예제 #1
0
// only buffer L band for farend
int32_t WebRtcAec_BufferFarend(void* aecInst,
                               const float* farend,
                               size_t nrOfSamples) {
  Aec* aecpc = aecInst;
  size_t newNrOfSamples = nrOfSamples;
  float new_farend[MAX_RESAMP_LEN];
  const float* farend_ptr = farend;

  // Get any error caused by buffering the farend signal.
  int32_t error_code = WebRtcAec_GetBufferFarendError(aecInst, farend,
                                                      nrOfSamples);

  if (error_code != 0)
    return error_code;


  if (aecpc->skewMode == kAecTrue && aecpc->resample == kAecTrue) {
    // Resample and get a new number of samples
    WebRtcAec_ResampleLinear(aecpc->resampler,
                             farend,
                             nrOfSamples,
                             aecpc->skew,
                             new_farend,
                             &newNrOfSamples);
    farend_ptr = new_farend;
  }

  aecpc->farend_started = 1;
  WebRtcAec_SetSystemDelay(
      aecpc->aec, WebRtcAec_system_delay(aecpc->aec) + (int)newNrOfSamples);

  // Write the time-domain data to |far_pre_buf|.
  WebRtc_WriteBuffer(aecpc->far_pre_buf, farend_ptr, newNrOfSamples);

  // Transform to frequency domain if we have enough data.
  while (WebRtc_available_read(aecpc->far_pre_buf) >= PART_LEN2) {
    // We have enough data to pass to the FFT, hence read PART_LEN2 samples.
    {
      float* ptmp = NULL;
      float tmp[PART_LEN2];
      WebRtc_ReadBuffer(aecpc->far_pre_buf, (void**)&ptmp, tmp, PART_LEN2);
      WebRtcAec_BufferFarendPartition(aecpc->aec, ptmp);
#ifdef WEBRTC_AEC_DEBUG_DUMP
      WebRtc_WriteBuffer(
          WebRtcAec_far_time_buf(aecpc->aec), &ptmp[PART_LEN], 1);
#endif
    }

    // Rewind |far_pre_buf| PART_LEN samples for overlap before continuing.
    WebRtc_MoveReadPtr(aecpc->far_pre_buf, -PART_LEN);
  }

  return 0;
}
예제 #2
0
static void EstBufDelayExtended(aecpc_t* self) {
  int reported_delay = self->msInSndCardBuf * sampMsNb * self->rate_factor;
  int current_delay = reported_delay - WebRtcAec_system_delay(self->aec);
  int delay_difference = 0;

  // Before we proceed with the delay estimate filtering we:
  // 1) Compensate for the frame that will be read.
  // 2) Compensate for drift resampling.
  // 3) Compensate for non-causality if needed, since the estimated delay can't
  //    be negative.

  // 1) Compensating for the frame(s) that will be read/processed.
  current_delay += FRAME_LEN * self->rate_factor;

  // 2) Account for resampling frame delay.
  if (self->skewMode == kAecTrue && self->resample == kAecTrue) {
    current_delay -= kResamplingDelay;
  }

  // 3) Compensate for non-causality, if needed, by flushing two blocks.
  if (current_delay < PART_LEN) {
    current_delay += WebRtcAec_MoveFarReadPtr(self->aec, 2) * PART_LEN;
  }

  if (self->filtDelay == -1) {
    self->filtDelay = WEBRTC_SPL_MAX(0, 0.5 * current_delay);
  } else {
    self->filtDelay = WEBRTC_SPL_MAX(
        0, (short)(0.95 * self->filtDelay + 0.05 * current_delay));
  }

  delay_difference = self->filtDelay - self->knownDelay;
  if (delay_difference > 384) {
    if (self->lastDelayDiff < 128) {
      self->timeForDelayChange = 0;
    } else {
      self->timeForDelayChange++;
    }
  } else if (delay_difference < 128 && self->knownDelay > 0) {
    if (self->lastDelayDiff > 384) {
      self->timeForDelayChange = 0;
    } else {
      self->timeForDelayChange++;
    }
  } else {
    self->timeForDelayChange = 0;
  }
  self->lastDelayDiff = delay_difference;

  if (self->timeForDelayChange > 25) {
    self->knownDelay = WEBRTC_SPL_MAX((int)self->filtDelay - 256, 0);
  }
}
예제 #3
0
static void EstBufDelayNormal(aecpc_t* aecpc) {
  int nSampSndCard = aecpc->msInSndCardBuf * sampMsNb * aecpc->rate_factor;
  int current_delay = nSampSndCard - WebRtcAec_system_delay(aecpc->aec);
  int delay_difference = 0;

  // Before we proceed with the delay estimate filtering we:
  // 1) Compensate for the frame that will be read.
  // 2) Compensate for drift resampling.
  // 3) Compensate for non-causality if needed, since the estimated delay can't
  //    be negative.

