Specific system needed for AVCHD1080 -> DVD - suggestions please!

[Telek]

Hello, and I'm sure that there are a lot of n00b questions like this, but I have a specific type of video editing requirement and would like to know what hardware I should get to accomplish this as quickly as possible on a modest budget.

I spent several hours today searching around for answers but haven't been able to find anything definitive.

We have people recording on CX100's about 5 minutes of footage in AVCHD 1080p @ 60fps. We to do standard simple editing (just cutting footage up and inserting prerecorded segments) and outputting on a DVD. To that 3 minutes of preencoded video is added so 8 minutes needs to be burnt to DVD.

I've specced out an i5 750 system that seems quite reasonable from a price-vs-performance perspective (as the i7 930 is only going to be 14% more performance for a 35% premium) - however what I don't really know is this: how much of an impact the video card will have?

Trick is that in order for this sytem to be used we need to be able to do it in at least realtime. Based on my best estimates that system with no video card assistance should be able to encode in 2.4x realtime. Even the most tripped out i7 would still max out at 1.6x realtime - still too slow without video assistance.

So how much difference inmprovement in rendering time will there be on that i5 system with a $100, $200, $300, $400 or $500 video card? How about a dedicated add-on card that can do DVD compression (any ideas?)

How much memory is actually used by the system? I ran a test on my laptop with Adobe Media Encoder CS4 and it wasn't even 1GB of memory used. People seem to recommend gobs and gobs of memory but is more than 4GB really necessary?

Is there really any serious benefit to getting a higher performance CPU?

Thanks for the help and I apologize for the n00b question

[edDV]

Who specified consumer AVCHD camcorders for this project? See that they are fired.

What software are you using for each step?

Define realtime. Including trsansfer from the camcorder? Step out the process.

[Telek]

Who specified consumer AVCHD camcorders for this project? See that they are fired.

No choice in the matter as it is an existing setup.

However based on what I said any suggestions about the hardware?

Thanks!

[edDV]

What software is used to cut and time stretch the 1 min?

Is the 3 min "pre-recorded" footage also pre-encoded? If so you only need to encode the fresh video. Then author + burn the DVD.

Encoding time mostly relates to CPU speed. GPU assist is specialized and limited. RAM over 2GB has little if any effect.

[Telek]

We havent chosen the software yet to do the time stretch - everything is currently done on an analog editing board.

Yes, the 3 minutes of pre-recorded footage will be encoded and ready to go, no processing required. We only need to encode the fresh video then author + burn.

So are GPUs mainly used then only for special effects via open gl and the like? Since we will have no special effects at all (aside maybe from from transition effects between clips) is there really much benefit to a non-embedded video card at all? Are there any add-on hardware cards that would assist this?

Of course another option would be to just change the camcorders to record in a smaller resolution or even in DVD quality directly, but I'm hoping to be able to keep the high def footage for post-processing and later use.

Thanks!

[edDV]

We havent chosen the software yet to do the time stretch - everything is currently done on an analog editing board.

Yes, the 3 minutes of pre-recorded footage will be encoded and ready to go, no processing required. We only need to encode the fresh video then author + burn.

So are GPUs mainly used then only for special effects via open gl and the like? Since we will have no special effects at all (aside maybe from from transition effects between clips) is there really much benefit to a non-embedded video card at all? Are there any add-on hardware cards that would assist this?

Of course another option would be to just change the camcorders to record in a smaller resolution or even in DVD quality directly, but I'm hoping to be able to keep the high def footage for post-processing and later use.

Thanks!

GPU assist to encoding is still semi-experimental and targeted mostly for web distribution formats rather than DVD MPeg2. There are realtime hardware encoders but I don't know of one that does AVCHD direct to DVD.

Maybe someone else has an idea.

[Telek]

I'd think with all the crazy hardware available on video cards these days there would be some benefit to any sort of video processing Oh well does anyone else have an idea?

[aedipuss]

got any artsy ponytailed folk with budget approval authority? if so talk it into a dual cpu Mac Pro 8-core 2.93GHz. not that it would necessarily do what you want in real time but it would be fun to play with.

but really why are you worried about real time processing of 1 min. or video??? i mean really, it takes longer to transfer the video to the comp, open it in the editor and set up the render than the actual rendering even at 2x real time.

iirc the next gen video editors like premiere cs5 may use gpu assist when they can.

[Telek]

Well there has got to be add-on cards designed for realtime DVD compression - I'm sure that the CPU can handle uncompressing the HD and resizing to DVD as long as it could offload the DVD compression cycles. Any ideas?

[edDV]

Well there has got to be add-on cards designed for realtime DVD compression - I'm sure that the CPU can handle uncompressing the HD and resizing to DVD as long as it could offload the DVD compression cycles. Any ideas?

Use MiniDV camcorders then an i7 will encode DVD ~2x.

Like I said the first time, whoever spec'd the AVCHD format for real time encoding to DVD should be fired.

