Mpeg2 and PCM video poblems

[skully_man01]

Hi all,

I've been tryin to fix a problem im having at work which is:

captured, edited, exported, made DVD (Mpeg2 + AC3 audio) and was sent to clients...

iv since had 6-7 copies returned (Mpeg2 + AC3 audio) with not being able to hear any audio, i therefore tried a new (Mpeg2 + PCM audio) copy with all clients now being able to view and now hear the concert, but having a problem with a video "glitch" (as if the decoder is having a hard time processing the footage quick enough in high action scenes, and therefore the image "sticks" and then continues when the processor is fine again) entirely theory)

as i havnt had this happen ever before, and after 4-5wks now of tryin and failing to fix the problem, with every idea we can come up with, im slowly pulling my hair out lol

IF ANYONE has any idea's on a possible fix i would love to hear it

Thanks in advance

[schlemiehl]

Hi skully_man01

<----
I've been tryin to fix a problem im having at work which is:
captured, edited, exported, made DVD (Mpeg2 + AC3 audio) and was sent to clients...
----->
Ok, let me guess: You grabbed some music show from TV, transformed it to a DVD, replicated the DVD several times, but the customrs couldn't play it. Am I right?
Please, if you have a question, be as precise as possible. If your english is too poor, try it in you native language. Many people do know howto read other languages, but neither speak nor write them well.

I can`t help you (and noone else could) if we do not know what it is all about. Please, have another attempt.

Have a nice day!

[paglamon]

iv since had 6-7 copies returned (Mpeg2 + AC3 audio) with not being able to hear any audio

Can YOU hear the audio ?

[skully_man01]

hi again,

sorry for the poor explanation of what the problem is with what i am having.

I work for a video production company (so yes schlemiehl i do know what i am talking about, but was rushed when i wrote it(thanks for the KIND heads up though)...

We recorded a dance company (1 of the 25 or so that we did last year), all but this concert have been fine with no "fix-ups" needed.

We recorded this concert, edited the footage and created the Master DVD, which was then duplicated using standalone Duplicators (the image is loaded to the HDD then burnt and checked as each dvd is completed, by the machine) which went to about 120 customers...in the format of Mpeg2 video with 192kb AC3 audio, on DVD-R verbatim discs.

We then had a few people come back saying that they were unable to get any audio whilst playing the DVD. I then made a reformated version of the DVD in Mpeg2 Video with PCM audio, sent this to the customers after testing it and recieved word back that the audio problem was now fixed but the footage was now "jerky/Lagging" every min or so when there is heavy movement. We are now having the same problem with all the discs that are being created to fix the problem, that are played in DVD players (standalone), but when played in a computer (which obviously has more computing/decoding) power the problem is non-existent.

I have since racked my, and the rest of my colleagues brains and a few outside friends in the industry for a solution and so far haven't been able to find a fully working version.

Any help would be wonderful and muchly appreciated,
Thanks

[UncasMS]

so you are saying:

- playback problems on standalone dvd player
- no problem when played on pc/mac/...?

what video bitrate and which authoring tool did you use?

[skully_man01]

thats correct

Video bitrate = 8000kb
Audio = PCM (standard 1536kbps @ 44khz sample rate)

I'm using Womble Mpeg Video Wizard 5.0 and its onboard burning software

[UncasMS]

Audio = PCM (standard 1536kbps @ 44khz sample rate)

you should try/use 48 khz


in case your 44 was a typo and you already used 48khz, then i'd say the data are within specs (unless you have a second or third audio stream with that bitrate - then the max. 10.08mbps were passed) so the next question is:

- have you used womble/that routine of yours SUCCESSFULLY before?
- have you tried burn speeds like half the maximum your media is capable of?
- could you try to reproduce the errors by getting to know brand/model of any of the players NOT playing your media properly?
- think about demuxing your streams and using a different authoring AND burning tool

[skully_man01]

yes i just realised that typo...the audio sample rate is at 48khz and there is only the 1 stereo audio stream that is being used along with the video footage and the menu.

I/we have not had to use this format prior to now due to using the most common and widely acceptable format combination of audio and video on DVD here in AUS. Mpeg2 with AC3 audio...hence the problems we are having attempting to create an alternative working format for these few customers.

i have tried using a slower burning speed and onboard post-burn testing to test if anything pops up but nothing has. the problem still occurs when played that is but nothing "abnormal" shows up from the tests.