  // 1) Compensating for the frame(s) that will be read/processed.
  current_delay += FRAME_LEN * aecpc->rate_factor;

  // 2) Account for resampling frame delay.
  if (aecpc->skewMode == kAecTrue && aecpc->resample == kAecTrue) {
    current_delay -= kResamplingDelay;
  }

  // 3) Compensate for non-causality, if needed, by flushing one block.
  if (current_delay < PART_LEN) {
    current_delay += WebRtcAec_MoveFarReadPtr(aecpc->aec, 1) * PART_LEN;
  }

  // We use -1 to signal an initialized state in the "extended" implementation;
  // compensate for that.
  aecpc->filtDelay = aecpc->filtDelay < 0 ? 0 : aecpc->filtDelay;
  aecpc->filtDelay =
      WEBRTC_SPL_MAX(0, (short)(0.8 * aecpc->filtDelay + 0.2 * current_delay));

  delay_difference = aecpc->filtDelay - aecpc->knownDelay;
  if (delay_difference > 224) {
    if (aecpc->lastDelayDiff < 96) {
      aecpc->timeForDelayChange = 0;
    } else {
      aecpc->timeForDelayChange++;
    }
  } else if (delay_difference < 96 && aecpc->knownDelay > 0) {
    if (aecpc->lastDelayDiff > 224) {
      aecpc->timeForDelayChange = 0;
    } else {
      aecpc->timeForDelayChange++;
    }
  } else {
    aecpc->timeForDelayChange = 0;
  }
  aecpc->lastDelayDiff = delay_difference;

  if (aecpc->timeForDelayChange > 25) {
    aecpc->knownDelay = WEBRTC_SPL_MAX((int)aecpc->filtDelay - 160, 0);
  }
}
int32_t WebRtcAec_Process(void *aecInst, const int16_t *nearend,
                          const int16_t *nearendH, int16_t *out, int16_t *outH,
                          int16_t nrOfSamples, int16_t msInSndCardBuf,
                          int32_t skew)
{
    aecpc_t *aecpc = aecInst;
    int32_t retVal = 0;
    short i;
    short nBlocks10ms;
    short nFrames;
    // Limit resampling to doubling/halving of signal
    const float minSkewEst = -0.5f;
    const float maxSkewEst = 1.0f;

    if (aecpc == NULL) {
        return -1;
    }

    if (nearend == NULL) {
        aecpc->lastError = AEC_NULL_POINTER_ERROR;
        return -1;
    }

    if (out == NULL) {
        aecpc->lastError = AEC_NULL_POINTER_ERROR;
        return -1;
    }

    if (aecpc->initFlag != initCheck) {
        aecpc->lastError = AEC_UNINITIALIZED_ERROR;
        return -1;
    }

    // number of samples == 160 for SWB input
    if (nrOfSamples != 80 && nrOfSamples != 160) {
        aecpc->lastError = AEC_BAD_PARAMETER_ERROR;
        return -1;
    }

    // Check for valid pointers based on sampling rate
    if (aecpc->sampFreq == 32000 && nearendH == NULL) {
       aecpc->lastError = AEC_NULL_POINTER_ERROR;
       return -1;
    }

    if (msInSndCardBuf < 0) {
        msInSndCardBuf = 0;
        aecpc->lastError = AEC_BAD_PARAMETER_WARNING;
        retVal = -1;
    }
    else if (msInSndCardBuf > 500) {
        msInSndCardBuf = 500;
        aecpc->lastError = AEC_BAD_PARAMETER_WARNING;
        retVal = -1;
    }
    // TODO(andrew): we need to investigate if this +10 is really wanted.
    msInSndCardBuf += 10;
    aecpc->msInSndCardBuf = msInSndCardBuf;

    if (aecpc->skewMode == kAecTrue) {
        if (aecpc->skewFrCtr < 25) {
            aecpc->skewFrCtr++;
        }
        else {
            retVal = WebRtcAec_GetSkew(aecpc->resampler, skew, &aecpc->skew);
            if (retVal == -1) {
                aecpc->skew = 0;
                aecpc->lastError = AEC_BAD_PARAMETER_WARNING;
            }

            aecpc->skew /= aecpc->sampFactor*nrOfSamples;

            if (aecpc->skew < 1.0e-3 && aecpc->skew > -1.0e-3) {
                aecpc->resample = kAecFalse;
            }
            else {
                aecpc->resample = kAecTrue;
            }

            if (aecpc->skew < minSkewEst) {
                aecpc->skew = minSkewEst;
            }
            else if (aecpc->skew > maxSkewEst) {
                aecpc->skew = maxSkewEst;
            }

