Dear Mr. Woller, I have taken some advice from Takashi Iwai and I am implementing dual codec support for CS4281 chip.
I wanted to have 4 channels input (FIFO0(primary codec) and FIFO1(secondary codec)) and 4 channels output (FIFO2 and FIFO3 in the same way). But what do I write to SRC Slot Assignment (SRCSA) register? I only have 4 slots while I need 8! Should I first write the playback and capture slots of the primary codec, then set up FIFO0 and FIFO2, and then write slots of the secondary codec to SRCSA and set up FIFO1 and FIFO3 ? If this is indeed hardware limitation then I have the following 3 questions: 1. I am going to use CS4299 codecs at 8000 Hz only. They have internal sample rate converters (SRC) working at 8000 Hz. Do I really need to use SRC in CS4281? What will happen if I just set up the FIFOs and do not configure SRCSA at all? 2. I really need in fact only input from left channels of both codecs and output to the right channels of both codecs. May I for example program SRCSA left capture slot CLSS to 10 (Left PCM record) and the right capture slot CRSS to 20 (Secondary Left PCM record) or 22, 24 etc? I would then do the same trick with the playback slots. I would get the capture stereo stream from left PCM channels of the primary and secondary codecs and play 2 channel stereo to the right channels of both codecs. 3. Is it possible to have all the 4 channels interleaved? I mean can two DMA engines write to the same memory buffer, just with 2 sample offset and skipping each 2 samples? Best regards, -- Tomasz Motylewski P.S. To ALSA developers: if my guess is right, then we may support all 4 channels full duplex only at a few predefines speeds. But we may use 4 SRC units and for example make one codec any-speed, or all playback any-speed, or all left channels (packed in a single stereo stream) any-speed. Does ALSA support such wild configurations? _______________________________________________________________ Don't miss the 2002 Sprint PCS Application Developer's Conference August 25-28 in Las Vegas -- http://devcon.sprintpcs.com/adp/index.cfm _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
