Editing Flash XDR / nanoFlash MPEG2 Quicktime footage in Final Cut Pro

[Tommy Schell]

Convergent Design recently released an evaluation version of Quicktime file support for the MPEG2 long GOP 4:2:2 compression profile, also known as XDCAM HD 422, for use with Final Cut Pro (and, potentially, with other editing software.
Forthcoming MXF file format support will facilitate usage of Flash XDR / nanoFlash footage with other NLE's as well.)
The Flash XDR can now record (evaluation) Quicktime files to Compact Flash memory cards inserted into the device, which can then be transferred over to an editing system.

In Final Cut Pro you can now minimize the lengthy render times associated with native MPEG2 long GOP editing.


MPEG2: a simple primer

Some common types of MPEG2 long GOP compression include:
HDV (18 to 25 Mbits / sec data rate, 4:2:0 colorspace, 1440x1080 compressed resolution for 1920x1080 1080i/p)
XDCAM EX (35 Mbits / sec, 4:2:0 colorspace, 1440x1080 or 1920x1080 for 1080i/p)
XDCAM HD 422 (typically 50 Mbits / sec to 100 Mbits / sec, 4:2:2 colorspace, 1920x1080 compressed resolution for 1080i/p)
For comparison, uncompressed HD 4:2:2 is 1,000 to 1,200 Mbits / sec.
Most I-Frame codecs are 100 to 220 Mbits / sec in HD.

The distinctive feature of MPEG2 long GOP compression, when compared to I-Frame compression, is that video frames are compressed temporally as well as spatially.
The I-Frame codecs (DVC Pro, Cineform, ProRes, etc) use only spatial compression, meaning that each frame is compressed individually and can be reconstructed individually.

With MPEG2, frames are organized into GOP's (group of pictures), typically 12 or 15 frames. Within a GOP, video information is shared, so that information that is repeated from 1 frame to the next (such as a background that does not change) is stored once within the GOP instead of being stored in each individual frame.
So MPEG2 uses temporal compression as well, meaning a particular frame will depend on other frames (other points in time) to be compressed and decompressed.

The major advantage of MPEG2 is greater efficiency of compression, meaning better quality at lower bit rates.
The major disadvantage is the difficulty of editing MPEG2, because the more complex encoding scheme induces lengthy render times when editing MPEG2 natively and preparing a sequence for output. Reconstructing the long GOP video during the rendering process is typically a time consuming process.


Editing Flash XDR Quicktime files natively, avoiding lengthy render

The Flash XDR (and nanoFlash, when it becomes available) supports 50 and 100 Mbit XDCAM HD 422 MPEG2 long GOP compression, (and will likely support MPEG2 at lower bit rates in the future).
Final Cut Pro (since version 6.0.2) supports native XDCAM HD 422 editing, for 50 Mbit.

Final Cut Pro now has a shortcut to help minimize rendering when editing MPEG2 natively. Here are the steps to achieve this with XDCAM HD 422 footage:

> set up a sequence / timeline as XDCAM HD 422
> in Final Cut Pro (6.0.2 or greater) -> User Preferences -> Render Control, set the codec to ProRes
> drop your 50 Mbit Quicktime clips directly into the timeline (you do not need to transcode first) for editing

What this does is render the effects in your sequence to an I-Frame codec (ProRes), and areas of the timeline which do not have effects applied are left alone. Your sequence is not encoded back to MPEG2 long GOP.
Because I-Frame encoding is faster than long GOP encoding, and because only the areas of the timeline with effects are rendered (re-encoded), to an I-Frame codec, this is where the time savings comes into play.

Note that if you place your MPEG2 footage directly into a ProRes or other I-Frame timeline, when you are ready to play out your sequence the MPEG2 will be transcoded to the I-Frame codec first, that is, it will be decompressed and recompressed to the I-Frame codec.
Certainly this is a viable option but it will add considerable time to the whole process.
(However if you choose "Render Selection" as opposed to "Render All" a transcode of the MPEG2 is probably avoided as the default behavior, but this approach is a bit messier and potentially error prone.)


Alternatively you can transcode all of your MPEG2 footage to an I-Frame codec in advance, which is a way to avoid native MPEG2 editing altogether. Transcoding, however, can be time consuming and creates an additional decompression/compression cycle for the video.

