modules/audio_coding/main/source/acm_pcma.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.
 */

#include "acm_pcma.h"

#include "acm_common_defs.h"
#include "acm_neteq.h"
#include "trace.h"
#include "webrtc_neteq.h"
#include "webrtc_neteq_help_macros.h"

// Codec interface
#include "g711_interface.h"

namespace webrtc {

ACMPCMA::ACMPCMA(WebRtc_Word16 codecID) {
  _codecID = codecID;
}

ACMPCMA::~ACMPCMA() {
  return;
}

WebRtc_Word16 ACMPCMA::InternalEncode(WebRtc_UWord8* bitStream,
                                      WebRtc_Word16* bitStreamLenByte) {
  *bitStreamLenByte = WebRtcG711_EncodeA(NULL, &_inAudio[_inAudioIxRead],
                                         _frameLenSmpl * _noChannels,
                                         (WebRtc_Word16*) bitStream);
  // Increment the read index this tell the caller that how far
  // we have gone forward in reading the audio buffer.
  _inAudioIxRead += _frameLenSmpl * _noChannels;
  return *bitStreamLenByte;
}

WebRtc_Word16 ACMPCMA::DecodeSafe(WebRtc_UWord8* /* bitStream */,
                                  WebRtc_Word16 /* bitStreamLenByte */,
                                  WebRtc_Word16* /* audio */,
                                  WebRtc_Word16* /* audioSamples */,
                                  WebRtc_Word8* /* speechType */) {
  return 0;
}

WebRtc_Word16 ACMPCMA::InternalInitEncoder(
    WebRtcACMCodecParams* /* codecParams */) {
  // This codec does not need initialization, PCM has no instance.
  return 0;
}

WebRtc_Word16 ACMPCMA::InternalInitDecoder(
    WebRtcACMCodecParams* /* codecParams */) {
  // This codec does not need initialization, PCM has no instance.
  return 0;
}

WebRtc_Word32 ACMPCMA::CodecDef(WebRtcNetEQ_CodecDef& codecDef,
                                const CodecInst& codecInst) {
  // Fill up the structure by calling
  // "SET_CODEC_PAR" & "SET_PCMA_FUNCTION."
  // Then call NetEQ to add the codec to it's database.
  if (codecInst.channels == 1) {
    // Mono mode.
    SET_CODEC_PAR(codecDef, kDecoderPCMa, codecInst.pltype, NULL, 8000);
  } else {
    // Stereo mode.
    SET_CODEC_PAR(codecDef, kDecoderPCMa_2ch, codecInst.pltype, NULL, 8000);
  }
  SET_PCMA_FUNCTIONS(codecDef);
  return 0;
}

ACMGenericCodec* ACMPCMA::CreateInstance(void) {
  return NULL;
}

WebRtc_Word16 ACMPCMA::InternalCreateEncoder() {
  // PCM has no instance.
  return 0;
}

WebRtc_Word16 ACMPCMA::InternalCreateDecoder() {
  // PCM has no instance.
  return 0;
}

void ACMPCMA::InternalDestructEncoderInst(void* /* ptrInst */) {
  // PCM has no instance.
  return;
}

void ACMPCMA::DestructEncoderSafe() {
  // PCM has no instance.
  return;
}

void ACMPCMA::DestructDecoderSafe() {
  // PCM has no instance.
  _decoderInitialized = false;
  _decoderExist = false;
  return;
}

// Split the stereo packet and place left and right channel after each other
// in the payload vector.
void ACMPCMA::SplitStereoPacket(uint8_t* payload, int32_t* payload_length) {
  uint8_t right_byte;

  // Check for valid inputs.
  assert(payload != NULL);
  assert(*payload_length > 0);

  // Move one bytes representing right channel each loop, and place it at the
  // end of the bytestream vector. After looping the data is reordered to:
  // l1 l2 l3 l4 ... l(N-1) lN r1 r2 r3 r4 ... r(N-1) r(N),
  // where N is the total number of samples.
  for (int i = 0; i < *payload_length / 2; i ++) {
    right_byte = payload[i + 1];
    memmove(&payload[i + 1], &payload[i + 2], *payload_length - i - 2);
    payload[*payload_length - 1] = right_byte;
  }
}

} // namespace webrtc