limits of PTE custom sync

[LumenLux]

I think I know the problem, but I thought I knew otherwise.

Many of us remember the joy when Igor brought us "Customize Synchronization" with time-line and now waveform. For me, it meant if I used this feature, I no longer had to worry that slides and soundtrack would end at separate times when a show was run on a different speed-capable machine. Now, my current effort seems to be proving my understanding (or memory) wrong.

I have a < 4min show. Slides are larger than usual, ie 200 - 800 kb. Sound is single mp3. I have PTE set to use Custom Synchronization. When I am in the Custom Sync screen, if I use the Play feature, the photos and sound are perfectly in sync, including some rather rapid cuts (no "effects".) But if on the same Custom Sync screen, I use the Preview function - then the slides can not keep up with the sound track! The Main screen Preview function yields the same problem. So, when my sound reaches a certain point, the photos are 4 slides behind. All this mind you with Custom Sync box checked. At the end of the show, the visual has apparently caught up. When I Create the show, the .exe file runs with the same problem as the Preview.

So, on the creator PC, the show is worthless because it loses sync. I have tried the exe file on two other PC's that seem to be able to handle it without the loss of sync.

My question:

Is this an issue that exists for slower PC's and even Custom Sync can't avoid it? Or, should I seek further to solve this in PTE? Have I misunderstood or forgotten the limits on Custom Sync?

[alrobin]

Robert,

This is something that I suspect will always be the case when you have a number of rapid cuts too close together for the system to process. Eventually the images seem to catch up with the music, but can drift behind while processing the rapid cuts.

[Igor]

Please tell me what usual time interval between slides on time-line?

What configuration of your PC and screen resolution.

On 1600 Mhz PC slide with JPEG image (1024x768, 350 KB) loads within 130 ms. (1/7 of second) And about 240 ms. on Celeron 900 Mhz.

So no problem with 500 ms. interval between two slides.

We have fast JPEG library. I know popular libraries that works in two times more slowely. But of course, there is more fast libraries. ACDSEE works in 1.5 times faster. But PTE loads JPEGs as Irfanview.

Duration of loading of JPEG image depends only on size of the file. Resolution of image (1024x768 or 800x600) doesn't matter.

So 200 KB 1024x768 Jpeg file will loads in 2 times faster than 400 KB 1024x768 Jpeg file.

But please don't increase compression in all cases! It is not necessary (and senselessly) if time interval 1 second or longer. Because even loading of large 350 KB JPEG takes only 1/7 of second!

If you want to place some slides very closely, in this case and only these JPEG files better to save with lesser size (150-200 KB).

[Guest guru]

So, if you want to know the loading time of a picture, open it with Irfanview and look in Image / Information the msec (last row).

You'll see that a 500 KB .bmp is much faster to open than a 500 KB .jpg (and this is logical), but also that a 7 MB bmp is loaded in 16 msec, and the same image saved "for Web" in Photoshop (quality High, 60%, 300 KB) opens in 397 msec, that is about 25 times slower ! (this time depends by picture's details and CPU power - I got these data using an AMD 2500+ Barton)

[Igor]

Interesting thing

Thank you Guido for this info! I just carefully compared as Jpeg loads in Irfanview and in PTE and found that Irfanview loads it on 20% faster.

But the most likely Irfanview contains very unpleasant mistake!

Jpeg format has two ways of loading: Fast and Quality. Quality method on 20% slower. And of course, we always used and use Quality method in PicturesToExe.

(If I set Fast method in PTE, it loads Jpeg exactly as Irfanview.)

But this Fast method of loading Jpeg which uses Irfanview, in some cases gives a little difference (you even don't see this difference). Some areas may contains defects. We've carefully explored this moment earlier.

Just look at these BMP screenshots, how PTE displays Jpeg image and Irfanview:

http://www.wnsoft.com/beta/CompareJpegQuality.zip (43 KB)

(It's displayed 5 Mpixel JPEG in 100% of view (without resizing) and cropped in Photoshop)

Irfanview.bmp contains small white vertical lines.

As I just checked PTE, ACDSEE, Photshop loads Jpeg in Quality method and has no difference. But unfortunatelly Irfanview uses Fast method with almost not visible defects.

It would be great if somebody could write to author of Irfanview about this problem.

With loading of BMP image there is one funny moment

Yes, it really loads very quickly, but for example we have 200 Kb Jpeg file and this image in BMP - 2,3 MB.

First time, when we read these files, loading takes absolutely equal time. It happens, because it necessary to read it from hard disc or even from slower CD-ROM! Only when you load same BMP again it loads quickly, because Windows already cached this file and it reads from a buffer in the fast memory of PC. I also was very wondered when found this "paradox". So it's not necessary to replace JPEGs and use BMP.

