modules/audio_coding/acm2/acm_codec_database.cc

/*
 *  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.
 */

// TODO(tlegrand): Change constant input pointers in all functions to constant
// references, where appropriate.
#include "modules/audio_coding/acm2/acm_codec_database.h"

#include "absl/strings/match.h"
#include "api/array_view.h"
#include "modules/audio_coding/acm2/rent_a_codec.h"

#if ((defined WEBRTC_CODEC_ISAC) && (defined WEBRTC_CODEC_ISACFX))
#error iSAC and iSACFX codecs cannot be enabled at the same time
#endif

namespace webrtc {

namespace acm2 {

namespace {

// Checks if the bitrate is valid for iSAC.
bool IsISACRateValid(int rate) {
  return (rate == -1) || ((rate <= 56000) && (rate >= 10000));
}

// Checks if the bitrate is valid for iLBC.
bool IsILBCRateValid(int rate, int frame_size_samples) {
  if (((frame_size_samples == 240) || (frame_size_samples == 480)) &&
      (rate == 13300)) {
    return true;
  } else if (((frame_size_samples == 160) || (frame_size_samples == 320)) &&
             (rate == 15200)) {
    return true;
  } else {
    return false;
  }
}

// Checks if the bitrate is valid for Opus.
bool IsOpusRateValid(int rate) {
  return (rate >= 6000) && (rate <= 510000);
}

}  // namespace

// Not yet used payload-types.
// 83,  82,  81, 80, 79,  78,  77,  76,  75,  74,  73,  72,  71,  70,  69, 68,
// 67, 66, 65

const CodecInst ACMCodecDB::database_[] = {
#if (defined(WEBRTC_CODEC_ISAC) || defined(WEBRTC_CODEC_ISACFX))
    {103, "ISAC", 16000, 480, 1, 32000},
#if (defined(WEBRTC_CODEC_ISAC))
    {104, "ISAC", 32000, 960, 1, 56000},
#endif
#endif
    // Mono
    {107, "L16", 8000, 80, 1, 128000},
    {108, "L16", 16000, 160, 1, 256000},
    {109, "L16", 32000, 320, 1, 512000},
    // Stereo
    {111, "L16", 8000, 80, 2, 128000},
    {112, "L16", 16000, 160, 2, 256000},
    {113, "L16", 32000, 320, 2, 512000},
    // G.711, PCM mu-law and A-law.
    // Mono
    {0, "PCMU", 8000, 160, 1, 64000},
    {8, "PCMA", 8000, 160, 1, 64000},
    // Stereo
    {110, "PCMU", 8000, 160, 2, 64000},
    {118, "PCMA", 8000, 160, 2, 64000},
#ifdef WEBRTC_CODEC_ILBC
    {102, "ILBC", 8000, 240, 1, 13300},
#endif
    // Mono
    {9, "G722", 16000, 320, 1, 64000},
    // Stereo
    {119, "G722", 16000, 320, 2, 64000},
#ifdef WEBRTC_CODEC_OPUS
    // Opus internally supports 48, 24, 16, 12, 8 kHz.
    // Mono and stereo.
    {120, "opus", 48000, 960, 2, 64000},
#endif
    // Comfort noise for four different sampling frequencies.
    {13, "CN", 8000, 240, 1, 0},
    {98, "CN", 16000, 480, 1, 0},
    {99, "CN", 32000, 960, 1, 0},
#ifdef ENABLE_48000_HZ
    {100, "CN", 48000, 1440, 1, 0},
#endif
    {106, "telephone-event", 8000, 240, 1, 0},
    {114, "telephone-event", 16000, 240, 1, 0},
    {115, "telephone-event", 32000, 240, 1, 0},
    {116, "telephone-event", 48000, 240, 1, 0},
#ifdef WEBRTC_CODEC_RED
    {127, "red", 8000, 0, 1, 0},
#endif
    // To prevent compile errors due to trailing commas.
    {-1, "Null", -1, -1, 0, -1}};

