Converting VOB tot MPEG2, different results on PC and Mac?

[HitTheRoad]

A friend of mine rips his DVD's on a PC. I rip mine on a Mac. He then converts his VOB's to MPEG2's. I do the same on my Mac.
Do we get the same MPEG2's? Much to our suprise we don't!

My MPEG2's are given the extension .mpeg. His VOB's are given the extension .mpg. We thought this didn't matter, and we still do. But while he and I are able to play his MPEG's from a USB stick on tv, my MPEG's can't be played this way.

Is there anyone who has an explanation for this?

The software I use is MPEG Streamclip 1.9.2 (for the Mac this is the most popular MPEG editing software).
The software my friend uses is MPEG Video Wizard DVD 5.0.

The only other difference is: before converting his VOB's to MPEG2's, he amplifies the VOB's and converts to AC3 at 256kbps. I don't. I just convert from VOB to MPEG2.

By the way, I can play my MPEG2's on my Mac using VLC or MPlayer OSX Extended. PC users are also able to play my MPEG2's on their computers.

This is one of my MPEG2's:

http://http://files.videohelp.com/u/203833/Mac%20(MPEG%20Streamclip).mpeg

This is one of my friend's MPEG2's:

http://files.videohelp.com/u/203833/PC%20(MPEG%20Video%20Wizard).mpeg

As you can see it's the same video from the same source (DVD). The file structure seems to be the same. But it isn't!

[hech54]

he amplifies the VOB's and converts to AC3 at 256kbps. I don't. I just convert from VOB to MPEG2.

What?

[HitTheRoad]

What?

As I understand it he 'normalises' the audio, as it is called in MPEG Video Wizard DVD 5.0. Which means the volume of the VOB is amplified (the audio on VOB files is usually too low to his liking). He then converts the VOB to MPEG2 while at the same time the PCM audio file is converted to AC3.

[Cornucopia]

Sounds like you are BOTH doing it wrong, in different ways. Yours COULD have been the cleaner way, but you are using not-so-good software to do it with, and it is likely screwing it up.

I used to suggest MPEGStreamclip, but encountered a number of errors. Have pointed them out to them, but they've never been fixed, just added more errors. They also do not keep their Win software up-to-date with their Mac software. I NO LONGER would recommend it.

I would have DL'd your clips, but NO WAY am I going to waste my time with 100+MB each, when 5-10MB could have sufficed. MediaInfo?

Scott

BTW, a VOB is a type of MPEG file (twin sister to MPEG2-PS), so if you do it right, you only need to re-wrap it to a MPEG2-PS container. No need to "convert" anything.

[djmajicmixx]

http://mediaarea.net/en/MediaInfo

Use This Free Program to Tell The Difference In The mpeg and mpg Files And Post The Difference.
If You Both Would Use The Same Program on PC and Mac You Would Probably Have The Same Output File Properties.

[videobruger]

Just to rule it out: Have you tried changing the MPEG extension on the MAC version to MPG. Perhaps your TV don't recognise the MPEG extension? (BTW MPEG Streamclip produce the extension MPG on PC and they are playable on a Phillips serie 5000 TV)

[aedipuss]

http://mediaarea.net/en/MediaInfo

Use This Free Program to Tell The Difference In The mpeg and mpg Files And Post The Difference.
If You Both Would Use The Same Program on PC and Mac You Would Probably Have The Same Output File Properties.

don't ever download programs from weird links. the mediainfo program is available from this website where you can be fairly certain it hasn't been replaced with a virus/trojan. the highlighted name of the program is a link to the download page.

[poisondeathray]

There are stream discontinuities detected if you open it in gspot (no mac version) . Probably from a bad multiplex . Demuxing and remuxing fixes that issue . So cornucopia is probably right mpegstreamclip is no good for this . The other video is fine as is

Software players are more resilient, so it's quite common that they can play bad files

[poisondeathray]

I "fixed" it by demuxing, and multiplexing it with muxman => no errors detected in various programs

Took that VOB and put it into the PC version of mpegstreamclip , file=>convert to MPEG . It definitely introduces stream discontinunities. Bad.

[djmajicmixx]

http://mediaarea.net/en/MediaInfo

Use This Free Program to Tell The Difference In The mpeg and mpg Files And Post The Difference.
If You Both Would Use The Same Program on PC and Mac You Would Probably Have The Same Output File Properties.

don't ever download programs from weird links. the mediainfo program is available from this website where you can be fairly certain it hasn't been replaced with a virus/trojan. the highlighted name of the program is a link to the download page.

The Link I provided Is The Same Link That Is Here But Straight From The Developer's Website. The Developer's Website Has More Info About The program. The link I Provided Is Not A Weird Link.

[aedipuss]

sorry but compared to a direct link on videohelp one from an unknown mediaarea looks suspicious.

