gstreamer/subprojects/gst-plugins-bad/sys/dwrite/libcaption/caption.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                */
/* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER                     */
/* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,              */
/* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN                  */
/* THE SOFTWARE.                                                                              */
/**********************************************************************************************/
#include "caption.h"
#include "eia608.h"
#include "utf8.h"
#include "xds.h"
#include <stdio.h>
#include <string.h>
////////////////////////////////////////////////////////////////////////////////
void
caption_frame_buffer_clear (caption_frame_buffer_t * buff)
{
  memset (buff, 0, sizeof (caption_frame_buffer_t));
}

void
caption_frame_state_clear (caption_frame_t * frame)
{
  frame->write = 0;
  frame->timestamp = -1;
  frame->state = (caption_frame_state_t) {
  0, 0, 0, SCREEN_ROWS - 1, 0, 0};      // clear global state
}

void
caption_frame_init (caption_frame_t * frame)
{
  xds_init (&frame->xds);
  caption_frame_state_clear (frame);
  caption_frame_buffer_clear (&frame->back);
  caption_frame_buffer_clear (&frame->front);
}

////////////////////////////////////////////////////////////////////////////////
// Helpers
static caption_frame_cell_t *
frame_buffer_cell (caption_frame_buffer_t * buff, int row, int col)
{
  if (!buff || 0 > row || SCREEN_ROWS <= row || 0 > col || SCREEN_COLS <= col) {
    return 0;
  }

  return &buff->cell[row][col];
}

int caption_frame_clear_char (caption_frame_t * frame, int row, int col)
{
  if (!frame->write) {
    return 0;
  }

  caption_frame_cell_t *cell = frame_buffer_cell (frame->write, row, col);

  if (cell) {
    memset (cell, 0, sizeof (caption_frame_cell_t));
    return 1;
  }

  return 0;
}

uint16_t _eia608_from_utf8 (const char *s);     // function is in eia608.c.re2c
int
caption_frame_write_char (caption_frame_t * frame, int row, int col,
    eia608_style_t style, int underline, const char *c)
{
  if (!frame->write || !_eia608_from_utf8 (c)) {
    return 0;
  }

  caption_frame_cell_t *cell = frame_buffer_cell (frame->write, row, col);

  if (cell && utf8_char_copy (&cell->data[0], c)) {
    cell->uln = underline;
    cell->sty = style;
    return 1;
  }

  return 0;
}

const utf8_char_t *
caption_frame_read_char (caption_frame_t * frame, int row, int col,
    eia608_style_t * style, int *underline)
{
  // always read from front
  caption_frame_cell_t *cell = frame_buffer_cell (&frame->front, row, col);

  if (!cell) {
    if (style) {
      (*style) = eia608_style_white;
    }

    if (underline) {
      (*underline) = 0;
    }

    return EIA608_CHAR_NULL;
  }

  if (style) {
    (*style) = cell->sty;
  }

  if (underline) {
    (*underline) = cell->uln;
  }

  return &cell->data[0];
}

////////////////////////////////////////////////////////////////////////////////
// Parsing
libcaption_stauts_t
caption_frame_carriage_return (caption_frame_t * frame)
{
  if (0 > frame->state.row || SCREEN_ROWS <= frame->state.row) {
    return LIBCAPTION_ERROR;
  }

  int r = frame->state.row - (frame->state.rup - 1);

  if (0 >= r || !caption_frame_rollup (frame)) {
    return LIBCAPTION_OK;
  }

  for (; r < SCREEN_ROWS; ++r) {
    uint8_t *dst = (uint8_t *) frame_buffer_cell (frame->write, r - 1, 0);
    uint8_t *src = (uint8_t *) frame_buffer_cell (frame->write, r - 0, 0);
    memcpy (dst, src, sizeof (caption_frame_cell_t) * SCREEN_COLS);
  }

  frame->state.col = 0;
  caption_frame_cell_t *cell =
      frame_buffer_cell (frame->write, SCREEN_ROWS - 1, 0);
  memset (cell, 0, sizeof (caption_frame_cell_t) * SCREEN_COLS);
  return LIBCAPTION_OK;
}

