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/*
* libzvbi - Caption decoder
*
* Copyright (C) 2000, 2001, 2002, 2005 Michael H. Schimek
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* $Id: caption_decoder-priv.h,v 1.2 2006/05/06 09:11:32 mschimek Exp $ */
#ifndef CAPTION_DECODER_PRIV_H
#define CAPTION_DECODER_PRIV_H
#include "cache-priv.h"
#include "event-priv.h"
#include "caption_decoder.h"
typedef enum {
FIELD_1 = 0,
FIELD_2,
MAX_FIELDS
} field_num;
#define FIELD_UNKNOWN MAX_FIELDS
/* Closed Caption definitions. */
#define CHANNEL_UNKNOWN 0
#define MAX_CHANNELS 8
/* Sec. 15.119 (d) Screen format. */
#define FIRST_ROW 0
#define LAST_ROW 14
#define MAX_ROWS (LAST_ROW + 1)
#define FIRST_COLUMN 0
#define LAST_COLUMN 31
#define MAX_COLUMNS (LAST_COLUMN + 1)
/** This structure maintains Closed Caption channel state. */
typedef struct {
/**
* Displayed and non-displayed buffer according to spec.
* Snapshot of displayed buffer at last row update.
*/
vbi3_char buffer[3][MAX_ROWS][MAX_COLUMNS];
/**
* For all buffers, if bit (1 << row) is set this row contains
* text, otherwise only TRANSPARENT_SPACEs. Intended to speed
* up copying and conversion of characters.
*
* When dirty[n] < 0 this buffer shall be erased to all
* TRANSPARENT_SPACEs before storing characters. Intended to
* avoid copying and erasing buffers which are never used.
*/
int dirty[3];
/** Index of displayed buffer, 0 or 1. */
unsigned int displayed_buffer;
/** Cursor position. */
unsigned int curr_row;
unsigned int curr_column;
/**
* Text window height in VBI3_CAPTION_MODE_ROLL_UP
* (ranges from curr_row - window_rows + 1 to curr_row inclusive).
*
* NOTE curr_row - window_rows + 1 can be < FIRST_ROW, this must
* be clipped before using window_rows:
* actual_rows = MIN (curr_row - FIRST_ROW + 1, window_rows);
*
* We won't do that at a Roll-Up Captions command because usually
* a Preamble Address Code follows which may change curr_row.
*/
unsigned int window_rows;
/**
* Current character attributes (foreground and background color,
* underlined, flash, italic).
*/
vbi3_char curr_attr;
/** Current caption mode or VBI3_CAPTION_MODE_UNKNOWN. */
vbi3_caption_mode mode;
/** Last time when text was transmitted on this channel. */
double last_timestamp;
} caption_channel;
/* General stuff. */
typedef void
caption_reset_fn (vbi3_caption_decoder * cd,
cache_network * cn,
double time);
typedef void
caption_delete_fn (vbi3_caption_decoder * cd);
/** @internal */
struct _vbi3_caption_decoder {
struct {
/* Closed Caption decoder */
/**
* Decoder state. We decode all channels in parallel, this
* way clients can switch between channels without data
* loss, or capture multiple channels with a single decoder
* instance.
*/
caption_channel channel[MAX_CHANNELS];
/**
* Current channel, switched by caption control codes. Can
* be @c CHANNEL_UNKNOWN (no channel number received yet).
*/
vbi3_pgno curr_ch_num;
/**
* To send a display update event (VBI3_EVENT_CC_PAGE) when the
* visible buffer of the current channel changed, but no more
* than once for each pair of Closed Caption bytes.
*/
caption_channel * event_pending;
} cc;
struct {
/* ITV decoder */
/** Incoming data. */
uint8_t buffer[256];
/** Number of bytes in buffer. */
unsigned int size;
} itv;
struct {
/* XDS decoder */
// vbi3_xds_demux demux;
} xds;
/* Master demultiplexer */
/** Receiving ITV data on field 1 (channel VBI3_CHAPTION_T2). */
vbi3_bool in_itv;
/** Receiving XDS data on field 2, as opposed to caption. */
vbi3_bool in_xds;
/**
* Caption control codes (two bytes) may repeat once for
* error correction on the first field. expect_ctrl[1] is
* only written, to save conditionals.
*/
int expect_ctrl[2][2];
/**
* Remember past parity errors: One bit for each call of
* vbi3_caption_decoder_feed(), most recent result in lsb. The idea
* is to disable the decoder if we get too many errors.
*/
unsigned int error_history;
/* Interface */
/** The cache we use. */
vbi3_cache * cache;
/** Current network in the cache. */
cache_network * network;
double timestamp;
double reset_time;
vbi3_videostd_set videostd_set;
/** Called by vbi3_caption_decoder_reset(). */
caption_reset_fn * virtual_reset;
_vbi3_event_handler_list handlers;
/** Called by vbi3_caption_decoder_delete(). */
caption_delete_fn * virtual_delete;
};
extern void
_vbi3_caption_decoder_resync (vbi3_caption_decoder * cd);
extern void
_vbi3_caption_decoder_destroy (vbi3_caption_decoder * cd);
extern vbi3_bool
_vbi3_caption_decoder_init (vbi3_caption_decoder * cd,
vbi3_cache * ca,
const vbi3_network * nk,
vbi3_videostd_set videostd_set);
#endif /* CAPTION_DECODER_PRIV_H */
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