Is Vegas OK for D-1?

Coursedesign wrote on 6/29/2004, 10:28 AM
I shoot mostly educational in-studio productions and am shopping for a setup that will give me the highest quality I can get without going to HD.

Distribution is NTSC and PAL, both DVD and broadcast.

After working on high end DVCAMs (Sony DSR-500), I still can't get enough quality (especially with a lot of keying).

Possible causes:

a) recording in 4:1:1 when rendered to 4:2:0 on DVD (or in PAL) becomes 4:1:0, ie. 97% of the chroma information is removed

b) artifacts from the Discrete Cosine Transform compression used in DV formats

Betacam SP preserves more chroma, about equal to 4:2:2 sampling. But the analog tape format has a lower S/N than the best digital formats.

Betacam SX is MPEG, so probably trickier to edit in Vegas.

DigiBeta is really nice, but shockingly expensive and still compressed albeit very mildly.

My thinking is to get a Sony DXC-D35 family camera head with a CA-D50 adaptor that outputs pure SDI (259 Mb/s serial digital) with only one single A/D conversion (straight from the camera DSP).

Instead of using a $50K tape deck I would feed the SDI cable straight into a $295 BlackMagic hi-speed PCI card with live encoding to a fast harddrive (single SDI stream doesn't even need a RAID per BlackMagic). This can be done in 8-bit D-1 at about 1GB/minute, but who cares with today's harddisk prices? I come from a film background so I don't have high shooting ratios in my material anyway, everything is carefully planned.

As best as I can tell this will give a picture quality that should look better than any other SD tape format (short of D-5).

Of course I don't get the conveniences of tape (easier field recording, archival, etc.), but for my situation this seems a reasonable tradeoff. (The DXC camera heads can be docked with a Beta SX, Beta SP or DVCAM back for field use.)

Now the $10,000 question:

How does Vegas handle D-1?

Do I need to use a proxy to get good hands-on editing performance?

(Long renders are no problem, this is not 9:59pm editing for the 10 o'clock news.)

Will all effects etc. work with this 8-bit uncompressed video?

What if I capture as 10-bit uncompressed (also supported by the SDI standard)?

Experienced advice would be much appreciated, as well as pointers to any potential problems with this recording method.

Comments

SonyEPM wrote on 6/29/2004, 11:32 AM
In the Decklink case, you could, today, capture with their app, load file into Vegas, apply processing of any type, render to Decklink QT codec, output via SDI (if that's needed).

You will need a pretty smokin' machine/drive array to handle capturing SDI, but if you have a system up to that task, performance in Vegas should be ok. Given the fact that you are going to be doing some heavy processing (keying + whatever else using QT uncompressed source) you probably aren't going to get full framerate without a prerender.
Coursedesign wrote on 6/29/2004, 12:47 PM
Thanks, I will try it and share my experiences.

BlackMagic recommended getting a server mobo to make sure the bus throughput wasn't throttled anywhere, and of course competent disk performance.

Do you have any current CPU recommendation for max. real life performance on a server mobo?

The new Xeon, announced as shipping today, looks good assuming it actually works... See http://www.pcpro.co.uk/?http://www.pcpro.co.uk/news/news_story.php?id=59918

Intel claims 30% better performance and support for PCI Express and DDR2, "expanded support for Streaming SIMD Extensions 3 (SSE3) Instructions for thread synchronization for better system responsiveness in media...", and 64-bit instructions [that some have said are compatible with AMD's Opteron].



RBartlett wrote on 8/5/2004, 11:40 AM
Anything above a 1.4GHz Xeon (RAMBUS PC800) family board (with AGP slot) will do. Smoky doesn't necessarily mean new, just not the regular overpriced gamer PC! (Dell made some i860 Workstation class machines that were pretty cheap when they were new 2+ years ago - they made good VideoToaster and DigiSuite/Velocity systems for Windows2k/DirectX8).

Consider (for not needing an EATX case, nor a "special" socketry PSU, nor buffered DDR266:

SuperMicro:
X5DAL-TG2
I-Will
DP533-S

If you don't mind paying more for an EATX case and respective PSU AND buffered or ECC DDR2:

Supermicro
X5DCE (non-SCSI)
X5DA8


If all the above are too pricey. You might scrape with a P4SCT from Supermicro (not the SCT+). This has a bus bandwidth limit of 266MByte/sec on the 64bit slots.

If you go SATA, consider a controller from RAIDCore or a 3ware Escalade series. You wan't to be wary of thinking of these as anything other than a RAid0 or RAID1+0 or RAid10 solution. Multimedia isn't the same through these types of boards as enterprise applications - the duty is often too long for you not to notice that they get sluggish in redundant modes.

If you go SCSI Adaptec 39320 (onboard or Pci64 slots) is fine, just don't buy any RAID engine. Again these are poor for long duty cycles found with multimedia. Windows striping (through disc management) is best.

Shrink wrapped storage solutions include those RTRX models from Medea.

You'll find that D1 is amply editable in many apps on such a machine. Each YUV stream is upwards of 22MB/sec (AVI container + audio excluded).

Vegas5 is 8bit RGB internally, AFAIK, but the dynamic range of your project will invariably squeeze in to this even with 8bit YUV sources (which maths suggests 10bit RGB pipelines are needed for) - but we won't get into that here. Seems like you could use your Vegas work inside XPRI at some point which I don't think spells anything rough for Vegas' future.

Happy uncompressed 4:2:2 >=259Mbps