[SDL] SDL Newbie questions: Audio latency and YUV Overlays

[Justin Schoeman]

** I am not on the list, so please cc me any replies! Thanks. ***

Hi eveybody,

I am busy trying to write my first real SDL app, a streaming video 
player.  I have the framework finished, and working well, but have the 
following two problems:

1) Audio latency:
I keep the audio playing continuously.  Whenever the audio callback 
fetches more data, I check the timestamp of the audio being played, and 
ensure that the same video frame is displayed.  Unfortunately, the audio 
plays about 0.5s _after_ the video.  When I check the size field in 
SDL_AudioSpec, it is 1024, or a delay of about 0.05s.  Is there any way 
to accurately determine the latency between the audio being fetched, and 
played?

2) YUV Overlay:
The hardware accelerated YUV overlay works great, but when run on a 
machine without HW acceleration (ATI Mach-64 with standard Mandrake 8.1 
drivers), only the first 4 pixels of the image are rendered, in the top 
left hand corner of the display!  The pixels do scale correctly when the 
window is resized, but still only the first four pixels are rendered 
(just larger).

Any help/hints would be greatly appreciated.

Thanks,

-justin