Avid Media Composer 4.0.5
 

Dear Friends,

I noticed that Avid Media Composer 4.0.5 is now available for download. This is a free update for those with Avid Media Composer Version 4.

I have attempted to find the release notes for this version without success.

Is anyone using this version?

If so, does our 100 Mbps Long-GOP work with 4.0.5?

There is no mention of CD nanoflash support in the readme file under AMA updates. Only updates for Ikegami GFCAM.

Here is a link to the readme file: http://avid.custkb.com/avid/app/self...348265&Hilite=

Dear Friends,

It appears that Avid Media Composer 4.0.5 works with our files the same as previous versions.

Thus, 50 Mbps Long-GOP works great, as does all I-Frame Only modes.

100 Mbps Long-GOP and higher have buffer errors when playing files on the timeline.

Dan, when you say "playing files from the timeline", does this means files that have been linked to by AMA? Does this also hold for files that have been copied onto local HDD or is it just coming off the card directly?

Dear Perrone,

Our 50 Mbps Long-GOP files work fine.

This is due to the fact that the Avid buffer size, to hold an entire group of pictures is just large enough.

With our 100 Mbps Long-GOP files, when one stops playing, then the Avid Media Composer may give a buffer error. We feel that this is due to the fact that the buffer is too small to hold the full long group of pictures, so it can not find the start of the GOP.

We have asked Avid to increase the size of their buffer.

In the meantime, if one just plays a timeline, without stopping or scrubbing, it should work fine, with 100 Mbps Long-GOP. But this is impractical.

The error is non-destructive, it is just annoying.

I do not think it matters where the source files are located.

Thanks for the info Dan. I have not yet tried the NanoFlash files in Avid. That's next week. :) This week was for material that I already have!

Perrone: also, see if you can replicate another issue Mark Job and I have noted. The AVID can largely deal with the 100mbs clips, if one doesn't mind the occasional momentary pause as the AVID reminds you it's choking on the buffer size. Annoying, but doable, as long as you're not scrubbing a bunch in the timeline.

The larger problem is that you can't seem to export any of the edited 100mbs stuff out of the application...the export always fails.

It will be a happy day when AVID fixes this bug.

Ok, I got the buffer size error from the MXF file (Garden of the Gods). I was not able to use the .mov version of the files. Also the MXF nor the MOV fast imported. The Garden of the Gods clip was recognized as XDCam HD. So that's GREAT!

I was also able to export a .MOV file DNxHD 36 and an .AVI file. My first attempt at a .MOV export failed and indicated I could not use "same as source". So I just did a custom .MOV with the export selections I wanted. Easy as pie.

I am using 4.0.4 of MC.

....And you cannot export the edited timeline out of the application ! You *May* be able to *Play out* the timeline in realtime if you have an Avid Mojo DX, Nitris, or an Adrenaline box. (??) You also may *NOT* be able to transcode the Long GOP 100 + data rate files into DNxHD either ! EDIT: Downloading and thoroughly testing 4.0.5 now. Stand by for a thorough report in a couple of days :-)

Strange Claims in Avid MC 4.0.5 Readme
 

Hi Dan:
On page 5 of the new Avid Media Composer Readme .pdf it states,

" The following have been added to this version of the editing application:

Avid supports linking to MPEG 2 HD Long GOP 102 Mbits media with AMA via the
GFCAM AMA plug-in......."

I find this statement quite interesting. I will investigate further to decipher exactly what it actually means.

Are you guys not able to replicate what I just did yesterday? I didn't have any trouble making a DNxHD file out of MC 4.0.4

Dear Mark,

Yes, that is very interesting.

I had to look up "GFCam":

Ikegami Press News

Guys - just a quick update -

First off - Lets tackle a few of the points raised in this thread - you cannot xport long gop media of any kind with QT Ref and this includes standard XDCam material @ 35Mb/s. This is a QT limitation rather than Avid. The QT handler cannot decode the LongGOP media "on the fly". This is not a Convergent Design limitation

Secondly - AMA will not work with the Nano, because you require the .MP4 and Sony file structure for XDCam work. This is essential metadata which tells the Avid how to stitch clips together etc. So if clips span cards etc it doesn't matter - they come up as one clip in a bin. if they go over the 2gig file limit it doesn't matter - they still appear as one clip in the bin. I would love AMA to work with the Nano but CD have a bit of work to do to make that a reality. In effect they would have to talk to Avid and possibly design their own AMA structure on the cards, or replicate Sony's. It seems Avid are open to this.