#ifdef WEBRTC_AEC_DEBUG_DUMP
            (void)fwrite(&aecpc->skew, sizeof(aecpc->skew), 1, aecpc->skewFile);
#endif
        }
    }

    nFrames = nrOfSamples / FRAME_LEN;
    nBlocks10ms = nFrames / aecpc->rate_factor;

    if (aecpc->ECstartup) {
        if (nearend != out) {
            // Only needed if they don't already point to the same place.
            memcpy(out, nearend, sizeof(short) * nrOfSamples);
        }

        // The AEC is in the start up mode
        // AEC is disabled until the system delay is OK

        // Mechanism to ensure that the system delay is reasonably stable.
        if (aecpc->checkBuffSize) {
            aecpc->checkBufSizeCtr++;
            // Before we fill up the far-end buffer we require the system delay
            // to be stable (+/-8 ms) compared to the first value. This
            // comparison is made during the following 6 consecutive 10 ms
            // blocks. If it seems to be stable then we start to fill up the
            // far-end buffer.
            if (aecpc->counter == 0) {
                aecpc->firstVal = aecpc->msInSndCardBuf;
                aecpc->sum = 0;
            }

            if (abs(aecpc->firstVal - aecpc->msInSndCardBuf) <
                WEBRTC_SPL_MAX(0.2 * aecpc->msInSndCardBuf, sampMsNb)) {
                aecpc->sum += aecpc->msInSndCardBuf;
                aecpc->counter++;
            }
            else {
                aecpc->counter = 0;
            }

            if (aecpc->counter * nBlocks10ms >= 6) {
                // The far-end buffer size is determined in partitions of
                // PART_LEN samples. Use 75% of the average value of the system
                // delay as buffer size to start with.
                aecpc->bufSizeStart = WEBRTC_SPL_MIN((3 * aecpc->sum *
                  aecpc->rate_factor * 8) / (4 * aecpc->counter * PART_LEN),
                  kMaxBufSizeStart);
                // Buffer size has now been determined.
                aecpc->checkBuffSize = 0;
            }

            if (aecpc->checkBufSizeCtr * nBlocks10ms > 50) {
                // For really bad systems, don't disable the echo canceller for
                // more than 0.5 sec.
                aecpc->bufSizeStart = WEBRTC_SPL_MIN((aecpc->msInSndCardBuf *
                    aecpc->rate_factor * 3) / 40, kMaxBufSizeStart);
                aecpc->checkBuffSize = 0;
            }
        }

        // If |checkBuffSize| changed in the if-statement above.
        if (!aecpc->checkBuffSize) {
            // The system delay is now reasonably stable (or has been unstable
            // for too long). When the far-end buffer is filled with
            // approximately the same amount of data as reported by the system
            // we end the startup phase.
            int overhead_elements =
                WebRtcAec_system_delay(aecpc->aec) / PART_LEN -
                aecpc->bufSizeStart;
            if (overhead_elements == 0) {
                // Enable the AEC
                aecpc->ECstartup = 0;
            } else if (overhead_elements > 0) {
                // TODO(bjornv): Do we need a check on how much we actually
                // moved the read pointer? It should always be possible to move
                // the pointer |overhead_elements| since we have only added data
                // to the buffer and no delay compensation nor AEC processing
                // has been done.
                WebRtcAec_MoveFarReadPtr(aecpc->aec, overhead_elements);

                // Enable the AEC
                aecpc->ECstartup = 0;
            }
        }
    } else {
        // AEC is enabled.

        EstBufDelay(aecpc);

        // Note that 1 frame is supported for NB and 2 frames for WB.
        for (i = 0; i < nFrames; i++) {
            // Call the AEC.
            WebRtcAec_ProcessFrame(aecpc->aec,
                                   &nearend[FRAME_LEN * i],
                                   &nearendH[FRAME_LEN * i],
                                   aecpc->knownDelay,
                                   &out[FRAME_LEN * i],
                                   &outH[FRAME_LEN * i]);
            // TODO(bjornv): Re-structure such that we don't have to pass
            // |aecpc->knownDelay| as input. Change name to something like
            // |system_buffer_diff|.
        }
    }

