Frame drop in firewire HDV transfer

[Dinu Bandyopadhyay]

Recently I purchased a Sony HDR-HC7. It came with Picture Motion Browser software for transferring HDV from the camera to my PC through the firewire port. In the past, I used the same port to transfer miniDV tapes, never experienced any drop frames. However, when I try to do the same for HDV from HC7, I noticed a large number of drop frames. Why? The bit rates are the same between DV and HDV, its the same firewire port and cable, the CPU is the same (1.7 GHz P4). Then why the drop frames? Also, when I turned the conversion (HDV-> DV) on, the same transfer from HC7 didn't suffer any frame drop, just like my older Sony miniDV (TRV27) camera. Any insight? Is getting a new computer (P4 2.8 GHz or faster per spec.) the only way to cure this frame drop problem in HDV transfer over firewire?

[JimboS]

Is the software you are using compatibable with HDV ??
Can your computer handle HDV??
Bit rates may be the same however , your in a whole new world......

[zoobie]

your problem is 1.7 GHz P4
page 75 of your manual will show minimum requirements

[edDV]

Did you use the same software for DV in the past?

Does the capture software show a preview picture during transfer? That is probably the problem. HDV preview requires a partial MPeg2 decode which is CPU intensive..

Try to use software that doesn't preview like HDVSplit, CapDVHS or other. Search the forums for HDV capture.


PS: You may still have difficulty playing the file with a 1.7 P4. Best player bet is VLC. If necessary set playback "deinterlace" (under video) to discard. That will play 1440x1080 HDV as 960x540 from a single field.

[Dinu Bandyopadhyay]

Thanks edDV. You are right, the preview was turned on. The CPU has to be busy in order to drop frames. Otherwise firewire transfer has to be identical between DV and HDV since everything else is the same. I didn't know where the processing time was spent. Now I do. I'll try HDVSplit.

Cheers

[dun4cheap]

Well lets note here is that firewire utilizes very little of the processor. Even with preview it should not have a dropped frame effect since its just a data transfer and not actual capture. Something key to note though is HDV being mpeg and not DV AVI itself can have drop outs in the GOP structure. So the problem could be the source itself and nothing more. With all that said, I hope your not going to punish yourself and edit HDV video on a 1.7 processor. For as cheap as a mother board and cpu combo is nowwadays why do this to yourself.

[edDV]

Well lets note here is that firewire utilizes very little of the processor. Even with preview it should not have a dropped frame effect since its just a data transfer and not actual capture.

True but IEEE-1394 DV/HDV transfer isn't a network controlled file copy (with all the packet verification and packet resends), DV and HDV transfers over IEEE-1394 are a real time stream transfer and thus subject to drops if the receiving computer is too busy to accept the stream. 25Mb/s (3.5MB/s) isn't an extreme speed but it is ~10x your fastest internet sustained connection.

The main problem comes with single drive systems that must share the disk for OS, applications and stream capture. Usually the OS has first interrupt call on the hard disk so if the OS takes the drive, after the IEEE-1394 capture buffer fills your input stream data flushes (creating drops). If you capture to a second dedicated drive all goes well and the OS and other applications are free to use the main drive.

Best capture drive is an internal or external PATA/SATA drive. PATA/SATA drives use hardware disk controllers and benefit from PCI bus mastering for complete isolation from CPU activity.

USB2 drives have a further complication that the CPU needs to process the software disk controller for the USB drive so the isolation isn't complete. This becomes a problem for older slower laptops.

[Dinu Bandyopadhyay]

HDVSplit did the trick, no more frame drop in firewire transfer! I copied the transferred segment on to a DVD and played it through a PS3, the PQ is as good as the original.

dun4cheap,you are right, HDV editing/authoring will need a more powerful machine. Conversion of a 2 min. m2t segment to DVD on my current PC took me about 15 mins. Since I got the HC7 only a week ago, I am playing with it to understand how I eventually do this: HC7 -> Blue Ray Disc -> PS3 -> HDTV. I am sure this site will be very useful, as it has been in the past, to achieve that goal.

[steadyhand]

I have a core 2 duo processor higher-end multimedia machine, and the same camera. I also experience the exact same problem.

