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h264 versus MPEG1 (really)
DATA first: I make my MPEG1 compressions using Heuris MPEGPro 2, and my h264 compressions using Compressor 3.04, both on my G5 dual 2 gig with OS 10.4.11 and 4 gig ram.
OK, here’s my problem in a nutshell…
We create a video reference system released on CD or DVD ROM, which allows the user to select a landmark (say, an overpass), and have the video loop around that landmark until he decides to select another landmark, or break out of the loop, at which time the video continues to play in a linear fashion. To do this, my programmer has written a small piece of code (C++, I believe), which references timecodes on an MPEG1 video.
Why MPEG1, you laugh?
-it is almost universally playable
-our major client considers Win2000 a modern OS, and Win2000 doesn’t support modern codecs, but does support MPEG1 just fine
(so why is this in a Mac forum? I do the compressions on a Mac…)
-it works with our software engineHowever, the video quality isn’t so hot, AND I have a client who’s demanding HD quality playback, which MPEG1 won’t do regardless of bit rate. I’d love to be able to use h264 or some other modern codec, as we’re looking to take this product to the next level of performance (and sale-ability). But my programmer says that any mp4-base codec isn’t working because it doesn’t use a fixed frame rate, and thus it gets bogged down when trying to locate start and end point of loops.
(It seems that I’ve seen this when playing back mpeg movies in QT Pro…I notice that there’s a “playback frame rate” item which doesn’t often hit the full 24 or 30 fps which I think it should…)
Can anyone suggest anything, or point me to sources of info that I can begin to plumb these depths? I’m the guy who does the compressions, but this seems to be beyond simple setting adjustments…
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8 Replies
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[Mike janowski] “which MPEG1 won’t do regardless of bit rate”
This will do MPEG-1 HD
https://www.digigami.com/megapeg/
[Mike janowski] “But my programmer says that any mp4-base codec isn’t working because it doesn’t use a fixed frame rate”
He’s wrong
[Mike janowski] “I notice that there’s a “playback frame rate” item which doesn’t often hit the full 24 or 30 fps which I think it should…) “
Perhaps your computer is not capable of playing back the HD content you have created.
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Two years from now, spam will be solved. – Bill Gates, World Economic Forum 2004 -
Thank you for your response.
And the reason I post the data about the system is to head of useless speculation like the last part of your answer, to whit:
Perhaps your computer is not capable of playing back the HD content you have created.
It is. Playback anywhere is not the problem. Accurately finding looping points is.
I own Digigami – thanks for the heads-up about its HD capability – and though I think it does an excellent job of making MPEG1 compressions, it too has problems interfacing with our software engine. I’ll try it again…
Finally, though I may have mis-quoted or mis-understood our programmer, an short declarative like “He’s wrong” really doesn’t provide me with the detail I need to solve this problem. I appreciate that you’re busy and don’t know me from Adam Ant, but if you’re gonna waste your time answering, make it worth both our whiles.
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[Mike janowski] “(It seems that I’ve seen this when playing back mpeg movies in QT Pro…I notice that there’s a “playback frame rate” item which doesn’t often hit the full 24 or 30 fps which I think it should…)”
[Mike janowski] “It is. Playback anywhere is not the problem. Accurately finding looping points is. “
Your first post was obviously unclear. You first talked about not hitting frame rates, now ‘looping points’ are the issue. (BTW – Don’t use QT Pro to accurately report frame rates).
Maybe I should question your GOPs, or how often you like to set an I frame?
[Mike janowski] “it too has problems interfacing with our software engine”
Shouldn’t that be that your ‘software engine’ has problems interfacing with the output it generates? After all, MPEG-1 is an ISO dating back to 1988, you need to work to it, not it to you.
[Mike janowski] ” an short declarative like “He’s wrong” really doesn’t provide me with the detail I need to solve this problem.”
What else can I say!? he says “that any mp4-base codec isn’t working because it doesn’t use a fixed frame rate, and thus it gets bogged down when trying to locate start and end point of loops”.
He’s wrong. Maybe he should figure out how often you set I frames.
[Mike janowski] “I appreciate that you’re busy and don’t know me from Adam Ant, but if you’re gonna waste your time answering, make it worth both our whiles.”
