Hi,

I have MC3.0 on Windows. I haven't figured everything out yet. But as I understand it, I should be exporting AAFs in Clip Browser 2, then importing those AAFs in MC3.0 (which point to MXF files placed in your AVID Media Files folders), then transcoding the XDCAM video files to DNxHD145 (virually no loss in quality) so that I can edit efficiently (without the jerkyness of GOP) and then output a quicktime reference (now possible since the video is DNxHD) to eventually make a DVD.

The problem is that if you transcode both video and audio to DNxHD145 (or to DV25 for example because you want to save space, take advantage of your SD MOJO, or not need HD for awhile) you lose the link to the XDCAMs in the Avid. The drag with this is you also lose link with the originals. In other words there is no such thing as batch transcoding as there is with importing or capturing.

Transcoding upon import would solve this I would think. You could import/transcode to DV25 then when you have your sequence you could import/transcode to DNxHD145 for final outputing. Will this be corrected in a future MC or have I got something mixed up?

Thank you
Richard Burman

at least I don't have to export the files with clip browser as AAf - but as I use the PDW-U1 I can directly import the proxies to MC - as I don't know where you import the clips from, I can't give you advise on this step. now I have to options:
1. I edit the sequence with the proxy media and batch import afterwards.
2. I batch import all media to hires befor editing.
anyway - after the batch import of the hires clips I transcode them to DNxHD 120 / 185 / 185x to edit smooth and to export QT ref clips. but you don't loose the connectivity to the xdcam clips. I just batch imported an project - no problem! just after the batch import of the offline clips, you have to transcode them again.

I agree that it might be a fine feature to select a "force transcode" during the batch import process.

hope that gave you some insight to the xdcam workflow.

regards M.

It is nice to know that doing a batch import is possible but it is too bad that it requires buying another machine.  What confuses me is that even after you transcode you have connectivity to the XDCAM footage and yet I don't. The only difference is that I import AAFs and you import from an XDCAM disk. The logic escapes me.

Thank you for your response.

Richard Burman

but somehow you have to get your clips from the disc / SxS card to your computer. so why should I first strip them to a AAF instead of importing them directly. that's maybe the point why you can't batch import...

Even if I import MXFs I still lose connectivity the moment I transcode. This means that offlining in SD and then onlining in HD is impossible.

I tried importing the files which were exported in Clip Browser using the 'MXF for XDCAM' selection (instead of 'MXF for NLE'). Same problem (plus the Main Concept watermark is visible).

Richard

 My guess is Moses.M is using XDCAM, and not EX footage, since the XDCAM format (the big cameras) have proxy media generated that you can edit with, then redig and reconform to.. the EX1 (in our case) puts a wrapper around the file and I then import it to our adrenaline system, I don't have the option of importing proxy media..

I think you are right. But that leaves us, who deal with EX, with the lack of connectivity to the original material. This seems like a step backwards from the usefullness of batch capturing your tapes. Is there an Avid person who can address this?

Richard

Richard,

A few different things going on here so I'll comment separately.

The workflow, in general, sounds fine if it suits your application. Note though that the clip browser software is a media transformer meaning that it takes the EX mp4 files, unwraps them (strips the metadata) and repackages them in a wrapper suitable for the interested party. In the case of Avid, one of the new wrappers of choice (in CP v2) appears to be AAF (Advanced Authoring Format). AAF is used by several programs as a common carrier language and can point to media of several different formats.

Now, solid state media tracks footage much like tape does. In other words, each card has an associated reel name and associated timecode to match. If you track this information through your editing process, you can always refer back to the original media say for an online conform (for example). The trick is to retain the original clip name and use another field for descriptive comments instead of changing the clip name to something more mnemonic. If you do this you can transcode your media to whatever format you like and as often as you like. Clearly, the less you do so the less likely you'll have unreferenced media.

A couple of asides:

DNxHD is a video codec, so audio never gets transcoded to DNX (for short). In fact, audio in Avid is always in one of three formats: AIFF, WAVE or PCM the last of which creates MXF wrapped files in the standard folder while the other two still use the OMFIMediaFiles path (I think, I haven't checked lately in v3 as I always use PCM for HD).

