MPEG4 Modifier v1.3.4 Released (Updated 2005-Dec-14)

[eXistenZ_69]

Originally Posted by Elias

This is a bug in MPEG4Modifier that needs to be fixed. Try importing the packed video stream directly to *.mp4 with MP4Box, MP4Box will unpack it and do it correctly. I've seen the same issue as you have right now when modifying MPEG-4 video with MPEG4Modifier, like for instance when changing Aspect Ratio from the left (not Display AR). Doing that has resulted in b0rked picture quality.

Packed bitstream has nothing to do with quality. What it does is to improve decoding in the *.avi container, because the *.avi container isn't really suited for MPEG-4 video, so it needs packed bitstream.

Oh no . Is this a rare bug? I mean what are the circumstances this does happen? Cause most of the time it seems to work well. The bad thing is that I don't have all original packed files anymore. I've unpacked a few and burned them and deleted the rest

If this is a known bug, why is MPEG4Modifier still so heavily promoted to do the unpacking???

Can the broken unpacked files be fixed?


Regards,

eXistenZ_69

[Elias]

I don't know how common this bug is in MPEG4Modifier. Moitah will have to investigate it with some of your samples If I remember correct, this also happens with AVC in avi, but I'm not sure if MPEG4Modifier can handle AVC.

[bond]

Originally Posted by Elias

If I remember correct, this also happens with AVC in avi, but I'm not sure if MPEG4Modifier can handle AVC.

mpeg4modifier doesnt handle avc

[Elias]

Originally Posted by bond

mpeg4modifier doesnt handle avc

Like I said, I wasn't sure. But as can be seen on the snapshots, it's not a matter of quality, it's a matter of two frames getting intertwined with each other. Clearly a bug.

[SeeMoreDigital]

Originally Posted by Elias

Like I said, I wasn't sure. But as can be seen on the snapshots, it's not a matter of quality, it's a matter of two frames getting intertwined with each other. Clearly a bug.

I think it's too early to say it's a bug with MPEG4 Modifier....

It would be helpful to establish which MPEG-4 direct-show decoder filter eXistenZ_69 was using when this issue was first observed


Cheers

[celtic_druid]

As far as I know it produces bit identical output and has when I have tested. Encode with XviD and pb enabled, run MPEG4Modifer to unpack, compare that to XviD with pb disabled and the output is the same.

There aren't still standalones that can't handle packed bitstream + multiple bframes are there though? Shouldn't they all have recieved firmware updates by now?

[SeeMoreDigital]

Originally Posted by celtic_druid

There aren't still standalones that can't handle packed bitstream + multiple bframes are there though? Shouldn't they all have recieved firmware updates by now?

Yep.... I would have thought so.... Even for most of those players with weird names we've never heard of.... and are never likely to hear of again

[eXistenZ_69]

I noticed the artefacts first on my Pioneer DVD-575, which uses a MT1389EE chipset. Then I checked on my pc in MPC 6.4.8.4 using the XviD 1.0.3 DShow decoder.

If you need any more info, please ask...


Regards,

eXistenZ_69

[laserfan]

Originally Posted by celtic_druid

...There aren't still standalones that can't handle packed bitstream + multiple bframes are there though?

Perhaps you are referring specifically to standalone DVD players, but my Pinnacle ShowCenter media players (SC1000, SC1000G, SC200) play these files, and AFAICT actually *prefer* pb. Anyway when I have a choice I PB and B-frames=2 for my conversions.

[SeeMoreDigital]

Originally Posted by laserfan

Perhaps you are referring specifically to standalone DVD players, but my Pinnacle ShowCenter media players (SC1000, SC1000G, SC200) play these files, and AFAICT actually *prefer* pb. Anyway when I have a choice I PB and B-frames=2 for my conversions.

Well I have exactly the same stand-alone as eXistenZ_69, and I have no trouble playing XviD B-VOP stream, with or without B-VOP.

That said, I do have a DivX multiple B-VOP stream, the player does not like

[eXistenZ_69]

Originally Posted by SeeMoreDigital

Well I have exactly the same stand-alone as eXistenZ_69, and I have no trouble playing XviD B-VOP stream, with or without B-VOP.

That said, I do have a DivX multiple B-VOP stream, the player does not like

Ahum, that's weird. What do you mean exactly with 'no trouble playing'? Cause the files DO play, BUT playback is jerky. This jerkiness isn't always very noticable. Most problematic are horizontal pans... And it only occurs with more than 1 consecutive b-frame.

Regards,

eXistenZ_69

[SeeMoreDigital]

Originally Posted by eXistenZ_69

Ahum, that's weird. What do you mean exactly with 'no trouble playing'? Cause the files DO play, BUT playback is jerky. This jerkiness isn't always very noticable. Most problematic are horizontal pans... And it only occurs with more than 1 consecutive b-frame.

Hi

Try this XviD 720x576 2B-VOP with PBS sample with your Pioneer DV-575A player. Also, why not do as I did and remove the PBS (packed bit-stream) with MPEG4 Modifier.

Both files appear to play fine for me.....