#ifdef WEBRTC_AEC_DEBUG_DUMP
    {
        int16_t far_buf_size_ms = (int16_t)(WebRtcAec_system_delay(aecpc->aec) /
            (sampMsNb * aecpc->rate_factor));
        (void)fwrite(&far_buf_size_ms, 2, 1, aecpc->bufFile);
        (void)fwrite(&aecpc->knownDelay, sizeof(aecpc->knownDelay), 1,
                     aecpc->delayFile);
    }
#endif

    return retVal;
}
// only buffer L band for farend
int32_t WebRtcAec_BufferFarend(void *aecInst, const int16_t *farend,
                               int16_t nrOfSamples)
{
    aecpc_t *aecpc = aecInst;
    int32_t retVal = 0;
    int newNrOfSamples = (int) nrOfSamples;
    short newFarend[MAX_RESAMP_LEN];
    const int16_t* farend_ptr = farend;
    float tmp_farend[MAX_RESAMP_LEN];
    const float* farend_float = tmp_farend;
    float skew;
    int i = 0;

    if (aecpc == NULL) {
        return -1;
    }

    if (farend == NULL) {
        aecpc->lastError = AEC_NULL_POINTER_ERROR;
        return -1;
    }

    if (aecpc->initFlag != initCheck) {
        aecpc->lastError = AEC_UNINITIALIZED_ERROR;
        return -1;
    }

    // number of samples == 160 for SWB input
    if (nrOfSamples != 80 && nrOfSamples != 160) {
        aecpc->lastError = AEC_BAD_PARAMETER_ERROR;
        return -1;
    }

    skew = aecpc->skew;

    if (aecpc->skewMode == kAecTrue && aecpc->resample == kAecTrue) {
        // Resample and get a new number of samples
        WebRtcAec_ResampleLinear(aecpc->resampler, farend, nrOfSamples, skew,
                                 newFarend, &newNrOfSamples);
        farend_ptr = (const int16_t*) newFarend;
    }

    WebRtcAec_SetSystemDelay(aecpc->aec, WebRtcAec_system_delay(aecpc->aec) +
                             newNrOfSamples);

#ifdef WEBRTC_AEC_DEBUG_DUMP
    WebRtc_WriteBuffer(aecpc->far_pre_buf_s16, farend_ptr,
                       (size_t) newNrOfSamples);
#endif
    // Cast to float and write the time-domain data to |far_pre_buf|.
    for (i = 0; i < newNrOfSamples; i++) {
      tmp_farend[i] = (float) farend_ptr[i];
    }
    WebRtc_WriteBuffer(aecpc->far_pre_buf, farend_float,
                       (size_t) newNrOfSamples);

    // Transform to frequency domain if we have enough data.
    while (WebRtc_available_read(aecpc->far_pre_buf) >= PART_LEN2) {
      // We have enough data to pass to the FFT, hence read PART_LEN2 samples.
      WebRtc_ReadBuffer(aecpc->far_pre_buf, (void**) &farend_float, tmp_farend,
                        PART_LEN2);

      WebRtcAec_BufferFarendPartition(aecpc->aec, farend_float);

      // Rewind |far_pre_buf| PART_LEN samples for overlap before continuing.
      WebRtc_MoveReadPtr(aecpc->far_pre_buf, -PART_LEN);
#ifdef WEBRTC_AEC_DEBUG_DUMP
      WebRtc_ReadBuffer(aecpc->far_pre_buf_s16, (void**) &farend_ptr, newFarend,
                        PART_LEN2);
      WebRtc_WriteBuffer(WebRtcAec_far_time_buf(aecpc->aec),
                         &farend_ptr[PART_LEN], 1);
      WebRtc_MoveReadPtr(aecpc->far_pre_buf_s16, -PART_LEN);
#endif
    }

    return retVal;
}
예제 #6
0
static void ProcessExtended(aecpc_t* self,
                            const int16_t* near,
                            const int16_t* near_high,
                            int16_t* out,
                            int16_t* out_high,
                            int16_t num_samples,
                            int16_t reported_delay_ms,
                            int32_t skew) {
  int i;
  const int num_frames = num_samples / FRAME_LEN;
#if defined(WEBRTC_UNTRUSTED_DELAY)
  const int delay_diff_offset = kDelayDiffOffsetSamples;
  reported_delay_ms = kFixedDelayMs;
#else
  // This is the usual mode where we trust the reported system delay values.
  const int delay_diff_offset = 0;
  // Due to the longer filter, we no longer add 10 ms to the reported delay
  // to reduce chance of non-causality. Instead we apply a minimum here to avoid
  // issues with the read pointer jumping around needlessly.
  reported_delay_ms = reported_delay_ms < kMinTrustedDelayMs
                          ? kMinTrustedDelayMs
                          : reported_delay_ms;
  // If the reported delay appears to be bogus, we attempt to recover by using
  // the measured fixed delay values. We use >= here because higher layers
  // may already clamp to this maximum value, and we would otherwise not
  // detect it here.
  reported_delay_ms = reported_delay_ms >= kMaxTrustedDelayMs
                          ? kFixedDelayMs
                          : reported_delay_ms;
#endif
  self->msInSndCardBuf = reported_delay_ms;

