Ken and Stuart,

Just to be clear, judder during the pan is not present or noticeable in the native AVCHD clip that came off the camera. It is the resultant encoded file that loses quality, not the source. Stu's workaround of not rendering the clip would obviously be one fix. Again, all I did was insert just that clip on the timeline, nothing else, and let VSX4 produce a new video file. I tried both same settings as the first clip and AVCHD (both came out identical).

At the end of the pan I stopped moving the camera and caught my kids and their cousins eating lunch. You can see an obvious degradation in the faces, particularly with one of the kids. This particular degradation was the most noticeable, more than the panning judder. And as I said, there is general loss of smoothness / soap opera quality that I could detect.

Me too - would be open to sharing sample files. Again, must be played on big TV and observed with a trained eye.

I will file a defect report and give Corel a chance to address, despite the last few years never getting results from support on other issues. Also, I have an aquaintence who is a professional videographer who uses Final Cut Pro. I may have him take a look and produce a movie to compare there as well.

[joneisele]

Hey folks - some good news here. I spoke with technical support today. The individual quickly discovered that I had turned off SmartRender. I had done so because I was having problems with another project, will spare you the details there. If SR is turned off it forces a render even of a native file. My mistake here - didn't realize that was how it works.

Once SR was turned on, the resultant project clip looked fine. I also tried several clips with audio tracks and so on and VSX4 and the video was good. I added transitions and also did not see a problem. However, adding a title did cause degradation whereever the title appeared.

Am I correct that SR only renders a *portion* of a clip vs. the whole clip? It would appear so based on my experimenting with titles (of various durations) and transitions, but I want to validate with others' understanding.

This reduces the scope of the problem, although I'm still not thrilled with the loss of quality. The tech support person said that would happen - analogy to making a copy of a CD or tape. I'm curious to know if other products have similar issues or if VSX4 has a poor encoder. I have a friend with Adobe Premier Pro and another with Final Cut. These clips are too big to email, so I have to figure out how to setup FTP or mail them a CD.

I don't use a lot of filters in my videos, but if one does, presumably this would cause some issues. I do use titles placed in video clips frequently, so the above is unfortunate.

Stuart: what was it that you did with your clips / projects that was a problem? Did you have SR turned on? Were you seeing a problem even in a simple experiment like this one?

[Natal]

Yup, smartrender will (should) render only those bits you have modified, such as titles, effects etc. The rest of the footage should stay as it is.

[erdna]

Joneisele, did you record in progressive (p) mode with your CX550?

[bstuartb]

Jon - I have been able to successfully prevent re-rendering, using VSPro4x, by customising the disk-maker options to the same bit rate (16800) as my camera. Curiously it apparently does use 'smart renderimg' without this hassle if you just try to output an AVCHD File, rather than an authored Disk. Of course you will have ticked the 'do not re-render compliant video' boxes.

(Note that MF7 prompts you to set the project properties to those of your clip(s), and then does it for you automatically)

The BIG PROBLEM is that the Authored disks do not play properly in any of my 3 different brand Bluray Players. They ALMOST play properly, as long as you do not TOUCH fast forward, or chapter skip etc. But even then they will fall over, freeze, and hang up the players at certain points. Editing out the suspect clips just shifts the problems around and wastes days of my time.

Conversely, VSPro4X, when allowed to re-render, does make fully playable disks. But then you suffer the horrible image degradation.

I wonder if ANYONE in the Corel development team bothers to read how unhappy we are. I suspect they are encouraged by their sales people only to add gee-whiz gizzmos, and none them (including the sales folk) actually use the software for serious HD. When I find a package that works properly for simple disk authoring I will be shouting from the roof tops. Maybe I'll have to go to mpeg school and write my own software.

Jon - have you (or anyone) yet tried to play a smart rendered authored AVCHD Disk (DVD) on a Bluray player? Did fast forward etc work? Did you manage to play all the way through, 20 minutes or more?

Regards, Bill S-B

[joneisele]

Erda: no ... just noticed I hadn't set the camera to 60p. Why did you ask? Is there some downside to using 60p over 60i? I'm not worried about storage. Will 60p AVCHD files go directly onto a BR disc or will they need to be re-rendered (and thus likely end up worse looking that the 60i)? Hopefully these questions make sense, still trying to understand this stuff.

Bill S-B: on a separate note, I'm trying to find a way to burn a better looking regular DVD from AVCHD video. I won't need to so in the future, but my daughter put together a presentation and it looks terrible on DVD created with VSX4. I realize DVD requires a lot more compression, but VSX4's encoder does a poor job. Notice a trend here? Separate topic and I'm still researching.

On the AVCHD note, I have not tried to do so. In fact, until I read your post, I didn't even realize you could put HD on a DVD. I will report back soon.

[joneisele]

Bill: I created an AVCHD disc and didn't have any issues with playing back, pause, forward, rewind. I didn't monkey with it extensively, just a quick test. The movie is only 7.5 minutes long in case that matters. I just went through the standard wizard and used the first menu that came up.

Unfortunately, VSX4 apparently rendered the clips even though they were already in AVCHD / H.264 format off my Sony camcorder. The quality, while better than a DVD, was not good. Lots of pixelation, etc.

I do not have a Blu Ray disc burner, but wagering we would experience the same problem. Have you tried a BD? How did you get an AVCHD without rendering?

I have a friend with Final Cut who I am going to have try a couple of things for me. One is to make a DVD from the above 7.5 minute movie, which is what got me started on all this stuff with the encoding. I will also have him render a couple of my test clips in AVCHD / H.264 and provide them back to me. Then I can compare Final Cut to VideoStudio.

Has anyone out there compared VSX4's encoding output to Premier Pro or Final Cut?