gstreamer/ext/closedcaption/bit_slicer.h
Edward Hervey b0b02e7cb5 closedcaption: Include zvbi raw vbi decoder code
Current code from zapping/zvbi as of 2018-03-14. Files copied
are all LGPL v2+.

Changes from original zvbi code:
* Switch to gst-debug logging system
* Use glib for endianness detection
* Fix compilation warnings
2018-05-28 14:50:01 +02:00

197 lines
4.9 KiB
C

/*
* libzvbi -- Bit slicer
*
* Copyright (C) 2000-2007 Michael H. Schimek
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA.
*/
/* $Id: bit_slicer.h,v 1.11 2008-02-24 14:18:13 mschimek Exp $ */
#ifndef __ZVBI_BIT_SLICER_H__
#define __ZVBI_BIT_SLICER_H__
#include "sampling_par.h"
VBI_BEGIN_DECLS
/**
* @addtogroup BitSlicer
* @{
*/
/**
* @brief Modulation used for VBI data transmission.
*/
typedef enum {
/**
* The data is 'non-return to zero' coded, logical '1' bits
* are described by high sample values, logical '0' bits by
* low values. The data is last significant bit first transmitted.
*/
VBI3_MODULATION_NRZ_LSB,
/**
* 'Non-return to zero' coded, most significant bit first
* transmitted.
*/
VBI3_MODULATION_NRZ_MSB,
/**
* The data is 'bi-phase' coded. Each data bit is described
* by two complementary signalling elements, a logical '1'
* by a sequence of '10' elements, a logical '0' by a '01'
* sequence. The data is last significant bit first transmitted.
*/
VBI3_MODULATION_BIPHASE_LSB,
/** 'Bi-phase' coded, most significant bit first transmitted. */
VBI3_MODULATION_BIPHASE_MSB
} vbi3_modulation;
/**
* @brief Bit slicer context.
*
* The contents of this structure are private.
* Call vbi3_bit_slicer_new() to allocate a bit slicer context.
*/
typedef struct _vbi3_bit_slicer vbi3_bit_slicer;
typedef enum {
VBI3_CRI_BIT = 1,
VBI3_FRC_BIT,
VBI3_PAYLOAD_BIT
} vbi3_bit_slicer_bit;
/**
* @brief Bit slicer sampling point.
*
* This structure contains information about
* a bit sampled by the bit slicer.
*/
typedef struct {
/** Whether this struct refers to a CRI, FRC or payload bit. */
vbi3_bit_slicer_bit kind;
/** Number of the sample times 256. */
unsigned int index;
/** Signal amplitude at this sample, in range 0 to 65535. */
unsigned int level;
/** 0/1 threshold at this sample, in range 0 to 65535. */
unsigned int thresh;
} vbi3_bit_slicer_point;
extern vbi_bool
vbi3_bit_slicer_slice_with_points
(vbi3_bit_slicer * bs,
uint8_t * buffer,
unsigned int buffer_size,
vbi3_bit_slicer_point *points,
unsigned int * n_points,
unsigned int max_points,
const uint8_t * raw)
_vbi_nonnull ((1, 2, 4, 5, 7));
extern vbi_bool
vbi3_bit_slicer_slice (vbi3_bit_slicer * bs,
uint8_t * buffer,
unsigned int buffer_size,
const uint8_t * raw)
_vbi_nonnull ((1, 2, 4));
extern vbi_bool
vbi3_bit_slicer_set_params (vbi3_bit_slicer * bs,
vbi_pixfmt sample_format,
unsigned int sampling_rate,
unsigned int sample_offset,
unsigned int samples_per_line,
unsigned int cri,
unsigned int cri_mask,
unsigned int cri_bits,
unsigned int cri_rate,
unsigned int cri_end,
unsigned int frc,
unsigned int frc_bits,
unsigned int payload_bits,
unsigned int payload_rate,
vbi3_modulation modulation)
_vbi_nonnull ((1));
extern void
vbi3_bit_slicer_set_log_fn (vbi3_bit_slicer * bs,
vbi_log_mask mask,
vbi_log_fn * log_fn,
void * user_data)
_vbi_nonnull ((1));
extern void
vbi3_bit_slicer_delete (vbi3_bit_slicer * bs);
extern vbi3_bit_slicer *
vbi3_bit_slicer_new (void)
_vbi_alloc;
/* Private */
typedef vbi_bool
_vbi3_bit_slicer_fn (vbi3_bit_slicer * bs,
uint8_t * buffer,
vbi3_bit_slicer_point *points,
unsigned int * n_points,
const uint8_t * raw);
/** @internal */
struct _vbi3_bit_slicer {
_vbi3_bit_slicer_fn * func;
vbi_pixfmt sample_format;
unsigned int cri;
unsigned int cri_mask;
unsigned int thresh;
unsigned int thresh_frac;
unsigned int cri_samples;
unsigned int cri_rate;
unsigned int oversampling_rate;
unsigned int phase_shift;
unsigned int step;
unsigned int frc;
unsigned int frc_bits;
unsigned int total_bits;
unsigned int payload;
unsigned int endian;
unsigned int bytes_per_sample;
unsigned int skip;
unsigned int green_mask;
_vbi_log_hook log;
};
extern void
_vbi3_bit_slicer_destroy (vbi3_bit_slicer * bs)
_vbi_nonnull ((1));
extern vbi_bool
_vbi3_bit_slicer_init (vbi3_bit_slicer * bs)
_vbi_nonnull ((1));
/** @} */
VBI_END_DECLS
#endif /* __ZVBI_BIT_SLICER_H__ */
/*
Local variables:
c-set-style: K&R
c-basic-offset: 8
End:
*/