  if (!self->farend_started) {
    // Only needed if they don't already point to the same place.
    if (near != out) {
      memcpy(out, near, sizeof(short) * num_samples);
    }
    if (near_high != out_high) {
      memcpy(out_high, near_high, sizeof(short) * num_samples);
    }
    return;
  }
  if (self->startup_phase) {
    // In the extended mode, there isn't a startup "phase", just a special
    // action on the first frame. In the trusted delay case, we'll take the
    // current reported delay, unless it's less then our conservative
    // measurement.
    int startup_size_ms =
        reported_delay_ms < kFixedDelayMs ? kFixedDelayMs : reported_delay_ms;
    int overhead_elements = (WebRtcAec_system_delay(self->aec) -
                             startup_size_ms / 2 * self->rate_factor * 8) /
                            PART_LEN;
    WebRtcAec_MoveFarReadPtr(self->aec, overhead_elements);
    self->startup_phase = 0;
  }

  EstBufDelayExtended(self);

  {
    // |delay_diff_offset| gives us the option to manually rewind the delay on
    // very low delay platforms which can't be expressed purely through
    // |reported_delay_ms|.
    const int adjusted_known_delay =
        WEBRTC_SPL_MAX(0, self->knownDelay + delay_diff_offset);

    for (i = 0; i < num_frames; ++i) {
      WebRtcAec_ProcessFrame(self->aec,
                             &near[FRAME_LEN * i],
                             &near_high[FRAME_LEN * i],
                             adjusted_known_delay,
                             &out[FRAME_LEN * i],
                             &out_high[FRAME_LEN * i]);
    }
  }
}
예제 #7
0
int32_t WebRtcAec_Process(void* aecInst,
                          const int16_t* nearend,
                          const int16_t* nearendH,
                          int16_t* out,
                          int16_t* outH,
                          int16_t nrOfSamples,
                          int16_t msInSndCardBuf,
                          int32_t skew) {
  aecpc_t* aecpc = aecInst;
  int32_t retVal = 0;
  if (nearend == NULL) {
    aecpc->lastError = AEC_NULL_POINTER_ERROR;
    return -1;
  }

  if (out == NULL) {
    aecpc->lastError = AEC_NULL_POINTER_ERROR;
    return -1;
  }

  if (aecpc->initFlag != initCheck) {
    aecpc->lastError = AEC_UNINITIALIZED_ERROR;
    return -1;
  }

  // number of samples == 160 for SWB input
  if (nrOfSamples != 80 && nrOfSamples != 160) {
    aecpc->lastError = AEC_BAD_PARAMETER_ERROR;
    return -1;
  }

  // Check for valid pointers based on sampling rate
  if (aecpc->sampFreq == 32000 && nearendH == NULL) {
    aecpc->lastError = AEC_NULL_POINTER_ERROR;
    return -1;
  }

  if (msInSndCardBuf < 0) {
    msInSndCardBuf = 0;
    aecpc->lastError = AEC_BAD_PARAMETER_WARNING;
    retVal = -1;
  } else if (msInSndCardBuf > kMaxTrustedDelayMs) {
    // The clamping is now done in ProcessExtended/Normal().
    aecpc->lastError = AEC_BAD_PARAMETER_WARNING;
    retVal = -1;
  }

  // This returns the value of aec->extended_filter_enabled.
  if (WebRtcAec_delay_correction_enabled(aecpc->aec)) {
    ProcessExtended(
        aecpc, nearend, nearendH, out, outH, nrOfSamples, msInSndCardBuf, skew);
  } else {
    if (ProcessNormal(aecpc,
                      nearend,
                      nearendH,
                      out,
                      outH,
                      nrOfSamples,
                      msInSndCardBuf,
                      skew) != 0) {
      retVal = -1;
    }
  }

