On Sunday 14 Aug 2005 20:20, Jason Tackaberry wrote: > On Sun, 2005-08-14 at 12:32 +0100, Ian Armstrong wrote: > > It depends on what you're doing as to which mode is best. If you try to > > use time-stretch in MythTV, then sync on every field gives the best > > results but you need to de-interlace first. If you simply want the best > > quality image, then sync on every frame is best because there is no need > > to de-interlace the source. > > I've installed 0.3.7c and using the latest ivtvdev driver (0.10.5). > This is certainly an enormous improvement over what I've seen in the > past. Progressive content looks very good: as good as the tv-out on my > nvidia card. (CPU load is slightly higher though.) > > Interlaced content also looks the same as with my nvidia card: in other > words, not good. There appears the usual combing and juddering > symptomatic of lack of vsync. Since mplayer doesn't support any sort of > vsync with xv, I imagine that ivtv itself does some sort of magic. > > ivtv says that it's "Using progressive mode," however, when I play back > video. Here's how I'm loading mplayer: > > mplayer -vo xv -fs /dev/video0 -cache 4096 -mc 0 > > (/dev/video0 outputs 720x480 NTSC.) > <snip> > I assume that because it's using progressive mode, none of the vsync > modes you described in your email are used. Is there something I'm > doing wrong, or some way I can enable this feature?
The line in the log about progressive mode, isn't really the vsync code. Scaling of interlaced video works different from progressive, so there are two modes for the scaling. Interlaced scaling of progressive video gives some ugly results, and to a lesser degree the reverse is also true. Again, it's hard-coded as to which mode it will be used. The log entry is actually the scaling mode being used. I won't post a patch, but if you want to edit the file(s) yourself you need to change the following (this is with 0.3.7c) To change the vsync mode: ivtv-irq.c - Line 178 - Change 512 to the new switch-point. To change the scaling mode: ivtv-ioctl.c - Line 715 - Change 0x200 to the new switch-point. Both numbers are actually the same, but one was entered in decimal, while the other hex. To allow For interlaced NTSC, just change the setting to 480. For the scaling mode, you cannot go above 0x200 (512) or scaling will break. There are known issues with the current drivers. One of them being that the audio & video can get out of sync. Also, xine can sometimes give smoother results than mplayer. -- Ian ------------------------------------------------------- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf _______________________________________________ ivtv-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ivtv-devel
