dropping frames with huffyuv @704x480

[andie41]

I have tried various options and am using wink2k, Maxtor 60GB, 7200 drive for captures, 384 MB ram and YUY2 NTSC @ 29.97 fps, I get virtually identical results capturing Svideo from digital cable tv, with the following:

VFW drivers and Virtualdub.
WDM drivers and iuVCR.
Fat32 and NTFS partions.
Different partitions-deleted, de-fragged and reformatted.

Results:
Uncompressed, 480x480, CPU @ 4%-18%, average frame rate 13,700 KB/s - 0 drops.

Huffyuv 2.1.1, 480x480, predict left, CPU @ 35%-53%, average frame rate 8,136 KB/s, 0 dropped frames.
Huffyuv 2.1.1, 480x480, predict gradient, CPU @ 50%-60%, average frame rate 7,844 KB/s, 0 dropped frames.


PicVideo @18, 704x480, CPU useage 67%-77%,approx frame rate 2795 KB/s - 0 drops.

Huffyuv 2.1.1, 704x480, predict left,CPU 48%-58%, average frame rate 10,480 KB/s, >10% dropped frames.

Huffyuv 2.1.1, 704x480, predict gradient, CPU 53%-63%, average frame rate 8,950 KB/s, >10% dropped frames.

My question is why does Huffyuv drops so many frames @ 704x480. The frame rate seems well within the capacity of my harddrive and the cpu usage is approximately 50%, or could it be the combination of a fairly high frame rate combined with a 50-60% cpu usage? Anyone ele have similar problems using the huffyuv codec?

[Poplar]

Have try some other capture program, such as AVI_IO? Certainly your CPU isn't fast enough. And I thought mine was slow (PIII-500)

[lpn1160]

unless you need that res to make dvd comp, why not just stick with what works. 480x480 is an xcellent res to grab vid. whats the end result you're lookin for? with a 450mhz, sounds like you are way ahead of the game anyway

[fmctm1sw]

Looks like you've done a lot of research. As already mentioned, I'd stick with 480x480 or 640x480 if you aren't burning DVD's. I got a 366 @433 (I think) and can't get quite as good results as you. I think you're maxed out on your system.

[GiantRobo]

People look at his CPU % at 704 x 480- it's only 50-60% which is not maxxed out. The problem is with the hard drive. I used to drop at least a couple frames all the time with Maxtor 7200 RPM 2MB Cache HDs at 720x480 @ 29.97. I only had 15 Gigs free space on that drive (good for around 30 minutes of capture at 720x480 @ 29.97) and had to defrag all the time. After upgrading to Western Digital's 8 MB Cache 80 Gig HD I drop no frames at all. My CPU is at 70-80% at 720x480 (29.97) and still drops no frames.

[andie41]

Thanks for the comments. I agree 480x480 with zero dropped frames is very good, especially as my system is on the lower end of requirements. However, I would like to get 704x480, if for no other reason than, I am unable to do so. Actually, I would like to save some home videos in DVD format to use with my "future" DVD writer.

Also, part of the enjoyment and frustrations of computers is overcoming the "gotchas." And I just don't understand why I am able to capture at greater frame rates in 480x480. I do suspect my Maxtor HD, but it is able to capture uncompressed 480x480 at 50% greater frame rate than the huffyuv 704x480 that fails. I will keep digging.

thanks,

andie

[andie41]

Although I still cannot capture reliably at 704x480, the dropped frames have gone from more than 10% to approximately 1%. I switched the PCTV Pro card from PCI slot 3 to PCI slot 1 and this seems to have improved the transfer rate considerably. If you are having difficulty with dropped frames, you might want to check the location of the capture card.

andie

[Anonymous65]

The Huff compressor is simply not as fast as most of the Mjpeg compressors. Not sure if this is because of the code, or the amount of processing needed to compress the video with Huff.
Just like some DV codecs are slow as a snail, and other are super fast. It's down to the code of the codec. I don't think Huff was written for speed.

[la_bomba]

...you might want to check the location of the capture card.

IMO the only explanation for this is that you have multiple drivers/hardware utilizing the same IRQ (ACPI), which might degrade performance.
My computer is a DAW (audio workstation) more than a video workstation, and since the beginning ACPI has only been f-cking with the audio output introducing pops and clicks (I use 4ch. 24/96)
So far I have not seen any benefits using ACPI , I think it sucks. (read: Microsoft)


/bomba

[andie41]

I finally "bit the bullet" and upgraded my system. Now running Athlon XP 1700 and am happy! happy! happy!

I can now capture at 704x480 and use huffy(any of the 3 options), picvideo @20, or uncompressed.

I guess I got most of the goodie out of my old OC'd Celeron.

andie