[wdmaudiodev] Re: GetMappings and GetPosition in WavePCI
- From: fox friend <foxfriend@xxxxxxxxx>
- To: wdmaudiodev@xxxxxxxxxxxxx
- Date: Wed, 28 Aug 2002 18:11:40 -0700 (PDT)
thanks, Frank,
i did check my order of releasing mappings. it was in
order.
however i found, when i tried to get mappings and
system failed me, later and even to the end, the
system would not call MappingAvailable at all. from
the document, MappingAvailabe should be called when
new mapping becomes available after i requests for
mapping through GetMapping have been refused. but why
system does not call it?
thank you for your help.
regards
Fox
--- Frank Berreth <fberreth@xxxxxxxxxxxxx> wrote:
>
> It seems to me you are releasing the mappings out of
> order. Win2k does
> check the order (which is kind-of a bug) and WinXP
> just doesn't care.
> So make sure you release the mappings in order.
>
> This posting is provided "AS IS" with no warranties,
> and confers no
> rights.
>
> -----Original Message-----
> From: fox friend [mailto:foxfriend@xxxxxxxxx]=20
> Sent: Tuesday, August 27, 2002 6:21 PM
> To: wdmaudiodev@xxxxxxxxxxxxx
> Subject: [wdmaudiodev] GetMappings and GetPosition
> in WavePCI
>
>
> i encounted a strange problem in writing WavePCI
> driver.=20
>
> if i start to play a wave file in media player, i
> can
> get some mappings from system and play. what
> happened
> to me is that the stream will play the wave file
> correct for the first 2 seconds, however the third
> sec
> will repeat the 2nd second's contents. then the
> system
> will stop and destroy this stream, then open a new
> one. nevertheless, the same thing will happen again.
> it always plays 2 seconds correctly, then repeat the
> 2nd second in the 3rd second. what's more, in the
> end
> of this wave, it will keep playing the last second's
> audio data without calling a stop. what happened
> here
> is when i call GetMapping, system will keep giving
> the
> same audio data instead of giving me an error
> NTSTATUS. so the last stream won's stop.=20
>
> if i start to play wave in sound recorder, it just
> stay at the beginning, and won't move forward at
> all.
> i will only get 5 small mappings here. after i
> release
> them, when i call getmappings again, it won't give
> me
> any more. GetPosition will be called only once
> before
> the status becomes RUN.
>
> once, i thought it was a problem related to
> GetPosition. but even though i used timer to
> calculate
> how much it should have played, the same thing would
> still happen. this timer was calculated according to
> the system time passed, sample size, sampling rate
> etc. i did doubt whether it is because of
> GetPosition.
>
> to clarify it, i once asked system for large trunk
> of
> data, around 0x50000 bytes, at the initial stage
> before Run (using media player). to my surprise, the
> system did not reject me, it did give me data.
> however
> the same thing happened again. this large trunk of
> data was sufficient for system play around 4
> seconds.
> when i checked those data, it had already contained
> the repeated data.
>
> then i did the whole thing in the opposite way. i
> just
> asked for small amount of data when each interrupt
> came, then played it immediately (still using media
> player). this amount of data was only enough for one
> and half interval between two interrupt. however
> what
> i saw was the same thing again.
>
> the more funny thing is the driver i wrote can work
> under XP using windows media play, while fail in
> win2000. however in both case, the soundrecorder
> won't
> play. it just stays at the beginning place. when
> i=20
> check the output message, the system still gives me
> only 5 small Mappings before the Run status in the
> initial stage. after that, though my driver keeps
> asking for new GetMapping, system will not give any
> more data. (i do releast those 5 Mappings)
>
> i really don't know why. is it still about
> GetMapping
> or GetPosition. thank you for any forthcoming reply.
>
> regards
> Fox
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