At Mon, 27 Oct 2008 10:15:07 +0500, Alexander E. Patrakov wrote: > > Takashi Iwai wrote: > > A few important features are in my mind: > > - continuous rate support > > In the sources, you have: > > > Note: 44.1kHz is possible, but is more complex because it uses a method > > whereby the channel ring marks each sample in the channel ring as valid > > or not, so to get 44.1kHz, some samples are simply tagged invalid. The > > "channel ring" is not the ring buffer that is used to get sound samples > > to the card. The "channel ring" is used to pass samples between > > different processing modules on the card. One of these processing > > modules is the SRC, another is the INs/OUTs, another is the hardware > > mixer, and yet another is the DSP. > > Do I understand correctly that the card internally resamples the sound > to a different rate using the zero-order-hold method? If so, I'd rather > not see this feature at all unless the "i_want_horrible_sound" parameter > is passed, because software can do it better, and some program will > surely default to using this hardware misfeature. Likely it's a wrong guess. emu20k1 has the following register bits. # define SRCCTL_PITCH_ROM (3<<11) /* pitch ROM select */ # define SRCCTL_PITCH_HIGH (0<<11) /* 0 to 8.0: very high quality */ # define SRCCTL_PITCH_EXT_HIGH (1<<11) /* 0.26 to 1.72: extermely high qual.*/ # define SRCCTL_PITCH_88kHZ (2<<11) /* 1.8375: 88.2kHz 48kHz */ # define SRCCTL_PITCH_96KHZ (3<<11) /* 2.0: 96kHz 48kHz */ Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
