Video opens with fake zoom Level (Aspect Ratio?)
 

Hi,
Having an old version of Bsplayer (1.41, i know it's old), as i tried with numerous Mpeg or WMV files, with some of them, when i open one of them, the video is opened smaller or bigger than it should be.

After opening some of videos, everytime i have to press "2" (Zoom Level %100) to fix video to its original size in Bsplayer. It's weird that some of Mpeg (using MediaConcept 1.0.78 decoder) and WMV (built-in WMV decoder of XP SP2) files open as original(as it should be, with %100 Zoom Level) with no problem but some them open in incorrect-fake "Zoom Level" and the only solution is to press "2" eveytime.

Quick hint, though one of my video's native size is 480x480, and after i open it, during playback i have to press "2" to see it in its original Zoom Level (size), then press ALT+3 to go to "Movie Info", then look at "Video Size" field, i see:

What does that mean? (See screenshot below):
The entire text in "Video Size" field: "480x480, Aspect: 4:3 (640x480)".

When i open the video below and press "2" (Zoom to %100), it gets slightly bigger:
http://img218.imageshack.us/img218/3059/problemid9.jpg


No-problem-having videos has only one size in that field (no Aspect:) as in the screenshot below:
http://img368.imageshack.us/img368/9...problemvi0.jpg

It's a complete disappointment that the fake video size had forced me to view the video in wrong zoom level.

Note: Unchecking "Keep Aspect Ratio" gave NO effect about problem.

What's the reason? I have other friends having same issue with Bsplayer!

Thanks!

The real problem it's into the pixel ratio. The file at 480x480 have a different pixel ratio than 1:1 (like 640x480 - normal resolution). SO, either the file lacks the information about the pixel ratio (the encoder doesn't write this information in file's header), either BSPlayer doesn't recognise that information. As I don't have any problems with such files I will take my chance and tell that the file it's inproper encoded.

Thanks for the info, so there's nothing to do for Bsplayer or decoders/filters?

As i have mailed that kind of files you about that problem, you confirmed that the initial video size is shown bigger than it should be.

I used MediaInfo to see if video is really 480x480 (as well as other videos affects that problem) and here is the report:

Video #0
Codec : MPEG-2 Video
Codec/Family : MPEG-V
Codec profile : Main@Main
Codec settings, Matrix : Standard
PlayTime : 3mn 34s
Bit rate mode : CBR
Bit rate : 2361 Kbps
Nominal bit rate : 2520 Kbps
Width : 480 pixels
Height : 480 pixels
Display Aspect ratio : 4/3
Frame rate : 29.970 fps
Standard : NTSC
Chroma : 4:2:0
Interlacement : Bottom Field First
Writing library : encoded by TMPGEnc (ver. 2.59.47.155)

And doesn't that mean that header is correct (480x480) but Bsplayer opens in different video size till i fix it by pressing "2"?

So, i couldn't understand why you didn't have such problem about that kind of files.

Thanks again.

Like I replyed by mail, for such a file, probably my setting was allready memorised by BSPlayer wich opened the file at a larger resolution, but with the correct aspect ratio !
Like you stated here, your problem it's in Aspect ratio and not in resolution. Your file it's 480x480 with a pixel aspect of 4:3 that should be 640x480 as real image resolution.

Well, my problem is about seeing initial(when opened by Bsplayer) dimension (size) different than the one when i press "2" on some videos. The video is opened nor 480x480 or 640x480, it opens in something like 480x360 or like that (found dimensions by gathering screenshot print-screen and selecting in mspaint)

So, just one answer, is it normal to see a 480x480 labeled movie as 640x480 when i press "2" (fixing Zoom Level to %100)? Isn't it a bug or miscalculation in Bsplayer?

Shouldn't Bsplayer open it in the same size like when i press "2" ?

Or forget everything, you can test what i've sent via mail(the video i've sent is different from the one in that topic, but having same issue) :) Just open file, then press "2", you'll see the change.

That were the things i want to know.

Note: In preferences of Bsplayer, i don't have any "Remember..." settings about Movie window size or kinda. So there wouldn't be any relationship about it.

Very thanks for caring that topic.