[HitTheRoad]

I used to suggest MPEGStreamclip, but encountered a number of errors.

Could you please elaborate on this? What errors? What problems does one encounter with VOB to MPEG2 conversions produced by MPEG Streamclip?

Sounds like you are BOTH doing it wrong, in different ways.

What's wrong with the way my friend produces MPEG2's from VOB's?

Just to rule it out: Have you tried changing the MPEG extension on the MAC version to MPG. Perhaps your TV don't recognise the MPEG extension?

MPG extensions are recognised by my Panasonic tv set. MPEG extensions aren't. So yes, I changed the MPEG extension to MPG. But it didn't help. The MPEG2 was recognised, but it still wouldn't play.

BTW, a VOB is a type of MPEG file (twin sister to MPEG2-PS), so if you do it right, you only need to re-wrap it to a MPEG2-PS container. No need to "convert" anything.

.
Does one really convert when pushing the "convert to MPEG" button? It takes only a few seconds to 'convert' a 100 MB VOB to MPEG2. I should think conversions take much more time.

There are stream discontinuities detected if you open it in gspot (no mac version). Probably from a bad multiplex . Demuxing and remuxing fixes that issue . So cornucopia is probably right mpegstreamclip is no good for this . The other video is fine as is

Posondeathray, Could you please check another MPEG2 I produced using MPEG Streamclip? Just to rule out the first MPEG2 you checked was sourced from a bad DVD. This is the new sample I uploaded:
http://files.videohelp.com/u/203833/another%20one%20created%20by%20MPEG%20Streamclip.mpeg

[poisondeathray]

This latest sample has fewer errors but still has them . Does this latest one play on your TV ?

MPEGStreamClip (the PC version at least) introduces those errors

But I don't know if the discontinunities are the reason behind your TV's playback problems .

[HitTheRoad]

This latest sample has fewer errors but still has them. Does this latest one play on your TV ?

Thank you for checking. And no, the latest one does not play on my tv.

Is there any software available for the Mac you guys would recommend? And is there any software for the Mac I can use to fix the many MPEG2's I already have?

[Cornucopia]

The app, as noticed by PDR, muxes (and I believe demuxes) incorrectly, introducing stuttering. Probably wrong packet size, designator or ordering (or combinations of those). It also totally screws up DV type conversions (even worse than the Quicktime engine that it is built upon). There are other problems, but I won't list them now. Don't particularly want to even get back into using that app even just so I could list them.

@djmajicmixx, don't know where you came up with that wierd URL, but the true source address for Mpegstreamclip is http://www.squared5.com/.

Scott

[HitTheRoad]

The app, as noticed by PDR, muxes (and I believe demuxes) incorrectly, introducing stuttering. Probably wrong packet size, designator or ordering (or combinations of those). It also totally screws up DV type conversions (even worse than the Quicktime engine that it is built upon).

Thank you for your explanation. Clear.
But what is it my friend is doing wrong, using MPEG Video Wizzard DVD?
And is there any software you would recommend for the Mac as an alternative to MPEG Streamclip?

[Ai Haibara]

Cornucopia: djmajicmixx's post was about MediaInfo, not MPEG Streamclip.

aedipuss: Actually, to my surprise, the mediaarea.net link is the same one listed for the Visit developer's site link on VH's Tools page for MediaInfo.

[Cornucopia]

Oh, OK got it. (Though I prefer to use VH's tool linking myself, whenever possible).

@OP, well Womble is good (makes pretty good products all around - so I'll revise what I said earlier and say his process is better), but you stated yourself that he/she normalized & converted the audio (to AC-3 from PCM). While this theoretically SHOULDN'T affect playback, the change in audio format can change the sync.

The way to check how clean of a conversion process is would be to run mediainfo on source rips, and again on conversions and check for differences (there are other more advanced MPEG test apps, but they are $$).

Scott

[poisondeathray]

Is there any software available for the Mac you guys would recommend? And is there any software for the Mac I can use to fix the many MPEG2's I already have?

There aren't as many options on a Mac

Also, PCM in MPEG-PS can be problematic for many muxers in general (linux, pc, mac - doesn't matter) . You can get suttering, audio clicking, other playback problems. But if you convert it to AC3, then most generic muxers won't have as many problems .

The only free/inexpensive way I can think to do this on a Mac is with command line tools (terminal) . You need Mac binaries of ffmpeg, sox, mplex (from mjpegtools) . If you search around people pre-compile them for OSX and other OS's , and sometimes people make GUI's around them (but they might not have enough control over the switches required) e.g. mplexer is a Mac GUI for mplex , iffmpeg is a GUI for ffmpeg

But first, we have to identify if the discontinunities are the real issue behind the playback problems on your TV (there can be other reasons for faulty playback)

Can you test this file demuxed, remuxed from "another one created by MPEG Streamclip.mpeg" on your TV ?