// Create database with all codec settings at compile time.
// Each entry needs the following parameters in the given order:
// Number of allowed packet sizes, a vector with the allowed packet sizes,
// Basic block samples, max number of channels that are supported.
const ACMCodecDB::CodecSettings ACMCodecDB::codec_settings_[] = {
#if (defined(WEBRTC_CODEC_ISAC) || defined(WEBRTC_CODEC_ISACFX))
    {2, {480, 960}, 0, 1},
#if (defined(WEBRTC_CODEC_ISAC))
    {1, {960}, 0, 1},
#endif
#endif
    // Mono
    {4, {80, 160, 240, 320}, 0, 2},
    {4, {160, 320, 480, 640}, 0, 2},
    {2, {320, 640}, 0, 2},
    // Stereo
    {4, {80, 160, 240, 320}, 0, 2},
    {4, {160, 320, 480, 640}, 0, 2},
    {2, {320, 640}, 0, 2},
    // G.711, PCM mu-law and A-law.
    // Mono
    {6, {80, 160, 240, 320, 400, 480}, 0, 2},
    {6, {80, 160, 240, 320, 400, 480}, 0, 2},
    // Stereo
    {6, {80, 160, 240, 320, 400, 480}, 0, 2},
    {6, {80, 160, 240, 320, 400, 480}, 0, 2},
#ifdef WEBRTC_CODEC_ILBC
    {4, {160, 240, 320, 480}, 0, 1},
#endif
    // Mono
    {6, {160, 320, 480, 640, 800, 960}, 0, 2},
    // Stereo
    {6, {160, 320, 480, 640, 800, 960}, 0, 2},
#ifdef WEBRTC_CODEC_OPUS
// Opus supports frames shorter than 10ms,
// but it doesn't help us to use them.
// Mono and stereo.
#if WEBRTC_OPUS_SUPPORT_120MS_PTIME
    {5, {480, 960, 1920, 2880, 5760}, 0, 2},
#else
    {4, {480, 960, 1920, 2880}, 0, 2},
#endif
#endif
    // Comfort noise for three different sampling frequencies.
    {1, {240}, 240, 1},
    {1, {480}, 480, 1},
    {1, {960}, 960, 1},
// TODO(solenberg): What is this flag? It is never set in the build files.
#ifdef ENABLE_48000_HZ
    {1, {1440}, 1440, 1},
#endif
    {1, {240}, 240, 1},
    {1, {240}, 240, 1},
    {1, {240}, 240, 1},
    {1, {240}, 240, 1},
#ifdef WEBRTC_CODEC_RED
    {1, {0}, 0, 1},
#endif
    // To prevent compile errors due to trailing commas.
    {-1, {-1}, -1, 0}};

// Create a database of all NetEQ decoders at compile time.
const NetEqDecoder ACMCodecDB::neteq_decoders_[] = {
#if (defined(WEBRTC_CODEC_ISAC) || defined(WEBRTC_CODEC_ISACFX))
    NetEqDecoder::kDecoderISAC,
#if (defined(WEBRTC_CODEC_ISAC))
    NetEqDecoder::kDecoderISACswb,
#endif
#endif
    // Mono
    NetEqDecoder::kDecoderPCM16B, NetEqDecoder::kDecoderPCM16Bwb,
    NetEqDecoder::kDecoderPCM16Bswb32kHz,
    // Stereo
    NetEqDecoder::kDecoderPCM16B_2ch, NetEqDecoder::kDecoderPCM16Bwb_2ch,
    NetEqDecoder::kDecoderPCM16Bswb32kHz_2ch,
    // G.711, PCM mu-las and A-law.
    // Mono
    NetEqDecoder::kDecoderPCMu, NetEqDecoder::kDecoderPCMa,
    // Stereo
    NetEqDecoder::kDecoderPCMu_2ch, NetEqDecoder::kDecoderPCMa_2ch,
#ifdef WEBRTC_CODEC_ILBC
    NetEqDecoder::kDecoderILBC,
#endif
    // Mono
    NetEqDecoder::kDecoderG722,
    // Stereo
    NetEqDecoder::kDecoderG722_2ch,
#ifdef WEBRTC_CODEC_OPUS
    // Mono and stereo.
    NetEqDecoder::kDecoderOpus,
#endif
    // Comfort noise for three different sampling frequencies.
    NetEqDecoder::kDecoderCNGnb, NetEqDecoder::kDecoderCNGwb,
    NetEqDecoder::kDecoderCNGswb32kHz,
#ifdef ENABLE_48000_HZ
    NetEqDecoder::kDecoderCNGswb48kHz,
#endif
    NetEqDecoder::kDecoderAVT, NetEqDecoder::kDecoderAVT16kHz,
    NetEqDecoder::kDecoderAVT32kHz, NetEqDecoder::kDecoderAVT48kHz,
#ifdef WEBRTC_CODEC_RED
    NetEqDecoder::kDecoderRED,
#endif
};

