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.)

Here is the excerpt from the log when I start it:

Aug 14 15:15:24 viper kernel: ivtv: Allocate DMA encoder MPEG stream: 128 x 
32768 buffers (4096KB total)
Aug 14 15:15:24 viper kernel: ivtv: Setup VBI API header 0x0000bd0d pkts 1 
buffs 4 ln 24 sz 1456
Aug 14 15:15:24 viper kernel: ivtv: Setup VBI start 0x0018ea04 frames 4 fpi 1 
lines 0x000000f1
Aug 14 15:15:25 viper kernel: saa7115: decoder disable output
Aug 14 15:15:25 viper kernel: saa7115: decoder enable output
Aug 14 15:15:27 viper kernel: ivtv: Allocate DMA decoder YUV stream: 24 x 43200 
buffers (1024KB total)
Aug 14 15:15:27 viper kernel: ivtv-osd: Need to adjust width to src_w 720 dst_w 
720 scaled_w 720
Aug 14 15:15:27 viper kernel: ivtv: master_width: 00200002   X-Coords: src 0  
dst 0
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2834 02d00280->02d002d0 0x2838 
02d00280->02d002d0
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x283c 00071c72->00080000 0x2844 
00071c72->00080000
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2854 001c71c8->00200002
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x285c 000e38e4->00100001 0x2864 
000e38e4->00100001
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2874 00000000->00000000
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2870 0010000c->00080004
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2890 00000000->00000000
Aug 14 15:15:27 viper kernel: ivtv: h_filter -> 0
Aug 14 15:15:27 viper kernel: ivtv-osd: Need to adjust height to src_h 480 
dst_h 480 scaled_h 960
Aug 14 15:15:27 viper kernel: ivtv: master_height: 00800000   Y-Coords: src 0  
dst 0
Aug 14 15:15:27 viper kernel: ivtv: Using progressive mode
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2934 00002000->00020000 0x293c 
00100000->00100000
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2944 00040000->00040000 0x294c 
000b0000->000b0000
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2930 00200000->00200000 0x2938 
00200000->00200000
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2928 00040000->00080000 0x292c 
00040514->00080514
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2920 00080000->00080000 0x2924 
00080514->00080514
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2918 01e001e0->01e003c0 0x291C 
01e000f0->01e001e0
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x296c 00000000->00000001
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2940 00100000->00200000 0x2948 
00100000->00200000
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2950 00020000->00010000 0x2954 
00020000->00010001
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2958 00020000->00010000 0x295C 
00020000->00010001
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2960 00ef01df->01200240
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x2964 00010001->00010001 0x2968 
00010001->00010001
Aug 14 15:15:27 viper kernel: ivtv: Update reg 0x289c 011e0017->011e0017
Aug 14 15:15:27 viper kernel: ivtv: v_filter_1 -> 0
Aug 14 15:15:27 viper kernel: ivtv: v_filter_2 -> 1
Aug 14 15:15:27 viper kernel: ivtv: Enable video output


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?

Thanks,
Jason.

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