Tools for MPEG judgement.

[kees1952]

Anybody knows whether a software tool exists (or is under construction) that will give me an objective judgement about the quality of an MPEG1, 2 or 4 encoded videostream ?
It must include information about bitrates, compression level, blocking, sharpness, encoding artifacts and so on.

Why this question: at the moment I'm engaged in specifying a "video on demand" system over an ADSL network. We need to know the necessary bandwith we have to use to end up with an acceptable quality for the end user. This without having to fall back on viewers panels for judgement of the material every time.

Thanks in advance, regards,
Kees Janssen.

[mats.hogberg]

Sounds completely impossible to me. Only way I can think of, is to have an application that you feed the source material and the finished encoded material, and performs a frame by frame, pixel by pixel comparision between the two. Only way to judge picture quality at all, is to have the original as comparision.

/Mats

[dcsos]

Run GSpot.exe it shows some info about a MPEG-4 but will tell all about the other MPEG types
[/url]http://www.headbands.com/gspot/

Run Bitrate Viewer for MPEG-2..great
http://www.afterdawn.com/software/video_software/dvd_tools/bitrate_viewer.cfmhttp://<br /> <br /> or use POWER DVD XP(4.0)...drag the file to the player..right c... support<br />http://www.google.com/search?hl=en&lr=&ie=UTF-8&oe=UTF-8&q=%22Measure+Bitrate+of+MPEG+4%22&btnG=Google+Se arch

also GET RID of WMP 9 until your client forces you to use it
If you instead use PLAYER 6.4 afterloading the MPEG in, GO FILE>PROPERTIES>ADVANCED and on the item label MPEG PLAYER or SPLITTER or DECODER (depends on what vendors third party software WMP is using to show you the file as window will not playback any files excet MPEG-1 or MICROSOFT MPEG-4 directly...)

anyway go here and on the right enry line in the ADVANCED mode window media player 6.4 show the BITRATE clearly

slowly, over time, WINDOWS OS'es have removed all the mature features of the MEDIA PLAYER with buggy garbage (like bass and treble controls)..SO you can no longer use the advanced features of MPLAYER 1
and MPLAYER 2 that viewed codec type, allow aspect stretch and even frame advance (gone) You used to be able to play selected "virtual clips" as well as have keyboard shortcuts to functions of the player (gone also)

also for money not freeware or share ware like above:
http://www.mpeg-analyzer.com/
www.interrainc.com
take a look at Snell and Wilcox's Mosalina http://www.snellwilcox.com/products/mosalina/

[DJRumpy]

Windows Media Player will play any file type via the Direct Show implementation, including MPEG-2, MPEG-1, MPEG-4 (WMV, Divx/XviD), MP3/MP2, etc. It is limited only by the codecs you have installed on your system. If you don't have an MPEG-2 codec, then it won't play them. If you do, it plays them without issuse.

The old versions of WMP will ignore any aspect ratio's in your MPEG's. The new version does use the aspect ratio (it only took them 9 versions to fix...). This is true under Win2K, and WinXP. Unknown if they fixed this in Win9x versions of Media Player.

On a side note, the old version of Windows Media Player is installed by default on all Windows installations under XP, and Win2K (no idea, but I assume the same is true for 9x). You'll find it in your
C:\Program Files\Windows Media Player\ folder.

MPLAYER2.EXE

You can also launch it from the START | RUN command. Just type in mplayer2.exe.

If you want to register this player as your default, hold the shift key while right clicking an MPEG file. Select OPEN WITH | Choose Program. When prompted with an application list, find Windows Media Player (look for the old 'action' icon, and not the new round media player logo). Ensure the 'Always Use This Program to Open These Files' is selected.

My player shows codec info, it also allows me to stretch the window (scale/aspect). I don't recall any version of media player that allowed frame advance though. What OS and version are you using?

