Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion.

Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules.

 

Go Back   Doom9's Forum > Video Encoding > MPEG-4 ASP

Reply
 
Thread Tools Search this Thread Display Modes
Old 4th December 2005, 19:02   #261  |  Link
Elias
Be Brave!
 
Elias's Avatar
 
Join Date: Dec 2004
Posts: 1,101
Quote:
Originally Posted by eXistenZ_69
Hello all,

I read somewhere on Doom9 unpacking a packed bitstream has no effect on image quality. Still, since I've started unpacking only recently (for playing on DivX/XviD capable DVD-player) I always compare the unpacked file to the original one when I encounter artefacts to assure myself of this fact. Until now I never found artefacts that weren't present in the packed file. Below you find links to image samples of the artefacting after unpacking. Does anyone have an explanation for this?

After unpacking:
http://img431.imageshack.us/img431/2...cropped1hi.png

Before unpacking:
http://img431.imageshack.us/img431/9...cropped6re.png

Some more info on the source file:

Packed bitstream: Yes
QPel: No
GMC: No
Interlaced: No
Aspect ratio: Square pixels
Quant type: H.263

I-VOPs: 686 (1,15%)
P-VOPs: 22864 (38,20%)
B-VOPs: 36298 (60,65%)
S-VOPs: 0 (0,00%)
N-VOPs: 0 (0,00%)

Max consecutive B-VOPs: 2
1 consec: 33,96%
2 consec: 66,04%

User Data: DivX999b000p, XviD0038

Regards,

eXistenZ_69
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.
__________________
Elias is offline   Reply With Quote
Old 4th December 2005, 20:51   #262  |  Link
eXistenZ_69
Registered User
 
Join Date: Mar 2003
Posts: 87
Quote:
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
eXistenZ_69 is offline   Reply With Quote
Old 4th December 2005, 21:51   #263  |  Link
Elias
Be Brave!
 
Elias's Avatar
 
Join Date: Dec 2004
Posts: 1,101
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.
__________________
Elias is offline   Reply With Quote
Old 4th December 2005, 22:02   #264  |  Link
bond
Registered User
 
Join Date: Nov 2001
Posts: 9,779
Quote:
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
__________________
Between the weak and the strong one it is the freedom which oppresses and the law that liberates (Jean Jacques Rousseau)
I know, that I know nothing (Socrates)

MPEG-4 ASP FAQ | AVC/H.264 FAQ | AAC FAQ | MP4 FAQ | MP4Menu stores DVD Menus in MP4 (guide)
Ogg Theora | Ogg Vorbis
use WM9 today and get Micro$oft controlling the A/V market tomorrow for free
bond is offline   Reply With Quote
Old 4th December 2005, 22:36   #265  |  Link
Elias
Be Brave!
 
Elias's Avatar
 
Join Date: Dec 2004
Posts: 1,101
Quote:
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.
__________________
Elias is offline   Reply With Quote
Old 4th December 2005, 23:54   #266  |  Link
SeeMoreDigital
Life looks better in UHD
 
SeeMoreDigital's Avatar
 
Join Date: Jun 2003
Location: Notts, UK
Posts: 11,664
Quote:
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
__________________
| I've been testing hardware media playback devices and software A/V encoders and decoders since 2001 | My Network Layout & A/V Gear |
SeeMoreDigital is offline   Reply With Quote
Old 5th December 2005, 00:28   #267  |  Link
celtic_druid
Registered User
 
celtic_druid's Avatar
 
Join Date: Oct 2001
Location: Melbourne, Australia
Posts: 2,171
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?
celtic_druid is offline   Reply With Quote
Old 5th December 2005, 11:02   #268  |  Link
SeeMoreDigital
Life looks better in UHD
 
SeeMoreDigital's Avatar
 
Join Date: Jun 2003
Location: Notts, UK
Posts: 11,664
Quote:
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
__________________
| I've been testing hardware media playback devices and software A/V encoders and decoders since 2001 | My Network Layout & A/V Gear |
SeeMoreDigital is offline   Reply With Quote
Old 5th December 2005, 12:37   #269  |  Link
eXistenZ_69
Registered User
 
Join Date: Mar 2003
Posts: 87
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
eXistenZ_69 is offline   Reply With Quote
Old 5th December 2005, 15:44   #270  |  Link
laserfan
Aging Video Hobbyist
 
Join Date: Dec 2004
Location: Off the Map
Posts: 2,462
Quote:
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.
laserfan is offline   Reply With Quote
Old 5th December 2005, 16:20   #271  |  Link
SeeMoreDigital
Life looks better in UHD
 
SeeMoreDigital's Avatar
 
Join Date: Jun 2003
Location: Notts, UK
Posts: 11,664
Quote:
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
__________________
| I've been testing hardware media playback devices and software A/V encoders and decoders since 2001 | My Network Layout & A/V Gear |
SeeMoreDigital is offline   Reply With Quote
Old 5th December 2005, 17:06   #272  |  Link
eXistenZ_69
Registered User
 
Join Date: Mar 2003
Posts: 87
Quote:
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
eXistenZ_69 is offline   Reply With Quote
Old 5th December 2005, 17:59   #273  |  Link
SeeMoreDigital
Life looks better in UHD
 
SeeMoreDigital's Avatar
 
Join Date: Jun 2003
Location: Notts, UK
Posts: 11,664
Quote:
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.....
__________________
| I've been testing hardware media playback devices and software A/V encoders and decoders since 2001 | My Network Layout & A/V Gear |
SeeMoreDigital is offline   Reply With Quote
Old 5th December 2005, 23:45   #274  |  Link
eXistenZ_69
Registered User
 
Join Date: Mar 2003
Posts: 87
Quote:
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.
eXistenZ_69 is offline   Reply With Quote
Old 5th December 2005, 23:49   #275  |  Link
SeeMoreDigital
Life looks better in UHD
 
SeeMoreDigital's Avatar
 
Join Date: Jun 2003
Location: Notts, UK
Posts: 11,664
Quote:
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
__________________
| I've been testing hardware media playback devices and software A/V encoders and decoders since 2001 | My Network Layout & A/V Gear |
SeeMoreDigital is offline   Reply With Quote
Old 5th December 2005, 23:57   #276  |  Link
eXistenZ_69
Registered User
 
Join Date: Mar 2003
Posts: 87
@SeeMoreDigital

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

Greetz,

eXistenZ_69
eXistenZ_69 is offline   Reply With Quote
Old 6th December 2005, 23:27   #277  |  Link
eXistenZ_69
Registered User
 
Join Date: Mar 2003
Posts: 87
@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
eXistenZ_69 is offline   Reply With Quote
Old 7th December 2005, 00:03   #278  |  Link
SeeMoreDigital
Life looks better in UHD
 
SeeMoreDigital's Avatar
 
Join Date: Jun 2003
Location: Notts, UK
Posts: 11,664
Quote:
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.

Quote:
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
__________________
| I've been testing hardware media playback devices and software A/V encoders and decoders since 2001 | My Network Layout & A/V Gear |

Last edited by SeeMoreDigital; 7th December 2005 at 00:06.
SeeMoreDigital is offline   Reply With Quote
Old 7th December 2005, 00:33   #279  |  Link
eXistenZ_69
Registered User
 
Join Date: Mar 2003
Posts: 87
@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 is offline   Reply With Quote
Old 7th December 2005, 22:52   #280  |  Link
eXistenZ_69
Registered User
 
Join Date: Mar 2003
Posts: 87
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
eXistenZ_69 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 12:44.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.