I don't think it's the processor completely, as my machine does everything with little effort, but I do suspect the software being used. Having said that, I have used other sw download packages like Ulead 11 Pro that can download HDV content, and I continue to get framedrops, although not as many as the camera software created. I continue to be suspicious of the firewire cable, camera firmware and tape type. I have not tried a HD-specific minidv tape, but am leaning that way.

[racer-x]

Try HDVSplit to capture. You can edit the m2t's with whatever you use. I have shot a hundred hours or better HDV with my HV20. All while reusing (many times) my standard DV tapes. In all that, I only experienced 1 frame dropout ever. I blame that incident on low battery in the Camcorder. I have since reused that tape with no problems..........

[Bodhisattva]

Thanks for contacting me.

[duffer2222]

Dear all,

Recently bought a HDR-HC5 which came with Picture motion browser. I shot some footage in HD this week end and am trying to transfer it to my PC.
2 problems.
-When I transfer in HD, the picture freezes after about 10 secs and transfer stops. Frame drop.
-When I transfer in DV (using the i.LINK converter HD-DV on my camcorder) the software does not seem to find any video and the transfer does not start at all (actually it does start but screen turns blue and it stops after 10 secs "no video found").

I do not mind having to transfer in DV, but would like to understand why it does not work.

Computer specs:

AMP Sempron 2400+ 1.7GHz
Memory 1536MB Ram
Video Card ATI radeon 9200 Pro AGP


Thanks a lot

[edDV]

Your computer specs indicate a single 80GB HDD. Is there space? HDV/DV require 13.5GB/hr. Also is the HDD defragmented?

A second drive would be better. Have you tried other software? Turn off monitoring while capturing.

[dun4cheap]

What program are you using to capture with?

[Dinu Bandyopadhyay]

Hmm, so both transfers stop 10 sec. after the start! I presume you have already played the tape back on your camcorder, just to make sure that there's really something recorded on it! Also check that you are not at the end of the recorded part! Sorry if it sounds too trivial. Other option is to use Window Movie Maker for the DV transfer, or HDVSplit for HDV transfer, see if you get anything.

[duffer2222]

Thanks to you all for replying.

-edDV: Am planning to buy a 500GB hard drive (really soon). I know that 80GB is not sufficient for this type of transfer. But if transfer does not work, what's the use of buying more storage?

-Dun4cheap: I use motion picture browser to capture. I also have Adobe premiere pro 2.0. Should I try this one?

-Dinu: The difference is that when transferring in HD, it does actually work (can see what I shot on monitor) for about 8 secs. It then stops, the picture on monitor freezing.
When transferring in DV (i.LINK converter HD-DV) it does not work at all (blue monitor).
-I have tried to use HDVsplit, but this software does not seem to recognize the Sony HDR-HC5.

Should I try adobe premiere pro 2.0?

Thanks again to you all for your help

[edDV]

Thanks to you all for replying.

-edDV: Am planning to buy a 500GB hard drive (really soon). I know that 80GB is not sufficient for this type of transfer. But if transfer does not work, what's the use of buying more storage?

-Dun4cheap: I use motion picture browser to capture. I also have Adobe premiere pro 2.0. Should I try this one?

-Dinu: The difference is that when transferring in HD, it does actually work (can see what I shot on monitor) for about 8 secs. It then stops, the picture on monitor freezing.
When transferring in DV (i.LINK converter HD-DV) it does not work at all (blue monitor).
-I have tried to use HDVsplit, but this software does not seem to recognize the Sony HDR-HC5.

Should I try adobe premiere pro 2.0?

Thanks again to you all for your help

First get DV working. Note that the camcorder needs to be set for DV downconversion. Use WinDV software for the basic test. You should also be able to transfer with Windows Movie Maker. Premiere 2.0 should also work but requires more computer resources.

HDV out again needs to be set in the camcorder menus. The camcorder won't be recognized as a HDV source until it is set to HDV out.

[duffer2222]

Thanks for reply.
I tried with WinDV. Capturing started but stopped after about 20 secs (18 frames dropped). Then image froze.
With Windows Movie Maker it just bugged from the start.

On my camcorder settings, I have got:

-VCR HDV/DV: HDV
-i.LINK CONV: ON (HDV-DV)
-DISP OUTPUT: V-OUT/PANEL

Do you need more info?

Thanks for help, once more.

Duffer