#ifdef WEBRTC_AEC_DEBUG_DUMP
  {
    int16_t far_buf_size_ms = (int16_t)(WebRtcAec_system_delay(aecpc->aec) /
                                        (sampMsNb * aecpc->rate_factor));
    OpenDebugFiles(aecpc, &webrtc_aec_instance_count);
    if (aecpc->bufFile) {
      (void)fwrite(&far_buf_size_ms, 2, 1, aecpc->bufFile);
      (void)fwrite(
        &aecpc->knownDelay, sizeof(aecpc->knownDelay), 1, aecpc->delayFile);
    }
  }
#endif

  return retVal;
}
예제 #8
0
static int ProcessNormal(Aec* aecpc,
                         const float* const* nearend,
                         int num_bands,
                         float* const* out,
                         int16_t nrOfSamples,
                         int16_t msInSndCardBuf,
                         int32_t skew) {
  int retVal = 0;
  short i;
  short nBlocks10ms;
  // Limit resampling to doubling/halving of signal
  const float minSkewEst = -0.5f;
  const float maxSkewEst = 1.0f;

  msInSndCardBuf =
      msInSndCardBuf > kMaxTrustedDelayMs ? kMaxTrustedDelayMs : msInSndCardBuf;
  // TODO(andrew): we need to investigate if this +10 is really wanted.
  msInSndCardBuf += 10;
  aecpc->msInSndCardBuf = msInSndCardBuf;

  if (aecpc->skewMode == kAecTrue) {
    if (aecpc->skewFrCtr < 25) {
      aecpc->skewFrCtr++;
    } else {
      retVal = WebRtcAec_GetSkew(aecpc->resampler, skew, &aecpc->skew);
      if (retVal == -1) {
        aecpc->skew = 0;
        aecpc->lastError = AEC_BAD_PARAMETER_WARNING;
      }

      aecpc->skew /= aecpc->sampFactor * nrOfSamples;

      if (aecpc->skew < 1.0e-3 && aecpc->skew > -1.0e-3) {
        aecpc->resample = kAecFalse;
      } else {
        aecpc->resample = kAecTrue;
      }

      if (aecpc->skew < minSkewEst) {
        aecpc->skew = minSkewEst;
      } else if (aecpc->skew > maxSkewEst) {
        aecpc->skew = maxSkewEst;
      }

#ifdef WEBRTC_AEC_DEBUG_DUMP
      (void)fwrite(&aecpc->skew, sizeof(aecpc->skew), 1, aecpc->skewFile);
#endif
    }
  }

  nBlocks10ms = nrOfSamples / (FRAME_LEN * aecpc->rate_factor);

  if (aecpc->startup_phase) {
    for (i = 0; i < num_bands; ++i) {
      // Only needed if they don't already point to the same place.
      if (nearend[i] != out[i]) {
        memcpy(out[i], nearend[i], sizeof(nearend[i][0]) * nrOfSamples);
      }
    }

    // The AEC is in the start up mode
    // AEC is disabled until the system delay is OK

    // Mechanism to ensure that the system delay is reasonably stable.
    if (aecpc->checkBuffSize) {
      aecpc->checkBufSizeCtr++;
      // Before we fill up the far-end buffer we require the system delay
      // to be stable (+/-8 ms) compared to the first value. This
      // comparison is made during the following 6 consecutive 10 ms
      // blocks. If it seems to be stable then we start to fill up the
      // far-end buffer.
      if (aecpc->counter == 0) {
        aecpc->firstVal = aecpc->msInSndCardBuf;
        aecpc->sum = 0;
      }

      if (abs(aecpc->firstVal - aecpc->msInSndCardBuf) <
          WEBRTC_SPL_MAX(0.2 * aecpc->msInSndCardBuf, sampMsNb)) {
        aecpc->sum += aecpc->msInSndCardBuf;
        aecpc->counter++;
      } else {
        aecpc->counter = 0;
      }

      if (aecpc->counter * nBlocks10ms >= 6) {
        // The far-end buffer size is determined in partitions of
        // PART_LEN samples. Use 75% of the average value of the system
        // delay as buffer size to start with.
        aecpc->bufSizeStart =
            WEBRTC_SPL_MIN((3 * aecpc->sum * aecpc->rate_factor * 8) /
                               (4 * aecpc->counter * PART_LEN),
                           kMaxBufSizeStart);
        // Buffer size has now been determined.
        aecpc->checkBuffSize = 0;
      }

      if (aecpc->checkBufSizeCtr * nBlocks10ms > 50) {
        // For really bad systems, don't disable the echo canceller for
        // more than 0.5 sec.
        aecpc->bufSizeStart = WEBRTC_SPL_MIN(
            (aecpc->msInSndCardBuf * aecpc->rate_factor * 3) / 40,
            kMaxBufSizeStart);
        aecpc->checkBuffSize = 0;
      }
    }

