On Wednesday 16 July 2008 12:22, Alan Horstmann wrote: > On Wednesday 16 July 2008 00:15, you wrote: > > At Mon, 7 Jul 2008 14:53:35 +0100, (snip) > > Well, I'd call it's a hardware "feature". No other hardwares do like > > that. > > > > As a workaround, we'll need to put zero'ed short samples before > > actually stopping the stream. > > > > I wonder whether this also occurs to pause operation, too. In the > > case of pause, it's a tougher problem... > > Thanks for the response on this one. I'm not sure how to test pause, > unless xmms uses that for 'PAUSE' button action, when the same effect is > seen. > > I did try setting various values for silence threshold and size, and when > (as per the original test) writing 1 period of sine followed by a 2nd > writei of experimental data, silence values could be found that would > eliminate the 'sustain effect'. However, when only the single period > writei occured I could not find any effective values. > > Unsurprisingly, my other ice1712 card, ST Audio /Hoontech DSP2000 shows the > same effect, so if it is a 'hardware feature' it presumably relates to the > way the envy24 chip operates? > > How would I go about experimenting with zeroing the stream just before > stopping? Do you mean in _pro_trigger()? Further info, I noticed in the envy24 datasheet, (rev 2.2 1.03.00) p 4-24 states (near bottom of page) '... when DMAs are stopped, the last latched value is retained. This "DC" value ...' so you were right about 'hardware feature'! Alan _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
