mciavi32: Add partial support for MCI_DGV_PLAY_REPEAT

[Joerg-Cyril.Hoehle at t-systems.com]

Bruno,

>If you ever have time, please take a look.
+            wma->dwCurrVideoFrame = wma->dwCurrAudioBlock = 0;
I'm sorry I'd reject this patch because it's missing integration for the MCI_FROM keyword.

Example using MS' clock.avi:
OPEN clock.avi alias c
WINDOW c State Show ; may still be needed in Wine
PLAY c FROM 2 TO 5 repeat
should open the window and repeat stepping the clock from 3 to 6 o'clock.
(You remember my MCI shell in bugzilla, don't you?)

You could argue that there's no need to bother for MCI_FROM, because it's not yet supported with audio output (see mmoutput.c). However, play c FROM x to y currently works with video only output (e.g. clock.avi), thus new patches should at least support what's already in place.

BTW (not in your patch):
         FIXME("Should recompute dwCurrAudioBlock, except unsynchronized sound & video\n");
Typo, should be "expect"

Supporting sound with MCI_FROM non-zero would be the matter of another patch for a volunteer...

In summary, I believe that a better patch would either add dwFromVideoFrame to WINE_MCIAVI or remember dwCurrentVideoFrame (but see below) at the entrance of MCIAVI_Player and use that.

Note that I'd expect any patch to handle this scenario correctly:
Play c FROM 2 TO 5 repeat
Play c TO 8 repeat
In native, the second play would *continue* playing from the current position upto 9 o'clock, then resume from 0 (not 3 o'clock, because 0 is the default FROM value in the second play command).

Well, that's probably too much for a single patch, since it would likely require keeping the player thread alive, just changing its start/repeat and end positions, rather than restarting a new one.

Regards,
	Jörg Höhle