Chris Blair
Forum Replies Created
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Sounds like you’re making progress. Keep us posted on how it turns out.
Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com
Read our blog http://www.videomi.com/blog -
Yup..we need more info. We need to know what your settings are when you compress to your MPEG2 file for the DVD. Also…I know a lot of DVD authoring programs will recompress an MPEG2 file if it doesn’t meet all the DVD specs when it’s loaded into the authoring program. I don’t use DVD Studio Pro so don’t know if it does it but every single Windows based authoring progam will (I’ve used dozens)…so worth checking to make sure you’re not compressing twice to MPEG2.
Are you keeping everything progressive throughout? Is the source footage 24P and if so are you keeping it 24P throughout with no pull-down anywhere (DVD players will typically add pulldown if it’s needed).
But we need to know your data rate settings in your MPEG file, field order or progressive scan, any filters getting applied etc.
Others on the list can address your DVDSP specific questions.
Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com
Read our blog http://www.videomi.com/blog -
Hmmm…interesting. Scaling 720P to 1080i should not result in a huge loss…there have been lots of engineering studies that have shown 720P and 1080i are very similar in terms of overall resolution. Now 1080P would show it, but 1080i should not.
If they have Final Cut on the laptop…I don’t understand why you export to HDV? Why not just export using the native XDCAM that came out of the JVC camcorder?? Or..is the FS-4 recompessing the signal out of the JVC camcorder to HDV? That would be the first thing I’d investigate…keep your signal in HDCAM since it’s 4:2:2 color space and it has a data rate of 35mb/sec. HDV is 4:2:0 and runs at 19mb/sec, so it’s way more compressed than the Sony XDCAM.
Next place I would look would be the settings coming out of Final Cut on the laptop…are they correct…meaning field order set properly, pixel resolution match your exported file, frame rate match etc.
Then I would check the scaling from the Kramer unit. We own some Kramer products and most are very good, but if you have even one incorrect setting, it can cause blurry, jittery video.
Last….is the Sanyo projector a true HD projector? It would need to project either 1280×720 or 1920×1080 to be true HD. Also, is the feed from the Kramer getting scaled yet again to whatever the size the projector is sending or does it match the projector.
Whew…you got a lot of cogs in your wheel…I’d check all those before switching camaras…I can’t imagine the Sony EX3 is going to be that much better than the JVC model you’re using.
Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com
Read our blog http://www.videomi.com/blog -
We’d need a lot more info to help at all on this. Read the sticky note at the top of the forum titled:
How to get FASTEST compression help – PLEASE READ
But I will say that compressing to HDV is NOT going to give you great quality. HDV is barely even a professional format. A lot of broadcasters either won’t accept it or the content has to only include a small percentage of HDV sourced material.
It’s typically MPEG2, 4:2:0 (half the color is thrown out) and the data rate is roughly 20mbits/sec…(that’s 2 Megabytes per second).
For comparison sake, according to Blackmagic Design’s website, uncompressed 8-bit 720P HD = 105 MB per/sec. So your exported footage is compressed at a whopping 52:1 and half the color is thrown out.
So I would think encoding to something more robust that doesn’t get rid of half your color and compress as heavily would be better choice.
Why not just use the native codec and avoid re-encoding? I believe the JVC camera you mention records to Sony XDCAM, which is double the data rate and I believe it’s 4:2:2. That’s why we need more info…like…what is the venue using for playback?(I’m assumig you’re talking about a remote location where the video is played??)
Also…depending on your shooting conditions, expectations may be higher than they should be. If you’re shooting in low or very contrasty light (with no articifical lighting added), then you’re going to have a tough time getting high quality images.
Give us more info and answer some of these questions and people can likely help you out.
Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com
Read our blog http://www.videomi.com/blog -
Todd Terry: We do mostly broadcast commercials, so we invariably get the “How much does a commercial cost?” question.
My typical smartass (although accurate) answer is “How long is a road? It just depends on where you want to go, and what kind of scenery you’d like along the way.”
That’s classic! I think I’ll steal that one!
Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com
Read our blog http://www.videomi.com/blog -
John Davidson wrote: When all files are downloaded on the other end, the user only has to click the first file (which should have a name like 30spot-open me) and their mac will rebuild the original file – nobody on the receiver end has to install anything.
The problem you’re likely going to run into with stations and cable systems is that most of their systems are automated…people are not involved and trying to convince a station to give your file special treatment will be difficult if not impossible. Not to mention if they’re using Telestream’s Flip Factory, adManager or Traffic Manager software…they’re all Windows only.
We can’t even get stations to implement Telestream provided fixes for the field reversal issue, which is just a tiny, simple plug-in that Telestream will provide and help setup for the station.
