How to achieve smart encoding from MXF files?

[sebazvideo]

I'm new to the MXF format just having bought my first camera with it, but I saw that in the MPEG 2 MXF exporter there is an option for "segment encode", which I read is what Edius calls smart encoding, meaning that only the clips that had any effects applied to them will re-encode, but those that don't have any changes will just be copied without re-encoding.

So I edited a timeline of about 20 minutes long, and I chose that exporter, changing a couple of things to match the format of the original file, such as 50 Mbits and 4:2:2 chroma, and obviously making sure that segment encoding is checked.

But when it starts encoding, it shows that it will take hours, until after twenty seconds or so it goes down to about 30 minutes, where it stays. So this means it's not smart-encoding, because the clips are all untouched saved for the first one which has a fade and a title, and the fade out on the last one.

By comparison, exporting the same timeline to Canopus HQ took about ten minutes, and that had to be encoded bit by bit to a different format.

So I was wondering, is there anything else I have to do to achieve smart encoding from MXF to MXF, or is it not possible?

[antonsvideo]

are your original clips from a PDW-700 or 800?

when you print to file, did you click XDCAM on the left? then enable conversion, and then select a suitable preset that matches the original

[sebazvideo]

Thanks, Anton. No, it's a Canon XF100. Although I did try what you suggested but it does exactly the same as the MXF MPEG2 exporter.

[antonsvideo]

can we see the full mediainfo properties of such a source clip

[sebazvideo]

can we see the full mediainfo properties of such a source clip

Sure:


Complete name : E:\Canon XF100\20120407193949\AA009601.MXF
Format : MXF
Commercial name : XDCAM HD422
Format profile : OP-1a
Format settings : Closed / Complete
File size : 1 002 MiB
Duration : 2mn 41s
Overall bit rate : 52.2 Mbps
Encoded date : 2012-04-07 15:46:56.000
Writing application : CANON XF100 1.00
Writing library : CANON XF100 1.00

Video
ID : 2
Format : MPEG Video
Commercial name : XDCAM HD422
Format version : Version 2
Format profile : 4:2:[email protected]
Format settings, BVOP : Yes
Format settings, Matrix : Custom
Format settings, GOP : M=3, N=15
Format_Settings_Wrapping : Frame
Duration : 2mn 41s
Bit rate : 50.0 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 29.970 fps
Standard : Component
Color space : YUV
Chroma subsampling : 4:2:2
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.805
Stream size : 961 MiB (96%)
Delay_SDTI : 56774868
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709

Audio #1
ID : 3
Format : PCM
Format settings, Endianness : Little
Format_Settings_Wrapping : Frame (AES)
Duration : 2mn 41s
Bit rate mode : Constant
Bit rate : 768 Kbps
Channel(s) : 1 channel
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 14.8 MiB (1%)
Delay_SDTI : 56774868

Audio #2
ID : 4
Format : PCM
Format settings, Endianness : Little
Format_Settings_Wrapping : Frame (AES)
Duration : 2mn 41s
Bit rate mode : Constant
Bit rate : 768 Kbps
Channel(s) : 1 channel
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 14.8 MiB (1%)
Delay_SDTI : 56774868

[antonsvideo]

great

now can I see a screenshot of the project settings, all expanded and the export settings, all options

[sebazvideo]

now can I see a screenshot of the project settings, all expanded and the export settings, all options

[GrassValley_PS]

In the future, please use Manage Attachments after you hit the reply button for attaching screenshots. PNG usually works best. Thanks.

[antonsvideo]

ok, you are using the MXF mpeg exporter

the MXF mpeg exporter has quality settings, it is impossible to guess what quality was used by the camera

so, try this test and confirm that segment encoding is working

1. export to mpeg MXF a few minutes and time the time taken
2. place the exported file on timeline and export again with the same settings, it should be super fast

here is how it works for me:

1. I place original MXF clip from 1440x1080 SP quality (25M) 50i camera on timeline
2. I choose export, XDCAM, enable conversion, now I choose the 1440x1080 SP 50i preset and export, it only takes the blink of an eye, segment encode works

there is a XDCAM 4:2:2 export preset, leave quality on normal, normal means no change in this case

[sebazvideo]

OK, so using the XDCAM exporter, this is what I found out. I selected a random segment of several clips that totaled 6:54;18. I exported between in and out making sure segment encode was selected, as well as 50 Mbps. I left quality at normal and it finished in 1 minute 15 secs, and the CPU was showing a use of about 35%. Then I exported again but selecting Closed GOP, and it was going to take over 6 minutes but the CPU was at 100%, so obviously it was rendering every frame, so I cancelled that.

Then I exported again selecting Superfine and unchecked closed GOP, and it took 2 mins 11 secs, with CPU at about 35%.

So my guess is that it's re-encoding only parts it needs to, around the clips boundaries, and copying the rest. It's good, but I think I will still export to Canopus HQ at the highest quality as long as I have the extra disk space. There's less loss of information that way.