Line data    Source code

       1             : /*
       2             :  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
       3             :  *
       4             :  *  Use of this source code is governed by a BSD-style license
       5             :  *  that can be found in the LICENSE file in the root of the source
       6             :  *  tree. An additional intellectual property rights grant can be found
       7             :  *  in the file PATENTS.  All contributing project authors may
       8             :  *  be found in the AUTHORS file in the root of the source tree.
       9             :  */
      10             : 
      11             : #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
      12             : 
      13             : #include "webrtc/base/checks.h"
      14             : #include "webrtc/base/sanitizer.h"
      15             : 
      16             : // TODO(Bjornv): Change the function parameter order to WebRTC code style.
      17             : // C version of WebRtcSpl_DownsampleFast() for generic platforms.
      18           0 : int WebRtcSpl_DownsampleFastC(const int16_t* data_in,
      19             :                               size_t data_in_length,
      20             :                               int16_t* data_out,
      21             :                               size_t data_out_length,
      22             :                               const int16_t* __restrict coefficients,
      23             :                               size_t coefficients_length,
      24             :                               int factor,
      25             :                               size_t delay) {
      26           0 :   int16_t* const original_data_out = data_out;
      27           0 :   size_t i = 0;
      28           0 :   size_t j = 0;
      29           0 :   int32_t out_s32 = 0;
      30           0 :   size_t endpos = delay + factor * (data_out_length - 1) + 1;
      31             : 
      32             :   // Return error if any of the running conditions doesn't meet.
      33           0 :   if (data_out_length == 0 || coefficients_length == 0
      34           0 :                            || data_in_length < endpos) {
      35           0 :     return -1;
      36             :   }
      37             : 
      38           0 :   rtc_MsanCheckInitialized(coefficients, sizeof(coefficients[0]),
      39             :                            coefficients_length);
      40             : 
      41           0 :   for (i = delay; i < endpos; i += factor) {
      42           0 :     out_s32 = 2048;  // Round value, 0.5 in Q12.
      43             : 
      44           0 :     for (j = 0; j < coefficients_length; j++) {
      45           0 :       rtc_MsanCheckInitialized(&data_in[i - j], sizeof(data_in[0]), 1);
      46           0 :       out_s32 += coefficients[j] * data_in[i - j];  // Q12.
      47             :     }
      48             : 
      49           0 :     out_s32 >>= 12;  // Q0.
      50             : 
      51             :     // Saturate and store the output.
      52           0 :     *data_out++ = WebRtcSpl_SatW32ToW16(out_s32);
      53             :   }
      54             : 
      55           0 :   RTC_DCHECK_EQ(original_data_out + data_out_length, data_out);
      56           0 :   rtc_MsanCheckInitialized(original_data_out, sizeof(original_data_out[0]),
      57             :                            data_out_length);
      58             : 
      59           0 :   return 0;
      60             : }