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Subject: mp3 buffer values with 8MB
From: Uwe Freese (mail_at_uwe-freese.de)
Date: 2003-01-18


Hello,

I changed the app.lds like Matthias described in his doc and it seems to
work.

But there's a problem when the buffer is filled the first time (after
turning on the device or starting playback from within the dir browser):
The playback stops after some seconds when the buffer thread fills the
buffer.
If I wait until the buffer is all "played back" (I heard nothing) and it
is filled again, it plays without problems.

Zagor said that this is because of the watermark values in mpeg.h.
But there are so many.. ;)

Can you please guess the "perfect" values for 8 MB? I tried the values
below, but playback then doesn't start until the buffer is filled
completely.

#define MPEG_SWAP_CHUNKSIZE 0x2000
#define MPEG_HIGH_WATER 2 /* We leave 2 bytes empty because otherwise we
                              wouldn't be able to see the difference between
                              an empty buffer and a full one. */
#define MPEG_LOW_WATER 0x80000 /* old value: 0x60000 */
#define MPEG_LOW_WATER_CHUNKSIZE 0x80000
#define MPEG_LOW_WATER_SWAP_CHUNKSIZE 0x20000
#define MPEG_PLAY_PENDING_THRESHOLD 0x20000
#define MPEG_PLAY_PENDING_SWAPSIZE 0x20000

Bye, Uwe.



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