////////////////////////////////////////////////////////////////////////////////
libcaption_stauts_t
eia608_write_char (caption_frame_t * frame, char *c)
{
  if (0 == c || 0 == c[0] || SCREEN_ROWS <= frame->state.row
      || 0 > frame->state.row || SCREEN_COLS <= frame->state.col
      || 0 > frame->state.col) {
    // NO-OP
  } else if (caption_frame_write_char (frame, frame->state.row,
          frame->state.col, frame->state.sty, frame->state.uln, c)) {
    frame->state.col += 1;
  }

  return LIBCAPTION_OK;
}

libcaption_stauts_t
caption_frame_end (caption_frame_t * frame)
{
  memcpy (&frame->front, &frame->back, sizeof (caption_frame_buffer_t));
  caption_frame_buffer_clear (&frame->back);    // This is required
  return LIBCAPTION_READY;
}

libcaption_stauts_t
caption_frame_decode_preamble (caption_frame_t * frame, uint16_t cc_data)
{
  eia608_style_t sty;
  int row, col, chn, uln;

  if (eia608_parse_preamble (cc_data, &row, &col, &sty, &chn, &uln)) {
    frame->state.row = row;
    frame->state.col = col;
    frame->state.sty = sty;
    frame->state.uln = uln;
  }

  return LIBCAPTION_OK;
}

libcaption_stauts_t
caption_frame_decode_midrowchange (caption_frame_t * frame, uint16_t cc_data)
{
  eia608_style_t sty;
  int chn, unl;

  if (eia608_parse_midrowchange (cc_data, &chn, &sty, &unl)) {
    frame->state.sty = sty;
    frame->state.uln = unl;
  }

  return LIBCAPTION_OK;
}

libcaption_stauts_t
caption_frame_backspace (caption_frame_t * frame)
{
  // do not reverse wrap (tw 28:20)
  frame->state.col = (0 < frame->state.col) ? (frame->state.col - 1) : 0;
  caption_frame_clear_char (frame, frame->state.row, frame->state.col);
  return LIBCAPTION_READY;
}

libcaption_stauts_t
caption_frame_delete_to_end_of_row (caption_frame_t * frame)
{
  int c;
  if (frame->write) {
    for (c = frame->state.col; c < SCREEN_COLS; ++c) {
      caption_frame_clear_char (frame, frame->state.row, c);
    }
  }
  // TODO test this and replace loop
  //  uint8_t* dst = (uint8_t*)frame_buffer_cell(frame->write, frame->state.row, frame->state.col);
  //  memset(dst,0,sizeof(caption_frame_cell_t) * (SCREEN_COLS - frame->state.col - 1))

  return LIBCAPTION_READY;
}

libcaption_stauts_t
caption_frame_decode_control (caption_frame_t * frame, uint16_t cc_data)
{
  int cc;
  eia608_control_t cmd = eia608_parse_control (cc_data, &cc);

  switch (cmd) {
      // PAINT ON
    case eia608_control_resume_direct_captioning:
      frame->state.rup = 0;
      frame->write = &frame->front;
      return LIBCAPTION_OK;

    case eia608_control_erase_display_memory:
      caption_frame_buffer_clear (&frame->front);
      return LIBCAPTION_CLEAR;

      // ROLL-UP
    case eia608_control_roll_up_2:
      frame->state.rup = 1;
      frame->write = &frame->front;
      return LIBCAPTION_OK;

    case eia608_control_roll_up_3:
      frame->state.rup = 2;
      frame->write = &frame->front;
      return LIBCAPTION_OK;

    case eia608_control_roll_up_4:
      frame->state.rup = 3;
      frame->write = &frame->front;
      return LIBCAPTION_OK;

    case eia608_control_carriage_return:
      return caption_frame_carriage_return (frame);

      // Corrections (Is this only valid as part of paint on?)
    case eia608_control_backspace:
      return caption_frame_backspace (frame);
    case eia608_control_delete_to_end_of_row:
      return caption_frame_delete_to_end_of_row (frame);

      // POP ON
    case eia608_control_resume_caption_loading:
      frame->state.rup = 0;
      frame->write = &frame->back;
      return LIBCAPTION_OK;

    case eia608_control_erase_non_displayed_memory:
      caption_frame_buffer_clear (&frame->back);
      return LIBCAPTION_OK;

    case eia608_control_end_of_caption:
      return caption_frame_end (frame);

      // cursor positioning
    case eia608_tab_offset_0:
    case eia608_tab_offset_1:
    case eia608_tab_offset_2:
    case eia608_tab_offset_3:
      frame->state.col += (cmd - eia608_tab_offset_0);
      return LIBCAPTION_OK;