Any feedback on this is appreciated.

Tommy Schell

[Douglas Scott]

If you use the FCP version of the XDcam files, does that mean that systems like AVID and Sony that work with the non FCP version can not use the FCP files at all?


Thanks,
Scott

[Tommy Schell]

As far as we know, the likes of Avid and Sony Vegas prefer MXF files.
We have not verified that they can take Quicktime files with the XDCAM HD 422 profile - possibly not.
MXF support is on the short list of features to add for the Flash XDR / nanoFlash.

Tommy Schell

[Douglas Scott]

If Quicktime files aren't used by Sony/AVID and MXF files are not supported yet, exactly which editing systems can use native XDR files as they are right now?

I just sent a couple sample native 50 Mbps files from the XDR to one of my national clients for a test to see if the files would drop into their XDcam HD editing system. I don't know if they are using AVID or not, but I would think that they are. I'll find out.

I hope I haven't jumped the gun by sending sample files and advertising to my clients that I can record XDcam HD files and that they are usable to them.

Are native files from XDR going to work in AVID or Sony editing systems?


Scott

[Dan Keaton]

Dear Douglas,

The native files, those produced by prior to version 0.0.117, and those produced by version 0.0.117 when not in Quicktime mode, are a custom file format, usable by the Flash XDR only.

These files can be written and played back by the Flash XDR, but not by Non-Linear Editors.

The Quicktime files are the first files that are compatible with some Non-Linear Editors.

As soon as we have MXF ready, then these files will be readable by many more Non-Linear Editors.

New firmware releases will be available, relatively soon, which will allow some of these additional options.

[Douglas Scott]

What is relatively soon as far as version upgrades?

The XDR is useless until I can send my clients from the field files they can use in their editing systems. I would say that AVID is mostly used by my national clients and Final Cut Pro is probably next in line.

FYI, on many of the projects I work on as a freelancer, we shoot a story in a day and I either FedEx the tapes to the editors for next morning editing or do a satellite uplink for editing that night. Some projects will take 2 or 3 days, but the tapes are sent out right after we finish shooting or the field producer takes the tapes with them. On some occasions, a courier is sent to the shoot location to take the tapes to the nearest airport for the next flight out.

The critical point here there isn't much time for transferring formats. I could get away with transferring from the XDR to a DVD or hard drive to be sent out, but I don't think there is time for loading the files into say FCP and rendering them into another format and output them onto a DVD or hard drive for shipping. There just isn't time at the best of locations.

When flash media comes down in price enough to send them to my clients, I will skip the transfer altogether. That is most likely a year away.

As I stated before, we need an operational menu system to review clips, etc., but more importantly are files that can be used by production houses throughout the USA and beyond. Until this is done, I have a very expensive paperweight with lots of promise.

Scott

[Dan Keaton]

Dear Douglas,

Here is a quote from a recent post by Mike Schell:

We should have a firmware update very soon. We are testing the 1080psf code now and Brent is working on a menu update. QT playback should be available next week.
__________________
Mike Schell
Convergent Design

The current release, 0.0.117, is designed to allow you to create QuickTime files for testing.

Next week you should be able to create QuickTime files, as well as play them back within the Flash XDR.

[Mike Schell]

Originally Posted by Douglas Scott

What is relatively soon as far as version upgrades?

The XDR is useless until I can send my clients from the field files they can use in their editing systems. I would say that AVID is mostly used by my national clients and Final Cut Pro is probably next in line.

FYI, on many of the projects I work on as a freelancer, we shoot a story in a day and I either FedEx the tapes to the editors for next morning editing or do a satellite uplink for editing that night. Some projects will take 2 or 3 days, but the tapes are sent out right after we finish shooting or the field producer takes the tapes with them. On some occasions, a courier is sent to the shoot location to take the tapes to the nearest airport for the next flight out.

The critical point here there isn't much time for transferring formats. I could get away with transferring from the XDR to a DVD or hard drive to be sent out, but I don't think there is time for loading the files into say FCP and rendering them into another format and output them onto a DVD or hard drive for shipping. There just isn't time at the best of locations.

When flash media comes down in price enough to send them to my clients, I will skip the transfer altogether. That is most likely a year away.

As I stated before, we need an operational menu system to review clips, etc., but more importantly are files that can be used by production houses throughout the USA and beyond. Until this is done, I have a very expensive paperweight with lots of promise.