// Enumerator for error codes when asking for codec database id.
enum {
  kInvalidCodec = -10,
  kInvalidPayloadtype = -30,
  kInvalidPacketSize = -40,
  kInvalidRate = -50
};

// Gets the codec id number from the database. If there is some mismatch in
// the codec settings, the function will return an error code.
// NOTE! The first mismatch found will generate the return value.
int ACMCodecDB::CodecNumber(const CodecInst& codec_inst) {
  // Look for a matching codec in the database.
  int codec_id = CodecId(codec_inst);

  // Checks if we found a matching codec.
  if (codec_id == -1) {
    return kInvalidCodec;
  }

  // Checks the validity of payload type
  if (!RentACodec::IsPayloadTypeValid(codec_inst.pltype)) {
    return kInvalidPayloadtype;
  }

  // Comfort Noise is special case, packet-size & rate is not checked.
  if (absl::EqualsIgnoreCase(database_[codec_id].plname, "CN")) {
    return codec_id;
  }

  // RED is special case, packet-size & rate is not checked.
  if (absl::EqualsIgnoreCase(database_[codec_id].plname, "red")) {
    return codec_id;
  }

  // Checks the validity of packet size.
  if (codec_settings_[codec_id].num_packet_sizes > 0) {
    bool packet_size_ok = false;
    int i;
    int packet_size_samples;
    for (i = 0; i < codec_settings_[codec_id].num_packet_sizes; i++) {
      packet_size_samples = codec_settings_[codec_id].packet_sizes_samples[i];
      if (codec_inst.pacsize == packet_size_samples) {
        packet_size_ok = true;
        break;
      }
    }

    if (!packet_size_ok) {
      return kInvalidPacketSize;
    }
  }

  if (codec_inst.pacsize < 1) {
    return kInvalidPacketSize;
  }

  // Check the validity of rate. Codecs with multiple rates have their own
  // function for this.
  if (absl::EqualsIgnoreCase("isac", codec_inst.plname)) {
    return IsISACRateValid(codec_inst.rate) ? codec_id : kInvalidRate;
  } else if (absl::EqualsIgnoreCase("ilbc", codec_inst.plname)) {
    return IsILBCRateValid(codec_inst.rate, codec_inst.pacsize) ? codec_id
                                                                : kInvalidRate;
  } else if (absl::EqualsIgnoreCase("opus", codec_inst.plname)) {
    return IsOpusRateValid(codec_inst.rate) ? codec_id : kInvalidRate;
  }

  return database_[codec_id].rate == codec_inst.rate ? codec_id : kInvalidRate;
}

// Looks for a matching payload name, frequency, and channels in the
// codec list. Need to check all three since some codecs have several codec
// entries with different frequencies and/or channels.
// Does not check other codec settings, such as payload type and packet size.
// Returns the id of the codec, or -1 if no match is found.
int ACMCodecDB::CodecId(const CodecInst& codec_inst) {
  return (CodecId(codec_inst.plname, codec_inst.plfreq, codec_inst.channels));
}

int ACMCodecDB::CodecId(const char* payload_name,
                        int frequency,
                        size_t channels) {
  for (const CodecInst& ci : RentACodec::Database()) {
    bool name_match = false;
    bool frequency_match = false;
    bool channels_match = false;

    // Payload name, sampling frequency and number of channels need to match.
    // NOTE! If |frequency| is -1, the frequency is not applicable, and is
    // always treated as true, like for RED.
    name_match = absl::EqualsIgnoreCase(ci.plname, payload_name);
    frequency_match = (frequency == ci.plfreq) || (frequency == -1);
    // The number of channels must match for all codecs but Opus.
    if (!absl::EqualsIgnoreCase(payload_name, "opus")) {
      channels_match = (channels == ci.channels);
    } else {
      // For opus we just check that number of channels is valid.
      channels_match = (channels == 1 || channels == 2);
    }

    if (name_match && frequency_match && channels_match) {
      // We have found a matching codec in the list.
      return &ci - RentACodec::Database().data();
    }
  }

  // We didn't find a matching codec.
  return -1;
}
// Gets codec id number from database for the receiver.
int ACMCodecDB::ReceiverCodecNumber(const CodecInst& codec_inst) {
  // Look for a matching codec in the database.
  return CodecId(codec_inst);
}

}  // namespace acm2

}  // namespace webrtc