modules/audio_coding/acm2/acm_codec_database.h

/*
 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

/*
 * This file generates databases with information about all supported audio
 * codecs.
 */

#ifndef MODULES_AUDIO_CODING_ACM2_ACM_CODEC_DATABASE_H_
#define MODULES_AUDIO_CODING_ACM2_ACM_CODEC_DATABASE_H_

#include "common_types.h"  // NOLINT(build/include)
#include "modules/audio_coding/acm2/rent_a_codec.h"
#include "typedefs.h"  // NOLINT(build/include)

namespace webrtc {

namespace acm2 {

// TODO(tlegrand): replace class ACMCodecDB with a namespace.
class ACMCodecDB {
 public:
  // kMaxNumCodecs - Maximum number of codecs that can be activated in one
  //                 build.
  // kMaxNumPacketSize - Maximum number of allowed packet sizes for one codec.
  // These might need to be increased if adding a new codec to the database
  static const int kMaxNumCodecs = 50;
  static const int kMaxNumPacketSize = 6;

  // Codec specific settings
  //
  // num_packet_sizes     - number of allowed packet sizes.
  // packet_sizes_samples - list of the allowed packet sizes.
  // basic_block_samples  - assigned a value different from 0 if the codec
  //                        requires to be fed with a specific number of samples
  //                        that can be different from packet size.
  // channel_support      - number of channels supported to encode;
  //                        1 = mono, 2 = stereo, etc.
  struct CodecSettings {
    int num_packet_sizes;
    int packet_sizes_samples[kMaxNumPacketSize];
    int basic_block_samples;
    size_t channel_support;
  };

  // Returns codec id from database, given the information received in the input
  // [codec_inst].
  // Input:
  //   [codec_inst] - Information about the codec for which we require the
  //                  database id.
  // Return:
  //   codec id if successful, otherwise < 0.
  static int CodecNumber(const CodecInst& codec_inst);
  static int CodecId(const CodecInst& codec_inst);
  static int CodecId(const char* payload_name, int frequency, size_t channels);
  static int ReceiverCodecNumber(const CodecInst& codec_inst);

  // Databases with information about the supported codecs
  // database_ - stored information about all codecs: payload type, name,
  //             sampling frequency, packet size in samples, default channel
  //             support, and default rate.
  // codec_settings_ - stored codec settings: number of allowed packet sizes,
  //                   a vector with the allowed packet sizes, basic block
  //                   samples, and max number of channels that are supported.
  // neteq_decoders_ - list of supported decoders in NetEQ.
  static const CodecInst database_[kMaxNumCodecs];
  static const CodecSettings codec_settings_[kMaxNumCodecs];
  static const NetEqDecoder neteq_decoders_[kMaxNumCodecs];
};

}  // namespace acm2

}  // namespace webrtc

#endif  // MODULES_AUDIO_CODING_ACM2_ACM_CODEC_DATABASE_H_