leansdr::dvb_deconvol_sync< Tin > Struct Template Reference

#include <dvb.h>

Inheritance diagram for leansdr::dvb_deconvol_sync< Tin >:

Collaboration diagram for leansdr::dvb_deconvol_sync< Tin >:

Classes
struct	sync_t

Public Types
typedef u8	decoded_byte

Public Member Functions
	dvb_deconvol_sync (scheduler *sch, pipebuf< Tin > &_in, pipebuf< decoded_byte > &_out)
void	run ()
Public Member Functions inherited from leansdr::runnable
	runnable (scheduler *_sch, const char *name)
Public Member Functions inherited from leansdr::runnable_common
	runnable_common (const char *_name)
virtual	~runnable_common ()
virtual void	shutdown ()

Public Attributes
int	resync_period
Public Attributes inherited from leansdr::runnable_common
const char *	name

Static Public Attributes
static const int	chunk_size = 64

Private Member Functions
void	init_syncs ()

Private Attributes
pipereader< Tin >	in
pipewriter< decoded_byte >	out
int	resync_phase
struct leansdr::dvb_deconvol_sync::sync_t	syncs [NSYNCS]
sync_t *	locked

Static Private Attributes
static const int	NSYNCS = 4

Additional Inherited Members
Protected Attributes inherited from leansdr::runnable
scheduler *	sch

Detailed Description

template<typename Tin>
struct leansdr::dvb_deconvol_sync< Tin >

Definition at line 719 of file dvb.h.

Member Typedef Documentation

decoded_byte

template<typename Tin >

typedef u8 leansdr::dvb_deconvol_sync< Tin >::decoded_byte

Definition at line 721 of file dvb.h.

Constructor & Destructor Documentation

dvb_deconvol_sync()

template<typename Tin >

leansdr::dvb_deconvol_sync< Tin >::dvb_deconvol_sync ( scheduler *  sch, pipebuf< Tin > &  _in, pipebuf< decoded_byte > &  _out  )

inline

Definition at line 725 of file dvb.h.

References leansdr::deconvol_sync< Tbyte, BYTE_ERASED >::init_syncs(), leansdr::deconvol_sync< Tbyte, BYTE_ERASED >::locked, and leansdr::deconvol_sync< Tbyte, BYTE_ERASED >::syncs.

                                                   : runnable(sch, "deconvol_sync_multipoly"),
                                                     resync_period(32),
                                                     in(_in),
                                                     out(_out, chunk_size),
                                                     resync_phase(0)
    {
        init_syncs();
        locked = &syncs[0];
    }

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Member Function Documentation

init_syncs()

template<typename Tin >

void leansdr::dvb_deconvol_sync< Tin >::init_syncs ( )

inlineprivate

Definition at line 792 of file dvb.h.

References leansdr::deconvol_sync< Tbyte, BYTE_ERASED >::sync_t::lut, leansdr::deconvol_sync< Tbyte, BYTE_ERASED >::NSYNCS, and leansdr::deconvol_sync< Tbyte, BYTE_ERASED >::syncs.

    {
        for (int s = 0; s < NSYNCS; ++s)
            // EN 300 421, section 4.5, Figure 5 QPSK constellation
            // Four rotations * two conjugations.
            // 180° rotation is detected as polarity inversion in mpeg_sync.
            //         2 | 0
            //         --+--
            //         3 | 1
            // 0°
            syncs[0].lut[0] = 0;

        syncs[0].lut[1] = 1;
        syncs[0].lut[2] = 2;
        syncs[0].lut[3] = 3;
        // 90°
        syncs[1].lut[0] = 2;
        syncs[1].lut[1] = 0;
        syncs[1].lut[2] = 3;
        syncs[1].lut[3] = 1;
        // 0° conjugated
        syncs[2].lut[0] = 1;
        syncs[2].lut[1] = 0;
        syncs[2].lut[2] = 3;
        syncs[2].lut[3] = 2;
        // 90° conjugated
        syncs[3].lut[0] = 0;
        syncs[3].lut[1] = 2;
        syncs[3].lut[2] = 1;
        syncs[3].lut[3] = 3;
    }

run()

template<typename Tin >

void leansdr::dvb_deconvol_sync< Tin >::run ( )

inlinevirtual

Reimplemented from leansdr::runnable_common.

Definition at line 737 of file dvb.h.

References leansdr::scheduler::debug, leansdr::deconvol_sync< Tbyte, BYTE_ERASED >::sync_t::in, leansdr::deconvol_sync< Tbyte, BYTE_ERASED >::locked, leansdr::deconvol_sync< Tbyte, BYTE_ERASED >::NSYNCS, leansdr::deconvol_sync< Tbyte, BYTE_ERASED >::sync_t::out, leansdr::runnable::sch, and leansdr::deconvol_sync< Tbyte, BYTE_ERASED >::syncs.

    {
        while (in.readable() >= chunk_size * 8 && out.writable() >= chunk_size)
        {
            int errors_best = 1 << 30;
            sync_t *best = NULL;

            for (sync_t *s = syncs; s < syncs + NSYNCS; ++s)
            {
                if (resync_phase != 0 && s != locked)
                    // Decode only the currently-locked alignment
                    continue;

                Tin *pin = in.rd();
                static decoded_byte dummy[chunk_size];
                decoded_byte *pout = (s == locked) ? out.wr() : dummy;
                int nerrors = s->deconv.run(pin, s->lut, pout, chunk_size);

                if (nerrors < errors_best)
                {
                    errors_best = nerrors;
                    best = s;
                }
            }

            in.read(chunk_size * 8);
            out.written(chunk_size);

            if (best != locked)
            {
                if (sch->debug)
                    fprintf(stderr, "%%%d", (int)(best - syncs));
                locked = best;
            }

            if (++resync_phase >= resync_period)
                resync_phase = 0;
        } // Work to do
    }     // run()

Member Data Documentation

chunk_size

template<typename Tin >

const int leansdr::dvb_deconvol_sync< Tin >::chunk_size = 64

static

Definition at line 723 of file dvb.h.

in

template<typename Tin >

pipereader<Tin> leansdr::dvb_deconvol_sync< Tin >::in

private

Definition at line 778 of file dvb.h.

locked

template<typename Tin >

sync_t* leansdr::dvb_deconvol_sync< Tin >::locked

private

Definition at line 790 of file dvb.h.

NSYNCS

template<typename Tin >

const int leansdr::dvb_deconvol_sync< Tin >::NSYNCS = 4

staticprivate

Definition at line 782 of file dvb.h.

out

template<typename Tin >

pipewriter<decoded_byte> leansdr::dvb_deconvol_sync< Tin >::out

private

Definition at line 779 of file dvb.h.

resync_period

template<typename Tin >

int leansdr::dvb_deconvol_sync< Tin >::resync_period

Definition at line 722 of file dvb.h.

resync_phase

template<typename Tin >

int leansdr::dvb_deconvol_sync< Tin >::resync_phase

private

Definition at line 780 of file dvb.h.

syncs

template<typename Tin >

struct leansdr::dvb_deconvol_sync::sync_t leansdr::dvb_deconvol_sync< Tin >::syncs[NSYNCS]

private

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The documentation for this struct was generated from the following file:

• plugins/channelrx/demoddatv/leansdr/dvb.h