Or we might be jumping through hoops and taking the long way around - there might be better Mac ripping software that allows you to go directly to MPEG-PS without all these issues . It might be a good idea to ask in the Mac subforum (and other Mac forums) there might be something easier to use that works

[HitTheRoad]

There aren't as many options on a Mac

I guess I have to switch from Mac to PC. From what I understand from Cornucopia and others on this forum all editing software and demuxers for the Mac rely on Apple's QuickTime, which has problems handling MPEG files.

But first, we have to identify if the discontinunities are the real issue behind the playback problems on your TV (there can be other reasons for faulty playback). Can you test this file demuxed, remuxed from "another one created by MPEG Streamclip.mpeg" on your TV ?

The file plays on my Panasonic, but without the audio.

I have collected a few thousand MPEG2's now, all created by MPEG Streamclip. Can I repair them using some Windows software? Or are they irreversible damaged?

[poisondeathray]

That 1st test file used no quicktime software (all open source ones, ffmpeg, sox, mplex) .

I don' t know if you can fix the old ones. You have to do some tests. Demux/remuxing it eliminated those particular errors listed in gspot, but there might be other issues

What about these ones ?

In particular, you want to listen for audio hissing , clicks and look for stuttering playback

[HitTheRoad]

What about these ones ?

Again, there's picture, but no sound. Both files still have PCM audio. Could it be it's the PCM audio?

[poisondeathray]

Yes it could be PCM audio . As mentioned above, many muxers have problems with MPEG-PS and PCM . While it's ok for authored DVD (VOB files), as a plain MPEG2-PS many decoders ALSO have problems with it as well .

[HitTheRoad]

Yes it could be PCM audio . As mentioned above, many muxers have problems with MPEG-PS and PCM . While it's ok for authored DVD (VOB files), as a plain MPEG2-PS many decoders ALSO have problems with it as well.

So the best way to produce MPEG2's from VOB's is to convert PCM's to AC3's?

[poisondeathray]

One more test, and if that doesn't work - maybe test a completely different source with something that is known to work with other hardware players (it just might be your TV can't handle it)

(It's a slight difference, but the audio in the mplex tests were converted to lpcm before muxing into the program stream)

[HitTheRoad]

One more test, if that doesn't work maybe test a completely different source (it just might be the TV can't handle it). It's a slight difference, but the audio was converted to lpcm before muxing into the program stream

Again, there's no sound.
Strange...
As I said, all mpg's my (above mentioned) friend produces CAN be played on my Panasonic tv set.
I first thought this had to do with him converting PCM to AC3. I then tried to play some of my own MPEG2's that have AC3 audio. But my Panasonic refused to play them.
So there must be something else...

[poisondeathray]

One more test, if that doesn't work maybe test a completely different source (it just might be the TV can't handle it). It's a slight difference, but the audio was converted to lpcm before muxing into the program stream

Again, there's no sound.
Strange...
As I said, all mpg's my (above mentioned) friend produces CAN be played on my Panasonic tv set.
I first thought this had to do with him converting PCM to AC3. I then tried to play some of my own MPEG2's that have AC3 audio. But my Panasonic refused to play them.
So there must be something else...

Those observations don't necessarily prove anything. Your Panasonic might just be "picky" - Cornucopia has known this for a long time, but we know for a fact that MPEGStreamClip introduces errors. Those errors might be causing your Panny to not play them at all . In addition, there might be something else done through the MPEGStreamClip processing (some other problems not identified yet), that causes future problems

Now - if you have some mpg's from your friend with PCM audio that play properly on your Panasonic, then that indicates new information

So we don't know if it' s just your TV being picky or if it's some other issue caused by MPEGStreamClip , because your own MPEG2's with AC3 had been processed with MPEGStreamClip

[HitTheRoad]

Now - if you have and mpg's from your friend with PCM audio that play properly on your Panasonic, then that indicates new information

Okay, I will ask him to send me some mpg's with PCM. I will report later.

[HitTheRoad]

I finally succeeded in producing MPEG2's I can play on my Panasonic Viera!

I just switched from MPEGStreamclip to Avidemux.

I don't know why, but Avidemux produces MPEG2's from VOB's in a different way than MPEGStreamclip.

In both cases, I chose the .mpg extension (in stead of .mpeg) and aac audio (my Panasonic Viera doesn't support PCM audio)

Here's a sample from a MPEG2 I took from a VOB, using Avidemux:

http://files.videohelp.com/u/203833/test.mpg

Here's a MPEG2 sample taken from the same VOB, produced by MPEGStreamclip:

http://files.videohelp.com/u/203833/test2.mpeg