es_parser_teletext.h

// Copyright 2020 Google Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
 
#ifndef PACKAGER_MEDIA_FORMATS_MP2T_ES_PARSER_TELETEXT_H_
#define PACKAGER_MEDIA_FORMATS_MP2T_ES_PARSER_TELETEXT_H_
 
#include <cstddef>
#include <cstdint>
#include <string>
#include <unordered_map>
#include <vector>
 
#include <packager/media/base/text_sample.h>
#include <packager/media/formats/mp2t/es_parser.h>
 
namespace shaka {
namespace media {
namespace mp2t {
 
const int64_t ttx_cue_duration_placeholder = 30 * 90000;  // 30s
 
class EsParserTeletext : public EsParser {
 public:
  EsParserTeletext(const uint32_t pid,
                   const NewStreamInfoCB& new_stream_info_cb,
                   const EmitTextSampleCB& emit_sample_cb,
                   const uint8_t* descriptor,
                   const size_t descriptor_length);
 
  EsParserTeletext(const EsParserTeletext&) = delete;
  EsParserTeletext& operator=(const EsParserTeletext&) = delete;
 
  bool Parse(const uint8_t* buf, int size, int64_t pts, int64_t dts) override;
  bool Flush() override;
  void Reset() override;
 
 private:
  using RowColReplacementMap =
      std::unordered_map<uint8_t, std::unordered_map<uint8_t, std::string>>;
 
  struct TextRow {
    TextAlignment alignment;
    int row_number;
    bool double_height;
    TextFragment fragment;
  };
 
  struct TextBlock {
    std::vector<TextRow> rows;
    RowColReplacementMap packet_26_replacements;
    int64_t pts;
  };
 
  bool ParseInternal(const uint8_t* data, const size_t size, const int64_t pts);
  bool ParseDataBlock(const int64_t pts,
                      const uint8_t* data_block,
                      const uint8_t packet_nr,
                      const uint8_t magazine,
                      TextRow& display_text);
  void UpdateCharset();
  TextRow BuildRow(const uint8_t* data_block, const uint8_t row) const;
  void ParsePacket26(const uint8_t* data_block);
  void UpdateNationalSubset(const uint8_t national_subset[13][3]);
  void SendCueStart(const uint16_t index);
  void SendCueEnd(const uint16_t index, const int64_t pts);
  void SendTextHeartBeat(const uint16_t index, const int64_t pts);
 
  static void SetPacket26ReplacementString(
      RowColReplacementMap& replacement_map,
      const uint8_t row,
      const uint8_t column,
      std::string&& replacement_string);
 
  NewStreamInfoCB new_stream_info_cb_;
  EmitTextSampleCB emit_sample_cb_;
 
  std::unordered_map<uint16_t, std::string> languages_;
  bool sent_info_ = false;
  uint8_t magazine_;
  uint8_t page_number_;
  std::unordered_map<uint16_t, TextBlock> page_state_;
  uint8_t charset_code_;
  char current_charset_[96][3];
  int64_t last_pts_;
  int64_t last_end_pts_;
  bool inside_sample_;
};
 
}  // namespace mp2t
}  // namespace media
}  // namespace shaka
 
#endif  // PACKAGER_MEDIA_FORMATS_MP2T_ES_PARSER_TELETEXT_H_