Quick Notation Question - Data Rates/Frame Rates/Interlacing

Finally upgraded to a decent prosumer camera and I'm trying to decipher what the manual is telling me about the many different formats it shoots and and the associated options. I keep seeing things like "There are two basic shooting modes: 720p and 1080i/p.", which I'm finding confusing. In my understanding, the "p" in 720p means progressive video and the "i" in 1080i means interlaced. So what do I make of 1080i/p?
On top of this, my camera shoots in "native" mode, which drops duplicate frames used in "over 60" formats. This will give me variations in the notation like:
720/24pN
720p Native 60 fps
1080i/24p
1080/24PN
Can someone give me a quick primer about frame rate vs data rate and explain how to read these notations? I'd appreciate it quite a bit.
Thanks!

There are so many cameras, capable of so many different formats that providing a manufacturer and model could be helpful in this discussion.
Jim's answer is absolutely correct but I'm going to re-state for clarification.
The i/p designation means you can chose to record as interlaced or progressive for a given resolution.
It sounds like your camera is designed to "capture" images at 60 frames per second, selecting "native" mode means extra frames are deleted and only the desired frames, based on frame rate setting, are recorded to memory. The advantage of "native" @ 24fps is you save space on your memory card. The advantage of NOT using "native" mode is that all 60 frames per second are recorded, but the file metedata tells playback software to only show the frames needed for the specified frame rate (i.e. 24). Since all 60 frames per second are recorded, you use more memory but you also have the option of retrieving all the those frames, if you so desire, at a later time (i.e. for smoother slo-mo).
To be honest I don't know what your spec of 1080i/24p means. If that is truly an option then I would guess it means it will record a 24p image but the metedata would indicate the file should playback at 30fps interlaced by adding the proper 3:2 pulldown. This would give you that "film" look in a broadcast compatible format.
For the most part, you don't want use use any interlaced settings. Very few display devices still in use can properly display interlaced images. Interlacing is only required in some broadcast specifications.
To answer the second part of your question;
Frame rates are an indication of how many times the moving image is captured over a given period (per second). Higher frame rates means smoother, more "real life" motion. Data rates can generally be considered an indication of image or audio quality. Higher levels of compression result in lower data rates and (generally) lower quality. If squeezing more hours of footage on fewer memory cards is more important than getting the best image quality, choose a lower data rate. Higher frame rates (more images per second) inherently require a higher data rate to retain the same quality as fewer frames at a lower data rate.

Similar Messages

I have a question about Data Rates.

Hello All.
This is a bit of a noob question I'm sure. I don't think I really understand Data Rates and how it applies to Motion... therefore I'm not even sure what kind of questions to ask. I've been reading up online and thought I would ask some questions here. Thanks to all in advance.
I've never really worried about Data Rates until now. I am creating an Apple Motion piece with about 15 different video clips in it. And 1/2 of them have alpha channels.
What exactly is Data Rate? Is it the rate in which video clip data is read (in bits/second) from the Disc and placed into my screen? In Motion- is the Data Rate for video only? What if the clip has audio? If a HDD is simply a plastic disc with a dye read by "1" laser... how come my computer can pull "2" files off the disc at the same time? Is that what data transfer is all about? Is that were RAM comes into play?
I have crunched my clips as much as I can. They are short clips (10-15seconds each). I've compressed them with the Animation codec to preserve the Alpha channel and sized them proportionally smaller (320x240). This dropped their data rate significantly. I've also taken out any audio that was associated with them.
Is data rate what is slowing my system down?
The data rates are all under 2MBs. Some are as low as 230Kbs. They were MUCH higher. However, my animation still plays VERY slowly.
I'm running a 3GigRam Powerbook Pro 2.33GHz.
I store all my media on a 1TB GRaid Firewire 800 drive. However for portability I'm using a USB 2 smartdisk external drive. I think the speed is 5200rpm.
I'm guessing this all plays into the speed at which motion can function.
If I total my data rate transfer I get somewhere in the vicinity of 11MBs/second. Is that what motion needs for it to play smoothly a 11MBs/second data connection? USB 2.0 is like what 480Mbs/second. So there is no way it's going to play quickly. What if I played it from my hard drive? What is the data rate of my internal HDD?
I guess my overall question is.
#1. Is my thinking correct on all of these topics? Do my bits, bytes and megs make sense. Is my thought process correct?
#2. Barring getting a new machine or buying new hardware. What can I do to speed up this workflow? Working with 15 different video clips is bogging Motion down and becoming frustrating to work with. Even if only 3-4 of the clips are up at a time it bogs things down. Especially if I throw on a glow effect or something.
Any help is greatly appreciated.
-Fraky

