leansdr::mpeg_sync< Tbyte, BYTE_ERASED > Struct Template Reference

#include <dvb.h>

Inheritance diagram for leansdr::mpeg_sync< Tbyte, BYTE_ERASED >:

Collaboration diagram for leansdr::mpeg_sync< Tbyte, BYTE_ERASED >:

Public Member Functions
	mpeg_sync (scheduler *sch, pipebuf< Tbyte > &_in, pipebuf< Tbyte > &_out, deconvol_sync< Tbyte, 0 > *_deconv, pipebuf< int > *_state_out=NULL, pipebuf< unsigned long > *_locktime_out=NULL)
void	run ()
void	run_searching ()
void	run_searching_fast ()
bool	search_sync ()
void	run_decoding ()
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	scan_syncs
int	want_syncs
unsigned long	lock_timeout
bool	fastlock
int	resync_period
Public Attributes inherited from leansdr::runnable_common
const char *	name

Private Attributes
pipereader< Tbyte >	in
pipewriter< Tbyte >	out
deconvol_sync< Tbyte, 0 > *	deconv
unsigned char	polarity
int	resync_phase
int	bitphase
bool	synchronized
int	next_sync_count
int	phase8
unsigned long	lock_timeleft
unsigned long	locktime
pipewriter< int > *	state_out
pipewriter< unsigned long > *	locktime_out
bool	report_state

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

Detailed Description

template<typename Tbyte, Tbyte BYTE_ERASED>
struct leansdr::mpeg_sync< Tbyte, BYTE_ERASED >

Definition at line 832 of file dvb.h.

Constructor & Destructor Documentation

mpeg_sync()

template<typename Tbyte, Tbyte BYTE_ERASED>

leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::mpeg_sync ( scheduler *  sch, pipebuf< Tbyte > &  _in, pipebuf< Tbyte > &  _out, deconvol_sync< Tbyte, 0 > *  _deconv, pipebuf< int > *  _state_out = NULL, pipebuf< unsigned long > *  _locktime_out = NULL  )

inline

Definition at line 839 of file dvb.h.

                                                            : runnable(sch, "sync_detect"),
                                                              scan_syncs(8),
                                                              want_syncs(4),
                                                              lock_timeout(4),
                                                              fastlock(false),
                                                              resync_period(1),
                                                              in(_in),
                                                              out(_out, SIZE_RSPACKET * (scan_syncs + 1)),
                                                              deconv(_deconv),
                                                              polarity(0),
                                                              resync_phase(0),
                                                              bitphase(0),
                                                              synchronized(false),
                                                              next_sync_count(0),
                                                              report_state(true)
    {
        state_out = _state_out ? new pipewriter<int>(*_state_out) : NULL;
        locktime_out = _locktime_out ? new pipewriter<unsigned long>(*_locktime_out) : NULL;
    }

Member Function Documentation

run()

template<typename Tbyte, Tbyte BYTE_ERASED>

void leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::run ( )

inlinevirtual

Reimplemented from leansdr::runnable_common.

Definition at line 864 of file dvb.h.

    {
        if (report_state && state_out && state_out->writable() >= 1)
        {
            // Report unlocked state on first invocation.
            state_out->write(0);
            report_state = false;
        }

        if (synchronized)
        {
            run_decoding();
        }
        else
        {
            if (fastlock)
                run_searching_fast();
            else
                run_searching();
        }
    }

run_decoding()

template<typename Tbyte, Tbyte BYTE_ERASED>

void leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::run_decoding ( )

inline

Definition at line 1028 of file dvb.h.

