New Info re: AVCHD transition "blips"

dalemccl · Post by **dalemccl** » Fri Apr 24, 2009 3:43 pm

markg,

I know how frustrating this X2 "blip" problem is and can understand why you would want to seek a different product.

Unfortunately, as Ken indicated, it will be hard to find a program that handles AVCHD without some type of problem. I tried Pinnacle Studio and Cyberlink PowerDirector and was not happy with the output. I did not try Adobe Premiere Elements 7 after reading their user forum and finding that there are AVCHD problems with that product as well. I did not try Adobe Premiere because of the high cost. I have read that Sony Vegas, which is also expensive, does pretty well with video from Sony AVCHD camcorders, but not as well with Canon video.

Maybe you will have better luck in finding a product that works well with AVCHD. I hope you do. In the meantime, Corel has indicated that they want to work on this "blip" problem, and as mentioned earlier in this thread, they need clips from the various brands and models of AVCHD camcorders to test with.

Would you be willing to upload your clips to Corel?

markg · Post by **markg** » Sat Apr 25, 2009 2:08 am

Ken Berry wrote:Well, I am serious when I say I wish you luck! And believe me, this is not a put down. Please come back and let us know if you find an editing package which works with AVCHD apart from the software which comes with the camera.

At this stage, unfortunately, that does seem to be the case. As far as I can tell so far, the only other software which purports to support AVCHD smart rendering is PowerDirector 7. Unfortunately, it seems to only support a maximum bitrate of 18Mbps which means that it won't work for the 24Mbps files from the Canon.

If I had to purchase a commercial video editing program right now, it most likely still would be VideoStudio X2. Instead however, I think I'm just going to make do with the Pixela software that came with the camera to do simple edits until such time as a commercial editing package that does a decent job becomes available - whether that be an updated version of VideoStudio or some other program.

If there was a guarantee that there would be an update to VideoStudio X2 within a reasonable timeframe that would fix this problem, I would go out and buy a copy now and just make do with it until then. Unfortunately, of course, there aren't any guarantees of this. There aren't even any guarantees that it will be fixed in the next version - even if there was it goes against the grain to have to pay for an update to fix a bug in the product that you originally paid for. It's quite possible that a competing product that does the job properly will come out before VideoStudio is fixed, so I'd rather keep my options open until then.

Of course, none of the above is specifically directed at anyone on this board - I know you don't work for Corel. I'm just trying to get the message through to Corel that not fixing this problem is costing them sales...

So I am afraid, at the moment, it seems that it is not just a matter of waiting for the software companies to catch up but for the hardware manufacturers to get their act together too.

I really don't think that's a good option - even if Canon were to release an update to the firmware for their camcorders, it still wouldn't help me edit the footage that I've already taken.

Meanwhile, I am sticking pretty close to my HDV camera, which does not give me any grief at all compared to its AVCHD brethren!!!

I can understand you on that, but by contrast, I'm not going to go out and buy a HDV camera just after buying a new AVCHD camera either!

Even with knowing about this problem, I don't regret buying an AVCHD camera - I'm glad to be able to be rid of tapes and I know that software support will eventually come - even if it takes a while. There were of course problems with HDV when it first came out as well...

markg · Post by **markg** » Sat Apr 25, 2009 2:15 am

dalemccl wrote:Would you be willing to upload your clips to Corel?

Yes, I will.

I'm going to do some further testing to better confirm my theory first though.

markg · Post by **markg** » Sat Apr 25, 2009 6:58 am

OK, I'm now in the process of uploading my sample footage to the FTP server - it's going to take a while...

From playing with this some more, I can confirm that the Smart Rendering code is seeking to 2 frames earlier than it should be - not only is it causing visible glitches just before the end of a cut and just after the start of a cut, but the end of the cut is finishing 2 frames earlier than it should be and the start of the cut is also starting 2 frames earlier than it should be.

I also did some further experimentation:

Taking the raw footage in and then outputting it from VideoStudio in the original format without any cuts results in a file that is slightly larger, but otherwise no different from the original - editing that output file still results in glitches.

If on the other hand the original footage is edited so as to trim the start of the original footage and then output using the smart render process, the resulting file can then be taken in to VideoStudio and edited without the end result showing signs of this glitch - as long as the original glitches are cut off the start and (if necessary) end of the intermediate file.

From this, it can be concluded that creating a file with VideoStudio which at least involves smart rendering of the start of the output file results in a file which VideoStudio can later read and smart render correctly, so it must be changing the format of the file so that the smart rendering code can seek to the correct frame offset. This could be used as a temporary workaround, but it is rather cumbersome and therefore pretty impractical...

Post by **Ken Berry** » Sat Apr 25, 2009 7:59 am

As I have been suggesting for quite a few months, people should not use SmartRender with AVCHD. Yes, it takes absolutely ages to render without it. And yes, there may be some loss in quality as a result of the rendering -- but if you maintain the original settings, I think any normal human eyes would have great difficulty picking any drop in quality after just one recoding.

markg · Post by **markg** » Sat Apr 25, 2009 10:21 am

Ken Berry wrote:As I have been suggesting for quite a few months, people should not use SmartRender with AVCHD. Yes, it takes absolutely ages to render without it. And yes, there may be some loss in quality as a result of the rendering -- but if you maintain the original settings, I think any normal human eyes would have great difficulty picking any drop in quality after just one recoding.