Data rate DOES make a difference, but I'd say your real problem has more to do with the fact that you're working on a Powerbook. Motion's real time capabilities derive from the capability of the video card. Not the processor. Some cards do better than others, but laptops are not even recommended for running Motion.
To improve your workflow on a laptop will be limited, but there are a few things that you can try.
Make sure that thumbnails and previews are turned off.
Make sure that you are operating in Draft Mode.
Lower the display resolution to half, or quarter.
Don't expect to be getting real time playback. Treat it more like After Effects.
Compressing your clips into smaller Animations does help because it lowers the data rate, but you're still dealing with the animation codec which is a high data rate codec. Unfortunately, it sounds necessary in your case because you're dealing with alpha channels.
The data rate comes into play with your setup trying to play through your USB drive. USB drives are never recommended for editing or Motion work. Their throughput is not consistent enough for video work. a small FW drive would be better, though your real problem as I said is the Powerbook.
If you must work on the powerbook, then don't expect real-time playback. Instead, build your animation, step through it, and do RAM previews to view sections in real time.
I hope this helps.
Andy

Multiclip Dropped Frames/Data Rates from from FW 800, 7200rpm Drive

I am using an external Lacie 7200 rpm "Little Big Disk" .. Editing DV Multiclips in Final Cut (3.6 MB/sec data rate per clip... 7 clips/streams) But it won't play back all at once, anything over 15 MB/sec data transfer rate (as I watch Activity Monitor) it starts choking and dropping frames til it just freezes. Lacie claims that this drive handles a steady 80MB/sec transfer rate... All I need to do all these streams is 26 MB/sec (That's the speed it does at work from an XSAN and no problem playing back 7 streams of DV) Is the bog down in my system the FW800, my RAM, processor, or the Cache of the drive? (16MB)

Do you have any other FireWire devices (incl. cameras) plugged into other ports on the computer or on the drive itself? There's only one FireWire bus on a G5, and it's shared between the FW800 port and the FW400 port on the back in addition to the FW400 port on the front.
If you have other devices plugged in, they can cause the entire bus to slow down to the speed of the slowest connected device.

YouTube - Key Frames, Data Rate, Encoding

All of my shooting is 16:9 and a great deal of that uploaded to YouTube. Having said that, their recommendation is MPEG4 (Divx, Xvid) format. Having said that, I do not see either Divx or Xvid as an option within FCE4. Any suggestions?
Also, when preparing videos for the Internet any help on the following would be greatly appreciated:
(1) Should one select "Prepare for Internet Streaming, Fast Start"?
(2) Key Frames (default is 24)
(3) Data Rate (defauls to 6400 kbits/sec)
Any recommendations for the above?
As always, thanks.
Lyman

The Divx codec is an purchased addon (demo is available for use xx days), though you may find that video being uploaded to YouTube using any codec may show little or no difference.
Searching the forum would have found a number of discussions, see here for one of them http://discussions.apple.com/message.jspa?messageID=6241782#6241782
Good luck.

