Exactly that's the case; the "normal" complex type of GNU Radio is really just 32bit floats IQIQIQIQ... ie. a single complex is nothing but two consecutive floating point numbers.
WAV files come in all types, encodings and storage quantizations. Typically, the header/tail are much shorter than the data, so if you can deal with how the data is put into your specific WAV, yeah, ignore the header. For everything else, refer to the wav_file_source (which has only compatibility with very specific WAVs), or learn all the fun that's in that container format. Cheers, Marcus On 16.03.2016 15:04, Henry Barton wrote: > This sounds interesting; I too have been wondering how IQ files > worked. I thought it must be alternating I bytes and Q bytes, or with > >8-bit radios, I words and Q words. But maybe the packed byte system > is right, since I can feed IQ recordings in WAV format directly into > GNUradio without stripping the headers. > > > > To: [email protected]; [email protected] > > From: [email protected] > > Date: Wed, 16 Mar 2016 10:24:02 +0100 > > Subject: Re: [Discuss-gnuradio] lack of understanding the different > formats to store samples > > > > Ok, let "I" and "Q" be single bits each, so each byte would then be > > > > IQIQIQIQ > > > > if I had to take a guess. > > > > You can get get back something that GR commonly deals with by doing > > > > packed to unpacked (type=B, bits per chunk = 1, endianness=your machine) > > -> IChar to Complex > > > > Best regards, > > Marcus > > On 16.03.2016 08:13, Ralph A. Schmid, dk5ras wrote: > > > Each byte seems to contain 4 1 bit I/Q samples. This is the text > from the > > > readme: > > > > > > "The output file size can be reduced by using "-b 1" option to > store four > > > 1-bit I/Q samples into a single byte." > > > > > > Ralph. > > > > > >> -----Original Message----- > > >> From: [email protected] > > >> [mailto:[email protected]] On > Behalf Of > > >> Marcus Müller > > >> Sent: Friday, March 11, 2016 2:53 PM > > >> To: [email protected] > > >> Subject: Re: [Discuss-gnuradio] lack of understanding the different > > > formats > > >> to store samples > > >> > > >> In what format are your 1bit samples? I'd assume they are just > the fact > > >> whether a byte is 0x00 or 0x01; in that case, just use unpacked > to packed. > > >> > > >> On 03/11/2016 10:24 AM, Ralph A. Schmid, dk5ras wrote: > > >>> Hi, > > >>> > > >>> Being an RF guy I must admit that I am somehow lost in the different > > >>> ways how samples are stored in files. I stumbled over this question > > >>> when I experimented with https://github.com/osqzss/gps-sdr-sim. It > > >>> works great when using 16 bit samples and using a simple > two-block grc > > >>> file, feeding them directly from a file source to the UHD sink. > > >>> However the 1 bit variant sounds promising, as the files are much > > >>> smaller this way and also the generation of them runs much faster. > > >>> > > >>> It must only be a matter of finding the right blocks and the right > > >>> settings to convert this, but my google search was highly confusing, > > >>> most probably due to different names for the same thing. > > >>> > > >>> So I do not only ask for how to use "four 1-bit I/Q samples into a > > >>> single byte" (taken from the readme of the gps-sdr-sim), but for a > > >>> more general overview how this stuff is done, to be prepared for > other > > >>> upcoming questions of this kind :) Up to now I solved those > issues by > > >>> an educated guess or even by try and error, what is not very > > > satisfying... > > >>> Ralph. > > >>> > > >>> > > >>> _______________________________________________ > > >>> Discuss-gnuradio mailing list > > >>> [email protected] > > >>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > >> > > >> _______________________________________________ > > >> Discuss-gnuradio mailing list > > >> [email protected] > > >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > > > _______________________________________________ > > Discuss-gnuradio mailing list > > [email protected] > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
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