Now on to the primary topic of the thread - I'm currently using 4.04 with 100Mbs Long GOP media. I am having no problem during playback, only when parked do I get the buffer size error. I have also successfully done a video mixdown at DnxHD 120. There is a catch - the video mixdown/export will fail if you begin on a frame with a buffer error (and possibly if you end - I didn't check that). I have not done exhaustive tests but it appears that provided the in and out points of your video mixdown are not buffer error frames, it does not matter if frames in between, including if they lie on edit points, contain buffer errors. it will successfully mixdown. If it will successfully mixdown it will also successfully export. This is at best a workaround, so I only post this info to help others. My tests are very limited and not exhaustive by any means - Mark Job has done a lot more work and his results seem to vary from mine. I don't imagine the behaviour in 4.05 will be any different. One factor is that I work at 25fps - while most here work at 30 or 24.

I'm in a unique position on this project - I have the luxury of using the JVC HM700 so all my clips are dual recorded to SD card (XDCam 35Mb/s). So if I can't get it to work I can switch media. I would not advise others to take on this Avid/100Mbs Long GOP workflow without running exhaustive tests.

BTW another workaround is to transcode all your source material to DnxHD.

Dear Perrone, John, and Mark,

Thank you for all of your testing and reports on your results.

Further info - well I've cut my first sequence sometimes if you start a cut with a frame that generates a buffer error it will stop the export/video mixdown process. This seemed different from my first test but I think it probably doesn't happen of every one of these frames.

To workaround this I constructed my timeline so that every cut started on an "I" frame. This involved moving clips up a couple of video tracks and trimming clips that began with buffer errors under so that edits still happened at the right time. I could then transcode the entire sequence to DnxHD using 0 frame handles.

This is a tedious workflow and I wouldn't recommend it, but it is a workaround for those that may be stuck with this.

Dear John,

Thank you for your insight into this problem.

We will be very happy when Avid decides to increase the size of their input buffer. Then, if my theory is correct, all of these issues will go away.

At this time, editing with our 50 Mbps Long-GOP and any I-Frame Only modes work great.

Based on your finding, it appears that any of our modes will work fine if they are transcoded to DNxHD first, before any cutting is performed. I say this since all of our files should start with an I-Frame.

It would be nice if someone could test, then confirm this.

Dear Friends,

I am not an Avid expert.

I am assuming that Avid will transcode our MXF files into DNxHD.

However, this may or may not be the case.

Comments from others are most welcome.

Dear Friends,

I have learned from Mr. Bill Ravens, that Avid 4.0.5 will transcode our Long-GOP files, up to 100 Mbps, to DNxHD. But Avid 4.0.5 will not transcode our 140 and 180 Mbps Long-GOP files.

Also, Edius will transcode our Long-GOP Files, including all bit-rates up to the current maximum of 180 Mbps, to DNxHD.

Of course, one can use I-Frame Only mode, and no transcoding is necessary.

Bill, thank you for the valuable information.

This seems odd to me.

When I did an import of 100mb Long GOP into Avid MC 4.0.4, it did a fast import as XDCam. It did not transcode to DNxHD. I have not tried other rates but will do so.

Edius SHOULD be transcoding into CanopusHQ and not DNxHD. Is this what you meant?

I'll try more stuff later in the week, but it would be helpful to have more sample material on the dowload page to test. There is mostly 100mb log-gop, 1 IMX and one 220 I-Frame.

Dear Perrone,

Yes, Avid should import our files as XDCam.

I was attempting to discuss that one can import our files, (as XDCam), then prior to editing, transcode them to DNxHD in Avid.

Bill Ravens ran quite a few tests, with our 180 Mbps Long-GOP files, with various Editors, and found that Edius would transcode these to DNxHD.

Then, he said that Avid would transcode our 50 and 100 Mbps XDCam files to DNxHD.

Ok, I understand better now. Thanks!

Transcoding to DNxHD in Avid Media Composer
 

....Dan, you can setup AMC to transcode to DNxHD upon clip import. Here's how it works. Once you're open in Media Composer, go to >Effects Palette>Settings Tab> Scroll Down to Media Creation>Import Tab>Video Resolution Drop Down List> You have several choices and flavours of DNxHD to select from. I think it would be easier to transcode upon import, then import native and transcode everything just prior to export, but you can do it that way as well. I hope this helps.

....Still testing Long GOP 100...Reports soon

Hi Dan - correct on the DnxHD front. I haven't tested anything but 100Mbs so I certainly wouldn't jump to any conclusions on other data rates as they may not decode at all in Avid.

I would suggest with LongGOP 100Mbs transcoding to DnxHD 120 which is the closest match - the loss should be minimal if anything measurable.

On the Avid front - are you in contact with Avid product development team? I know they don't give much away on that front.