If you "want HD for future", use HVD format camcorders that will export SD DV format realtime.

Like aedipuss suggests, handling procedure takes more time than processing. We still don't know your work flow.

[Telek]

As I mentioned the fact that we are using the HDRCX100 is not relevant - and cannot be changed. It is the only device suited for what we are doing.

As for the workflow the entire turnaround time must be less than 10 minutes. We currently handle that via analog SD output on the camcorder to real-time mixer board and record on a normal analog dvd recorder. Handling is about 3 minutes since it's done realtime and all that needs to happen is plugging in the memory card with 6 minutes of video, pressing play, doing the record with some realtime splicing and dubbing, and finalization of the disk takes 2 of the 3 minutes of overhead.

Please no more suggestions or critques about the hardware -- I only seek to find a way to digitize our process and to do that I need to be able to, at the very least, recompress to DVD in realtime. The only thing that we can change will be the format in which the camcorders is recording to, but as I mentioned we would prefer to keep it as HD if possible.

[aedipuss]

you make very little sense. you say you're willing to spend $500 on a video card but only want an i5 cpu. get the best cpu you can and skip the expensive gpu. here's an intel q6600 taking a 1 minute avchd 1920x1080 30p video and stretching it to a 2 minute 720x480 dvd spec mpeg-2 .mpv in vegas. in under a 1min 30sec. with audio as a .mpg takes exactly 1:30. if a mac pro or i7 intel box can't beat that by a mile i'm einstein for building my old machines past the laws of physics.

[Telek]

What I said was that a reasonably priced i7 machine will give 15% more performance (based on several different benchmarks that I have seen) than an i5 machine for about $300 more. To me that is not cost effective.

If the $500 video card could give me a 100-200% performance increase then it would certainly be worth the money. Even a 50% performance increase for $500 is better than 15% for $300.

The benchmarking and research that I have done suggests that even the most tricked out i7 overclocked to nearly 4GHz would require 1.5x to recompress - however it's possible that my benchmarks are incorrect as I have yet to actually purchase any hardware.

Your screenshot is quite helpful and intrigues me - what video card do you have in that machine? Does Vegas have any support for GPU assistance?

I also forgot to mention that our video is 1440x1080@60fps or 1920x1080@60fps.

Thanks!

[aedipuss]

the vid card is a nvidia 8600gt from a few years ago. vegas pro doesn't use it at all for rendering, but it does use all 4 cores of the cpu.

i don't want to get your hopes up. the material i used as source for the last test turned out to be 720p, sorry. 1080 60fps source stretched from 1 to 2 minutes on a q6600 takes 2min 30sec.

if the extra money for a $500 vid card is available, i'd use it to build a dual quad core intel server board into a desktop instead of a single cpu. it would be my dream machine for the dv/hdv to dvd work i do. vegas will use all the cores. or vegas can do distributed networked rendering over several machines.

if you REALLY need fast then a dedicated hardware encoder is called for. last time i checked they were quoting this one as 4-5 times faster then realtime.
http://www.grassvalley.com/products/firecoder_blu

[thymej]

It would be interesting to know how the quality compares to what x264.exe can do vs the FIRECODER Blu.

And it would be interesting also to know how HCenc compires to the FIRECODER Blu. HCenc can do the DVD encode you want.

[Telek]

aedipuss that is awesome - thank you for that helpful info! That firecoder is only about $550 now so it actually wouldn't be out of the question.

If possible would you mind doing a test at 720p 60fps to DVD without timestretching? That would be very helpful!

[edDV]

You might want to demo the GV/Canopus Edius editor for more operational compatibility with the Firecoder. Edius can handle the time stretch and has hardware acceleration options. Grass Valley has good application support. Call them.

http://www.grassvalley.com/products/edius_5
http://www.grassvalley.com/products/edius_5/any_workflow

[aedipuss]

aedipuss that is awesome - thank you for that helpful info! That firecoder is only about $550 now so it actually wouldn't be out of the question.

If possible would you mind doing a test at 720p 60fps to DVD without timestretching? That would be very helpful!

no problem - 1 min 720 60p to dvd spec mpeg-2 with no timestretch using q6600cpu in vegas. ~ 1min 43sec.

[Telek]

Great - thanks!

If your Q6600 t overclocked at all?

If not then the i5 system should be about 30% faster at stock speeds as well. Still not realtime but pretty decent at 1.3x.

I realized as well that we should be able to do the physical burning of the DVD concurrently with the next edit. This means that we have about 8 minutes to encode ~5.5 minutes of video, so 1.3x should just be able to squeeze by under the wire.

From what I can tell I should be able to overclock 10-20% perfectly stable (as a lot of others have been overclocking 30-40% stable) which would be overall perfect.

[aedipuss]

they are 2.4ghz running at 2.8 with standard voltages and a decent air cooler. never a problem at this speed.



they run 3.6ghz fine also but win7 doesn't always boot, so 2.8ghz it is.