[UPDATE] AR signaling in AVIs: Is there a method compatible with standalones?

[kurkosdr]

Hi there.

I have a couple of Divx certified DVD players lying around, all purchased circa 2008.

In 2008, Divx Corp released a version of their Dr Divx that supports AR signaling in avi files. So, I guess that the method used by Dr Divx for encoding AR signaling in avi's is now part of the official "Divx standard", and thus supported by the certified devices. Or, at the very least, the method used by Dr Divx is your best hope at getting a certified standalone to play avi files with AR signaling correctly.


So, the question is: What method does Dr Divx uses to encode AR signaling? Is it the same that Avidemux uses? Is it the same Handbrake uses?

If Handbrake and Avidemux encode AR signaling in the same way Dr Divx does, then I can make anamorphic videos with avidemux without worrying about appearing squeezed in my standalone.

Any help welcome.

[kurkosdr]

First test results: Not Good. The method avidemux uses to encode AR singaling in AVIs doesn't work on certified standalones.

I just returned home, loaded a 720x576 VOB file in avidemux, then selected "MPEG-4 ASP (Xvid)" in Video, clicked "Configure", selected "predefined aspect ratio" and set it to PAL 16:9. Avidemux produced an AVI file that had a resolution of 720x576 and an aspect ratio of 16:9. VLC plays it perfectly as a 16:9 file, while media info also sees a 16:9 aspect ratio.

But, when I loaded it to a Divx certified standalone (toshiba), it plays it either as 4:3 or as square pixeled (couldn't tell), which means that it doesn't see the AR signaling properly.

So unless Dr Divx uses some different method to encode AR singaling in AVIs, one that can potentially be compatible with Divx standalones, then I guess that we are back to the usual 720x400.

PS: There is another tool called MPEG4 modifier. Which method does this use? Does it use the avidemux method or the dr divx method? What about handbrake?

[SeeMoreDigital]

Just-so-as-you-know...

All "MPEG-4" hardware players, that are capable of supporting "aspect ratio signalling detection" will look for the signalling data within the "video stream" - not the container...

MPEG4 Modifier places the aspect ratio signalling data within the video stream.

Sufficed to say, NOT ALL hardware players support "aspect ratio signalling" detection!


Cheers

[kurkosdr]

All "MPEG-4" hardware players, that are capable of supporting "aspect ratio signalling detection" will look for the signalling data within the "video stream" - not the container...

MPEG4 Modifier places the aspect ratio signalling data within the video stream.

Thanks for the answer!

I guess we need a list that will show which encoders place AR signalling in the video stream, and which in the container. I think it will help many users.

MPEG 4 modifier = stream
Avidemux =
Handbrake =
Dr Divx =

If you know any of the above, please post.

[SeeMoreDigital]

As far as I'm aware, there are no .AVI muxing applications capable of placing "aspect ratio signalling" at the container level...

[Midzuki]

The Open-DML AVI standard includes a VIDEOPROPERTYHEADER for video streams, which allows to indicate the output resolution in the sense of Matroska's DisplayWidth and DisplayHeight elements.

The problem is that DirectShow does not read those values (at least the DirectShow documentation does not mention support for this feature). MPEG4 has an aspect ratio flag stored in the bitstream as well, and ffdshow as well as a few other decoders use this aspect ratio, raising the wrong impression that anamorphically-encoded video would properly work in AVI. But truth is, AVI is as unsuitable for anamorphically-encoded video as OGM.

( http://www.alexander-noe.com/video/amg/en_myths.html )

[SeeMoreDigital]

Alex Noe's information is pretty old now and dates back to a time when no MPEG-4.2 direct-show decoders supported aspect ratio signalling detection, regardless of whether the MPEG-4.2 stream was placed within the .AVI or .MKV containers, or even ISO 14496-14 approved .MP4 container. I know this, because I was one the more vocal Doom9 forum members pushing for aspect ratio signalling detection support for both software and hardware players.

From what I remember, the 3vix guys were the first to release a MPEG-4.2 direct-show based decoder, quickly followed by Xvid, then Nero. And finally DivX a few years later.

