filmmaker1977
Carbonite Member
this Rob Lohman is the same wrangler of the dvinfo.net, Lady X, etc?
RAW vs. REDCODE RAW
- Thread starter Jannard
- Start date
Ok. I'm still confused about some terminology. What is on-board recording? Is it internal drives, or anything that mounts onto the camera rig? What is the max data rate that the red drive and red flash can record? Also, what RAID drive do people know of that could record 4k RAW at 60 frames? Hmmm?
I'm glad you guys responded to the whole 2k RAW= 2k windowed question. That clears up that whole issue. But of course I have another question because I'm so damn nosy. What is the max frame rate of 2k 4:4:4 RGB scaled?
Thanks
I'm glad you guys responded to the whole 2k RAW= 2k windowed question. That clears up that whole issue. But of course I have another question because I'm so damn nosy. What is the max frame rate of 2k 4:4:4 RGB scaled?
Thanks
Sorry. I didn't know that the slow-mo and redcode thread had a whole discussion on "on-board". I'm still wondering if you guys were thinking of making a digital mag that would work like the venom, which could capture info at a high rate and also still mount onto the camera rig.
Well, the RED team has been referring to the RED-DRIVE and REDFLASH external units as "onboard," because they were originally supposed to slide into the camera body. When they had to be changed to external drives because they needed the space inside the camera, the label didn't really change. But I fully understand your confusion. Right now it's best to just refer to the actual device that will be doing the recording.SF Geek said:
They haven't yet released specs yet for the RED-DRIVE and REDFLASH modules, so we don't have all of the information. However, we do know that they will have USB2, Firewire 400/800, and eSATA ports, so take from that what you will.
I made a little chart with all of the different modes that you may find useful here:SF Geek said:
http://www.dvxuser.com/V6/showthread.php?p=756845#post756845
Rob Lohman
Red Team
filmmaker1977 said:
Guilty as charged!
Hey Haakon,
I checked your link, but your chart isn't up. As I recall you didn't have frame rates for 2k scaled RGB 4:4:4. You seem to know quite a lot about about this technology so if I may, I'll ask you some questions and give the red team a break.
What's the bit-rate of an eSATA port? Also, and this one's a little more complicated, how are linear and log different? I'm speaking in terms of the bit depth. I hope I said that right.
thanks.
by the way, did anyone notice that Jim's icon keeps changing?
I checked your link, but your chart isn't up. As I recall you didn't have frame rates for 2k scaled RGB 4:4:4. You seem to know quite a lot about about this technology so if I may, I'll ask you some questions and give the red team a break.
What's the bit-rate of an eSATA port? Also, and this one's a little more complicated, how are linear and log different? I'm speaking in terms of the bit depth. I hope I said that right.
thanks.
by the way, did anyone notice that Jim's icon keeps changing?
laboprod
Active member
SF Geek said:
I think that SATA2, which should the same speed as eSATA, is going up to 3Gbps/sec but this is the port, which doesn't mean that your HDD is going that speed.... and I do not think you can have a single HDD going that speed...
I found this chart. It is just a little bit old, as SATA2 is now available, and it should be twice faster than SATA1, but not sure if it is realy the case...
Coming from RED I camera, the linear recording is 12 bit and the log is 10 bit.
Yes I saw that.... it's funny...SF Geek said:
What's an HDD? Hard disk drive?
If eSATA goes up to 3 gigs a second, couldn't it handle the 900 some odd megs that the camera puts out at it's maximum, 4k RAW 60fps? Maybe the red drive couldn't spin fast enough but couldn't flash storage do it?
I was asking about log and linear because I don't know what the terms mean. I'm guessing they are 2 different ways to code information? Can some one simplify it for me?
If eSATA goes up to 3 gigs a second, couldn't it handle the 900 some odd megs that the camera puts out at it's maximum, 4k RAW 60fps? Maybe the red drive couldn't spin fast enough but couldn't flash storage do it?
I was asking about log and linear because I don't know what the terms mean. I'm guessing they are 2 different ways to code information? Can some one simplify it for me?
laboprod
Active member
Elo SF Geek,
Yes HDD is Hard disk drive. Be carrefull about the speed it is 3gbits/sec, which is approximately 300MBytes/sec. The problem with HDD is that they are mechanical, and there is physical head that read the data on the disks, and that is the bottleneck of this technology. You can use 15'000 rotation per minutes HDD, and have the quickest head, but you are still stuck with those mecanical limitations...