I am now in the process of burning a new master after...
re-editing the originally imported footage that was used to make the AC3 version, and then convert it to a new copy of Mpeg2 with PCM audio and then burn one containing only 53-54mins of footage (half of std quality DVD capacity, can fit 2hrs)

[UncasMS]

if i were you, i'd try and have some friends/colleagues test the dvd data either already burned with your standard equipment or maybe even let someone download your data and burn it himself and test it on some dvd/bd player.

if quite a few of your customers had issues then this error must be reproducible.

you are not using an unusual "copy protection" scheme on your disc or are you?
are all these customers located in AUS or are you having ntsc users as well?

in case you might want somebody else test your data and should you be able to provide it via say ftp let me know - i could test it on 3 different dvd (region 2) and a bd player (region b)

[skully_man01]

i have been/am testing the dvds in 4 different (2 different brands) standalone dvd players and 3 computers (1 mac and 2 pc) using
MAC - standard DVD player, VLC media player
PC - VLC Media Player

There is no copy protection being used at all

7 of the 120 customers are having this problem with ALL of the roughly 3000 DVDs that have been made using this computer, and roughly 1000 using this new edition of womble and have all worked seamlessly up to that point and i have made around a futhere 200 DVDs since the problem occured which work fine (in Mpeg2 + AC3)

the thing is i cant figure out why the audio is now fixed but as to why the video footage is "jerky/laggs" when there is high visual activity on screen yet the audio plays on seamlessly unaffected by the video problem, when watching it on a DVD Player and plays seamlessly in a computer (on both dvd and from the data files)

[UncasMS]

the thing is i cant figure out why the audio is now fixed but as to why the video footage is "jerky/laggs" when there is high visual activity on screen yet the audio plays on seamlessly unaffected by the video problem, when watching it on a DVD Player and plays seamlessly in a computer (on both dvd and from the data files)

with 8000kbps video and 15xx kbps audio you are close to the maximum overall bitrate allowed for a standard dvd (10.08mbps) so maybe some player's chipsets are a bit finicky and overloaded.

why on the other hand an ac3 stream with 192kbps is not recognised is over my head.

since you say that with lpcm sound the remaining problem is jerky video, maybe you should try a lower bitrate for the video stream like 6000kbps for example to NOT max out the overall bitrate?!

[schlemiehl]

Hi Skully,

as I see, you found .s.o. who seems to know what he`s talking about (Thanks, UncaMS!)

Just a few remarks:

1. If eveything else fails, try to reencode all that stuff with an external encoder, if you need _very_ quick results, spilt up the concert(s) in segments and use several machines. Forehandedly, allow some overlapping. And: use the same encoder and the same settings for each of the Clips!
If this done, cut'em to the edges and retry.
Beware: ffMpeg for example has to be told to use DVD compliant settings concerning GOP size and Bufsize.
GOP <= 15, Bufsize 224kb, B-frames 2 is OK
If you want more, just ask.

For the most cases, one of those xThousands of GUIs for MEncoder and/or ffMpeg freeware frontends will will do, but, please, do the 2pass way, it`s by far more effective.

But I think, no time to hurry, you have wasted enough of your time, so tomorrow will be soon enough.

Choose _two_ Pass_ encoding at about 5000 KB/s for video; do NOT try to demux, remux and such fancy things if you really have to produce s.th. that works AND you never have tried before without being under pressure. Always think of Murphy`s Law.
Frankly speaking, Womble is a great editor, but not a genuine encoder or re-coder. Sometimes you have to predigest its food...

2. Keep your "old" Womble Project alive, if you have marked a lot of specific chapter entries. You can save them from the DVD tree by right clicking the TITLE entry as Chapter List FIle (*.txt). See related postings on Womble.com.
You can reimport them into you "new" project.
Next time you might be better off with a mime show )
.
3. Ask one of those "problematic" users if he would be so kind and sell you his old player. Or offer him a brand new one - today`s prices for players are somwhere near the shipping costs And you can try yourself if the Disk is OK or not.
If you are working for a company, two hours of your hanging around not knowing what to do is more expensive than my suggestion.

Greetings!


Schlemmy