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rtl: clean up work function

This commit is contained in:
Dimitri Stolnikov 2012-05-27 14:27:05 +02:00
parent 674e084bdf
commit 6194958d71
1 changed files with 19 additions and 22 deletions
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41
lib/rtl/rtl_source_c.cc
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@ -27,7 +27,7 @@
#include "config.h"
#endif
#include <rtl_source_c.h>
#include "rtl_source_c.h"
#include <gr_io_signature.h>
#include <boost/assign.hpp>
@ -45,7 +45,9 @@ using namespace boost::assign;
#define BUF_SIZE (16 * 32 * 512)
#define BUF_NUM 32
#define BUF_SKIP 1 // buffers to skip due to garbage
#define BUF_SKIP 1 // buffers to skip due to initial garbage
#define BYTES_PER_SAMPLE 2 // rtl device delivers 8 bit unsigned IQ data
/*
* Create a new instance of rtl_source_c and return
@ -109,12 +111,12 @@ rtl_source_c::rtl_source_c (const std::string &args)
_buf[i] = (unsigned short *) malloc(BUF_SIZE);
_buf_head = _buf_used = _buf_offset = 0;
_samp_avail = BUF_SIZE;
_samp_avail = BUF_SIZE / BYTES_PER_SAMPLE;
// create a lookup table for gr_complex values
for (unsigned int i = 0; i <= 0xffff; i++) {
#if 1 // little endian
_lut.push_back( gr_complex( (float(i & 0xff) - 127.5f) *(1.0f/128.0f),
_lut.push_back( gr_complex( (float(i & 0xff) - 127.5f) * (1.0f/128.0f),
(float(i >> 8) - 127.5f) * (1.0f/128.0f) ) );
#else // big endian
_lut.push_back( gr_complex( (float(i >> 8) - 127.5f) * (1.0f/128.0f),
@ -132,7 +134,7 @@ rtl_source_c::rtl_source_c (const std::string &args)
_dev = NULL;
ret = rtlsdr_open( &_dev, dev_index );
if (ret < 0)
throw std::runtime_error("Failed to open rtlsdr device.");
throw std::runtime_error("Failed to open rtlsdr device.");
if (rtl_freq > 0 || tuner_freq > 0) {
if (rtl_freq)
@ -142,21 +144,21 @@ rtl_source_c::rtl_source_c (const std::string &args)
ret = rtlsdr_set_xtal_freq( _dev, rtl_freq, tuner_freq );
if (ret < 0)
throw std::runtime_error(
str(boost::format("Failed to set xtal frequencies. Error %d.") % ret ));
throw std::runtime_error(
str(boost::format("Failed to set xtal frequencies. Error %d.") % ret ));
}
ret = rtlsdr_set_sample_rate( _dev, 1024000 );
if (ret < 0)
throw std::runtime_error("Failed to set default samplerate.");
throw std::runtime_error("Failed to set default samplerate.");
ret = rtlsdr_reset_buffer( _dev );
if (ret < 0)
throw std::runtime_error("Failed to reset usb buffers.");
throw std::runtime_error("Failed to reset usb buffers.");
ret = rtlsdr_set_tuner_gain_mode(_dev, 1);
if (ret < 0)
throw std::runtime_error("Failed to enable manual gain mode.");
throw std::runtime_error("Failed to enable manual gain mode.");
_running = true;
@ -248,25 +250,24 @@ int rtl_source_c::work( int noutput_items,
{
boost::mutex::scoped_lock lock( _buf_mutex );
while (_buf_used < 3 && _running)
_buf_cond.wait( lock );
while (_buf_used < 3 && _running) // collect at least 3 buffers
_buf_cond.wait( lock );
}
if (!_running)
return WORK_DONE;
unsigned short *buf = _buf[_buf_head];
unsigned short *buf = _buf[_buf_head] + _buf_offset;
if (noutput_items <= int(_samp_avail)) {
for (int i = 0; i < noutput_items; ++i)
*out++ = _lut[ *(buf + _buf_offset + i) ];
*out++ = _lut[ *(buf + i) ];
_buf_offset += noutput_items;
_samp_avail -= noutput_items;
return noutput_items;
} else {
for (int i = 0; i < int(_samp_avail); ++i)
*out++ = _lut[ *(buf + _buf_offset + i) ];
*out++ = _lut[ *(buf + i) ];
{
boost::mutex::scoped_lock lock( _buf_mutex );
@ -276,18 +277,14 @@ int rtl_source_c::work( int noutput_items,
}
buf = _buf[_buf_head];
_buf_offset = 0;
int remaining = noutput_items - _samp_avail;
for (int i = 0; i < remaining; ++i)
*out++ = _lut[ *(buf + _buf_offset + i) ];
*out++ = _lut[ *(buf + i) ];
_buf_offset = remaining;
_samp_avail = (BUF_SIZE/2) - remaining;
return noutput_items;
_samp_avail = (BUF_SIZE / BYTES_PER_SAMPLE) - remaining;
}
return noutput_items;