Analog capture question

[eandmwilson]

For analog capture, what sort of bandwidth is needed? Do PCI, USB 2.0 and Firewire cards (and their internal busses) have enough bandwidth to suck decent quality out of an analog line?

PCI seems to be the slowpoke at 130 MB/s, but since the USB 2.0 and Firewire cards pump their stuff through the system bus, or along PCI channels, aren't they all capable of the same performance?

[Krispy Kritter]

The bus usually isn't the bottleneck. The limiting factor is usually the capture card. Some use software encoding, which places the load on the cpu, others use hardware encoding, and handle the work themselves.

[edDV]

For analog capture, what sort of bandwidth is needed? Do PCI, USB 2.0 and Firewire cards (and their internal busses) have enough bandwidth to suck decent quality out of an analog line?

PCI seems to be the slowpoke at 130 MB/s, but since the USB 2.0 and Firewire cards pump their stuff through the system bus, or along PCI channels, aren't they all capable of the same performance?

Describe your capture goals. Uncompressed capture is usually done from a PCI card. Industry standard for connecting an external uncompressed capture device is SMPTE-259M (270-360Mb/s)* which would require a special PCI card to receive the single coax connection.

External analog capture devices usually hardware encode to a relatively low bitrate video format (typ 4-35Mb/s).

IEEE-1394 is well suited for connecting DV, HDV and MPeg2 TS streams with standardized protocols. Network connection over IEEE-1394 is subject to many tranmission errors when attempting to move wideband video.

USB2 as a network connection also has difficulty with wideband video. USB2 has no industry standards for video transfer. Some devices, including several capture devices use USB2 controlled by prorietary drivers.

So as you can see, quality realtime video transfer is all about protocols, not just bandwidth.

*Ref formats
http://www.miranda.com/library.en/Digital%20Standards/Std_BW_booklet.pdf

[jman98]

I started out a little over 5 years with the ATI All-in-Wonder card. I was unsatisfied with the quality it produced (it uses software encoding), so I bought a Dazzle DVC II PCI card. I loved the Dazzle. They don't make it anymore. I now use the Hauppauge PVR-350 PCI card, which I think is maybe the best card I've ever used. Both the old Dazzle and the Hauppauge use hardware encoding, which I adamantly believe is superior to software encoding. I am HIGHLY skeptical of any USB based solutions, which is exactly what Dazzle moved to. I suggest Hauppauge PCI based cards, but you should be aware that they only can capture in MPEG-1 and MPEG-2 and not AVI, if that is important to you. The old DVC II by Dazzle was the same.

[eandmwilson]

My primary goals are analog input (or at best SVHS) for old camcoder tapes and VHS, maybe using it as a DVR from a DirectTv box (though this would be akward, i admit). The newer AIW cards are still software encoded?

And where does the 13 GB/hr rate come from? I've seen that numder thrown around a bit.

[edDV]

My primary goals are analog input (or at best SVHS) for old camcoder tapes and VHS, maybe using it as a DVR from a DirectTv box (though this would be akward, i admit). The newer AIW cards are still software encoded?

And where does the 13 GB/hr rate come from? I've seen that numder thrown around a bit.

13GB/hr sounds like DV format. Your camcorders are VHS?

All-in-wonder cards have partial hardware support if you use the MMC software. These cards are good but famous for unstable drivers.

To cap your S-Video DirecTV output I'd suggest a hardware MPeg2 encoding card like the Hauppage PVR-250 or 350. It will encode without using much computer resource. Others exist like the new ATI Elite (Theater 550) class but those are still not ready for prime time and currently are the source of major frustration.

The PVR 250/350 cards are well proven and well supported with software. The new PVR-150 is having it's share of driver problems as well. Get the older card if you just want something that works.

[FulciLives]

And where does the 13 GB/hr rate come from? I've seen that numder thrown around a bit.

1 hour of DV is about 13GB

If you intend to "play" with your footage i.e., want to use "filters" to clean up video noise or need to do extensive editing etc. then consider using something like the Canopus ADVC-110 or DataVideo DAC-100 as these devices (external boxes that connect via FireWire) convert analog A/V into the DV format and do so very well (both have locked audio support).

If you are OK with direct-to-MPEG capture then for internal use consider the Hauppauge WinTV PVR 250 or 350 models. For external use there is the Hauppauge WinTV PVR USB2.

Another option is the ADS Instant DVD 2.0 (very recently "upgraded" to the ADS Instant DVD+MP3 model which can do AC-3 audio on capture). Anyways not long ago I tried the ADS Instant DVD 2.0 (an external USB 2.0 device that is a hardware MPEG capture device) and thought the image quality was most excellent (I'd say better than Hauppauge) but it can only do one unattended scheduled recording at a time whereas the Hauppauge units excel at scheduled recordings (great for TV recordings).

- John "FulciLives" Coleman

[dphirschler]

use hardware encoding, which I adamantly believe is superior to software encoding.

Hardware encoding* is only superior in speed and the load it places on your CPU. Hardware encoding is real time which cannot possibly deliver the quality that software encoding can. Plus, the file size of a software encoded video will be much smaller since it can use multipass VBR. But if you are talking only RTE (real time encoders) then hardware will win.

*At least the hardware encoding you described. I believe there are hardware encoders that can do multipass VBR such as the one inside the Pioneer DVD recorders with harddrives.


Darryl

[edDV]

use hardware encoding, which I adamantly believe is superior to software encoding.

Hardware encoding* is only superior in speed and the load it places on your CPU. Hardware encoding is real time which cannot possibly deliver the quality that software encoding can. Plus, the file size of a software encoded video will be much smaller since it can use multipass VBR. But if you are talking only RTE (real time encoders) then hardware will win.

