Le Thursday 22 January 2009 16:25:42 Stefano Guidoni, vous avez écrit :
This patch solves bug 7385: Function ADPCM_StreamSize must return a buffer size, which is a multiple of block align. This buffer size is calculated taking into account input-blockalign, output-blockalign and adpcm-samplesperblock.
Hi.
Excuse me for contacting you directly, but that patch didn't enter the source tree, because of the "while" loops.
I've been trying for hours to guess by trial and (tons of) error the right formula not involving any "magic" number (besides 7, which is the number of bytes per channel in adpcm block header afaik), but I could not reach the right result: after ~ten seconds, the result of my computation diverges from yours, and audio starts repeating/skipping. Probably operation rounding errors. and/or integer overflows.
Could you explain me how you reached that formula ? Mainly, I don't understand why there is no trace of the number of samples per seconds, nor why you multiply a plock align with another block align in the denominator of source size computation when source is adpcm.
By advance, many thanks for enlightening me.
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Vincent Pelletier