Scott

Hi Scott-
Just for my clarification, your #1 priority (for the Flash XDR) is MXF file support, so our files can be played back (and edited) on an Avid system, without transcode?

MXF support is planned in the very near future. We are working on 1080psf and audio control this week. Next comes QT file playback followed by MXF support. Our native file (CDV) is already very close to the MXF file format, so I anticipate a short development cycle.

At what cost does Compact Flash become a viable media to transfer files? The 32GB cards (good for 70 mins at 50 Mbps) are now $85. If your files are less than 30 minutes in length, you could consider a 16GB card for transfers.

[Paul Cronin]

Hi Mike,

Wow where have I been this my first look at the XDR and I am very interested in pulling the trigger. I shoot with EX1 and use FCS2. I have a few questions:

What is the availability of the unit?
Do I need a SDI input like Matrox MXO2?
Are the 32GB cards available?

If the unit does all you claim I have a few clients who will jump up and down when I give them HD 422.

I will go to your site and see what I can find out and search this forum.

Edited:
Sorry for the old questions. I have now started to catch up and hope your XDR Flash hits the market soon and works with FCS2.

[Douglas Scott]

Originally Posted by Mike Schell

Hi Scott-
Just for my clarification, your #1 priority (for the Flash XDR) is MXF file support, so our files can be played back (and edited) on an Avid system, without transcode?

MXF support is planned in the very near future. We are working on 1080psf and audio control this week. Next comes QT file playback followed by MXF support. Our native file (CDV) is already very close to the MXF file format, so I anticipate a short development cycle.

At what cost does Compact Flash become a viable media to transfer files? The 32GB cards (good for 70 mins at 50 Mbps) are now $85. If your files are less than 30 minutes in length, you could consider a 16GB card for transfers.

Hi Mike:

Since the XDR is built around the XDcam format, I believe the unit should be able to have a file that any XDcam editing system can work with, e.g., Sony, AVID, etc. as soon as possible.

Next, Final Cut Pro is very popular so the ability to edit on that platform is essential as well. This will surely be the format for your future Nano customers and current XDR users of in-house productions.

A normal day of interviews & b-roll uses 6 to 10 - 30 minute tapes. This would need roughly 4- 32 g CF cards. When the cards are at or under the $25 per card, you'll be in the competition range of tape stock. Even though you can reuse the cards, I would need to have 3 or 4 sets of 4 in stock at all times when sending cards off to clients. The turn around would probably be around a week. Of course as cards get larger in size, the math would be done for these base numbers of roughly 5 hours per day of footage. On long days, the tape count goes up.

The cost of cards is one reason why I'm using the drop onto DVD or hard drive method of deliver. Another concern is whether my clients are going to have the readers available for a CF card workflow.

In the end, until my clients can edit the footage/files, cards, size and their costs are a mute point.


Cheers,
Scott

[John Richard]

Scott:

Some cost & time advantages to consider with the XDR / Sony XDCAMHD 4:2:2 ...

1. Expensive VTR deck not required. Sub $20 USB800 Compact Flash card reader does the job AND does it so much faster. Your former tape clients would love the lack of high dollar VTR time or need.

2. No tape capture time and cost. The time to transfer files from Compact Flash cards to a portable hard drive is negligible compared to process of capturing from tape to hard drive. Your former tape clients would love the elimination of tape capture labor.

3. Hard drive reuse is many times that of tape reuse.

3. 10 to 20 tapes vs. 1 portable hard drive being FedX'ed

These saving advantages are already available to FCP 6.02 and up - QT (.mov)
These savings will be soon available to any MXF NLE that handles this Sony XDCAMHD 422 codec.

Bottom line - if you were on the other end of the chain - which would you rather receive from the videographer - 10 to 20 tapes that have to all be captured, or a portable hard drive with all the footage already digitized ready to be copied onto the file server or edit bay raid?

[Douglas Scott]

Originally Posted by John Richard

Scott:
These saving advantages are already available to FCP 6.02 and up - QT (.mov)
These savings will be soon available to any MXF NLE that handles this Sony XDCAMHD 422 codec.

Bottom line - if you were on the other end of the chain - which would you rather receive from the videographer - 10 to 20 tapes that have to all be captured, or a portable hard drive with all the footage already digitized ready to be copied onto the file server or edit bay raid?

