Takashi Iwai wrote: > Charles Eidsness wrote: > > It looks like the parse_audio_format_i_type function at line 2369 of usbaudio.c > > (linux v2.6.23) doesn't support the case where bSubframeSize (fmt[5]) = 4 bytes > > and bBitResolution (fmt[6]) = 24 bits, which should correspond to a S24_LE (or > > BE) type. I'm developing a new USD DAC which supports this mode (24-bit sample > > in a 4 byte package). Right now Linux sends me S32_LE formated data, which is > > wrong. Would it be possible to expand this function to support S24_LE/BE? It > > would only require adding a few lines of code. > > Yes, it's possible, of course. > > BTW, is this behavior strictly defined? I fail to find in the > usb-audio spec that bBitResolution specifies the lower bits, not the > higher bits... The spec assumes that 24-bit samples use S24_3LE. 24-bit samples in 32-bit words are an extension that must be handled with some device- specific code (like with the UA-1000). (The audio 2.0 spec allows 32-bit words, and the wording seems to imply that samples are aligned to the most significant bit, i.e., that S32_LE would be used in this case.) Regards, Clemens _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
