subprojects/gst-plugins-bad/sys/dwrite/libcaption/xds.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                     */
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/* THE SOFTWARE.                                                                              */
/**********************************************************************************************/
// http://www.theneitherworld.com/mcpoodle/SCC_TOOLS/DOCS/CC_XDS.HTML#PR
#include "xds.h"
#include "caption.h"
#include <string.h>

void
xds_init (xds_t * xds)
{
  memset (xds, 0, sizeof (xds_t));
}

int
xds_decode (xds_t * xds, uint16_t cc)
{
  switch (xds->state) {
    default:
    case 0:
      xds_init (xds);
      xds->class_code = (cc & 0x0F00) >> 8;
      xds->type = (cc & 0x000F);
      xds->state = 1;
      return LIBCAPTION_OK;

    case 1:
      if (0x8F00 == (cc & 0xFF00)) {
        xds->checksum = (cc & 0x007F);
        xds->state = 0;
        return LIBCAPTION_READY;
      }

      if (xds->size < 32) {
        xds->content[xds->size + 0] = (cc & 0x7F00) >> 8;
        xds->content[xds->size + 1] = (cc & 0x007F);
        xds->size += 2;
        return LIBCAPTION_OK;
      }
  }

  xds->state = 0;
  return LIBCAPTION_ERROR;
}