4200RPM ok for DV transfer?

[choirislife923]

I'm planning on using iMovie HD to edit my videos. I currently have a Mac Mini with a 80 GB 4200 RPM hard drive. Would this be ok for video transfer? should I expect to get some dropped frames when capturing?

i remember in the PC world when I had an issue (like a capture app that would drop frames), I would go to WinDV and capture with that. Is there a freeware alternative on the mac that is like this?

[live4ever]

No, it will be fast enough. But you really should get a dedicated Firewire external for DV (since hard drives are so cheap these days).

[strpyw]

As early as in the G3 days, I have been using a 2.5 inch 4200 rpm hard drive in an external firewire enclosure to do all my imovie capture and editing and serve for storage for the idvd burn file. Never any problem in a Mac.

[terryj]

It will not be a problem with capturing, no.
But if this is your only HD, you should then invest in a FW
Ext Drive like live4 said. Video eats up space quickly,
and if you plan on doing lots of editing, the OS will use what
avaialble space their is as a "scratch disck" partition,
and you'll find yourself out of space quickly.

I'm also guessing you have 256mb of Ram as well...?
80gb is good enough to start with, but I would make an
investment in a FW 80GB or better ( 160GB is norm)
to offline Projects after capture ( capture in on main,
move to FW to edit, thus you won't have to worry about
the main drive being clogged) then eventually, invest in more ram ( move up to 1GB.)

[choirislife923]

It will not be a problem with capturing, no.
But if this is your only HD, you should then invest in a FW
Ext Drive like live4 said. Video eats up space quickly,
and if you plan on doing lots of editing, the OS will use what
avaialble space their is as a "scratch disck" partition,
and you'll find yourself out of space quickly.

I'm also guessing you have 256mb of Ram as well...?
80gb is good enough to start with, but I would make an
investment in a FW 80GB or better ( 160GB is norm)
to offline Projects after capture ( capture in on main,
move to FW to edit, thus you won't have to worry about
the main drive being clogged) then eventually, invest in more ram ( move up to 1GB.)

im a novice from the PC world of video editing, so I know what you guys are talking about. ~11.2 GBs an hour of DV...yea. I have 512MB of RAM (i was brave enough to pry open my mac with a putty knife to pop it in), so I think I would be OK. I bought the 512 for $40, after mail in rebates, mainly due to the 1GB being to expensive, so I know I wont make the move to 1GB anytime soon.

[NightWing]

Just tried out the one click DV to Disk in iDVD. No problems. The video was 16 minutes long. Told it to go to the internal HD.

Have the stock 80gb hd 4200. But added the 1gb ram module and a internal Pioneer Superdrive.

Have even dumped on the run over the local network to a fast PC. No problems.

Would recomend also an external HD for capture. There are quite a few on sale at different places this week.

[sjk]

(i was brave enough to pry open my mac with a putty knife to pop it in)

FYI:

"Opening Mac Mini without Putty Knife"

Maybe next time?

[NightWing]

(i was brave enough to pry open my mac with a putty knife to pop it in)

FYI:

"Opening Mac Mini without Putty Knife"

Maybe next time?

That fits with the guy and the chopsticks method!
http://www.pconline.com.cn/market/hk/daogou/0502/552885.html


But for us crazy's here is the putty knife....
Pry at your own risk!

http://eshop.macsales.com/shop/mac-mini/

[sjk]

"The Ultimate Chopstick-assisted disassemble guide of Mac-mini" ... funny!!

[choirislife923]

(i was brave enough to pry open my mac with a putty knife to pop it in)

FYI:

"Opening Mac Mini without Putty Knife"

Maybe next time?

eh..i rather follow the apple service manual..gives me a excuse when i screw something up..and sounds better than "my chopstick had split in half when i tried using it to open my mac mini."

[edDV]

4200RPM and 256MB RAM is plenty for transfer so long as they operate in isolation. Your bottleneck is the single drive. Keep other activity to a minimum while transferring DV. The OS's taking possession of the single drive is your main concern.

[alph]

I thought I had understood that transferring DV from a DV camera was more like a file transfer than capturing in that there is no transcoding occurring and that the data is just copied over as is.

If this is true, and I had understood it properly, are dropped frames even possible given the nature of DV?

Thank you,
Alph

[NightWing]

Simply a file transfer... I think it could be possible to drop if not fast enough or the data is damage.

[edDV]

I thought I had understood that transferring DV from a DV camera was more like a file transfer than capturing in that there is no transcoding occurring and that the data is just copied over as is.

If this is true, and I had understood it properly, are dropped frames even possible given the nature of DV?

Thank you,
Alph

Note: This discussion applies equally to a Mac or PC. They use essentially the same hardware architecture for HDD control. Driver optimizations may differ.

Alph,

DV is a stream transfer not a file transfer. A file transfer includes error corrrection and provision for resending data if transfer errors occur. That does not happen with a DV transfer.

The DV information originates either from the live camera, analog transcode pass-through*, or is played back from DV tape. It is a continuous 30-36Mbps stream over the IEEE-1394 that is 10-70 times faster than your fastest internet download and yet, does this without provision for packet resends. Buffering of this input is minimal due to the size of the data stream (~4MB/sec). Any disturbance to this stream can easily cause data gaps (e.g. pixel, line or field drops).

The path for the stream is IEEE-1394 input card or port to the PCI bus, then PCI bus to hard disk controller to HDD. If the PCI bus maintains a direct connection (known as bus mastering) then the hardware is able to receive the data with low probablity of error. However, the OS can interrupt the bus, take priority and do its own thing including taking control of the drive. When this happens the hardware buffer quickly fills and the stream data goes bye bye.

PCI bus mastering technology allows separate independent activity on the PCI bus without CPU or OS intervention. If you use a separate hard disk controller and drive to transfer your video, then the DV stream to HDD path can remain entact even when the OS is doing its own thing on the main OS drive. That is why the better configuration for video is a second drive and disk controller. RAID only becomes necessary when multi-stream realtime hardware cards are used.

If you are using a single disk system (like a notebook), the challenge is to keep OS activity to a minimum during the data transfer.


*analog to DV stream transcode is done in real time with the camcorder's DV hardware codec.

PS, before someone asks, an extenal HDD USB2 drive does not maintain this separation. PCI to USB2 transfer is CPU intensive and subject to OS prioritization. Expect more dropouts if you try to transfer directly to a USB2 drive.

An external IEEE-1394 HDD has the technical possibiliy of maintaining separation, but the system does not default into that mode. Driver optimization is required.

[alph]

Cheers edDV

Thanks

[lenti_75]

i remember in the PC world when I had an issue (like a capture app that would drop frames), I would go to WinDV and capture with that. Is there a freeware alternative on the mac that is like this?

I'm in a pc world and NEVER had any dropped frames. it's not about mac or p, is about how you use it, and the configuration.

and 4200 should be fine, it's a mac....

and NO, there is no freware for mac....you should know that

[pixeljammedia]

You could always Quit all other Apps when you open your capture App (iMovie HD) Bring iMovie to the front and then hit Command-Option-Escape. This will bring up the "Force Quit Applications" Window, select all other apps including Finder, click "foece quit" and then close the window. There should be no other applications occupying the system or flushing a cache, so you shouldn't have to worry about dropped frames.