Another Data Rate Too High Error Question

Hi all,
I have seen quite a few posts about pgc errors, but most of them deal with slideshows and not video; and I can't find anything with the REF=KApgc error.
I'm just putting all of my home movies onto an authored DVD, not rocket science. I'm using the 'Film Submenu' preset with only 5 main movies, things like Easter, Birthday, etc. My transition for each button is a slate (for lack of a better word) that says exactly what it is and when it happened, before each movie plays.
After I had everything set up, I realized I didn't have an ability to "play all" that would include these slates. Simple solution, make a 'play all' button that links to a timeline that has everything in it - the slate, then the movie, next slate, next movie and so on. (When I say movie - they are all .mov files rendered out from After Effects, even the slates)
My transcode settings are NTSC DV High Quality 7mb VBR 2 Pass and the "maximum quality" box is checked.
When I run the 'Check Disc' all is fine. Preview the disc, all is fine.
Build Disc: Hours of Transcoding then the error: Data Rate Too High at *timecode* REF=KApgc.
When this movie is by itself with a button click, it's fine. It's only in the "play all" timeline that it produces the error.
If the data rate isn't too high in one place, why is it too high in another? It's the same thing, just a longer timeline.
Please Help!
Thanks.

Thanks Jeff,
I feel kind of silly for not thinking of that as a solution to my play all dilemma. That's why you're the expert I guess.
A better solution would be to create a playlist of all of your other timelines; that way, only one copy of each gets burned to disc.
Hopefully the "data rate" error will go away with these changes.
-Jeff
Can I place my slates that are just assets (.mov) in the playlist or can I only put timelines in there?
Thanks again,
-Jim

Video (or Video + Audio) Data Rate

Wondered if anyone here might know of a software utility that has the ability to scan QuickTime compatible files and either display the video (or video + audio) data rate excursion or, as an alternative, graph the instantaneous variation in the data rate over time.

Apple +I (show info) in QT player will show you the framerate and bitrate while playing.
Thanks for your suggestion, Rick. However, I must point out that the data rate so displayed is simply the total average for the entire clip and not the instantaneous (i.e., constantly changing) variance with time. Preliminary observations tend to indicate the single pass H.264 algorithm begings roughly 10% under the requested data rate and quickly settles very near the target. The multipass algorithm, on the other hand, appears to begin in the vicinity of 300% above the targeed data rate and monotonically decreases throughout the remainder of the movie clip. So much for a quick qualitative analysis based on observations during the actualy encoding process.
What I now wish to do is actually perform a bit of quantitative analysis and, based on those results, correlate actual data rates with the ability of a given H.264 multipass file to sync to an iPod. Basically, I am trying to determine whether or not a user data rate input is used as a comparator during the initial phase of multipass H.264 coding and, if so, how it is implemented. (I.e., how are the delta values handled -- linearly, exponentially, etc.) In addition, I wish to compare QT v7.0.3 with v7.0.4 clips to determine why the latter are less iPod compatible. Too, there remains a question as to whether or not any data rate information is now embedded in the clips themselves since various work arounds tried (i.e., clipping file lengths) have proven unsuccessful.

WLC Data Rates behaviour

Hello everyone!
I have some questions about the data rates configuration in WLC. I've been reading Cisco documentation and this forum, but as I've seen some contradictory information I would like you to clarify me some points.
I want to disable 802.11b clients, so for that I'm going to disable 1, 2, 5.5 and 11Mbps data rates (other option could be set these as supported only). Then, I have to assign at least one of the other data rates as mandatory...
I could think in one of these three options
Option 1: all 802.11g data rates as mandatory. In this case, as far as I understand:
Broadcast are sent to the lowest data rate
Multicast are sent to the highest data rate (but if a client is connected to other data rate than the highest, then multicast frames are sent to this data rate supported by the client, is that right??). Basically, you cannot be sure at which data rate multicast frames are sent as it can change depending on the clients.
Clients can connect as soon as they support one of the mandatory data rate
Option 2: one 802.11g data rate as mandatory. This would define better the cell limits.
Broadcast and multicast are sent at the same data rate
Clients can connect if they support the mandatory data rate
Option 3: set two data rates as mandatory (or the OFDM required data rates: 6,12, 24Mbps), and the others as supported
Broadcast are sent at the lowest data rate
Multicast are sent at the highest data rate (shifting back to the lowest if a customer cannot connect to this data rate)
Clients can connect if they support at least one of the mandatory data rates.
Am I right with this assumptions? I have read some other different behaviors, like broadcast and multicast are sent at the same common data rate...
I hope I have explained myself...
Thank you very much for your support.
Carolina