Flash memory is a different thing and might go faster....
About bit depth and log/lin: with 12 bit depth there is 4096 steps possible in each color (RGB) and lin, which is for linear, means that the steps are going from 1 to 4096 in a straight line, when in 10 bit there is only 1024 possible steps but there are not going for 1 to 1024 in a straight line, but in a curve.
You will record 12 bit lin when shooting RGB, and 10 bit log when shooting RAW.
The dynamic range of film is also define as log (which is the opposite to video camera), and when you scan a film, people normally store the images in the cineon format in 10 bit log.
Hope it helps,
antoine.
Yes HDD is Hard disk drive. Be carrefull about the speed it is 3gbits/sec, which is approximately 300MBytes/sec. The problem with HDD is that they are mechanical, and there is physical head that read the data on the disks, and that is the bottleneck of this technology. You can use 15'000 rotation per minutes HDD, and have the quickest head, but you are still stuck with those mecanical limitations...
Flash memory is a different thing and might go faster....
About bit depth and log/lin: with 12 bit depth there is 4096 steps possible in each color (RGB) and lin, which is for linear, means that the steps are going from 1 to 4096 in a straight line, when in 10 bit there is only 1024 possible steps but there are not going for 1 to 1024 in a straight line, but in a curve.
You will record 12 bit lin when shooting RGB, and 10 bit log when shooting RAW.
The dynamic range of film is also define as log (which is the opposite to video camera), and when you scan a film, people normally store the images in the cineon format in 10 bit log.
Hope it helps,
antoine.
laboprod
Active member
Well I am not HDD expert.... HDD are made of platter (disks) which have two sides, and are rotating in permanence (at variable speed, 15'000 rpm being a very fast one) and of sereval "heads" that, I think, can turn upside down from one face of the platter to the other. Therefore there is one head per platter.
Transfer rates are confusing in part because of the phrase "transfer rate" can mean so many different things. One of those is the rate at which the hard disk can physically read data from the surface of the platter and transfer it to the internal drive cache or read buffer, ready for sending over the interface to the system. This is the drive's internal data transfer rate. This is opposed to the speed that the data can then be sent from the buffer over the interface to the system, which is the external data transfer rate.
The transfer rate is constrict by the platter's rotation speed and the the density of the data (how tightly packed the data is into each linear inch of disk track). The density of the data is calculated in sectors per track, which is a phisical spec of the HDD.
Modern disk drives use zoned bit recording, which means that the inner tracks have fewer sectors per track than the outer ones. That is why is you use the inner track of your HDD (by using only a little bit of it) your transfer rate would be faster.
The cacul is: Data Transfer Rate = (Spindle Speed / 60 * Sectors-Per-Track * 512 * 8)
But this is theorical, and I think, only a "real life" benchmark test will tell you the speed of your drive.
But if you look to the little chart I've post, the "burst transfer rate" is the external transfer rate, so it is not the real transfer rate, which should be close to the benchmark test, which are around 50MBytes/sec (that is for SATA1).
Hope it is not too much confusing.
antoine.
Transfer rates are confusing in part because of the phrase "transfer rate" can mean so many different things. One of those is the rate at which the hard disk can physically read data from the surface of the platter and transfer it to the internal drive cache or read buffer, ready for sending over the interface to the system. This is the drive's internal data transfer rate. This is opposed to the speed that the data can then be sent from the buffer over the interface to the system, which is the external data transfer rate.
The transfer rate is constrict by the platter's rotation speed and the the density of the data (how tightly packed the data is into each linear inch of disk track). The density of the data is calculated in sectors per track, which is a phisical spec of the HDD.
Modern disk drives use zoned bit recording, which means that the inner tracks have fewer sectors per track than the outer ones. That is why is you use the inner track of your HDD (by using only a little bit of it) your transfer rate would be faster.
The cacul is: Data Transfer Rate = (Spindle Speed / 60 * Sectors-Per-Track * 512 * 8)
But this is theorical, and I think, only a "real life" benchmark test will tell you the speed of your drive.
But if you look to the little chart I've post, the "burst transfer rate" is the external transfer rate, so it is not the real transfer rate, which should be close to the benchmark test, which are around 50MBytes/sec (that is for SATA1).