*At least the hardware encoding you described. I believe there are hardware encoders that can do multipass VBR such as the one inside the Pioneer DVD recorders with harddrives.

Darryl

If the need is PVR from a broadcast source (e.g. fast capture, 80%+ quality and low hassle) use hardware encoding.

If you anticipate heavy correction filtering, cap high bitrate MPeg2 or DV (Canopus/DataVideo) then edit-filter and encode.

If you are trying to preserve a one of a kind treasure and are willing to spend most of a day to get an optimized DVD disc, then capture uncompressed, add filters and encode slowly with multipass VBR.

[mikiem]

FWIW, throwing my own 2 cents worth in...

I personally don't like hardware compression on capture because in the past I've found it too limiting -- lose all sorts of options. Most CPUs can more then handle it (I think software encoding was 1st practical around the 1 gig mark), and more capable then an encoding chip (or I'd like to think so after spending the $ :P ). I do agree that software re-encoding after capture is better quality, but that's using my eyes, source, hardware. Internal bandwidth isn't much of an issue nowdays, but that doesn't mean other apps and processes running won't screw it up. [my equivilent of the years ago I had a 5 mile walk to school in 4 feet of snow story: SCSI AV drives used to cost $1000+ US for 8 gig, & yeah, still got one packed away somewhere. ]

I'm of the hi-bandwidth, edit, re-encode school myself, meaning either a DV box or ATI MMC mpg2 at 20, but that's me.

[jman98]

I respectfully disagree with dphischler's comments. I can record with my PVR-350 at bit rates of about 9100 Kbps and then re-encode with CCE using 3 pass VBR to get excellent results. I do use the same card to record TV shows without re-encoding and I think it looks as good as the original broadcast at lower bit rates than 9100. All of this stuff is subjective though. Maybe ATI is better now and maybe higher CPUs help, but I can tell you that ATI lost me forever as a customer with their crappy performance 5 years ago when you had to have a 2 GHz CPU or so to even attempt to record DVD resolution video. My 1 GHz CPU at the time couldn't record anything with my ATI card above SVCD or I would lose frames like crazy.
ATI also had some weird sync issues that effected some PCs, such as mine, and I just had enough of dealing with all the crap required to make it work. I knew one guy who using an older ATI card than mine was getting terrific SVCD quality out of it and he told me that he had to use a 2 disk RAID system to get that kind of quality.

I suppose it all depends on what we are talking about and if you are, say, using an ATI card to record video at very high bit rates and then re-encoding it using something like CCE, we're basically getting to the same place by different means.

[FulciLives]

Most hardware MPEG encoding/capture cards (like the Hauppauge line) can record MPEG-2 up to 15,000kbps

The Hauppauge units say they go up to 12,000kbps but really can handle 15,000kbps

The ADS Instant DVD 2.0 can also handle 15,000kbps MPEG-2 capture.

So as suggested by jman98 one can always use a hardware MPEG capture card to do a 15,000kbps capture then apply filters and re-encode with a software MPEG encoder (like CCE or TMPGEnc Plus etc.).

However even 15,000kbps MPEG-2 is a lot more compressed than say DV or HuffyUV etc. so for the quality nut that likes to re-encode I still say DV is the best way to go (despite the NTSC 4:1:1 color sampling "error").

Of course the nice thing about hardware MPEG-2 capture (be it a capture card like the Hauppauge or a stand alone DVD recorder) is that with a high enough quality source and bitrate once can do recording in real time with very decent (if not excellent) results.

Personally I use a stand alone DVD recorder now and I am (mostly) happy with it but I do miss the "old way" of doing a (in my case) PICVideo MJPEG capture then using AviSynth to filter and CCE for a multi-pass VBR encode. Currently I don't have a "working" capture card on my computer anymore but I will probably eventually get a Canopus ADVC-110 or DataVideo DAC-100 for those "special" recordings where I want to do it the "old school" way.

- John "FulciLives" Coleman

[jagabo]

Eandmwilson, You might find this post about capture device types useful:

https://forum.videohelp.com/viewtopic.php?p=1371883#1371883

[Jester700]

I just wanted to correct that first misunderstanding re: bus speed, since nobody else did. PCI runs at 133MB/s (megabytes) - that's 1064Mb/s (megabits). Which is over 2x as fast as the 480Mb/s of USB2.0.

[jagabo]

I just wanted to correct that first misunderstanding re: bus speed, since nobody else did. PCI runs at 133MB/s (megabytes) - that's 1064Mb/s (megabits). Which is over 2x as fast as the 480Mb/s of USB2.0.

Not to mention the that the overhead of USB is much higher. It can only deliver about half it's rated bandwidth and CPU usage is high.

Also don't forget that USB and Firewire chips use the PCI bus for their transfers, even if they're integrated on the motherboard.

AGP and PCI Express, on which the ATI AIW cards sit, have the highest bandwidth.

[FulciLives]

PCI, USB, FIREWIRE etc. makes no difference.

There are capture cards/devices that work fine for all three types despite which "connection" is fastest or slowest etc.

Makes no difference.

It's a moot point.

- John "FulciLives" Coleman

[edDV]

PCI, USB, FIREWIRE etc. makes no difference.

There are capture cards/devices that work fine for all three types despite which "connection" is fastest or slowest etc.

Makes no difference.

It's a moot point.

- John "FulciLives" Coleman

My main concern with USB2 devices remains the lack of video or control standards. Each device needs special drivers to be written for each and every software application. Most application developers stopped specific card support long ago and now write mainly to the DirectShow API.

DirectShow needs to be expanded to include external tuners and video capture but until it does, you better like the bundled software.