Re: GRC max sample rate

[Marcus Müller]

There's no change in format at all.

On 25.07.20 10:22, Koyel Das (Vehere) wrote:
> Hi Paul,
>
> Thanks for your help. Can you please give an example? Like if usrp source 
> outputs 16 bit complex as I Q I Q I Q I Q for 4 IQ samples where I and Q are 
> 16 bit complex then what will be the change in the format after vector to 
> stream conversion? I understood that usrp source block already gives binary 
> file where I and Q are written alternately as above or interleaved. So I am 
> unable to understand when you say vector to stream will interleave I and Q 
> samples.
>
> Regards,
> Koyel
>
> Get Outlook for iOS<https://aka.ms/o0ukef>
> ________________________________
> From: Discuss-gnuradio 
> <discuss-gnuradio-bounces+koyel.das=vehere.com@gnu.org> on behalf of Paul 
> Boven <p.boven@xs4all.nl>
> Sent: Saturday, July 25, 2020 1:31:20 PM
> To: discuss-gnuradio@gnu.org <discuss-gnuradio@gnu.org>
> Subject: Re: GRC max sample rate
>
> Hi Koyel,
>
> On 7/25/20 9:19 AM, Koyel Das (Vehere) wrote:
>> Will there be packet drops if USRP source is set at 32 bit complex float
>> in grc when receiving at 100 MSPS each from two channels? That makes
>> 2*100e6*64 (32 bit I and 32 bit Q) = 12800e6 or 12.8 gbps. I am unable
>> to set usrp source block to 16 bit complex as then the usrp source block
>> is not compatible with file sink which doesn’t have option for 16 bit
>> complex.
> The USRP block is (as far as I could find) the only block in all of GNU
> Radio that uses the 'Complex Int16' type. Which is a bit confusing, but
> it is just a vector with a length of 2, alternating the I and Q channels
> as 16 bit shorts.
>
> You can simply convert it to interleaved int16 by using a 'Vector to
> Stream' block, with these settings:
>
> io_type: short
> num_items: 2
> vec_length: 1
>
> These 16 bit integers can then be written to disk (if it can keep up),
> memory, transferred over the network, or turned into floats for further
> processing.
>
> We use this to efficiently stream raw samples over the internet using a
> ZMQ Pub Sink.
>
> Regards, Paul Boven.
>
>