    {
        while (in.readable() >= SIZE_RSPACKET + 1 && out.writable() >= SIZE_RSPACKET && (!state_out || state_out->writable() >= 1) && (!locktime_out || locktime_out->writable() >= 1))
        {
            Tbyte *pin = in.rd(), *pend = pin + SIZE_RSPACKET;
            Tbyte *pout = out.wr();
            unsigned short w = *pin++;

            for (; pin <= pend; ++pin, ++pout)
            {
                w = (w << 8) | *pin;
                *pout = (w >> bitphase) ^ polarity;
            }

            in.read(SIZE_RSPACKET);
            Tbyte syncbyte = *out.wr();
            out.written(SIZE_RSPACKET);
            ++locktime;

            if (locktime_out)
                locktime_out->write(locktime);

            // Reset timer if sync byte is correct
            Tbyte expected = phase8 ? MPEG_SYNC : MPEG_SYNC_INV;

            if (syncbyte == expected)
                lock_timeleft = lock_timeout;

            phase8 = (phase8 + 1) & 7;
            --lock_timeleft;

            if (!lock_timeleft)
            {
                if (sch->debug)
                    fprintf(stderr, "Unlocked\n");

                synchronized = false;
                next_sync_count = 0;

                if (state_out)
                    state_out->write(0);

                return;
            }
        }
    }

run_searching()

template<typename Tbyte, Tbyte BYTE_ERASED>

void leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::run_searching ( )

inline

Definition at line 886 of file dvb.h.

    {
        bool next_sync = false;
        int chunk = SIZE_RSPACKET * scan_syncs;

        while (in.readable() >= chunk + 1 // Need 1 ahead for bit shifting
               && out.writable() >= chunk // Use as temp buffer
               && (!state_out || state_out->writable() >= 1))
        {
            if (search_sync())
                return;

            in.read(chunk);
            // Switch to next bit alignment
            ++bitphase;

            if (bitphase == 8)
            {
                bitphase = 0;
                next_sync = true;
            }
        }

        if (next_sync)
        {
            // No lock this time
            ++next_sync_count;

            if (next_sync_count >= 3)
            {
                // After a few cycles without a lock, resync the deconvolver.
                next_sync_count = 0;
                if (deconv)
                    deconv->next_sync();
            }
        }
    }

run_searching_fast()

template<typename Tbyte, Tbyte BYTE_ERASED>

void leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::run_searching_fast ( )

inline

Definition at line 924 of file dvb.h.

    {
        int chunk = SIZE_RSPACKET * scan_syncs;

        while (in.readable() >= chunk + 1 // Need 1 ahead for bit shifting
               && out.writable() >= chunk // Use as temp buffer
               && (!state_out || state_out->writable() >= 1))
        {
            if (resync_phase == 0)
            {
                // Try all bit alighments
                for (bitphase = 0; bitphase <= 7; ++bitphase)
                {
                    if (search_sync())
                        return;
                }
            }

            in.read(SIZE_RSPACKET);

            if (++resync_phase >= resync_period)
                resync_phase = 0;
        }
    }

search_sync()

template<typename Tbyte, Tbyte BYTE_ERASED>

bool leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::search_sync ( )

inline

Definition at line 949 of file dvb.h.

    {
        int chunk = SIZE_RSPACKET * scan_syncs;
        // Bit-shift [scan_sync] packets according to current [bitphase]
        Tbyte *pin = in.rd(), *pend = pin + chunk;
        Tbyte *pout = out.wr();
        unsigned short w = *pin++;

        for (; pin <= pend; ++pin, ++pout)
        {
            w = (w << 8) | *pin;
            *pout = w >> bitphase;
        }

        // Search for [want_sync] start codes at all 204 offsets
        for (int i = 0; i < SIZE_RSPACKET; ++i)
        {
            int nsyncs_p = 0, nsyncs_n = 0;   // # start codes assuming pos/neg polarity
            int phase8_p = -1, phase8_n = -1; // Position in sequence of 8 packets
            Tbyte *p = &out.wr()[i];

            for (int j = 0; j < scan_syncs; ++j, p += SIZE_RSPACKET)
            {
                Tbyte b = *p;

                if (b == MPEG_SYNC)
                {
                    ++nsyncs_p;
                    phase8_n = (8 - j) & 7;
                }

                if (b == MPEG_SYNC_INV)
                {
                    ++nsyncs_n;
                    phase8_p = (8 - j) & 7;
                }
            }