[eXistenZ_69]

Originally Posted by SeeMoreDigital

Hi

Try this XviD 720x576 2B-VOP with PBS sample with your Pioneer DV-575A player. Also, why not do as I did and remove the PBS (packed bit-stream) with MPEG4 Modifier.

Both files appear to play fine for me.....

I'm afraid you're missing the point

My problem is artefacting caused exactly by unpacking with MPEG4Modifier.

[SeeMoreDigital]

Originally Posted by eXistenZ_69

I'm afraid you're missing the point

My problem is artefacting caused exactly by unpacking with MPEG4Modifier.

Eh!

What happens when you remove the packed bit-stream of the file I provided for you, using MPEG4 Modifier?

How well does it play in your DV-575A?


Cheers

[eXistenZ_69]

@SeeMoreDigital

I'll try the file tomorrow evening. Too late to do it today...

Greetz,

eXistenZ_69

[eXistenZ_69]

@SeeMoreDigital

Ok, I did the test with the sample you provided. The original packed version as well as the one I unpacked with MPEG4Modifier played fine without any noticable differences. But this doesn't change the fact that the Pioneer DV-575A doesn't handle packed bitstream well in general. I've encountered enough cases where there was very noticable jerkiness that got resolved by unpacking.

What was the intention of your test anyways? It's not my player that's causing problems here (well yeah, if it would handle PB well I wouldn't need to unpack of course), but MPEG4Modifier causing corrupt streams when unpacking under certain circumstances. Remember, the corruption is visible when playing back on pc in MPC 6.4.8.4 using the XviD 1.0.3 DShow decoder.


Greetz,

eXistenZ_69

[SeeMoreDigital]

Originally Posted by eXistenZ_69

@SeeMoreDigital

Ok, I did the test with the sample you provided. The original packed version as well as the one I unpacked with MPEG4Modifier played fine without any noticable differences. But this doesn't change the fact that the Pioneer DV-575A doesn't handle packed bitstream well in general. I've encountered enough cases where there was very noticable jerkiness that got resolved by unpacking.

In my opinion that's too general a statement.

I think we need to know a lot more about the encoder settings you use and even how your player is set-up.... For all we know, in some cases you could be playing cropped and resized 23.976/29.970 FPS content and outputting it as PAL. Or you could have borked the MetaData AVI codes.

Originally Posted by eXistenZ_69

@What was the intention of your test anyways? It's not my player that's causing problems here (well yeah, if it would handle PB well I wouldn't need to unpack of course), but MPEG4Modifier causing corrupt streams when unpacking under certain circumstances. Remember, the corruption is visible when playing back on pc in MPC 6.4.8.4 using the XviD 1.0.3 DShow decoder.

Hang on a minute.... In the above paragraph you said "this doesn't change the fact that the Pioneer DV-575A doesn't handle packed bitstream well ". But now you are saying it's MPEG-4 Modifier that's causing you "corrupt streams"....... I'm confused

The purpose behind providing you with an encode was so you could find out for yourself that the DV-575A can play MPEG-4 ASP streams "with" or "without" packed bit-stream. And that MPEG4 Modifier can indeed remove the packed bit-stream correctly..... Which it can.... and you did.

I think you may need to review your encoding techniques and the settings you've been using..... Including why you feel you need to remove packed bit-stream in the first place!


Cheers

[eXistenZ_69]

@SeeMoreDigital

Why are you making this so complicated?

1) Many PB files play noticably jerky on my Pioneer. Unpacking resolves that. Hence the need for me (and others if you look up some player-specific threads on specialized forums for DivX/XviD players) to do that. Encoder settings and player/TV settings can't be an issue since unpacking only changes frame order and after unpacking the file plays smoothly.

2) (Not directly related to my Pioneer player!) MPEG4Modifier messes up during unpacking in some cases resulting in corrupt stream (see my screenshots in one of my earlier posts). Why MPEG4Modifier? Cause good-looking PB file goes in and bad-looking unpacked file comes out Besides, Elias replied he witnessed this too on some occasions!

Now, regarding 1), if you want I can search for some samples where you can witness very noticable jerkiness that vanishes after unpacking...

And ragarding 2), I'll try unpacking my problem sample with MP4Box and see if the corruption still happens. According to Elias it should work fine in MP4Box...

Phew, I hope it is clear now

Regards,

eXistenZ_69

[eXistenZ_69]

I muxed the problem sample into an mp4 container with MP4Box (+ YAMB as gui). The stream should have gotten unpacked this way (remove N-VOP option was selected). The resulting mp4 file doesn't show the artefacting I noticed after unpacking with MPEG4Modifier.


Greetz,

eXistenZ_69

[SeeMoreDigital]

Originally Posted by eXistenZ_69

I muxed the problem sample into an mp4 container with MP4Box (+ YAMB as gui). The stream should have gotten unpacked this way (remove N-VOP option was selected). The resulting mp4 file doesn't show the artefacting I noticed after unpacking with MPEG4Modifier.

Okay....

As a cross-reference, use YAMB again to de-mux the MPEG-4 in MP4 stream back to MPEG-4 in AVI. Then play this new .AVI file to see if it displays any artefacts!


Cheers