Monday ;)

Can you upload it somewhere and post an URL or make it available in another way so that other users can also test this possible bug?
:wink:

BSPeter,There are much. But i'm not able to upload all of them because they're big. However here is another one which describes the same issue as in my thread, download here:

As you can download the original, open video, then press "2" (or right click->Video->Zoom->%100), you will see that window size will be a litte bigger.(Also see Movie Info by pressing ALT+3 to see "Video Size" field, when you press "2", dimension is changed based on the size labeled "Aspect" in that field.)

Size will change to 768x576 for a 720x576 labeled movie.

http://www.anaivanovic.com/media/movies/Zira%20V1.wmv

That applies different on some videos as vice-versa, i mean, some videos gets smaller when i press "2" (which fixes Zoom Level to %100).

Some videos run without such problem.

Thanks...

Behaviour CONFIRMED.
Cannot test further now; also rather busy to-morrow (Sunday).
:wink:

Thanks Peter for the confirmation, however more strange, i have another file uploaded, after it opens with BSPlayer it behaves different in my desktop PC and notebook, in desktop when i press "2" video size gets smaller, on notebook it gets bigger as well as based on different video sizes shown on "Movie Info" labeled "Aspect:...".. But you'll see the change somehow.

And also for that-problem-having files, initial window size is not also their native resolution, i mean the video opens nor 352x240 or 320x240, it opens in something like 352x260 or kinda for the file below which is actually labeled 352x240 (looked via MediaInfo). (get a screenshot of entire sceen by print screen button, then select video area in MSPaint, then look at bottom-right of the screen to see what the video size is actually in pixels.)

I also uploaded that file, you can test further when you're free:

http://rapidshare.com/files/179625372/NESCAFE.mpg.html
(Rapidshare allows 10 times of downloads for the file :evil: )

Note: Again, I don't have "Remember Movie Window Size" checked under Preferences->Video tab, so there's nothing to do about that setting if someone thinks that as a solution, it stays uncheckd but that behaviour still exists.

Thanks...

From the first video ("Zira V1.wmv") BSPlayer retrieves these information: 720x576, Aspect: 11520:8640 (768x576)
The AR is 4:3, I don't know why BSPlayer multiply the width by 16, don't know why it thinks that 720x576 is 4:3 (or why wants to approximate it to the DAR instead of the SAR) and don't know why it can't divide those numbers by 288 (to get the 4:3 AR). Anyway the last dimensions (the ones in the parenthesis) are the height and the height multiplied by the DAR.

On my PC the video starts as 720x540px (4:3 Aspect Ratio)
When I press "SHIFT+1" (which is Original aspect ratio) the right size is applied (720x576)
If I press "2" (which is Zoom 100%) the size applied is 768x576

So the scenario is this one:
- When the video open ups, BSPlayer set its AR to the DAR and its size to the original width of the video per the DAR (WIDTHxWIDTH:DAR)
- When "SHIFT+1" is pressed, BSPlayer keeps the video width and then change the height accordingly to the original SAR (WIDTHxWIDTH:SAR)
- When "2" is pressed, BSPlayer sets the size to the one calculated with the DAR info (HEIGHT*DARxHEIGHT)

I think the same thing applies to the second video file.

Maybe the problem is in the coded files and not in BSPlayer, it depends on the information given by the video file.
If the PAR is stored into the video file, then BSPlayer correctly convert the SAR to the DAR by multiplying it by the PAR (so the PAR in the video files have to be changed in order for BSPlayer to correctly calculate the DAR).
Instead if the DAR is stored in the video file the DAR have to be changed in the video file since BSPlayer correctly uses that value to display the video on screen.

So, to me, it seems that the problem resides in the video files instead of in BSPlayer.
What BSPlayer devs can do to help you/us is to add an option (to be added to the Video section of BSPlayer preferences) do force the SAR (or Original aspect ratio) to be used when the movie starts.