Hello,
thank you Scott and George!
I read the post, and it is ok, and I finally have found some information in Cisco's website:
http://www.cisco.com/c/en/us/td/docs/wireless/controller/7-4/configuration/guides/consolidated/b_cg74_CONSOLIDATED/b_cg74_CONSOLIDATED_chapter_01011.html#ID2482
"Access points running recent Cisco IOS versions transmit multicast frames at the highest configured basic rate and management frames at the lowest basic mandatory rates, can cause reliability problems. Access points running LWAPP or autonomous Cisco IOS should transmit multicast and management frames at the lowest configured basic rate. Such behavior is necessary to provide good coverage at the cell's edge, especially for unacknowledged multicast transmissions where multicast wireless transmissions might fail to be received. Because multicast frames are not retransmitted at the MAC layer, clients at the edge of the cell might fail to receive them successfully. If reliable reception is a goal, multicast frames should be transmitted at a low data rate. If support for high data rate multicast frames is required, it might be useful to shrink the cell size and disable all lower data rates.
Depending on your requirements, you can take the following actions:
If you need to transmit multicast data with the greatest reliability and if there is no need for great multicast bandwidth, then configure a single basic rate, that is low enough to reach the edges of the wireless cells.
If you need to transmit multicast data at a certain data rate in order to achieve a certain throughput, you can configure that rate as the highest basic rate. You can also set a lower basic rate for coverage of nonmulticast clients."
Based on your experience, does it have any sense to have configured all datarates as mandatory? This is the current configuration I have in our controllers but it wasn't done by me.
Thanks.
Carolina

Max Data Rate: AGP 2x?!

Bought myself a new MSI-KT6 Delta a few weeks ago (MSI-6590), and have had no problems until now.
First up, my GeForce 4 Ti 4600 decided to suddenly die. Random characters on the screen in text mode, flickery colours and corrupt pixels everywhere. Windows wouldn't detect it properly anymore.
Bought a new Powercolor Radeon 9600 XT with VIVO today. Downloaded the new drivers, and loaded up some Battlefield, all good. Runs nice and smooth. COD, Quake 3, etc, no problems at all.
Halo, however... BAD. Even with the basic graphics settings and no Pixel-Shading, it runs at 4 frames a second, and nothing I do changes this, from lowest to highest with Pixel-Shaders 2.0. Although there's a visual difference, it's just as slow.
So I loaded up ATI control Panel and used SmartGart to enable 8x and Fast-Writes... Rebooted, lots of flickering screen, and Windows XP is now software-rendering everything (Transparent menus take 100% CPU to fade in)
Wait for SmartGart to fix my graphics again, and it's all back to 4x and no fast-write.
Loaded up SiSoft Sandra, to check the settings in there...
Mainboard: "Max Data Rate: AGP 2x"
AGP Card: "Data Transfer Modes Support: 1x, 2x"
"AGP Bus is unused or AGP card not fully AGP compatible"
Er... should this be right? BIOS wont let me select an AGP speed, it's "Auto" and I can't select it. I'm a little concerned that my Motherboard may have been damaged! I'll go get the latest Halo Patch, but it doesn't change the fact that I can't use 8x or Fast-Write.
I'm a little apprehensive about flashing my BIOS, made more difficult by the fact that I have no working floppy drive.
CPU: AMD 2600+
RAM: 2x512mb DDR 333MHz Kingston
AlphaGremlin

Well, I updated the VIA drivers, and an updated Sandra. AGP is running at 8x, and Fast-Writes are enabled! I don't know what the hell SmartGart was going on about, but it appears to slunk away and disappeared completely from the ATI control panel since the last reinstall of drivers.
So there's one problem solved... but I don't know what's up with Halo... I can set it to the lowest settings and it still runs like an elephant with three legs, even with the -useff option for Fixed Function shaders... ah well, that's a matter for another forum, eh?
Interesting note: Sandra reports my 120gb drive as 605gb... should I be trusting it?
AlphaGremlin

