diff options
Diffstat (limited to 'src/common_audio/signal_processing_library/main/source/randomization_functions.c')
-rw-r--r-- | src/common_audio/signal_processing_library/main/source/randomization_functions.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/src/common_audio/signal_processing_library/main/source/randomization_functions.c b/src/common_audio/signal_processing_library/main/source/randomization_functions.c new file mode 100644 index 0000000000..6bc87c76ff --- /dev/null +++ b/src/common_audio/signal_processing_library/main/source/randomization_functions.c @@ -0,0 +1,52 @@ +/* + * Copyright (c) 2011 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 contains implementations of the randomization functions + * WebRtcSpl_IncreaseSeed() + * WebRtcSpl_RandU() + * WebRtcSpl_RandN() + * WebRtcSpl_RandUArray() + * + * The description header can be found in signal_processing_library.h + * + */ + +#include "signal_processing_library.h" + +WebRtc_UWord32 WebRtcSpl_IncreaseSeed(WebRtc_UWord32 *seed) +{ + seed[0] = (seed[0] * ((WebRtc_Word32)69069) + 1) & (WEBRTC_SPL_MAX_SEED_USED - 1); + return seed[0]; +} + +WebRtc_Word16 WebRtcSpl_RandU(WebRtc_UWord32 *seed) +{ + return (WebRtc_Word16)(WebRtcSpl_IncreaseSeed(seed) >> 16); +} + +WebRtc_Word16 WebRtcSpl_RandN(WebRtc_UWord32 *seed) +{ + return WebRtcSpl_kRandNTable[WebRtcSpl_IncreaseSeed(seed) >> 23]; +} + +// Creates an array of uniformly distributed variables +WebRtc_Word16 WebRtcSpl_RandUArray(WebRtc_Word16* vector, + WebRtc_Word16 vector_length, + WebRtc_UWord32* seed) +{ + int i; + for (i = 0; i < vector_length; i++) + { + vector[i] = WebRtcSpl_RandU(seed); + } + return vector_length; +} |