The reason? It would mean setting up a special watch folder for these problem files…which the stations and cable systems refuse to do. And believe me…we’ve asked…in fact we got telestream to figure out the problem by sending them several of the files stations were having problems with….within an hour they emailed back and said that there was nothing wrong with our encoded files, but that some of their presets for playout servers did indeed reverse the fields (usually a 720×480 to 720×486 conversion issue or vice-versa). They said it was an EASY fix…but the station would need to set up that special folder since the plug-in wouldn’t need to run on “non-problem” files. The stations refused (several)…saying they couldn’t do that because their engineers and IT people wouldn’t allow changes to the system (despite the fact that it FIXED a glaring problem with the quality of their spot playback).
Perhaps some networks would be willing to do something like DMG chop for a program length file, but my guess is many would not, especially if they’re PC based with Telestream products as well.
We’ve researched this issue of speed since the early part of this decade when we first started FTP’ing spots (2002 to be exact)…and there is no good, affordable solution that we’ve found works for both the sender and the receiver when it comes to files over about 250MB.
Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com
Read our blog http://www.videomi.com/blog -
I downloaded the file and VLC says it’s supposed to be a 720×486 file, but when I size it to 100% there are about 20 pixel black bars on each side of the frame. So it appears the video is squished and black bars are added to the sides to make it 720×486.
In Quicktime, there’s what looks like a 40-50pixel white bar on the right side, and again, it appears the video is squished and the white bar is somehow getting added to make the file 720×486. Quicktime reports the format as H.264 at 654×486, but it reports the normal size as 720×486…which is very strange.
Your movie also displayed this way (with the white bar) in mutliple browsers when I played it. So it looks like something is messed up with your sizing on the file, which could account for the artifacting. We’d need to know what you used to compress it, what the original file is (format/codec), what settings you’re using in the compression program etc.
It’s probably best to size for computer screens if that’s your final output & playback…so if it’s a 4:3 file, something like 640×480 is going to work better on a computer screen.
Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com
Read our blog http://www.videomi.com/blog -
I think You Send It has a 2GB limit on uploads…so in Bob’s case it wouldn’t help unless he sent two separate files that were then put back together on the other end…which is likely not an option.
The only solution that I know of for files as large as 3GB would be a T3 line, which has a (supposedly) constant speed of 44.6 Mbps. So you could theoretically upload about 250MB per minute, or 3GB in roughly 12 minutes.
Of course the downside is the cost of a T3 line would be in the thousands per month!
As a comparison, a T1 line would take about 30 times longer…or 6 hours on average to upload a 3GB file, but where we’re located it only costs a few hundred a month and you can also put your phone system on it since it’s actually a telephone based copper line. So in our case, it’s about the same as paying for a separate phone system and internet cable.
But I can’t imagine trying to use it to upload a 3GB file.
Somebody mentioned breaking it into packets…which is I believe what bit-torrent does. But I think for that to work you have to have mutliple people (peers) downloading the file at the same file. So if only one person is doing downloading, I don’t think you’re able to take advantage of the principals of torrents. Maybe that poster was talking about something else…but I know I’ve uploaded and downloaded 1GB or larger files in an hour via bit-torrent, but in those cases there were dozens of peers and also “seeders”…which are others who were uploading the same file while I was downloading it.
Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com
Read our blog http://www.videomi.com/blog -
I’m not sure I fully understand the question…but if the final output is for web viewing, you’re going to have to compress the video using a modern codec like H264, which is likely going to negate the advantage of using 16bit. Even using high-profile H264, chroma is sampled at 4:2:0 (down from 4:4:4 I believe if your original is 16 bit), and your bit-depth will be 8 bit….down from your original 16bit.
However…H264 is typically very good at maintaining nice gradients and doesn’t typically introduce serious banding issues. It probably won’t hurt to do your originals at 16bit though…so no issues there. Just be aware you’re going to be
Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com
Read our blog http://www.videomi.com/blog -
Louis Sparre: By the way when I export as animation codec or 8bit uncompressed it looks stellar… but when I downconvert that to dv ntsc it looks like butt again.
You just answered your own question! DV NTSC throws our half you color (it’s 4:2:0), then it compresses your video down to 2.5MB/sec (audio at 1MB/sec) for a total data throughput of roughly 3.5MB/sec.
You DVCProHD footage is 4:2:2, has roughly five times the pixel resolution and uses a professional, modern codec that….while using a high compression ratio…is far more efficient at how it compresses. I believe DVCProHD is typically 100Megabits/sec (10MB) and it compares pretty well to Cineform and Apple ProRes in terms of quality and compression ratio.
Try using DVCPro50 instead of DV. It’s 4:2:2 and only 3:1 compression (roughly 50Megabits/sec or 5MB, hence the 50 designation). Or…use H264…it looks incredibly good at data rates as low as 25Mbits/sec. I believe in Quicktime Pro you would use 2500 as the data rate as it uses Kilobits instead of Mbits or Mbytes as it’s designation.
Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com
Read our blog http://www.videomi.com/blog