    // If |checkBuffSize| changed in the if-statement above.
    if (!aecpc->checkBuffSize) {
      // The system delay is now reasonably stable (or has been unstable
      // for too long). When the far-end buffer is filled with
      // approximately the same amount of data as reported by the system
      // we end the startup phase.
      int overhead_elements =
          WebRtcAec_system_delay(aecpc->aec) / PART_LEN - aecpc->bufSizeStart;
      if (overhead_elements == 0) {
        // Enable the AEC
        aecpc->startup_phase = 0;
      } else if (overhead_elements > 0) {
        // TODO(bjornv): Do we need a check on how much we actually
        // moved the read pointer? It should always be possible to move
        // the pointer |overhead_elements| since we have only added data
        // to the buffer and no delay compensation nor AEC processing
        // has been done.
        WebRtcAec_MoveFarReadPtr(aecpc->aec, overhead_elements);

        // Enable the AEC
        aecpc->startup_phase = 0;
      }
    }
  } else {
    // AEC is enabled.
    if (WebRtcAec_reported_delay_enabled(aecpc->aec)) {
      EstBufDelayNormal(aecpc);
    }

    // Call the AEC.
    // TODO(bjornv): Re-structure such that we don't have to pass
    // |aecpc->knownDelay| as input. Change name to something like
    // |system_buffer_diff|.
    WebRtcAec_ProcessFrames(aecpc->aec,
                            nearend,
                            num_bands,
                            nrOfSamples,
                            aecpc->knownDelay,
                            out);
  }

  return retVal;
}
예제 #9
0
// only buffer L band for farend
int32_t WebRtcAec_BufferFarend(void* aecInst,
                               const float* farend,
                               int16_t nrOfSamples) {
  Aec* aecpc = aecInst;
  int newNrOfSamples = (int)nrOfSamples;
  float new_farend[MAX_RESAMP_LEN];
  const float* farend_ptr = farend;

  if (farend == NULL) {
    aecpc->lastError = AEC_NULL_POINTER_ERROR;
    return -1;
  }

  if (aecpc->initFlag != initCheck) {
    aecpc->lastError = AEC_UNINITIALIZED_ERROR;
    return -1;
  }

  // number of samples == 160 for SWB input
  if (nrOfSamples != 80 && nrOfSamples != 160) {
    aecpc->lastError = AEC_BAD_PARAMETER_ERROR;
    return -1;
  }

  if (aecpc->skewMode == kAecTrue && aecpc->resample == kAecTrue) {
    // Resample and get a new number of samples
    WebRtcAec_ResampleLinear(aecpc->resampler,
                             farend,
                             nrOfSamples,
                             aecpc->skew,
                             new_farend,
                             &newNrOfSamples);
    farend_ptr = new_farend;
  }

  aecpc->farend_started = 1;
  WebRtcAec_SetSystemDelay(aecpc->aec,
                           WebRtcAec_system_delay(aecpc->aec) + newNrOfSamples);

  // Write the time-domain data to |far_pre_buf|.
  WebRtc_WriteBuffer(aecpc->far_pre_buf, farend_ptr, (size_t)newNrOfSamples);

  // Transform to frequency domain if we have enough data.
  while (WebRtc_available_read(aecpc->far_pre_buf) >= PART_LEN2) {
    // We have enough data to pass to the FFT, hence read PART_LEN2 samples.
    {
      float* ptmp = NULL;
      float tmp[PART_LEN2];
      WebRtc_ReadBuffer(aecpc->far_pre_buf, (void**)&ptmp, tmp, PART_LEN2);
      WebRtcAec_BufferFarendPartition(aecpc->aec, ptmp);
#ifdef WEBRTC_AEC_DEBUG_DUMP
      WebRtc_WriteBuffer(
          WebRtcAec_far_time_buf(aecpc->aec), &ptmp[PART_LEN], 1);
#endif
    }

    // Rewind |far_pre_buf| PART_LEN samples for overlap before continuing.
    WebRtc_MoveReadPtr(aecpc->far_pre_buf, -PART_LEN);
  }

  return 0;
}
예제 #10
0
static void ProcessExtended(Aec* self,
                            const float* const* near,
                            size_t num_bands,
                            float* const* out,
                            size_t num_samples,
                            int16_t reported_delay_ms,
                            int32_t skew) {
  size_t i;
  const int delay_diff_offset = kDelayDiffOffsetSamples;
#if defined(WEBRTC_UNTRUSTED_DELAY)
  reported_delay_ms = kFixedDelayMs;
#else
  // This is the usual mode where we trust the reported system delay values.
  // Due to the longer filter, we no longer add 10 ms to the reported delay
  // to reduce chance of non-causality. Instead we apply a minimum here to avoid
  // issues with the read pointer jumping around needlessly.
  reported_delay_ms = reported_delay_ms < kMinTrustedDelayMs
                          ? kMinTrustedDelayMs
                          : reported_delay_ms;
  // If the reported delay appears to be bogus, we attempt to recover by using
  // the measured fixed delay values. We use >= here because higher layers
  // may already clamp to this maximum value, and we would otherwise not
  // detect it here.
  reported_delay_ms = reported_delay_ms >= kMaxTrustedDelayMs
                          ? kFixedDelayMs
                          : reported_delay_ms;
#endif
  self->msInSndCardBuf = reported_delay_ms;