Indeed, today, it's more difficult to find an MPEG-4.2 direct-show decoder that does not support aspect ratio signalling detection.

When it comes to hardware players, both MediaTek and SigmaDesigns released hardware decoding chip-sets at pretty much the same time, capable of supporting aspect ratio signalling detection.

Unfortunately, if you have an hardware player fitted with an ESS Vibratto I or II chip-set, you'll be out of luck. See here: http://forum.doom9.org/showthread.php?p=645982#post645982


Cheers

[Midzuki]

SMD,

:thanks: a lot for NEVER getting the point of anything I write or quote. :rolleyes:

As far as I'm aware, there are no .AVI muxing applications capable of placing "aspect ratio signalling" at the container level...

[SeeMoreDigital]

SMD,

:thanks: a lot for NEVER getting the point of anything I write or quote. :rolleyes:Oh... I get what you say Midzuki.

But may I suggest you refer to more current, rather than outdated information (as a reference) !?

Have a nice day :rolleyes:

[kurkosdr]

Anyway, I guess it all comes
down to the official "Divx standard" (yes, there is an official divx standard, according to which the certification stickers are given)

If the standard includes some method for putting AR info in avi files (be it ANY method), then we are just going to use that, as it will be supported by all certified players.
If the standard includes no method for putting AR info in avi files, then we are back to the usual square pixels, as in that case AR signaling detection is a "bonus feature" supported only by some players (much like srt subtitles or GMC) and not part of the standard.

I posted a question in the divx forums some days ago about that very subject (if ar signaling is included in the standard), but I didn't get any answer (the place is very quiet after the sonic purchase).

P.S.: This (http://labs.divx.com/node/14526 ) and this (http://labs.divx.com/node/15906 ) are the only "specifications" divx corp has published about the standard. Maybe some knowledgable doom9 member can read them and tell us if there is anything there related to AR signaling.

P.S.: Maybe we can squeeze the AR specification out of Dr.Divx's source code, but that would take a very knowledgeable member...

[SeeMoreDigital]

Anyway, I guess it all comes
down to the official "Divx standard" (yes, there is an official divx standard, according to which the certification stickers are given)Not really...

Although DivX's first certification program did not accommodate aspect ratio signalling detection (in any form) for it's certified players this did not prevent A/V chip-set and hardware player manufacturers adding functionality that exceeded DivX's "limited" certification program.

Indeed, if A/V chip-set and hardware player manufacturers had stuck rigidly to DivX's "limited" certification program we would not have had hardware players capable of playing MPEG-4 streams encoded with more than one B-frame or DTS audio. Along with other basic stuff we've come to expect from our hardware players!

By-the-way. What are the makes and model numbers of your hardware players?

[kurkosdr]

By-the-way. What are the makes and model numbers of your hardware players?
Too many to remember, and on different houses too (but all of them purchased after 2008).

That's why I always stick to the lowest common denominator (aka the official standard) and avoid features that exceed the standard like DTS, GMC etc which may be ok on one player but not on the other.

That's why, unless there is some revision of the official standard that allows some form of ar signaling, then it's square pixels for me.

That's why it's important to get the specs (not just for me, but for everyone who has multiple players and wants guaranteed compatibility) and any possible revisions of the specs. The links on my previous post is the most recent i could find.

[SeeMoreDigital]

That's why I always stick to the lowest common denominator (aka the official standard) and avoid features that exceed the standard like DTS, GMC etc which may be ok on one player but not on the other.
Just to be clear, the "official standard" was developed by the Moving Picture Experts Group (MPEG) and is formally known as the "MPEG-4 ISO/IEC 14496 standard" (for more information see here: http://forum.doom9.org/showthread.php?t=73022). This "official standard" has nothing to do with DivX certification.

[kurkosdr]

This "official standard" has nothing to do with DivX certification.
Well in that case, we need the standard according to which the divx certifications are given. They can't just give those stickers away, there's got to be a bullet list of features a player has to meet. We need to get our hands on that list (and any possible revisions). If there is something in that list mentioning aspect ratio detection, then we will use that method. Else, it's back to square pixels.

I am posting this from a cellphone right now, but when i get back home i ll try to look at the divx specs and the dr divx code and see if there is something there.

