Date: Thu, 16 Apr 1998 19:51:38 -0400 From: Randall Hopper <rhh@ct.picker.com> To: Chris Csanady <ccsanady@friley585.res.iastate.edu>, freebsd-multimedia@FreeBSD.ORG Subject: Re: Bt848 questions... Message-ID: <19980416195138.B25620@ct.picker.com> In-Reply-To: <199804120450.XAA02189@friley585.res.iastate.edu>; from Chris Csanady on Sat, Apr 11, 1998 at 11:50:36PM -0500 References: <199804120450.XAA02189@friley585.res.iastate.edu>
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Chris Csanady: I see you've already got 2 good responses to your mail. Let me see if I can help some. |How exactly is the video rendered into windows, and how does the scaling |work? Does the direct video allow for the graphics card to do the scaling? | |I usually use 1600x1200, and would rather the video consume more than a |4x3" area. :) As Amancio mentioned, with the current driver RGB data is pushed over the PCI bus. In RGB mode, the capture card (e.g. Hauppauge Wincast) does the scaling. The Bt848 chip on the card is limited for NTSC to scale RGB up to 640x480 in all color depths. So in pixels, that's the biggest TV block you'll see on your screen in FreeBSD. On my 21" monitor @ 1600x1200, that's a good-size block about 6"x4.5". However, even if you run 1600x1200 like I do sometimes, you can still get full-screen TV on-demand thanks to XFree86 and software mode switching. When you run Fxtv (a FreeBSD TV app), you can tell it to go full-screen on-command (via key, mouse, or GUI button). Under the hood, it software-switches video modes to 640x480 and positions the viewport so your TV window fills the screen. Hit another key and your back to your previous mode (1600x1200). So you get the best of both worlds. Now, the Bt848 chip also supports YUV transfers to the video card, letting it do scaling and colorspace conversion, but XFree needs some work to support this last I heard. With mode switching instead, I find I really don't have any need for it (YUV/vidcard scaling). |Any comments on the relative quality of specific brands? I second the good comments about Hauppauge Wincast TV cards. |As an aside, I am also looking for a new sound card. Is there any real |audible difference in sound quality between the SB16 WaveEffects and AWE64? |I am only interested in audio playback/recording, etc. I'd hate to shell |out any more money for an ISA card than I have to. :\ Don't know anything about the "WaveEffects" part. If MIDI/wavetable isn't important to you, I wouldn't shell out the few extra bucks for an AWE64. Functionally AFAIK, the non-wavetable part of the SB32/AWE32*/AWE64* cards is a SB16. Just look for a SB16 card. PnP or non-PnP is fine, but pick a non-PnP if you have a choice. However, keep in mind that the SB16 component on SB16/SB32/AWE32*/AWE64* cards are NOT all the same. If digital record/playback sound quality is important. Make sure you get one with the Vibra16 chipset. It's also made by Creative Labs, fully SB16 chipset compatible, used on some of their SB16 (and derived) cards, and it doesn't have the ambient noise problem that the original SB16 chipset does. It is used on some SB16 (and derived) cards and not others. It was used on all the SB32s as far as I know, for example (I have one). Worth a check. However, if video/audio conferencing is important to you (full-duplex audio), you may want to look at other choices. To get full-duplex on SB16 and derived cards, sound drivers have to play games like using 8-bit in one direction and 16-bit in the other. Luigi has mentioned that his drivers support it, but there are other cards where such games aren't necessary. Luigi and others that are into MBone and vid/aud conf can give you the scoop there. Personally, I'm real happy with my SB32. Records/plays audio very nicely, like the wavetable for MIDIs, and it's compatible with lots of existing S/W. 28.8k modem here (no MBone for me), so full-duplex isn't a big deal here. Hope this helps. Randall To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-multimedia" in the body of the message
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