Hope it is not too much confusing.
antoine.
Sorry about that. They are still testing things and working out specs, so at this point it's difficult to make an all-inclusive chart that has all of the answers for everyone. I still think that it did have a lot of useful information on it, but I do want them to get the accurate information out so I'm going to refrain from reposting it until they make some further progress.SF Geek said:
That being said, the chart did list the framerates for 2K scaled REDCODE RGB 4:4:4, and they are 1-60p.
laboprod answered most of that while I was away, but in essence everything he's said is right. eSATA stands for "external SATA," and it has an equivalent speed to SATA300 (or SATA-II), which is 2.4Gb/s - or 300MB/s. The difference between "bit" (lowercase "b") and "byte" (uppercase "B") is crucial here, as the data rates on the RED spec sheets are in bytes, and not bits (there are 8 bits in one byte). To make matters more confusing, SATA-II is also known as "SATA 3.0 Gb/s," but as it uses 8B/10B encoding, the result is an actual data transfer rate of 2.4 Gb/s, or 300 MB/s - not 3.0Gb/s.SF Geek said:
Anyway, it is also important to understand that the theoretical transfer rate of the eSATA (300MB/s) may be far greater than a single hard drive itself can read, write, and send the data as laborpod also pointed out. The performance of individual hard drives can vary greatly, depending on the rotation speed (listed in RPM), level of onboard cache, type of connection and more. Also, most hard drive manufacturers declare the best transfer rates that a particular hard drive can acheive, but all hard drives transfer data much more slowly on the inner zone than the outer zone, where it is spinning faster. The difference can be as much as 200%. Therefore, depending on all of these circumstances, the easy way to spell it out is that no one drive can handle the data requirements of uncompressed RAW footage from RED regardless of the transfer type, and you're going to need to use a system of multiple hard disk drives (in a RAID array) to take advantage of that method of recording. As has been pointed out, you may easily need 10 drives or more - and recording times are still somewhat limited. All of those drives need power, and all of those drives need to remain cool, dust-free, and free from excessive shock/vibrations. As you can see, recording in such a matter is much more complex/expensive/cumbersome than the other onboard choices. But hey, if you need 4.5K uncompressed RAW footage, RED makes that option a reality! Now you just have to figure out how you're going to edit it... ;-)
Also of importance:
eSATA cable length is restricted to 2 metres (while USB and Firewire can span longer distances), and eSATA does not provide power, which means that external 2.5" disks - which would otherwise be powered over the USB or Firewire cable - need a separate power cable when connected over eSATA.
Hopefully some of that information helps... if you still need further clarifications let me know and I will do my best to answer what I can!
Speaking only for myself, I'm a DP by trade but into computers and technology very much as well. Part of it I think is growing up and being surrounded by computers, but it's also just my passion for it that leads me to learn more. The cool thing is that I get to be a part of an era where filmmaking and (digital) technology are converging for the first time, and beautiful things are happening because of it. I feel lucky!
On the other side of the coin, you could ask me a question about sports or cars or country music and I wouldn't be able to help you at all. I guess we all have our thing.
On the other side of the coin, you could ask me a question about sports or cars or country music and I wouldn't be able to help you at all. I guess we all have our thing.
laboprod
Active member
Hey SF_Geek, it is my pleasure to share my "knowledge", it helps me understand things even better, and it is always good exercice to resume topic.
About me, I have sociology and anthropolgy background, but my interest in computer, lead me to computer tech jobs, and my interest in motion graphics lead me to editing, and camera jobs (not DP, just shooting for local news, interviews, conference, and also contribuate on some local short films). My main revenue comes from computer tech, but my true passion goes to image compositing....and also I like nature where there is huge flat landscape...I would love to shoot some horse rider in Mongolia....with the RED I
As Haakon says, interest and curiosity is the key, but we are tight to the TIME factor (only 24h in a day
About me, I have sociology and anthropolgy background, but my interest in computer, lead me to computer tech jobs, and my interest in motion graphics lead me to editing, and camera jobs (not DP, just shooting for local news, interviews, conference, and also contribuate on some local short films). My main revenue comes from computer tech, but my true passion goes to image compositing....and also I like nature where there is huge flat landscape...I would love to shoot some horse rider in Mongolia....with the RED I
As Haakon says, interest and curiosity is the key, but we are tight to the TIME factor (only 24h in a day