  if (!self->farend_started) {
    for (i = 0; i < num_bands; ++i) {
      // Only needed if they don't already point to the same place.
      if (near[i] != out[i]) {
        memcpy(out[i], near[i], sizeof(near[i][0]) * num_samples);
      }
    }
    return;
  }
  if (self->startup_phase) {
    // In the extended mode, there isn't a startup "phase", just a special
    // action on the first frame. In the trusted delay case, we'll take the
    // current reported delay, unless it's less then our conservative
    // measurement.
    int startup_size_ms =
        reported_delay_ms < kFixedDelayMs ? kFixedDelayMs : reported_delay_ms;
#if defined(WEBRTC_ANDROID) || defined(WEBRTC_GONK)
    int target_delay = startup_size_ms * self->rate_factor * 8;
#else
    // To avoid putting the AEC in a non-causal state we're being slightly
    // conservative and scale by 2. On Android we use a fixed delay and
    // therefore there is no need to scale the target_delay.
    int target_delay = startup_size_ms * self->rate_factor * 8 / 2;
#endif
    int overhead_elements =
        (WebRtcAec_system_delay(self->aec) - target_delay) / PART_LEN;
    WebRtcAec_MoveFarReadPtr(self->aec, overhead_elements);
    self->startup_phase = 0;
  }

  EstBufDelayExtended(self);

  {
    // |delay_diff_offset| gives us the option to manually rewind the delay on
    // very low delay platforms which can't be expressed purely through
    // |reported_delay_ms|.
    const int adjusted_known_delay =
        WEBRTC_SPL_MAX(0, self->knownDelay + delay_diff_offset);

    WebRtcAec_ProcessFrames(self->aec,
                            near,
                            num_bands,
                            num_samples,
                            adjusted_known_delay,
                            out);
  }
}
예제 #11
0
int32_t WebRtcAec_Process(void* aecInst,
                          const float* const* nearend,
                          size_t num_bands,
                          float* const* out,
                          size_t nrOfSamples,
                          int16_t msInSndCardBuf,
                          int32_t skew) {
  Aec* aecpc = aecInst;
  int32_t retVal = 0;

  if (out == NULL) {
    return AEC_NULL_POINTER_ERROR;
  }

  if (aecpc->initFlag != initCheck) {
    return AEC_UNINITIALIZED_ERROR;
  }

  // number of samples == 160 for SWB input
  if (nrOfSamples != 80 && nrOfSamples != 160) {
    return AEC_BAD_PARAMETER_ERROR;
  }

  if (msInSndCardBuf < 0) {
    msInSndCardBuf = 0;
    retVal = AEC_BAD_PARAMETER_WARNING;
  } else if (msInSndCardBuf > kMaxTrustedDelayMs) {
    // The clamping is now done in ProcessExtended/Normal().
    retVal = AEC_BAD_PARAMETER_WARNING;
  }

  // This returns the value of aec->extended_filter_enabled.
  if (WebRtcAec_extended_filter_enabled(aecpc->aec)) {
    ProcessExtended(aecpc,
                    nearend,
                    num_bands,
                    out,
                    nrOfSamples,
                    msInSndCardBuf,
                    skew);
  } else {
    retVal = ProcessNormal(aecpc,
                           nearend,
                           num_bands,
                           out,
                           nrOfSamples,
                           msInSndCardBuf,
                           skew);
  }

#ifdef WEBRTC_AEC_DEBUG_DUMP
  {
    int16_t far_buf_size_ms = (int16_t)(WebRtcAec_system_delay(aecpc->aec) /
                                        (sampMsNb * aecpc->rate_factor));
    OpenDebugFiles(aecpc, &webrtc_aec_instance_count);
    if (aecpc->bufFile) {
      (void)fwrite(&far_buf_size_ms, 2, 1, aecpc->bufFile);
      (void)fwrite(
        &aecpc->knownDelay, sizeof(aecpc->knownDelay), 1, aecpc->delayFile);
    }
  }
#endif

  return retVal;
}