[dcsos]

If you're really interested in AUTOMATING the analysis of streams
the SNELL and WILCOX product above is super capable altho very expensive (It looks like a paid gig but you don't say

To DJ RUMPY:
I was just trying to point out that the stock WINDOWS os from the box will only PLAY MPEG-1 and Mirofoft's MPEG-4.. Windows as a company refuses to pay the MPEG COMMITTEEs like apple and others in the industry and relies on the user purchase of third party software to PLAY in this MEDIA PLAYER, thank you for the direct show explanation


Using WINDOWS XP or 2000, do the following
GO TO RUN>BROWSE>WINDOWS(orWINNTinthe2000 case)>SYSTEM32
and launch MEDIA PLAYER.EXE

This is the original WINDOWS MEDIA PLAYER THAT CAN FRAME ADVANCE (just change the scale from time to frames and use the triangle on the TIME LINE to advance a frame at a time (or the arrow key)This player has many keyboard shortcuts (not documented largely) and also takes all the CODECS you load..

This player allows you to unlock aspect as well as seperate the PLAYER WINDOW from the MEDIA WINDOW (LIKE ALL THE CURRENT DVD SOFT PLAYERS POWER AND WIN DVD) To seperate the player, double click the title bar

HAVE FUN!

The old versions of WMP will ignore any aspect ratio's in your MPEG's. The new version does use the aspect ratio (it only took them 9 versions to fix...)

Thanks but I was trying to say If you need to change the aspect ratio temporarily for playback..YOU CAN'T DO IT IN THE PLAYER ANYMORE
and I think MEDIA PLAYER 9 SUCKS because when I load a 720x480 MPEG 1 into the PLAYER I have to re-adjust everything before it opens at the NATIVE SIZE..The PLayer prefers to show all of MIRCOSOFTS ANNOYING ADVERTISING and show my clip at 320x240 even when my ZOOM settings say 100%

[DJRumpy]

Thanks but I was trying to say If you need to change the aspect ratio temporarily for playback..YOU CAN'T DO IT IN THE PLAYER ANYMORE
and I think MEDIA PLAYER 9 SUCKS because when I load a 720x480 MPEG 1 into the PLAYER I have to re-adjust everything before it opens at the NATIVE SIZE..The PLayer prefers to show all of MIRCOSOFTS ANNOYING ADVERTISING and show my clip at 320x240 even when my ZOOM settings say 100%

In my Win2K/WinXP install, MPlayer does allow you to resize (change the aspect ratio on the fly, vertically, horizontally, or both, scaling as needed). It's version 9.0. On your zoom/size problem, turn of the auto-start options, like 'Now Playing'. You an also hide the strip of pointless buttons on the left (look for a tiny arrow right on the left middle edge of the actual video image area). This, plus hiding the playlist garbage, will give you essentialy the same image area as the old version 6 players.

I'm in total agreement regarding the MPEG-2 codecs. Microsoft has gotten extremely cheap regarding add-on's like this. I'm suprised they aren't offering it as an addon purchase, like they do for other useful OS software (plus pak's, Pro versions of the OS, etc).

[dcsos]

Thanks for the HEADS UP about those features YOU FOUND that I never learned about because of bad experience with 8 and 7...
I'm gonna turn off the auto-start options and RE-EXPERIENCE the player the way you've forced it to behave itself..Thank You
after all..It does a have those excellent new brightness etc. screen parameters control no other player but PowerDVDXP has.

And we'll have to watch TERMINATOR 2 in WMP next week!
cause its coming out in HI-DEF to the consumer (a 1st) on DVD as a file for your computer (not set-top) to play..(I hear its some kind of ASF or WMV MPEG-4file- but 2000x1080pixels or such)

[disturbed1]

For mpeg-1 & 2 I use Pixel Tools mpeg repair.

It displays forward and backward motion vectors, complete gop info, slice info. Intra, forward, backward, interpolated, skipped, not coded, and quantization for I, P, and B frames. Has about 300 other functions but you get the idea.

