AF100 and external recorder

[Noel Evans]

Three hours is a long time. I just grabbed a 15 second clip and transcoded to prores HQ in FCP, total transcode time was 4 seconds. Which equates to about 24 minutes for 1.5 hours of footage. Of course it would take me longer than that as I use the log and transfer to review, cut some ends and log info as well, but I do that anyway even if my shots are i frame (same thing I do with p2).

 

[nugat]

Yes, closer, but still not exactly accurate. The EBU recommendation is that if you're going to be using MPEG-2, then you have to have at least 50 mbit long-GoP 422. That 50mbit recommendation is only for MPEG-2. The EBU hasn't issued any recommendation or comment on h.264 acquisition formats as far as I know.

You can see the official recommendation document here. And note, that recommendation is dated December 2008. The HMC150 had barely been on the market a couple of months when that recommendation was released. They said that they had issued this recommendation based on codec tests done between Autumn 2007 and Spring 2008 -- in other words, the whole AVCCAM format wasn't even tested because it didn't exist yet!

I'm sure there will come a recommendation sooner or later from the EBU related to h.264 acquisition, but the existing recommendation they made was specifically and solely related to MPEG-2.

The only thing you can take from that document and apply negatively towards the h.264 cameras is that the EBU did recommend that acquisition should be done at 4:2:2, and the existing AVCCAM and NXCAM products don't meet that (at least, not without using an external recorder).

The only h.264 recommendation I've found from the EBU is regarding HDTV transmission, where they said 1920x1080 HDTV is properly encoded for transmission in h.264 at a bitrate of 12-14mbps for "fixed MUXing" and 10-12mbps for "statistical MUXing".
Page 18 of this document.

AVC-I was tested by EBU in 2007 (Visca&Hoffman "HDTV production codecs tests") , results were the basis for rec124. http://tech.ebu.ch/Jahia/site/tech/cache/bypass/publications "EBU Tech Review n" October 31, 2008--go to page 30 to get this document titled "HDTV Production codecs tests".
AVCCAM is the brand name for Panasonic AVC HD non-intra 420 codec based line. H.264/MPEG4p10 ( AVC-Advanced Video Coding) is one standard with 17 profiles.
Wiki:
"H.264/MPEG-4 Part 10 or AVC (Advanced Video Coding) is a standard for video compression, and is currently one of the most commonly used formats for the recording, compression, and distribution of high definition video. The final drafting work on the first version of the standard was completed in May 2003.
H.264/MPEG-4 AVC is a block-oriented motion-compensation-based codec standard developed by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC Moving Picture Experts Group (MPEG). It was the product of a partnership effort known as the Joint Video Team (JVT). The ITU-T H.264 standard and the ISO/IEC MPEG-4 AVC standard (formally, ISO/IEC 14496-10 - MPEG-4 Part 10, Advanced Video Coding) are jointly maintained so that they have identical technical content."

Rec124 says:
"It is recommended that:
• If the production/archiving format is to be based on I-frames only, the bitrate should not be
less than 100 Mbit/s.
• If the production/archiving format is to be based on long-GOP MPEG-2, the bitrate should
not be less than 50 Mbit/s."

That can only be construed in one way: Sony MPEG2 422 50 mbit is ok, and AVC-I 100mbit is ok. So are all Avid and GVG100mbit 422 Intra codecs (covered in the Visca 2007 research) as well as ProRes SQ and faster because it's intra.
H264/MPEG4 GoP profiles (like AVC HD/AVCCAM) are not approved here in any way. Since they are 420 they simply fail an earlier precondition.

 

[Barry_Green]

AVC-I is a whole different ballgame, it's an intraframe-only codec.

The question was asked about AVCHD, being 24mbps, and whether the EBU's recommendation rules it out because the EBU specifies 50mbps. My response was that the EBU has not made any sort of evaluation of long-GoP h.264 such as AVCHD, and as far as I know, that's an accurate observation.

 

[nugat]

AVC-I is a whole different ballgame, it's an intraframe-only codec.

The question was asked about AVCHD, being 24mbps, and whether the EBU's recommendation rules it out because the EBU specifies 50mbps. My response was that the EBU has not made any sort of evaluation of long-GoP h.264 such as AVCHD, and as far as I know, that's an accurate observation.