Yes John, the benefits of an all-digital workflow will be nice and that's what everyone wants except maybe the tape manufacturers.

However, the FCP version is not a stable version at this time and not recommended by C-D for production work yet. The other question is when is the MXF version going to be ready? Soon could mean next week or 6 months depending on your definitions.

So for your "Bottom Line" the file that the customer gets has to be something they can work with and that is not a reality as of today and in the next week or so if you're not using FCP, you are still out of the loop.

Scott

[John Richard]

Originally Posted by Douglas Scott

So for your "Bottom Line" the file that the customer gets has to be something they can work with and that is not a reality as of today and in the next week or so if you're not using FCP, you are still out of the loop.

Scott

That is a valid point. The C-D engineers seem to work quickly as can be seen in the numerous firmware upgrades. For what little it's worth, I would imagine MXF files will be available within a month.

I've just gotten a break and started testing our alpha unit on an XLH1 and XHG1 and the results are beautiful - color appears much more accurate over HDV and richer. Mosquito noise and jaggies (aliasing) are greatly reduced. Just shot some 100mb scenes panning a forest with tons of details like pine needles and small leaf bushes all in dappled light. The mosquito noise dropped noticeably over the same shot in 50mb. Closeups of seed grasses and leaves gently blowing in the wind were indistinguishable between 50mb and 100mb.

Will be looking for another opening to shoot some torture tests like waves crashing on shore or a waterfall to see the difference between HDV, HDCAM422 at 50mb, and then at 100mb.

Using the workflow that Tommy Schell described above. XLH1 > HD-SDI > XDR > USB Compact Flash reader > drop files onto FCP timeline sequence > Multibridge Pro HDMI out to a Samsung 1080P DLP 67" monitor and HD-SDI out to a Panasonic LCD BTH1700 monitor.

The time to transfer the files to the hard drive from the Compact Flash Card; less than a minute. (Not even necessary if you want to edit off the card).
The time to capture the files from the tape; about 20 minutes.

The recent QT .mov firmware upgrade is a real treat to get a feel for what a gem the XDR is. Eager, as many are, for QT production work grade firmware version as well as MXF version. We use Edius for much of our work and imagine it will have to wait for the MXF version files.

[Mike Schell]

Originally Posted by Douglas Scott

Hi Mike:

Since the XDR is built around the XDcam format, I believe the unit should be able to have a file that any XDcam editing system can work with, e.g., Sony, AVID, etc. as soon as possible.

Next, Final Cut Pro is very popular so the ability to edit on that platform is essential as well. This will surely be the format for your future Nano customers and current XDR users of in-house productions.

A normal day of interviews & b-roll uses 6 to 10 - 30 minute tapes. This would need roughly 4- 32 g CF cards. When the cards are at or under the $25 per card, you'll be in the competition range of tape stock. Even though you can reuse the cards, I would need to have 3 or 4 sets of 4 in stock at all times when sending cards off to clients. The turn around would probably be around a week. Of course as cards get larger in size, the math would be done for these base numbers of roughly 5 hours per day of footage. On long days, the tape count goes up.

The cost of cards is one reason why I'm using the drop onto DVD or hard drive method of deliver. Another concern is whether my clients are going to have the readers available for a CF card workflow.

In the end, until my clients can edit the footage/files, cards, size and their costs are a mute point.


Cheers,
Scott

Hi Scott-
Thanks for the explanation. We agree completely in the need for an XDCAM comaptible file (MXF). Our current CDV file format is already very close to MXF, we just need to add the headers for full compatibility.

In a few days we will release a new firmware update with 1080psf support for QT. We'll also have a lot more menus enabled, including system and audio menus.

Next week we are concentrating on QT file playback with the abaility to playback the last clip (recordered) or to select any individual clip for playback.

After these updates, we'll dive into MXF support, which is slated for a November release. We're also looking into a QT <-> MXF translator from Open Cube (a French software company). While we will have QT and MXF support, the ability to convert to the "other" format will always be a useful utility as we will never be able to record QT and MXF simultaneously.

I would assume the CF card prices will continue their 40-50% yearly price drop curve for the foreseeable future. So, CF may just replace tape in the not too distant future. BTW, CF card readers (USB) are around $15.