Wikis:
SAR, PAR, DAR

Just had a few minutes to download and have a quick look at Nescafe.mpg
Behaviour also CONFIRMED for second (mpg) video.
BS.Player's media info reports for ..
..Zira V1.wmv : . 720x576, Aspect: 11520:8640 (768x576) (WMP only mentions 720 x 576)
..Nescafe.mpg: 352x240, Aspect: 704000:439440 (384x240)
[For the mpg GSpot reports Pic wxh: 352 x 240 SAR 1.467 (22:15) PAR 1.091 and DAR 1.600 (8:5)]
:wink:
(Have to run now again)

Thanks Tizio for your detailed information.
On my desktop computer i have same video size reported in Movie Info for Zira V1.wmv:
720x576, Aspect: 11520:8640 (768x576) and also granted everything you said about the first video(Zira V1.wmv), on my PC video also starts at: 720x540px (4:3 Aspect Ratio) and the rest is same as what you stated.


Peter, as you confirmed the second one, also in my desktop computer (using same BSplayer version and same video file, Nescafe.mpg), Movie Info is shown as:
352x240, Aspect: 4:3 (320x240)

On another computer that uses same video file (Nescafe.mpg) and Bsplayer, Movie Info is shown as same as yours:
352x240, Aspect: 704000:439440 (384x240)
(Also i wonder why there is difference on both computers, both have 1024x768 as desktop res.)

But the change becomes on either computers when i press "2" that fixes video size to given aspect ratio resolution in Movie Info.

However, to understand Tizio's excellent informations, as a summary, is the issue based on video file not with Bsplayer?...

Anyway, there are more files with different formats having same issue, and as i stated previously, some of them are fine (They only have one resolution reported in Movie Info, with no "Aspect" addition).

However, the things are a bit confusing, hope i didn't bother anyone and thanks for caring it.

Maybe add to this request?
Maybe this post is somewhat related?
:wink:

Beside that problem, however i wonder another thing whether it has a relationship or not. For the video named "Nescafe.mpg" (see its link below:);

In my desktop computer (Geforce 4 MX440 64MB, 14" monitor(don't laugh, it's really old i know and 1024x768 desktop res, using same BSplayer version and same video file, Nescafe.mpg), "Video Size" in Movie Info is shown as:
352x240, Aspect: 4:3 (320x240)

On my notebook computer that uses same video file (On-board 8MB Trident Cyberblade Aladdin Ai1, 13.3" LCD display, i know it's also too old, don't mind) and "Video Size" in Movie Info is shown as:
352x240, Aspect: 704000:439440 (384x240)
(both computers have 1024x768 as desktop res.)

What is the reason of that difference?

It is possible that also the video decoder or the splitter to have influence regarding the info extracted from the video file.

My only guess about it was same as yours. On notebook decoding is done via native decoder in XP SP2 (quartz.dll), but in desktop computer it's decoded by MainConcept Mpeg decoder (i like it). Maybe other MainConcept users (1.0.0.78 ) can confirm the resolution if it's the reason of difference.

That is the unique difference i've noticed.

PS: It's not a good thing for BSplayer by suffering from decoding filters about calculating right video size.

Just tried with the second video:
With default MPEG-I splitter (quartz.dll) I have 352x240, Aspect: 704000:439440 (384x240)
With MainConcept 352x240, Aspect: 4:3 (320x240)

With elecard demultiplexer, I have 352x240, Aspect: 704000:439440 (384x240)

I believe one of the decoders doesn't read pixel aspect ratio or ignore it.

So, the conclusion? :) I'm not keen on changing my decoder because of that little difference. Because it can also decode MPEG-2, whereas default MPEG-1(quartz.dll) decoder cannot.

However, for the first problem (wrong video dimension), is the answer based on video files (DAR,PAR,SAR issue) which Tizio described well? Or will BSPlayer have an option to run video in dimension that is actually labeled...

Personally I will prefer to have BSPlayer opening the files in real dimension (reading SAR and PAR) but I am not sure the problem is in the way it interprets this information or the filters generate this issue.

If the file is 480x480 (SAR) or even stranger than this, 480x576, that's obvious that the pixel aspect ratio it's not 1. But, this is ancient history, I don't believe someone uses those days such things. From a 480x480 you can have a 4:3 640x480 file. Usually, that's the real file, but you can also have a 720x576 file.