Also, you don't have to use DV25 in order to use your Mojo, downconverting (mode switching) your project format from HD to SD should do the trick -- not all codecs are supported but I believe DNX is not an issue.

Finally, DV25 is a particularly bad SD codec to use with EX originated footage even when going to DVD as a delivery medium. As a suggestion, forget about the existence of DV25 when working with HD projects. If you really insist on transcoding HD footage to SD because final delivery is DVD, please use just about any other SD codec in the higher ranking quality (e.g., DV50, 3:1, 2:1, 1:1 and others). DV25 has a nice way of making a beautiful shot in HD go sour! Having said that, I recommend that you stick to HD til the end. The results of compressed MPEG2 SD (DVD) using an HD QT reference are outstanding compared to those say from HD transcoded to DV25 and then exported as something like Sorenson3 and then compressed to MPEG2. That's putting HD through the meat grinder!

Back to your concerns. Even if there is a way to track footage back to the shooting cards, loosing reference to the original MP4 files is not usually an issue when you are creating deliverables on the same machine that you edit, particularly if you are going to DVD. Think of your DNX media as your post production media masters and forget about the MP4. You can always store these and ultimately if necessary (worse case scenario) conform these by hand but the instances when you need to do this is when you are offlining somewhere, onlining somewhere else and maybe mastering on a thrid system yet.

I'm not sure why you say there is no "batch transcoding"? There may be an issue of multiplicity of media but otherwise simply import your AAF's created in CB and transcode the whole lot in one shot by placing them all in one bin. You can also do this by creating proxy master clips (copies of clips not of media).

On a last comment, again, forget about DV25. Don't transcode twice. Transcode to DNX once and edit that. MC3 on a modern machine slices through that like butter! I realize that an investment in a Mojo is upsetting when you realize that it is strictly an SD device and doesn't do much when working with HD, but it is much preferable to view HD media on an LCD via a graphics card (in the absence of DNA hardware) rather than downconverted to something soft and blurry (compared to HD!)

I hope this helps. Cheers, David.

ok - I use XDCAM HD 422. but having the ability to batch import is a basic necessity.

GCapps has this right Richard. EX footage is not the same as XDCAM footage. The latter creates MXF wrapped media while Sony solid state cams create MP4 wrapped footage an no proxies. This is not an Avid issue, it is a Sony issue. The reasons for them having done this don't really matter but what needs to be kept in mind is that XDCAM disc based shooting is mainly conceived as a tape replacement media format. In other words, you shoot each reel on a disc and at the end of the shoot you have a stack of discs. No media transfer is conceived for disc based XDCAM prior to post. (This allows Sony to sell more media!)

Solid state based XDCAM is different. With cards costing say $1K, clearly you are not going to shoot a doc on 100 of these. They are buffer media devices with the idea being that you transfer the contained media to some other data device (hard drive, DVD, data tape, Blu-ray... note the last of these... guess what XDCAM discs are?). This transferred footage becomes the holy grail in the solid state world - they are your originals. What's on the card is irrelevant; you shoot, transfer and reformat.

A method to retain trackability (in the tape batch capture sense) is in place. Sony's concept is that you transfer solid state footage to XDCAM disc media via software and a deck. This renders (transforms) all of your EX footage to XDCAM equivalent including proxy footage just as if it had been shot with a disc based cam. So the solution is there, it's just a matter of whether you wish to use this method. Most small cam users don't typically want to go and get an XDCAM deck as it goes somewhat against the idea of using a small solid state camera in the first place...

then again, there's production, post production and marketing. The three rarely meet! (we're lucky if the first two meet...)

More 2c thoughts. David.

 Hi David,

I posed the same question on another forum and my respondent's solution seems too good to be true. He does have transcoding happening on import. His methods seem unusual though. Do you understand it? And what is DNxHD185? Note that his profile lists Avid Liquid.

http://www.dvinfo.net/conf/sony-xdcam-ex-cinealta/135058-ex-avid-workflow.html

Richard

I've used Cineform HDv before on HDV project in Sony Vegas, it's really great. I don't have experience for Cineform HD yet on EX, but I won't be surprise it works well too.

The only downside for that is the intermediate file generated is VERY BIG in size since it's little compressed.