gstreamer/subprojects/gst-plugins-bad/sys/dwrite/libcaption/eia608.c

/**********************************************************************************************/
/* The MIT License                                                                            */
/*                                                                                            */
/* Copyright 2016-2017 Twitch Interactive, Inc. or its affiliates. All Rights Reserved.       */
/*                                                                                            */
/* Permission is hereby granted, free of charge, to any person obtaining a copy               */
/* of this software and associated documentation files (the "Software"), to deal              */
/* in the Software without restriction, including without limitation the rights               */
/* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell                  */
/* copies of the Software, and to permit persons to whom the Software is                      */
/* furnished to do so, subject to the following conditions:                                   */
/*                                                                                            */
/* The above copyright notice and this permission notice shall be included in                 */
/* all copies or substantial portions of the Software.                                        */
/*                                                                                            */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR                 */
/* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,                   */
/* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE                */
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/* THE SOFTWARE.                                                                              */
/**********************************************************************************************/
#include "eia608.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

////////////////////////////////////////////////////////////////////////////////
int eia608_row_map[] = { 10, -1, 0, 1, 2, 3, 11, 12, 13, 14, 4, 5, 6, 7, 8, 9 };
int eia608_reverse_row_map[] =
    { 2, 3, 4, 5, 10, 11, 12, 13, 14, 15, 0, 6, 7, 8, 9, 1 };

const char *eia608_style_map[] = {
  "white",
  "green",
  "blue",
  "cyan",
  "red",
  "yellow",
  "magenta",
  "italics",
};

static inline uint16_t
eia608_row_pramble (int row, int chan, int x, int underline)
{
  row = eia608_reverse_row_map[row & 0x0F];
  return eia608_parity (0x1040 | (chan ? 0x0800 : 0x0000) | ((row << 7) &
          0x0700) | ((row << 5) & 0x0020) | ((x << 1) & 0x001E) | (underline ?
      0x0001 : 0x0000));
}

uint16_t
eia608_row_column_pramble (int row, int col, int chan, int underline)
{
  return eia608_row_pramble (row, chan, 0x8 | (col / 4), underline);
}

uint16_t
eia608_row_style_pramble (int row, int chan, eia608_style_t style,
    int underline)
{
  return eia608_row_pramble (row, chan, style, underline);
}

uint16_t
eia608_midrow_change (int chan, eia608_style_t style, int underline)
{
  return eia608_parity (0x1120 | ((chan << 11) & 0x0800) | ((style << 1) &
          0x000E) | (underline & 0x0001));
}

int
eia608_parse_preamble (uint16_t cc_data, int *row, int *col,
    eia608_style_t * style, int *chan, int *underline)
{
  (*row) =
      eia608_row_map[((0x0700 & cc_data) >> 7) | ((0x0020 & cc_data) >> 5)];
  (*chan) = ! !(0x0800 & cc_data);
  (*underline) = 0x0001 & cc_data;

  if (0x0010 & cc_data) {
    (*style) = eia608_style_white;
    (*col) = 4 * ((0x000E & cc_data) >> 1);
  } else {
    (*style) = (0x000E & cc_data) >> 1;
    (*col) = 0;
  }

  return 1;
}

int
eia608_parse_midrowchange (uint16_t cc_data, int *chan, eia608_style_t * style,
    int *underline)
{
  (*chan) = ! !(0x0800 & cc_data);

  if (0x1120 == (0x7770 & cc_data)) {
    (*style) = (0x000E & cc_data) >> 1;
    (*underline) = 0x0001 & cc_data;
  }

  return 1;
}

////////////////////////////////////////////////////////////////////////////////
// control command
eia608_control_t
eia608_parse_control (uint16_t cc_data, int *cc)
{
  if (0x0200 & cc_data) {
    (*cc) = (cc_data & 0x0800 ? 0x01 : 0x00);
    return (eia608_control_t) (0x177F & cc_data);
  } else {
    (*cc) = (cc_data & 0x0800 ? 0x01 : 0x00) | (cc_data & 0x0100 ? 0x02 : 0x00);
    return (eia608_control_t) (0x167F & cc_data);
  }
}