A free demo is available to qualified persons.
http://www.pixeltools.com/MpegRepair.html

What bitrate ADSL are you using? Cable companies broadcast their VOD at 3.75 mbs 528x480 or at 352x480. Complete encoding specs Here

[kees1952]

THx guys for your replies. And yes, I forgot to mention, it does not need to be free software. I have to make a decision to buy something on the market or to have it developed by our software guys. The last option is very expensive as you know, so I prefer buying something already on the market (which obviously has more advantages then price only).

I'm interested in automatic "measuring" of the quality of MPEG video streams, not "looking" at them by whatever media player.
I will certainly contact the Snell&Wilcox company for their product seems very promising.

Thx again, regards, Kees Janssen.[/quote]

[BJ_M]

m-probe is the defacto standard for mpeg stream checking .. http://www.ktechtelecom.com/MProbe200.htm .. it is also VERY expensive ...
it will tell you more about your mpeg file than you could understand in 10 years http://www.ktechtelecom.com/Mprobe2000.pdf




the mosalina product is not bad but I felt it didnt really give me that much info (they sent me a full featured demo version) for the money ..

Bit rate viewer - will give you almost exactly the same info (Qvalues) and bit rate though mosalina lays it out better for reports and printing .

[BJ_M]

i should say though -- for "automatic "measuring" of the quality of MPEG video streams"

mosalina is really set up for this very well

there are also hardware stream checkers -- but they are for transport stream (uplink/downlink check)

[DJRumpy]

Just a follow up in case your not familiar with the options you need...

To enable the variable resize, you must turn on both of these options:
View | Video Size | {enable both options there}

To get better video output (more CPU intensive), select
TOOLS | OPTIONS | {Performance Tab}
Ensure video acceleration is set to FULL. Click the Advanced Button. Set the Digital Video slider to 'Small'. This wil make the CPU work harder when it has to scale your video. The output will look better at the cost of CPU cycles.
You can also try turning off some of the legacy and overlay support. Ensure that they actually help your output though, by checking each one, and playing a clip at full screen. Look specifically for resize artifacts after disabling each option. If you see no difference, then leave it enabled.
On the Player tab, uncheck the 'Start Player in Media Guide'. You can also turn off the auto-codec download here.
I would also uncheck the 'Display anchor window when in skin mode'.
On the Media Library tab, uncheck the 'Update My Music Files by retrieving missing information' option. It never seems to work, and I personally don't like media player accessing the internet on every mp3 I play. You should also check out the Privacy, and Security tabs.

[SaSi]

m-probe is the defacto standard for mpeg stream checking .. http://www.ktechtelecom.com/MProbe200.htm .. it is also VERY expensive ...
it will tell you more about your mpeg file than you could understand in 10 years http://www.ktechtelecom.com/Mprobe2000.pdf

Funny thing is that I have found another MProbe program, doing MPEG video and audio analysis, from another company. See http://www.acterna.ru/library/appnotes/mpeg/mpeg_dolby_elementary_stream_analysis.shtml

However, both the MPEG committees as well as the Broadcasting Union forums do testing by means of encoding reference video streams and have a specific mixture of experts and "lame" viewers view the resulting video using their "mere" eyes.

Programs like MPROBE and insruments like MPEG analysers are very useful in verifying the integrity and correctness of the MPEG streams. However, I think that a program that can decode the video stream into a sequence of uncompressed frames and compare each one with the equivalent frames of an uncompressed reference stream can perform any "comparison rule" between each frame and "calculate" a difference factor. Obviously, the catch here is how to perform the calculation. Mere pixel value subtraction would be pointless. For example if the encoded video is off by a value of 2 for each colour element for each pixel, this would result in a huge difference for each frame. But would be invisible to the eye. Whereas an encoded stream with random green macroblocs would deliver a much less difference, but these would be totaly visible.

[SaSi]

And by the way, the MProbe program advertised in the Acterna site, has a pdf description with reference to the (obviously previous) company named Wavetek Wandel Goltermann.

[BJ_M]

those are the same program (mprobe) , just diff. dealers ...