            // Detect most likely polarity
            int nsyncs;

            if (nsyncs_p > nsyncs_n)
            {
                polarity = 0;
                nsyncs = nsyncs_p;
                phase8 = phase8_p;
            }
            else
            {
                polarity = -1;
                nsyncs = nsyncs_n;
                phase8 = phase8_n;
            }

            if (nsyncs >= want_syncs && phase8 >= 0)
            {
                if (sch->debug)
                    fprintf(stderr, "Locked\n");

                if (!i)
                { // Avoid fixpoint detection in scheduler
                    i = SIZE_RSPACKET;
                    phase8 = (phase8 + 1) & 7;
                }

                in.read(i); // Skip to first start code
                synchronized = true;
                lock_timeleft = lock_timeout;
                locktime = 0;

                if (state_out)
                    state_out->write(1);

                return true;
            }
        }
        return false;
    }

Member Data Documentation

bitphase

template<typename Tbyte, Tbyte BYTE_ERASED>

int leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::bitphase

private

Definition at line 1081 of file dvb.h.

deconv

template<typename Tbyte, Tbyte BYTE_ERASED>

deconvol_sync<Tbyte, 0>* leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::deconv

private

Definition at line 1078 of file dvb.h.

fastlock

template<typename Tbyte, Tbyte BYTE_ERASED>

bool leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::fastlock

Definition at line 836 of file dvb.h.

in

template<typename Tbyte, Tbyte BYTE_ERASED>

pipereader<Tbyte> leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::in

private

Definition at line 1076 of file dvb.h.

lock_timeleft

template<typename Tbyte, Tbyte BYTE_ERASED>

unsigned long leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::lock_timeleft

private

Definition at line 1085 of file dvb.h.

lock_timeout

template<typename Tbyte, Tbyte BYTE_ERASED>

unsigned long leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::lock_timeout

Definition at line 835 of file dvb.h.

locktime

template<typename Tbyte, Tbyte BYTE_ERASED>

unsigned long leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::locktime

private

Definition at line 1086 of file dvb.h.

locktime_out

template<typename Tbyte, Tbyte BYTE_ERASED>

pipewriter<unsigned long>* leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::locktime_out

private

Definition at line 1088 of file dvb.h.

next_sync_count

template<typename Tbyte, Tbyte BYTE_ERASED>

int leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::next_sync_count

private

Definition at line 1083 of file dvb.h.

out

template<typename Tbyte, Tbyte BYTE_ERASED>

pipewriter<Tbyte> leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::out

private

Definition at line 1077 of file dvb.h.

phase8

template<typename Tbyte, Tbyte BYTE_ERASED>

int leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::phase8

private

Definition at line 1084 of file dvb.h.

polarity

template<typename Tbyte, Tbyte BYTE_ERASED>

unsigned char leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::polarity

private

Definition at line 1079 of file dvb.h.

report_state

template<typename Tbyte, Tbyte BYTE_ERASED>

bool leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::report_state

private

Definition at line 1089 of file dvb.h.

resync_period

template<typename Tbyte, Tbyte BYTE_ERASED>

int leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::resync_period

Definition at line 837 of file dvb.h.

resync_phase

template<typename Tbyte, Tbyte BYTE_ERASED>

int leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::resync_phase

private

Definition at line 1080 of file dvb.h.

scan_syncs

template<typename Tbyte, Tbyte BYTE_ERASED>

int leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::scan_syncs

Definition at line 834 of file dvb.h.

state_out

template<typename Tbyte, Tbyte BYTE_ERASED>

pipewriter<int>* leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::state_out

private

Definition at line 1087 of file dvb.h.

synchronized

template<typename Tbyte, Tbyte BYTE_ERASED>

bool leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::synchronized

private

Definition at line 1082 of file dvb.h.

want_syncs

template<typename Tbyte, Tbyte BYTE_ERASED>

int leansdr::mpeg_sync< Tbyte, BYTE_ERASED >::want_syncs

Definition at line 834 of file dvb.h.

---

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

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