uint16_t
eia608_control_command (eia608_control_t cmd, int cc)
{
  uint16_t c = (cc & 0x01) ? 0x0800 : 0x0000;
  uint16_t f = (cc & 0x02) ? 0x0100 : 0x0000;

  if (eia608_tab_offset_0 == (eia608_control_t) (cmd & 0xFFC0)) {
    return (eia608_control_t) eia608_parity (cmd | c);
  } else {
    return (eia608_control_t) eia608_parity (cmd | c | f);
  }
}

////////////////////////////////////////////////////////////////////////////////
// text
static const char *
utf8_from_index (int idx)
{
  return (0 <= idx && EIA608_CHAR_COUNT > idx) ? eia608_char_map[idx] : "";
}

static int
eia608_to_index (uint16_t cc_data, int *chan, int *c1, int *c2)
{
  (*c1) = (*c2) = -1;
  (*chan) = 0;
  cc_data &= 0x7F7F;            // strip off parity bits

  // Handle Basic NA BEFORE we strip the channel bit
  if (eia608_is_basicna (cc_data)) {
    // we got first char, yes. But what about second char?
    (*c1) = (cc_data >> 8) - 0x20;
    cc_data &= 0x00FF;

    if (0x0020 <= cc_data && 0x0080 > cc_data) {
      (*c2) = cc_data - 0x20;
      return 2;
    }

    return 1;
  }
  // Check then strip second channel toggle
  (*chan) = cc_data & 0x0800;
  cc_data = cc_data & 0xF7FF;

  if (eia608_is_specialna (cc_data)) {
    // Special North American character
    (*c1) = cc_data - 0x1130 + 0x60;
    return 1;
  }

  if (0x1220 <= cc_data && 0x1240 > cc_data) {
    // Extended Western European character set, Spanish/Miscellaneous/French
    (*c1) = cc_data - 0x1220 + 0x70;
    return 1;
  }

  if (0x1320 <= cc_data && 0x1340 > cc_data) {
    // Extended Western European character set, Portuguese/German/Danish
    (*c1) = cc_data - 0x1320 + 0x90;
    return 1;
  }

  return 0;
}

int
eia608_to_utf8 (uint16_t c, int *chan, char *str1, char *str2)
{
  int c1, c2;
  int size = (int) eia608_to_index (c, chan, &c1, &c2);
  utf8_char_copy (str1, utf8_from_index (c1));
  utf8_char_copy (str2, utf8_from_index (c2));
  return size;
}

uint16_t
eia608_from_basicna (uint16_t bna1, uint16_t bna2)
{
  if (!eia608_is_basicna (bna1) || !eia608_is_basicna (bna2)) {
    return 0;
  }

  return eia608_parity ((0xFF00 & bna1) | ((0xFF00 & bna2) >> 8));
}

// prototype for re2c generated function
uint16_t _eia608_from_utf8 (const utf8_char_t * s);
uint16_t
eia608_from_utf8_1 (const utf8_char_t * c, int chan)
{
  uint16_t cc_data = _eia608_from_utf8 (c);

  if (0 == cc_data) {
    return cc_data;
  }

  if (chan && !eia608_is_basicna (cc_data)) {
    cc_data |= 0x0800;
  }

  return eia608_parity (cc_data);
}

uint16_t
eia608_from_utf8_2 (const utf8_char_t * c1, const utf8_char_t * c2)
{
  uint16_t cc1 = _eia608_from_utf8 (c1);
  uint16_t cc2 = _eia608_from_utf8 (c2);
  return eia608_from_basicna (cc1, cc2);
}