That's certainly not a solution and it's not even a good work around - you yourself have said in this forum that AVCHD editing has problems even with smart rendering turned off.

I did do a test with smart rendering off and it did produce a file without glitches, but I'm just doing straight cuts. Reading through other threads, it looks like even without smart rendering there are still glitches with AVCHD when working with transitions and titles...

Even with the file that I created with smart render turned off, there was still the problem that the entire video was 2 frames off - i.e. the video started and finished 2 frames earlier in the source video than it should have. Not nearly as bad, but still not great - I don't think it's unreasonable to expect frame accurate editing...

Outputting to DVD compatible MPEG2 format also showed the 2 frame offset problem as well.

It's interesting that although VideoStudio has problems seeking to the correct frame when it's rendering, it doesn't seem to have the same problem with seeking when previewing clips.

I really do think this is a bug in VideoStudio - it may be being triggered by changes to the format of the AVCHD files being created by the new cameras, but it's still a bug in VideoStudio nonetheless - at least IMHO.

RickMen · Post by **RickMen** » Mon May 04, 2009 12:42 am

I have (tried to) read this thread with interest but its a long winding one, anyway, I just want to add my 2 bits.

I experienced the same issue with my MPEG2 TS PAL HD format (not AVCHD!) at FD standard (1920x1080) from my JVC HD-GZ40 . I too got the "blips" at the start of each new clip just after each transition. I didn't burn it to DVD instead just play the rendered movie on my media streamer which is connected to my HDTV, the 'blips' were quiet obivous. I then updated my X2 Pro version with the patch, re-rendered the project and still got the same issue (although I didn't reboot my machine at the time [does this make a differences?], anyway after that I went to bed. Next morning I switched on the smart proxy (due to the fact that the playback was also poor & jumpy [I have a quad 9400 2.66 Mhz 4Gb RAM], the smart proxy fixed the playback issue. I then rerun the created movie stage on the same project (no changes/edits from the previous attempt) and no more "blips"! in my rendered movie. I'm not sure what fixed it but the 'blips' aren't there anymore.

michal_h · Post by **michal_h** » Mon May 04, 2009 7:45 am

RickMen wrote:I have (tried to) read this thread with interest but its a long winding one, anyway, I just want to add my 2 bits.

I experienced the same issue with my MPEG2 TS PAL HD format (not AVCHD!) at FD standard (1920x1080) from my JVC HD-GZ40 . I too got the "blips" at the start of each new clip just after each transition. I didn't burn it to DVD instead just play the rendered movie on my media streamer which is connected to my HDTV, the 'blips' were quiet obivous. I then updated my X2 Pro version with the patch, re-rendered the project and still got the same issue (although I didn't reboot my machine at the time [does this make a differences?], anyway after that I went to bed. Next morning I switched on the smart proxy (due to the fact that the playback was also poor & jumpy [I have a quad 9400 2.66 Mhz 4Gb RAM], the smart proxy fixed the playback issue. I then rerun the created movie stage on the same project (no changes/edits from the previous attempt) and no more "blips"! in my rendered movie. I'm not sure what fixed it but the 'blips' aren't there anymore.

you are very lucky

michal_h · Post by **michal_h** » Mon May 04, 2009 8:30 am

I have just uploaded my clips to Corel's FTP but I do not believe it will help...

I hope that next version of VideoStudio will have no AVCHD bugs...

RickMenHome · Post by **RickMenHome** » Tue May 12, 2009 5:34 am

I just completed my 2nd movie in PAL HDMV and the 'blips' are back, I can't seem to reproduce how I got rid of them in my 1st movie. Strange!! & annoying. I again used smart proxy (but didn't update for the patch as I already have it). I re-run the rendering but still had the 'blips'

One question, what does "smart rendering" do? and should I use it?

Coral · Post by **Coral** » Tue May 12, 2009 6:27 am

RickMenHome wrote:One question, what does "smart rendering" do? and should I use it?

If the properties of your movie match exactly like the settings in the editor, the parts of the movie that match will not be re-rendered. You should leave smart rendering on.

If, for example, you change the bit rate, all of movie will be re-rendered. While if you add just a transition, only the transition part will be re-rendered. That will save time and avoid deterioration from re-rendering the whole movie.

RickMenHome · Post by **RickMenHome** » Tue May 12, 2009 6:38 am

settings in the editor

What do you mean by editor? Project properties?

Coral · Post by **Coral** » Tue May 12, 2009 6:58 am

All the settings that are in the Video Save Options (Media Studio Pro).

If for example, your movie has a constant bit rate of 6000 kbps and in the editor you use , say, 5000 kbps, smart rendering will not work and all the movie will be re-rendered.

If you work again on your movie and leave the same bit rate but include a transition effect. Only the transition part will be re-rendered.

I hope I'm clear.

RickMenHome · Post by **RickMenHome** » Tue May 12, 2009 7:12 am

ah, okay, I'm a VSX 2 Pro user (not Media Studio Pro) so, for VS X2 whats the equalivent?

Coral · Post by **Coral** » Tue May 12, 2009 7:29 am

In VS X2 smart rendering can be found in Share > Create Video File > Same as Project Settings or Same as First Video Clip > Options.

In VS X2 smart rendering is a default setting.

The result will be the same as I have explained further up.