Re: [Discuss-gnuradio] Increasing ALSA Sampling Rate

[George S. Williams]

On 1/31/2011 4:22 PM, Marcus D. Leech wrote:
> audio_alsa_source[hw:2,1]: get_period_size failed: Invalid argument
>
> I think the clue is in the above.
>
> It looks like the device-specific driver for this hardware doesn't contain the 
> "PERIOD_SIZE" parameter
>    in the configuration description for the hardware, and Gnu Radio uses that 
> information for buffer
>    planning purposes (using it for set_output_multiple() ).  Not clear whether 
> there's a fix or not, and
>    whether the fix belongs in Alsa or Gnu Radio.

Would this keep Gnu Radio from using the card at 1792000 but still allow 
896000?

Using this in config.conf
[audio_alsa]
verbose = true

And setting samp_rate to 896000

GRC returns this-
PCM name: hw:1,1
Access types:
    MMAP_INTERLEAVED     YES
    MMAP_NONINTERLEAVED  NO
    MMAP_COMPLEX         NO
    RW_INTERLEAVED       YES
    RW_NONINTERLEAVED    NO
Formats:
    S8                   YES
    S16_LE               YES
Number of channels
    min channels: 1
    max channels: 1
    1 channels  YES
Sample Rates:
    min rate:  119466 (dir = 1)
    max rate: 1792000 (dir = 0)
      8000  NO
     16000  NO
     22050  NO
     32000  NO
     44100  NO
     48000  NO
     96000  NO
    192000  NO

So I would think that Gnu Radio should know about the higher rate?? The 
flowgraph does execute at 896000.

But, if I set samp_rate to 1792000, I get the get_period_size failed: 
Invalid argument error.

Just trying to understand this stuff- still in the steep part of the 
learning curve.

George