////////////////////////////////////////////////////////////////////////////////

int
eia608_to_text (char *buf, ssize_t size, uint16_t cc_data)
{
  eia608_style_t style;
  const char *text = 0;
  char char1[5], char2[5];
  char1[0] = char2[0] = 0;
  int row, col, chan, underline;
  int ret;

  if (!eia608_parity_varify (cc_data)) {
    text = "parity failed";
  } else if (0 == eia608_parity_strip (cc_data)) {
    text = "pad";
  } else if (eia608_is_basicna (cc_data)) {
    text = "basicna";
    eia608_to_utf8 (cc_data, &chan, &char1[0], &char2[0]);
  } else if (eia608_is_specialna (cc_data)) {
    text = "specialna";
    eia608_to_utf8 (cc_data, &chan, &char1[0], &char2[0]);
  } else if (eia608_is_westeu (cc_data)) {
    text = "westeu";
    eia608_to_utf8 (cc_data, &chan, &char1[0], &char2[0]);
  } else if (eia608_is_xds (cc_data)) {
    text = "xds";
  } else if (eia608_is_midrowchange (cc_data)) {
    text = "midrowchange";
  } else if (eia608_is_norpak (cc_data)) {
    text = "norpak";
  } else if (eia608_is_preamble (cc_data)) {
    eia608_parse_preamble (cc_data, &row, &col, &style, &chan, &underline);
    ret = snprintf(buf, size, "cc %04X (%04X) '%s' '%s' (preamble: row: %d col: %d style: %d chan: %d underline: %d)",
        cc_data, eia608_parity_strip (cc_data), char1, char2, row, col, style, chan, underline);
  } else if (eia608_is_control (cc_data)) {
    switch (eia608_parse_control (cc_data, &chan)) {

      default:
        text = "unknown_control";
        break;

      case eia608_tab_offset_0:
        text = "eia608_tab_offset_0";
        break;

      case eia608_tab_offset_1:
        text = "eia608_tab_offset_1";
        break;

      case eia608_tab_offset_2:
        text = "eia608_tab_offset_2";
        break;

      case eia608_tab_offset_3:
        text = "eia608_tab_offset_3";
        break;

      case eia608_control_resume_caption_loading:
        text = "eia608_control_resume_caption_loading";
        break;

      case eia608_control_backspace:
        text = "eia608_control_backspace";
        break;

      case eia608_control_alarm_off:
        text = "eia608_control_alarm_off";
        break;

      case eia608_control_alarm_on:
        text = "eia608_control_alarm_on";
        break;

      case eia608_control_delete_to_end_of_row:
        text = "eia608_control_delete_to_end_of_row";
        break;

      case eia608_control_roll_up_2:
        text = "eia608_control_roll_up_2";
        break;

      case eia608_control_roll_up_3:
        text = "eia608_control_roll_up_3";
        break;

      case eia608_control_roll_up_4:
        text = "eia608_control_roll_up_4";
        break;

      case eia608_control_resume_direct_captioning:
        text = "eia608_control_resume_direct_captioning";
        break;

      case eia608_control_text_restart:
        text = "eia608_control_text_restart";
        break;

      case eia608_control_text_resume_text_display:
        text = "eia608_control_text_resume_text_display";
        break;

      case eia608_control_erase_display_memory:
        text = "eia608_control_erase_display_memory";
        break;

      case eia608_control_carriage_return:
        text = "eia608_control_carriage_return";
        break;

      case eia608_control_erase_non_displayed_memory:
        text = "eia608_control_erase_non_displayed_memory";
        break;

      case eia608_control_end_of_caption:
        text = "eia608_control_end_of_caption";
        break;
    }
  } else {
    text = "unhandled";
  }

  if (text != 0) {
    ret = snprintf (buf, size, "cc %04X (%04X) '%s' '%s' (%s)", cc_data, eia608_parity_strip (cc_data), char1, char2, text);
  }

  return ret;
}

void
eia608_dump (uint16_t cc_data)
{
  char *text = NULL;
  int bufsz;

  bufsz = eia608_to_text (NULL, 0, cc_data);
  text = malloc(bufsz + 1);
  eia608_to_text (text, bufsz + 1, cc_data);
  fprintf (stderr, "%s\n", text);

  free (text);
}