I am not sure which question you refer to: the OP asked about outboard recorders. My remark was simply that 50mbit minimum for MPEG2 GoP422 is the EBU pan-european rec, not just an internal BBC requirement.
And yes, EBU R124 rules out h.264/MPEG4 in its AVCHD (Panny speak for the codec profile used on the AVCCAM line) implementation because it is 420. 422 sampling is a precondittion in that recommendation.
A lot of confusion comes from using "H264" and "MPEG4p10" and "AVC" as if they were different standards.There is only one standard H264/MPEG4p10(AVC) with 17 profiles maintained jointly by two committees: ITU and ISO/MPEG.

 

[BerkeleyBob]

I thought the Atomos Ninja was going to be out this month after a December delay for further testing. Not much about a release date on their website. Anyone have an update on that unit?

 

[nugat]

I couldn't seem to find any other threads when searching or looking around, so I apologize in advance. I just spent the day at a professional video store in LA today, as I am nearing the time to upgrade my camera. I was pretty set on the HPX-170 or HMC-150, but when I explained to the staff there that my primary work consists of weddings and documentaries, they talked me into the AF100. I own a 7D as well, so I have a bunch of Canon glass, and I have already made the decision to purchase the AF100 when they get it in stock in a month or so. My question is: is it worth the extra $2000- $3000 for a Ki Pro Mini or Nano Flash? I was told that the HDSDI outputs uncompressed 4:2:2 video, which would allow for much better quality and such. I can afford one, but is it really worth it?

Also, if I shoot in variable frame rates, say 12p, would it still output through HDSDI?

Thanks

And as to the meritum of this thread it is not advisable IMHO to listen to salesmen on the choice of a professional money earning tool. They earn money on selling, not wedding/docus shooting. In my opinion AF100 is very poorly suited for docus and weddings. The shallow DOF is just a detriment, The lack of a decent zoom with a rocker is non-fixable. After you rig it with a shoulder mount and proper EVF the cost will be at a HPX371 level. And that cam is just made for the kind of jobs.

 

[nugat]

I thought the Atomos Ninja was going to be out this month after a December delay for further testing. Not much about a release date on their website. Anyone have an update on that unit?

I am on the priority list with 6 ordered long time ago and never heard from them.

 

[ChuckS]

The first time you have a sd card failure you will kiss your external recorder.

I've shot terabytes of footage on CF cards and never had a failure, nor do I personally know anyone who has had a failure, this is not what I would use to determine whether I needed an external recorder. If you decide you need one, the Nano flash is a great way to go.

And as to the meritum of this thread it is not advisable IMHO to listen to salesmen on the choice of a professional money earning tool. They earn money on selling, not wedding/docus shooting. In my opinion AF100 is very poorly suited for docus and weddings. The shallow DOF is just a detriment, The lack of a decent zoom with a rocker is non-fixable. After you rig it with a shoulder mount and proper EVF the cost will be at a HPX371 level. And that cam is just made for the kind of jobs.

meritum, I don't even know what that means? I thought this whole shallow DOF debate was settled with the 5DMkII? Just because you can have a shallow DOF doesn't mean you have to have a shallow DOF. I use my DSLR for documentaries all the time and people absolutely love the look, I don't think I've even powered up my EX3 in three months.

I agree with the premise that you should try to go without it as long as you can, if there's a compelling reason to have to get an external recorder then I guess you have to get one. But I'd wait. Just my 2 cents...

 

[robertrogoz]

I've shot terabytes of footage on CF cards and never had a failure, nor do I personally know anyone who has had a failure, this is not what I would use to determine whether I needed an external recorder. If you decide you need one, the Nano flash is a great way to go.

Well CF is not SDHC, I was lobbying really hard to have CF card recording on AF100, but obviously Panasonic decided to go with cheap and unreliable media. SD cards fail in either cold or heat- I personally had 3 SDHC cards dying in a span of 1.5 years. I will never use Transcend or Lexar, for now I never had Sandisc die on me as of yet. But just to clarify you can't start comparing CF and SDHC in reliability, two different beasts.

 

[ChuckS]

Sorry, I didn't realize that they used the smaller SDHC cards in the AF100. I'm using the Kingston 32GB 133's in my DSLR's, I have six of them, I leave them in the car, my pocket, I pretty much do everything your not supposed to do with a memory card [even commenting on forums about how I haven't had any problems :huh:] and never had a failure.

When things just work its really easy to get complacent, I should pay more attention.