[Guest guru]

when we read these files, loading takes absolutely equal time. It happens, because it necessary to read it from hard disc or even from slower CD-ROM

"Absolutely" equal time? The .bmp must be read (longer time because the file is big) but is quickly processed, .jpg requires much less time to be read but must be decompressed (more CPU time).

[Igor]

I've experimented with 2,3 MB BMP and 350 KB Jpeg (both 1024x768).

And loading was equal on 1600 Mhz's PC. And on 3000 Mhz Jpeg will load even more faster. But reading from hard disc almost doesn't depend on speed of CPU.

[LumenLux]

Such good, credible, expert help! Thank you everyone.

As usual, your answers helped me to not waste time looking for a non-existent solution. And, I now have better understanding of factors that will likely come up again in one way or another. And of course, Igor, you are excellent on your understanding and programing for us. It seems the only thing you can't do is make my old machine perform like a new one. So thank you all.

Knowing the facts allowed me to solve the problem by just reducing file size. The original problem (on this 780 mhz PC was to make 65 slide cuts in 28 seconds. As soon as I reduced the file sizes from orginal 300-600 kb to 60 - 150 kb, even my old machine carried out PTE instructions. The specs you provided helped to see what an easy solution it could be. But still wanting max quality, I used the larger files when some of the photos were again used in same show with more time to appreciate the quality.

Now quoting Admin Igor (if you are still here)

And loading was equal on 1600 Mhz's PC. And on 3000 Mhz Jpeg will load even more faster. But reading from hard disc almost doesn't depend on speed of CPU.

That statement leads me to another "problem" some of us were discussing at http://www.picturestoexe.com/forums//index...&f=2&t=2650&st=

Please jump over there and see if you can give some more quick useful help after my latest experience that I don't know how to conclude.

[Leif]

Interesting thing

It would be great if somebody could write to author of Irfanview about this problem.

Answer from Irfan:

"Hmm, the fast decode method was used in older versions ;-)

Newer versions use also the quality method => same image.

=> I assume, the guy used an older version for testing.

For normal images, you can't usually see a significant difference, the

images are nearly idenctical. In some special cases, with gray levels, you

can see a difference ..."

[Jill]

Hi everyone

This is my first post to the Forum so I hope it works.

I have been playing around with the 10 slide version of PTE for a while now, but have only just got round to getting the full registered version. Should have got it sooner it is a fantastic program, many thanks to Igor for all his hard work.

I am having the same problem as LumenLux with slides not playing in sync on my PC. 'Play' works perfectly but 'Preview' and 'Exe' does not.

I have created my first proper sequence and it will not play correctly, it always misses out the same slide near the middle of the sequence. The previous slide fades in, then jerks & fades in again, then it misses 1 or 2 slides, then the next slide is in sync with the music.

My spec is PIII 450mhz with 128mb ram.

I create the jpegs 1024 x 768 by 'save for web' and compress to 50%, Image sizes range from 57k to max of 196k, most are 100k to 120k. The jerking/missing images occur a couple of slides after the long! (7.5 & 8 sec) dissolves, most other dissolves are 3 - 4 secs. Most screen times are 500ms, to try & keep the slides moving, although I did have 1 & 1.5 sec around the problem areas. Maybe I need to leave longer gaps after the long dissolves? to allow the system to catch up, but I thought this would cause the sequence to stand still too long on a faster machine.

Do long dissolves take more processing power than short ones?

I also have another problem with runing the show. I have an intro sequence which is created to 'close show after last slide' and 'run application after last slide'. This second sequence is one slide with a series of buttons that allow the viewer to select which sequence to run and then close the show when they choose. It is created with 'when show ends keep last slide on screen' . When the 'close' button is pressed I then want to run a final sequence which has credits etc. and close the show. I have set the properties of the 'close' button to be 'run application and exit'. However it seems to exit first then run the application. So that the show displays the desktop then runs the final credits, thus breaking the flow of the whole show.

Am I doing something wrong or is it meant to work that way. The end sequence is set to 'show first transition form desktop' but I have also tried without this set and it doesn't seem to make any difference.

Thanks in advance for any help you can give.

Jill (North Wales)

PS I may not get to read any replies until next weekend, I am on a VERY SLOW dial up service and it takes forever to page through the Forum. So I tend to only check it at weekends.

[alrobin]

Hi, Jill,

Welcome to the Forum!

Go into the timeline view and check to see whether the grey horizontal bar touches the next transition marker at the point where the transitions are not smooth or are repeating. Try shortening the long transitions at that point to see whether this solves the problem or not. The transitions need time to complete, with about a quarter to a half a second between the end of one and the start of another, particularly if your pc is an older model (e.g. P3).

Slow transitions do take more processing time - "cuts" are usually not as much of a problem, unless one is trying to jam too many into a short period of time.