[jmac698]

I always use anamorphic encodes. In Autogk for example, force 4:3 aspect. When done, load in mpeg4modifier and click 16:9.
This changes the video stream.
It plays properly in VLC, and WDTV. An LG bluray player didn't work.
Doesn't matter though; just assume that the files will work someday when you get a new player.
Also, you can work around it today: Set your preferences to widescreen TV on your player, to unsqueeze 4:3 playback to 16:9. You can also use zoom on your TV. Mine has Zoom 1 which zooms a letterbox to fullscreen.
There is some combination that always works; however in worst case it looks right but zoomed a bit too much.
1.78:1 videos can always be worked around perfectly.

[kurkosdr]

I Also, you can work around it today: Set your preferences to widescreen TV on your player, to unsqueeze 4:3 playback to 16:9.
I thought of that, but the dvd player I use most (a toshiba 19DV615DG) pillarboxes 4:3 pictures and outputs them as 16:9 pictures, so the TV can't do the 4:3 to 16:9 stretch trick, because the image is already a 16:9 picture. There is no setting that will set the player to stretch 4:3 pictures and not pillarbox them, or output the picture as is. And guess what, it doesn't support ar signaling detection for clips made with avidemux either (that bad luck of mine...) Also, no zoom features in my tv. I could set the "tv type" in the dvd player to 4:3 but that would put horizontal bars to 16:9 movies.

Anyway, i ll just try with MPEG4 modifier and DrDivx and post results. If it works, fine, else i am calling it a defeat and i ll just use square pixels and go to bed.

[kurkosdr]

Hi again,

I 've played around with some programs that can produce .avi (.divx) files. The results:

Avidemux (using xvid): Produces anamorphic avi file. VLC can read the anamorphic flag and play the movie correctly, WMP and standalones can't read the anamorhic flag and thus play it squezeed.

MPEG 4 modifier: Seems to change the same anamorphic flag xvid uses. So, VLC can read the anamorphic flag and play the movie correctly, WMP and standalones can't read the anamorhic flag and thus play it squezeed.

Divx Plus Converter (using home theater profile): Doesn't do anamorphic and doesn't claim to.

Dr. Divx latest beta + Divx 6.8.4 (http://www.oldversion.com/DivX.html): Claims it can produce anamorphic avi (.divx) files, but I couldn't manage to make it produce an anamorphic file. I manually enter "Custom" in resolution settings, set it to 720x576, and then change it to "16:9 aspect ratio". Resolution setting stays at 720x576, but the produced file actually has a resolution of 720x400.

So, in order to be able to make anamoprhic avi's compatible with standalones (aka Divx-certified hardware), the following miracles must happen: 1) Someone to manage to make Dr. Divx produce an anamorphic file 2) The anamorphic flag Dr. Divx uses to be different that the one xvid/mpeg 4 modifier uses (because the latter doesn't work) 3) That flag be part of the Divx-certification process, so all standalones have it.

When it comes to hardware players, both MediaTek and SigmaDesigns released hardware decoding chip-sets at pretty much the same time, capable of supporting aspect ratio signalling detection.
Can you point to a sample anamorphic avi or divx file that works with the above chipsets? in other words, where and how I need to place the anamorphic flag inside the avi so that it will work with these chipsets?

[SeeMoreDigital]

When it comes to "hardware" (stand-alone) player compatibility, I've never had any problems using MPEG4 Modifier.

It all comes down to the feature set of the "hardware" player. Some "hardware" players support aspect ratio signalling detection some don't. That's how it's always been...

Here's a link to a couple of 720x480 anamorphic test cards for you to try: http://www.mediafire.com/?3u3bkpssb72l7ze

Both of which are detected correctly when played with my Pioneer DV-575A (MediaTek) player. All four of my Xtreamer hardware "network" media players (Realtek). And my old Zensonic and Ziova network media players (Sigma).

All as stated within this recent DivX playback on DVD Player not working (http://forum.doom9.org/showthread.php?p=1508295) topic.


Cheers

[kurkosdr]

It all comes down to the feature set of the "hardware" player. Some "hardware" players support aspect ratio signalling detection some don't. That's how it's always been...

