[Eric Lanouette]

Thank you guys for all the reply.

Like you, I’m not sold to the idea of using the XIV as a video production SAN…

You may not know it but the thing is a beast with sky rocking specs. Some call it the IBM Enterprise flagship SAN as it uses dual 20Gbps infiniband and dual 600Gbps Infiniband switches to interconnect each storage unit and the overall bandwidth can achieve 9.1Gbps reads / 6.8Gbps writes.

As it cost nothing, I will conduct some test with the XIV to see how it performs and what kind of latency I get.

I need to know what is the usual latency and acceptable limit on SAN used for video production storage. Is 17ms too high?

Eric

[Eric Lanouette]

Richard,

Do you plan to release a Mac version of MX Light?

Thanks

Eric

[Eric Lanouette]

As a mac user, I hope that the BM software dev team that is working hard on the FCPX support will find some time to add an interlaced capture mode to Media Express soon.

[Eric Lanouette]

I’m waiting for a way to deactivate the deinterlacer since they release the unit. In my case, I don’t even want it to support native interlaced coding (PicAFF, MBAFF), just bypassing the auto deinterlacer feature.

I can’t figure it’s hard to add an option or simply release an alternate firmware that deactivate the deinterlacer.

For your post-prod workflow, I doubt the Pro Recorder is outputting an H.264 file that is 100% Bluray compliant.

[Eric Lanouette]

Here some thoughts about your example :

01. There is a quality gain but it’s imperceptible to the eye. You don’t see it but the noise, sharp edges and others picture details are reproduced more accurately. That’s why the file is bigger.

02. Never, never, never use bitrate as a quality measure, it’s not. At the same resolution, some content will need more bitrate than others to achieve the same quality level. The best example is a sport game vs a news interview. If the static news interviews is okay at 500Kbps, the sport game with lots of action, fast moving camera and scenes cuts will be horrible.

What I understand is that you want to encode each of your files, whatever the content or resolution, to the maximum perceptible quality. Instead using an average bitrate for video encoding, you should use a constant quality index.

01. Download the last nightly build of handbrake for your system at https://build.handbrake.fr/

02. In the video panel, encode it using “Constant Quality” with an RF value around 19 to begin with.

03. In the advanced panel, max out all the options and disable mb-tree.

04. Review the encoded video and lower the RF value to 18 to increase quality or increase it to 20 to lower the quality until you find the right spot that please you.

05. Don’t look at the bitrate, ignore it.

You don’t need to go insane with the encoding options because at a point you will get about no quality increase or file size decrease. Some good options to use are :

b-adapt=2:rc-lookahead=50:ref=6:bframes=6:direct=spatial:me=umh:subq=10:merange=32:psy-rd=1.0,0.10:analyse=all:trellis=2:no-mb-tree=1

In the advanced panel, paste them in the x264 advanced option string and adjust the quality slider in the video panel. The video might not play on mobile devices as I don’t see it as a requirement in your post.

As the video is scaled down there will be less noise and artefacts in it so an RF value of 19 can be low (too much quality). Note that I mainly use RF 16 for a 1920×1080 video to retain more grain and quality but some will always tell you that it’s too high or too low…

Eric

[Eric Lanouette]

Scott,

Video glitches are gone but I cannot confirm if the audio will stay in sync for an hour and half as I only capture short clips.

If you buy one, I would recommend to output progressive content from your camera to bypass the average deinterlacer in the H.264 Pro Recorder.

Eric

[Eric Lanouette]

For legal reasons HDMI input is unable to capture from copy protected HDMI sources. Always confirm copyright ownership before capture or distribution of content.

https://en.wikipedia.org/wiki/High-bandwidth_Digital_Content_Protection

[Eric Lanouette]

Joshua,

Maybe pro video users think this box is featuring an interlaced capture mode because specs lists 1080i50, 1080i59.94, 1080i60 as supported formats but no where in the user guide or on the Backmagic website I can find anything clear about an “internal deinterlacer”. As buyers rarely read the user manual before owning the product, they will discover when reading the page 11 :

“Capture from progressive and interlaced video sources is supported and the captured file is stored in a progressive format for maximum compatibility…”

I think this important information should be added to the specs sheet on the Blackmagic H.264 Pro Recorder product page for clarity. Video professionals that need it for interlaced capture will stop buying the box and less peoples will be asking for an native interlaced capture mode.

I’m glad to heard you very much want to add that feature in the future. I only hope it will be as soon as this year.

Eric

[Eric Lanouette]

Joshua,

Like some other people here, I’m still hoping for an interlaced encoding mode in a near future. The lack of support for that feature in a pro device is somewhat strange.

As the video glitches looks to be gone, if the audio can stay in sync for long clip, it will only miss an interlaced encoding mode for this box to be perfect as the high CPU usage is related to MediaExpress.

Eric

[Eric Lanouette]

Thank you Andrew for the links

I also confirm that the video glitches are gone with DesktopVideo 8.2.1rc3 and MediaExpress 2.4rc45. Good job BM!

Now, we need a proper way to capture interlaced content. I hope that bringing an interlaced capture mode is the next feature they will implement.

Eric