      // Unhandled
    default:
    case eia608_control_alarm_off:
    case eia608_control_alarm_on:
    case eia608_control_text_restart:
    case eia608_control_text_resume_text_display:
      return LIBCAPTION_OK;
  }
}

libcaption_stauts_t
caption_frame_decode_text (caption_frame_t * frame, uint16_t cc_data)
{
  int chan;
  char char1[5], char2[5];
  size_t chars = eia608_to_utf8 (cc_data, &chan, &char1[0], &char2[0]);

  if (eia608_is_westeu (cc_data)) {
    // Extended charcters replace the previous charcter for back compatibility
    caption_frame_backspace (frame);
  }

  if (0 < chars) {
    eia608_write_char (frame, char1);
  }

  if (1 < chars) {
    eia608_write_char (frame, char2);
  }

  return LIBCAPTION_OK;
}

libcaption_stauts_t
caption_frame_decode (caption_frame_t * frame, uint16_t cc_data,
    double timestamp)
{
  if (!eia608_parity_varify (cc_data)) {
    frame->status = LIBCAPTION_ERROR;
    return frame->status;
  }

  if (eia608_is_padding (cc_data)) {
    frame->status = LIBCAPTION_OK;
    return frame->status;
  }

  // skip duplicate controll commands. We also skip duplicate specialna to match the behaviour of iOS/vlc
  if ((eia608_is_specialna(cc_data) || eia608_is_control(cc_data)) && cc_data == frame->state.cc_data) {
    if (timestamp < 0 && caption_frame_popon (frame))
      frame->timestamp += (1 / 29.97);
    return LIBCAPTION_OK;
  }

  if (timestamp >= 0) {
      frame->timestamp = timestamp;
      frame->status = LIBCAPTION_OK;
  } else if (caption_frame_popon (frame)) {
    frame->timestamp += (1 / 29.97);
  }

  frame->state.cc_data = cc_data;

  if (frame->xds.state) {
    frame->status = xds_decode (&frame->xds, cc_data);
  } else if (eia608_is_xds (cc_data)) {
    frame->status = xds_decode (&frame->xds, cc_data);
  } else if (eia608_is_control (cc_data)) {
    frame->status = caption_frame_decode_control (frame, cc_data);
  } else if (eia608_is_basicna (cc_data) || eia608_is_specialna (cc_data)
      || eia608_is_westeu (cc_data)) {

    // Don't decode text if we dont know what mode we are in.
    if (!frame->write) {
      frame->status = LIBCAPTION_OK;
      return frame->status;
    }

    frame->status = caption_frame_decode_text (frame, cc_data);

    // If we are in paint on mode, display immiditally
    if (LIBCAPTION_OK == frame->status && caption_frame_painton (frame)) {
      frame->status = LIBCAPTION_READY;
    }
  } else if (eia608_is_preamble (cc_data)) {
    frame->status = caption_frame_decode_preamble (frame, cc_data);
  } else if (eia608_is_midrowchange (cc_data)) {
    frame->status = caption_frame_decode_midrowchange (frame, cc_data);
  }

  return frame->status;
}

////////////////////////////////////////////////////////////////////////////////
int
caption_frame_from_text (caption_frame_t * frame, const utf8_char_t * data)
{
  ssize_t size = (ssize_t) strlen (data);
  caption_frame_init (frame);
  frame->write = &frame->back;

  for (size_t r = 0; (*data) && size && r < SCREEN_ROWS;) {
    // skip whitespace at start of line
    while (size && utf8_char_whitespace (data)) {
      size_t s = utf8_char_length (data);
      data += s, size -= s;
    }