H.264 All-Intra Data Rates Significantly Higher

Does the built-in H.264 codec encode I-frame only files differently? I am trying to determine the optimal GOP length for high bitrate exports. Image quality seems to degrade, even in the I-frames, when using key frame distances greater than one.
After performing a series of tests to characterize the Adobe H.264 encoder, I discovered that exported files are significantly larger when key frame distance equals one frame (N=1). The average video data rate for a test file rendered with the Adobe H.264 encoder is as follows:
N=1 : 2.17 bpp : 24I
N=2 : 0.66 bpp : 12I + 12P
N=3 : 0.59 bpp : 8I + 8B + 8P
Note how the data rate drops 70% (from 2.17 to 0.66 bpp) even though 50% of the I-frames still exist when N=2. By comparison, here is the video data rate when exporting with QuickTime H.264:
N=1 : 0.89 bpp : 24I
N=2 : 0.70 bpp : 12I + 12P
N=3 : 0.64 bpp : 8I + 16P
The following chart shows data rates at key frame distances from 1-48 frames for Adobe H.264, QuickTime H.264 (via Adobe), QuickTime Pro, and Expression Encoder 4 Pro. Data rates are consistent among all encoders at GOP lengths greater than one. There is an anomoly with the Adobe H.264 codec compressing all-intra files.
The observed behavior occurs in all profiles, which were tested at Levels 4.1, 4.2, 5.0, and 5.1:
Image quality is better in the Adobe H.264 all-intraframe file, especially with respect to detail retention. The pictures below show sections of two consecutive frames magnified 400%. The file with N=2 is less accurate and contains noticeable blocking. Even the I-frames don't look as good in the files where N>1.
The test file was a seventeen second Premiere Pro sequence consisting of H.264, MPEG-2, and AE files with effects applied. Exports were rendered from the Premiere Pro timeline and from a V210 uncompressed 4:2:2 intermediate file of the sequence. The following settings were used:
Format: H.264
Width: 1280
Height: 720
Frame Rate: 24 fps
Field Order: Progressive
Aspect: Square Pixels (1.0)
TV Standard: NTSC
Profile: Baseline, Main, and High
Levels: 4.1, 4.2, 5.0, 5.1
Render at Maximum Bit Depth: Enabled
Bitrate Encoding: VBR, 2-Pass
Target Bitrate: Maximized for each Profile/Level
Maximum Bitrate: Maximized for each Profile/Level
Key Frame Distance: 1, 2, 3, 4, 5, 6, 7, 8, 12, 24, 48
Use Maximum Render Quality: Enabled
Multiplexer: MP4
Stream Capability: Standard
Software:
Adobe Media Encoder CS6 Creative Cloud v6.0.3.1 (64-bit)
Premiere Pro CS6 Creative Cloud v6.0.3
Windows 7 SP1
QuickTime Pro for Windows v7.6.9 (1680.9)
MediaInfo 0.7.62 (for GOP and data rate information)

I think the short answer is yes,
a h.264 encoder does I-frame only differently. I frames are complete expressions of a picture with no temporal compression information.
P frames use _P_redictive information. IE information from prior frames.
B frames use _B_i-directional predictive frame information.
h.264 gets the majority of it's bit saving from use of B and P frames. When you do I-frame only you only get the block compression and none of the advantages of P and B frames. Thus the GOP N=1 doesn't get very good bit's per pixel.
Having said all that I do find your comment...
Profitic wrote:
Note how the data rate drops 70% (from 2.17 to 0.66 bpp) even though 50% of the I-frames still exist when N=2. By comparison, here is the video data rate when exporting with QuickTime H.264:
... very interesting. Indeed, why is the datarate 70% less when it should at best be 50% for GOP N=2. 50% less should be the same I-frame information plus 0 bytes for the B frame between them. (GOP = I,B,I). Any more than that and it is throwing away bits from the I-frame. So, this seems to be to be a ratecontrol bug.
http://en.wikipedia.org/wiki/Group_of_pictures
"The GOP structure is often referred by two numbers, for example, M=3, N=12. The first number tells the distance between two anchor frames (I or P): it is the GOP size. The second one tells the distance between two full images (I-frames): it is the GOP length. For the example M=3, N=12, the GOP structure is IBBPBBPBBPBBI. Instead of the M parameter the maximal count of B-frames between two consecutive anchor frames can be used."