I’ll answer you in the most succinct way I know, usually. I don’t waste my time here answering questions, I do it out of the goodness of my heart. If you don’t like it, well, I’ll happily give you a refund.
Thanks.
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Two years from now, spam will be solved. – Bill Gates, World Economic Forum 2004 -
Mike,
I think the answer is that MP4 will likely work…and figuring out how to set encoding parameters related to identifying specific frames or timecode is the solution.
Unfortunately I don’t know the answer to setting those to improve the software engine’s ability to hit those specific points. But I imagine if you do a few google searches about I frames and GOPs related to MP4, you’ll get a better idea and some information that could help you narrow it down.
And one thing I’ll add…the arrogant tone that permeates a lot of these forums has always irritated me (as it obviously did you).
It’s as if everyone is trying to show how much more they know than the poor guy or girl that posts just trying to solve a problem…or that they’re deconstructing the depth of information someone provided in their question.
Frankly, it embarrasses me. No-one would talk that way to someone in person and I don’t know why it’s acceptable or why it’s allowed on these forums. Sure people are giving of their time, experience and knowledge to help others. But the last thing most of the people seeking answers need is more attitude. They probably have already gotten enough of that at work already….and that’s why they’ve turned to the people on the Creative Cow.
Ok…I feel better.
Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com -
Thank you, Chris.
You’ll be happy to know that I forwarded your post about installing QT for Windows to my programming team, to forewarn them, as they were beginning to investigate the Quicktime APIs for possible use. Just about all of our clients are Windows-centric, and most of them don’t have QT. In fact a point of pride (not to mention marketing) with this product is that we’ve developed it to work without – in many cases, in spite of – in-house IT departments. So installing something seen as invasive, like QT, is probably a no-go.
My first move is going to be to re-do the compressions using more keyframes. And to learn more about GOPs vs. performance. Or at least forward the info to someone who actually understands it!
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Sorry if might come across as arrogant, rest assured I speak to everybody with this tone.
Chris, thanks for following me around, picking up the pieces and feeding off my scraps. 😉
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Two years from now, spam will be solved. – Bill Gates, World Economic Forum 2004 -
Daniel Low Sorry if might come across as arrogant, rest assured I speak to everybody with this tone. Chris, thanks for following me around, picking up the pieces and feeding off my scraps. 😉
I have no idea what that means. Just because you speak with that tone with everyone doesn’t magically make it ok.
The intent of these forums is to help people solve problems. Not become a contest for “who’s knows more than who.” I joined the Cow about 4 years ago, posted a handful of times on various forums…and was greeted with responses like yours to Mike. I didn’t contribute again for two years after that.
I found it incredibly unprofessional to join what’s billed as “creative COMMUNITIES of the world” and immediately be lectured about how to ask questions, and be admonished because I didn’t know what I was talking about. That’s not what a “community” is supposed to be. When I joined, I was 9 years into owning my own company, with 22 years of experience, including an Emmy award for a documentary on PBS.
The majority of people that come to the compression forums are people that are NOT doing compression on a daily basis. In fact, in the world of video production, there are relatively few people who can say they do it full-time. So while I respect your knowledge, I, and obviously others who visit this forum, find the tone unprofessional and unncessary.
Thankfully the tone on the majority of forums has improved tremendously since I first joined. Most people that come to this forum typically do so because they do compression occasionally and are rightfully stumped by its complexity. The last thing they need is a kick in the face when they’re just looking for guidance.
Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com -
Truly eloquent, Chris. Thanks for the reminder.
We here at The COW had noticed the same tendency you did. We started this nearly 15 years ago, when there were literally only a few hundred of us using these tools. Things were still fine for the first few hundreds of thousands of people…but once we crossed the half-million mark, we noticed that the signal to noise ratio was moving in the wrong direction.
As a result, we instituted our real name policy. We found that the tone changed virtually overnight. We continue to encourage things to work their way up the ladder of professional discourse. There’s so much experience across our forums, and across The COW, that we ought to be able to make it as easy to share.
So thanks for the reminder, Chris, not just on this thread, but across The COW. We’re workin’ on it, and we appreciate everyone’s diligence….and of course, their sharing. We wouldn’t be here without you.
Regards,
Tim Wilson
Creative COW
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