    // get charcter count for wrap (or orest of line)
    utf8_size_t char_count = utf8_wrap_length (data, SCREEN_COLS);
    // write to caption frame
    for (size_t c = 0; c < char_count; ++c) {
      size_t char_length = utf8_char_length (data);
      caption_frame_write_char (frame, r, c, eia608_style_white, 0, data);
      data += char_length, size -= char_length;
    }

    r += char_count ? 1 : 0;    // Update row num only if not blank
  }

  caption_frame_end (frame);
  return 0;
}

////////////////////////////////////////////////////////////////////////////////
size_t
caption_frame_to_text (caption_frame_t * frame, utf8_char_t * data, int full)
{
  int r, c, uln, crlf = 0, count = 0;
  size_t s, size = 0;
  eia608_style_t sty;
  (*data) = '\0';

  for (r = 0; r < SCREEN_ROWS; ++r) {
    crlf += count, count = 0;
    for (c = 0; c < SCREEN_COLS; ++c) {
      const utf8_char_t *chr =
          caption_frame_read_char (frame, r, c, &sty, &uln);
      // dont start a new line until we encounter at least one printable character
      if (full ||
          (0 < utf8_char_length (chr) && (0 < count
              || !utf8_char_whitespace (chr)))) {
        if (0 < crlf) {
          memcpy (data, "\r\n\0", 3);
          data += 2, size += 2, crlf = 0;
        }

        s = utf8_char_copy (data, chr);
        data += s, size += s, ++count;
      }
    }
  }

  return size;
}

////////////////////////////////////////////////////////////////////////////////
size_t
caption_frame_dump_buffer (caption_frame_t * frame, utf8_char_t * buf)
{
  int r, c;
  size_t bytes, total = 0;
  bytes =
      sprintf (buf,
      "   timestamp: %f\n   row: %02d    col: %02d    roll-up: %d\n",
      frame->timestamp, frame->state.row, frame->state.col,
      caption_frame_rollup (frame));
  total += bytes, buf += bytes;
  bytes =
      sprintf (buf,
      "   00000000001111111111222222222233\t   00000000001111111111222222222233\n"
      "   01234567890123456789012345678901\t   01234567890123456789012345678901\n"
      "  %s--------------------------------%s\t  %s--------------------------------%s\n",
      EIA608_CHAR_BOX_DRAWINGS_LIGHT_DOWN_AND_RIGHT,
      EIA608_CHAR_BOX_DRAWINGS_LIGHT_DOWN_AND_LEFT,
      EIA608_CHAR_BOX_DRAWINGS_LIGHT_DOWN_AND_RIGHT,
      EIA608_CHAR_BOX_DRAWINGS_LIGHT_DOWN_AND_LEFT);
  total += bytes;
  buf += bytes;

  for (r = 0; r < SCREEN_ROWS; ++r) {
    bytes = sprintf (buf, "%02d%s", r, EIA608_CHAR_VERTICAL_LINE);
    total += bytes, buf += bytes;

    // front buffer
    for (c = 0; c < SCREEN_COLS; ++c) {
      caption_frame_cell_t *cell = frame_buffer_cell (&frame->front, r, c);
      bytes = utf8_char_copy (buf, (!cell
              || 0 == cell->data[0]) ? EIA608_CHAR_SPACE : &cell->data[0]);
      total += bytes, buf += bytes;
    }

    bytes =
        sprintf (buf, "%s\t%02d%s", EIA608_CHAR_VERTICAL_LINE, r,
        EIA608_CHAR_VERTICAL_LINE);
    total += bytes, buf += bytes;

    // back buffer
    for (c = 0; c < SCREEN_COLS; ++c) {
      caption_frame_cell_t *cell = frame_buffer_cell (&frame->back, r, c);
      bytes = utf8_char_copy (buf, (!cell
              || 0 == cell->data[0]) ? EIA608_CHAR_SPACE : &cell->data[0]);
      total += bytes, buf += bytes;
    }

    bytes = sprintf (buf, "%s\n", EIA608_CHAR_VERTICAL_LINE);
    total += bytes, buf += bytes;
  }

  bytes =
      sprintf (buf,
      "  %s--------------------------------%s\t  %s--------------------------------%s\n",
      EIA608_CHAR_BOX_DRAWINGS_LIGHT_UP_AND_RIGHT,
      EIA608_CHAR_BOX_DRAWINGS_LIGHT_UP_AND_LEFT,
      EIA608_CHAR_BOX_DRAWINGS_LIGHT_UP_AND_RIGHT,
      EIA608_CHAR_BOX_DRAWINGS_LIGHT_UP_AND_LEFT);
  total += bytes, buf += bytes;
  return total;
}

void
caption_frame_dump (caption_frame_t * frame)
{
  utf8_char_t buff[CAPTION_FRAME_DUMP_BUF_SIZE];
  caption_frame_dump_buffer (frame, buff);
  fprintf (stderr, "%s\n", buff);
}