Here's a link to a couple of 720x480 anamorphic test cards for you to try: http://www.mediafire.com/?3u3bkpssb72l7ze

Thanks for replying. I am now in my parents' place for vacation. They have a Schaub Lorenz (mediatek) player which supports both xvid's anamoprhic and the test pattern's anamorphic. But the real test will be the Toshiba player I have at home, as it doesn't support xvid's anamorphic. Will it support the test pattern's anamorphic?

The really weird thing is that WMP supports the test pattern's anamorphic, despite the fact it doesn't support xvid's anamorphic! So there is hope that my Toshiba player will exhibit a similar behavior to WMP and support the test patterns anamorphic.

Also, you seem to use a different pixel AR setting than Mpeg4 modifier's predefined ones. I think it's 32:27 Could you also post the pixel AR I should use for PAL? (720x576) Did you use Mpeg4 modifier or some other program to make the test pattern?


PS: The reason i want my anamorphic AVIs to be playable in all players is because I want to upload them on my site. So I can't say to my visitors "if you have a mediatek or sigma player go on, but if you have an ESS player you 're out of luck". So if I can find an anamorphic method that works with ESS, it's good, if not, I ll go with square pixels.

[SeeMoreDigital]

PS: The reason i want my anamorphic AVIs to be playable in all players is because I want to upload them on my site. So I can't say to my visitors "if you have a mediatek or sigma player go on, but if you have an ESS player you 're out of luck". So if I can find an anamorphic method that works with ESS, it's good, if not, I ll go with square pixels.Several years ago I did some tests with some ESS Vibratto II chip-set (http://forum.doom9.org/showthread.php?s=&threadid=82765) based players and..... none of them supported "aspect ratio signalling" detection for MPEG-4 Part-2 video streams placed within the .AVI container.

Perhaps what you are proposing to do on your web site has already been done on Doom9. See here: http://forum.doom9.org/showthread.php?t=91616


Cheers

[kurkosdr]

Several years ago I did some tests with some ESS Vibratto II chip-set (http://forum.doom9.org/showthread.php?s=&threadid=82765) based players and..... none of them supported "aspect ratio signalling" detection for MPEG-4 Part-2 video streams placed within the .AVI container.
Did any ESS Vibratto II chips made it inside Divx 6 - certified players? Divx 3~5 - certified players, or non certified players, are hopeless, as they don't even support XSUBs or sometimes not even AC3 inside avi files (only MP3). So if ESS Vibratto II chips didn't make it inside Divx 6 - certified players, it's not a problem. If they did, then it's square pixels for sure.

Anyway, i 'll try the test pattern with my toshiba player, which i consider the lowest common denominator for Divx 6, and report back.

[sneaker_ger]

Zoran (888) chipsets also support the MPEG-4-Modifier method.

[Jawor]

But the Zoran Vaddis 966 chipset apparently does not... unless it's firmware-dependent (tested on a Philips DVP3142/12).

[jmac698]

I make extreme anamorphic now - 720x576 from HD and custom aspect set to match exactly the autocrop from the HD source. And forget about ITU resizing, I tested my TV and it doesn't resize to any standard, just crops arbitrarily, it's always wrong. Only a few older videos use proper ITU, you can tell when it's about 712 pixels wide with small black bars, that it came from analog source. But now modern film scans are all digital and use full 720 width. I am thinking about doing an image matching experiment to find the *de facto* scaling relative to an HD release of same material. I wonder if it meets any standard? Standards are irrelevant, someone somewhere clicks a default at a prompt in Premiere to create the final project or whatever. People who do these things are not necessarily informed or particular about aspect, if it looks general ok on some TV at the office it's done. I doubt it's even taught anywhere in schools. For example I worked with a whole team of 8 graphic designers and not one of them knew anything about gamma, and always wondered why they're stuff looked ok on Mac but too dark on PC (this was before vista).

[pandy]

maybe WSS will help? hard encoded WSS i mean.

[kurkosdr]

maybe WSS will help? hard encoded WSS i mean.

Can you elaborate please?

How can you put WSS inside an avi file?