What is the Data Rate of the Cache in Adobe Premiere CS6

Hi,
Trying to build a raid array to edit with and want to know how much speed i need for caching read/write drive for premiere and After Effects. I'm of the impression that the cache doesn't need more than a single 7200rpm drive (~120MB/s) but really i have no clue what the data rate that adobe caches to is or what the data rate to read is
so it's 2 questions
how fast does premiere write the cache? (i know this is system dependent but a ballpark figure would be good for say a sandy bridge i5 2500k system with a 2 raid 7200rpm drive)
and
what's the data rate to read the cache in a 1080 24p file?
also, when doing the final export does premiere/after effects read from the Cache or the original files or both?
thx,
Jayson
youtube.com/AWDEfilms

ok i've figured out the physics of this question.
The Cache Read data rate is always larger than the Cache Write data rate, because the computer would have to be rendering to Cache faster than realtime for the Write rate to be higher, which would make it unnecessary to render to cache in the 1st place. So I'm really only worried about the Cache read data rate. Does adobe have a paper that tells us what the data rate is for different sequences.
my 3 common workflows are
canon h.264 1080 24p
AVChd 1080 24p from my GH2 with a 44mb
and
r3d 5k epic footage 24p - (this is painful to edit )
anyone know where this info is?
thx,
Jayson
youtube.com/AWDEfilms

Apple tv slow data rate

HI Guys, i have a problem with one of my Apple TV. I currently have 2 Apple TV and one is having a slow data rate. I have Apple AirPort Time Capsule 2TB (latest gen) with most devices running on wireless connection and I checked the data rate (from the base station) on one Apple TV is showing 65Mbps and on another its showing between 6-13Mbps. The signal reception on both AppleTV is excellent. I have tried unplugging, restarting and restoring the AppleTV with no luck. The model number on this AppleTV is A1427. Any other ideas?

Hi arustandi,
Thanks for the question. If I understand correctly, one of the Apple TV's has a slow connection. I see you have already done a bit of troubleshooting. I would recommend that you read this article, it may be able to help with the slow connection.
Wi-Fi and Bluetooth: Potential sources of wireless interference - Apple Support
Thanks for using Apple Support Communities.
Have a great day,
Mario

What chokes H.264 footage: data rate or video dimensions?

I apologize for posting in here but this board is SO much better than the Quicktime or Compressor boards, and it's all the same workflow anyhow!
What I'm wondering is what chokes H.264 videos. Is it low bit rates? High bit rates? Big dimensions? I have an 854x480 video at 500kbps and it looks great, but even on my PowerMac there is slight stuttering, and some alpha tester feedback I've gotten tells me that a lot of slower computers are choking on the video badly.
The file size is ridiculously small, so if increasing the data rate makes it easier to decode, that would be nice.

It's neither - or either, if you will. H.264 achieves unprecedented levels of compression, which means that it's a lot more CPU-intensive to play back in real time. It simply doesn't play well on older hardware. Even slower G5s for example have problems playing back full HD H.264, particularly if it's progressive. It also depends on your GPU - certain GPUs support H.264 decoding, thus significantly offloading the CPU.
One general rule, though: the higher your data rate at any given frame size and frame rate, the less work the decoder needs to do. I'd try to go for approx. 800 kbps at your chosen frame size and see if that helps.
HTH,
Ron

PGC...data rate too high

Hallo,
message
nunew33, "Mpeg not valid error message" #4, 31 Jan 2006 3:29 pm describes a certain error message. The user had problems with an imported MPEG movie.
Now I receive the same message, but the MPEG that is causing the problem is created by Encore DVD itself!?
I am working with the german version, but here is a rough translation of the message:
"PGC 'Weitere Bilder' has an error at 00:36:42:07.
The data rate of this file is too high for DVD. You must replace the file with one of a lower data rate. - PGC Info: Name = Weitere Bilder, Ref = SApgc, Time = 00:36:42:07"
My test project has two menus and a slide show with approx. 25 slides and blending as transition. The menus are ok, I verified that before.
First I thought it was a problem with the audio I use in the slide show. Because I am still in the state of learning how to use the application, I use some test data. The audio tracks are MP3s. I learned already that it is better to convert the MP3s to WAV files with certain properties.
I did that, but still the DVD generation was not successful.
Then I deleted all slides from the slide show but the first. Now the generation worked!? As far as a single slide (an image file) can not have a bitrate per second, and there was no sound any more, and as far as the error message appears AFTER the slide shows are generated, while Encore DVD is importing video and audio just before the burning process, I think that the MPEG that is showing the slide show is the problem.
But this MPEG is created by Encore DVD itself. Can Encore DVD create Data that is not compliant to the DVD specs?
The last two days I had to find out the cause for a "general error". Eventually I found out that image names must not be too long. Now there is something else, and I still have to just waste time for finding solutions for apparent bugs in Encore DVD. Why doesn't the project check find and tell me such problems? Problem is that the errors appear at the end of the generation process, so I always have to wait for - in my case - approx. 30 minutes.
If the project check would have told me before that there are files with file names that are too long, I wouldn't have had to search or this for two days.
Now I get this PGC error (what is PGC by the way?), and still have no clue, cause again the project check didn't mention anything.
Any help would be greatly appreciated.
Regards,
Christian Kirchhoff

Hallo,
thanks, Ruud and Jeff, for your comments.
The images are all scans of ancient paintings. And they are all rather dark. They are not "optimized", meaning they are JPGs right now (RGB), and they are bigger then the resolution for PAL 3:4 would require. I just found out that if I choose "None" as scaling, there is no error, and the generation of the DVD is much, much faster.
A DVD with a slide show containing two slides and a 4 second transition takes about 3 minutes to generate when the scaling is set to something other than "None". Without scaling it takes approx. 14 seconds. The resulting movies size is the same (5,35 MB).
I wonder why the time differs so much. Obviously the images have to be scaled to the target size. But it seems that the images are not scaled only once, that those scaled versions of the source images are cached, and those cached versions are used to generate then blend effect, but for every frame the source images seem to be scaled again.
So I presume that the scaling - unfortunately - has an effect on the resulting movie, too, and thus influences the success of the process of DVD generation.
basic situation:
good image > 4 secs blend > bad image => error
variations:
other blend times don't cause an error:
good image > 2 secs blend > bad image => success
good image > 8 secs blend > bad image => success
other transitions cause an error, too:
good image > 4 secs fade to black > bad image => error
good image > 4 secs page turn > bad image => error
changing the image order prevents the error:
bad image > 4 secs blend > good image => success
changing the format of the bad image to TIFF doesn't prevent the error.
changing colors/brightness of the bad image: a drastic change prevents the error. I adjusted the histogram and made everything much lighter.
Just a gamma correction with values between 1.2 and 2.0 didn't help.
changing the image size prevents the error. I decreased the size. The resulting image was still bigger than the monitor area, thus it still had to be scaled a bit by Encore DVD, but with this smaller version the error didn't occur. The original image is approx. 2000 px x 1400 px. Decreasing the size by 50% helped. Less scaling (I tried 90%, 80%, 70% and 60%, too) didn't help.
using a slightly blurred version (gaussian blur, 2 px, in Photoshop CS) of the bad image prevents the error.
My guess is that the error depends on rather subtle image properties. The blur doesn't change the images average brightness, the balance of colors or the size of the image, but still the error was gone afterwards.
The problem is that I will work with slide shows that contain more images than two. It would be too time consuming to try to generate the DVD over and over again, look at which slide an error occurs, change that slide, and then generate again. Even the testing I am doing right now already "ate" a couple of days of my working time.
Only thing I can do is to use a two image slide show and test image couple after image couple. If n is the number of images, I will spend (n - 1) times 3 minutes (which is the average time to create a two slides slide how with a blend). But of course I will try to prepare the images and make them as big as the monitor resolution, so Encore DVD doesn't have to scale the images any more. That'll make the whole generation process much shorter.
If I use JPGs or TIFFs, the pixel aspect ratio is not preserved when the image is imported. I scaled one of the images in Photoshop, using a modified menu file that was installed with Encore DVD, because it already has the correct size for PAL, the pixel aspect ratio and the guides for the save areas. I saved the image as TIFF and as PSD and imported both into Encore DVD. The TIFF is rendered with a 1:1 pixel aspect ratio and NOT with the D1/DV PAL aspect ration that is stored in the TIFF. Thus the image gets narrowed and isn't displayed the way I wanted it any more. Only the PSD looks correct. But I think I saw this already in another thread...
I cannot really understand why the MPEG encoding engine would produce bit rates that are illegal and that are not accepted afterwards, when Encore DVD is putting together all the stuff. Why is the MPEG encoding engine itself not throwing an error during the encoding process? This would save the developer so much time. Instead they have to wait until the end, thinking everything went right, and find out then that there was a problem.
Still, if sometime somebody finds out more about the whole matter I would be glad about further explanations.
Best regards,
Christian

Audio Data Rate digitizing DVCPRO50 over firewire

I'm having this weird issue when I digitize DVCPRO50 footage into one of my Dual 2Ghz G5s. For some reason, once the clips are in (I'm bringing in entire tapes) -- the audio data rate is at a strange number (like 47722 khz) rather than the standard 48khz. And that number is not consistent -- it ranges from 37782 to 47991. Has anyone ever seen this? It seems to be something with this machine or version of FCP because I can digitize on another G4 or G5 running 4.5 and it comes in fine. But then I have to transfer it via FW drive which is a big hassle. The specs are: Dual 2ghz G5, Panasonic DVCPRO50 SD93 Firewire deck, internal 1TB raid, 2.5GB RAM.
Please help if you have any ideas.
Thanks.
Aaron

It it maybe a situation where the source uses Drop Frame timecode and the FCP capture setting doesn't? Or vice versa?
I haven't done the math yet to check, but your sample rate numbers could reflect errors resulting from FCP trying to compute NDF sample rates while looking at incoming DF timecode. Or vice versa.
The different sample rates would then be the result of different length clips, which would have more or less DF "adjustments" in them, and so would produce different apparent sample rates if view as NDF clips.
Like I said it's just a guess, but check out to see that your DF or NDF timecode settings are the same for the source as for the capture.
Maybe I'm right. Or maybe I'm talking through my hat. It's happened before...

Disable data rate to a specific AP only?

Hello everyone, Im using Cisco 5508 with 7.0.220.0 code and I just wanted to know if its possible to disable some data rates to a specific group of APs and not affect the rest of the APs
Another question is about almost the same thing but related to WLAN Radio Policy. If I enable a specific WLAN to use radio policy 802.11g-only, all the clients using this WLAN can only associate to 802.11g data rates??? are there any other things to consider on about this policy?.
thanks in advance for your time and help!!!!

Rasika is right on... you need to upgrade if you want to use RF Profiles...
Another question is about almost the same thing but related to WLAN Radio Policy. If I enable a specific WLAN to use radio policy 802.11g-only, all the clients using this WLAN can only associate to 802.11g data rates???
> Clients can only connect on the 2.4ghz either 802.11b g or n
are there any other things to consider on about this policy?
> Setting the policies on the WLAN just defines what you want to be able to associate to that WLAN. For example, wireless ip phones you might set it to 5ghz only, so phones have to be able to connect using only the 5ghz. If there were any 2.4ghz device only trying to access that wlan, they wouldn't be able to associate. Another example is like guest ssid... I always only allow then on the 2.4ghz, not on the 5ghz.
Thanks,
Scott
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Quick Notation Question - Data Rates/Frame Rates/Interlacing

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