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Diffstat (limited to 'third_party/libwebrtc/common_audio/signal_processing/resample_by_2_internal.c')
-rw-r--r-- | third_party/libwebrtc/common_audio/signal_processing/resample_by_2_internal.c | 689 |
1 files changed, 689 insertions, 0 deletions
diff --git a/third_party/libwebrtc/common_audio/signal_processing/resample_by_2_internal.c b/third_party/libwebrtc/common_audio/signal_processing/resample_by_2_internal.c new file mode 100644 index 0000000000..99592b20b5 --- /dev/null +++ b/third_party/libwebrtc/common_audio/signal_processing/resample_by_2_internal.c @@ -0,0 +1,689 @@ +/* + * 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 header file contains some internal resampling functions. + * + */ + +#include "common_audio/signal_processing/resample_by_2_internal.h" +#include "rtc_base/sanitizer.h" + +// allpass filter coefficients. +static const int16_t kResampleAllpass[2][3] = { + {821, 6110, 12382}, + {3050, 9368, 15063} +}; + +// +// decimator +// input: int32_t (shifted 15 positions to the left, + offset 16384) OVERWRITTEN! +// output: int16_t (saturated) (of length len/2) +// state: filter state array; length = 8 + +void RTC_NO_SANITIZE("signed-integer-overflow") // bugs.webrtc.org/5486 +WebRtcSpl_DownBy2IntToShort(int32_t *in, int32_t len, int16_t *out, + int32_t *state) +{ + int32_t tmp0, tmp1, diff; + int32_t i; + + len >>= 1; + + // lower allpass filter (operates on even input samples) + for (i = 0; i < len; i++) + { + tmp0 = in[i << 1]; + diff = tmp0 - state[1]; + // UBSan: -1771017321 - 999586185 cannot be represented in type 'int' + + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[0] + diff * kResampleAllpass[1][0]; + state[0] = tmp0; + diff = tmp1 - state[2]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[1] + diff * kResampleAllpass[1][1]; + state[1] = tmp1; + diff = tmp0 - state[3]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[3] = state[2] + diff * kResampleAllpass[1][2]; + state[2] = tmp0; + + // divide by two and store temporarily + in[i << 1] = (state[3] >> 1); + } + + in++; + + // upper allpass filter (operates on odd input samples) + for (i = 0; i < len; i++) + { + tmp0 = in[i << 1]; + diff = tmp0 - state[5]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[4] + diff * kResampleAllpass[0][0]; + state[4] = tmp0; + diff = tmp1 - state[6]; + // scale down and round + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[5] + diff * kResampleAllpass[0][1]; + state[5] = tmp1; + diff = tmp0 - state[7]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[7] = state[6] + diff * kResampleAllpass[0][2]; + state[6] = tmp0; + + // divide by two and store temporarily + in[i << 1] = (state[7] >> 1); + } + + in--; + + // combine allpass outputs + for (i = 0; i < len; i += 2) + { + // divide by two, add both allpass outputs and round + tmp0 = (in[i << 1] + in[(i << 1) + 1]) >> 15; + tmp1 = (in[(i << 1) + 2] + in[(i << 1) + 3]) >> 15; + if (tmp0 > (int32_t)0x00007FFF) + tmp0 = 0x00007FFF; + if (tmp0 < (int32_t)0xFFFF8000) + tmp0 = 0xFFFF8000; + out[i] = (int16_t)tmp0; + if (tmp1 > (int32_t)0x00007FFF) + tmp1 = 0x00007FFF; + if (tmp1 < (int32_t)0xFFFF8000) + tmp1 = 0xFFFF8000; + out[i + 1] = (int16_t)tmp1; + } +} + +// +// decimator +// input: int16_t +// output: int32_t (shifted 15 positions to the left, + offset 16384) (of length len/2) +// state: filter state array; length = 8 + +void RTC_NO_SANITIZE("signed-integer-overflow") // bugs.webrtc.org/5486 +WebRtcSpl_DownBy2ShortToInt(const int16_t *in, + int32_t len, + int32_t *out, + int32_t *state) +{ + int32_t tmp0, tmp1, diff; + int32_t i; + + len >>= 1; + + // lower allpass filter (operates on even input samples) + for (i = 0; i < len; i++) + { + tmp0 = ((int32_t)in[i << 1] << 15) + (1 << 14); + diff = tmp0 - state[1]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[0] + diff * kResampleAllpass[1][0]; + state[0] = tmp0; + diff = tmp1 - state[2]; + // UBSan: -1379909682 - 834099714 cannot be represented in type 'int' + + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[1] + diff * kResampleAllpass[1][1]; + state[1] = tmp1; + diff = tmp0 - state[3]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[3] = state[2] + diff * kResampleAllpass[1][2]; + state[2] = tmp0; + + // divide by two and store temporarily + out[i] = (state[3] >> 1); + } + + in++; + + // upper allpass filter (operates on odd input samples) + for (i = 0; i < len; i++) + { + tmp0 = ((int32_t)in[i << 1] << 15) + (1 << 14); + diff = tmp0 - state[5]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[4] + diff * kResampleAllpass[0][0]; + state[4] = tmp0; + diff = tmp1 - state[6]; + // scale down and round + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[5] + diff * kResampleAllpass[0][1]; + state[5] = tmp1; + diff = tmp0 - state[7]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[7] = state[6] + diff * kResampleAllpass[0][2]; + state[6] = tmp0; + + // divide by two and store temporarily + out[i] += (state[7] >> 1); + } + + in--; +} + +// +// interpolator +// input: int16_t +// output: int32_t (normalized, not saturated) (of length len*2) +// state: filter state array; length = 8 +void WebRtcSpl_UpBy2ShortToInt(const int16_t *in, int32_t len, int32_t *out, + int32_t *state) +{ + int32_t tmp0, tmp1, diff; + int32_t i; + + // upper allpass filter (generates odd output samples) + for (i = 0; i < len; i++) + { + tmp0 = ((int32_t)in[i] << 15) + (1 << 14); + diff = tmp0 - state[5]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[4] + diff * kResampleAllpass[0][0]; + state[4] = tmp0; + diff = tmp1 - state[6]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[5] + diff * kResampleAllpass[0][1]; + state[5] = tmp1; + diff = tmp0 - state[7]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[7] = state[6] + diff * kResampleAllpass[0][2]; + state[6] = tmp0; + + // scale down, round and store + out[i << 1] = state[7] >> 15; + } + + out++; + + // lower allpass filter (generates even output samples) + for (i = 0; i < len; i++) + { + tmp0 = ((int32_t)in[i] << 15) + (1 << 14); + diff = tmp0 - state[1]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[0] + diff * kResampleAllpass[1][0]; + state[0] = tmp0; + diff = tmp1 - state[2]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[1] + diff * kResampleAllpass[1][1]; + state[1] = tmp1; + diff = tmp0 - state[3]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[3] = state[2] + diff * kResampleAllpass[1][2]; + state[2] = tmp0; + + // scale down, round and store + out[i << 1] = state[3] >> 15; + } +} + +// +// interpolator +// input: int32_t (shifted 15 positions to the left, + offset 16384) +// output: int32_t (shifted 15 positions to the left, + offset 16384) (of length len*2) +// state: filter state array; length = 8 +void WebRtcSpl_UpBy2IntToInt(const int32_t *in, int32_t len, int32_t *out, + int32_t *state) +{ + int32_t tmp0, tmp1, diff; + int32_t i; + + // upper allpass filter (generates odd output samples) + for (i = 0; i < len; i++) + { + tmp0 = in[i]; + diff = tmp0 - state[5]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[4] + diff * kResampleAllpass[0][0]; + state[4] = tmp0; + diff = tmp1 - state[6]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[5] + diff * kResampleAllpass[0][1]; + state[5] = tmp1; + diff = tmp0 - state[7]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[7] = state[6] + diff * kResampleAllpass[0][2]; + state[6] = tmp0; + + // scale down, round and store + out[i << 1] = state[7]; + } + + out++; + + // lower allpass filter (generates even output samples) + for (i = 0; i < len; i++) + { + tmp0 = in[i]; + diff = tmp0 - state[1]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[0] + diff * kResampleAllpass[1][0]; + state[0] = tmp0; + diff = tmp1 - state[2]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[1] + diff * kResampleAllpass[1][1]; + state[1] = tmp1; + diff = tmp0 - state[3]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[3] = state[2] + diff * kResampleAllpass[1][2]; + state[2] = tmp0; + + // scale down, round and store + out[i << 1] = state[3]; + } +} + +// +// interpolator +// input: int32_t (shifted 15 positions to the left, + offset 16384) +// output: int16_t (saturated) (of length len*2) +// state: filter state array; length = 8 +void WebRtcSpl_UpBy2IntToShort(const int32_t *in, int32_t len, int16_t *out, + int32_t *state) +{ + int32_t tmp0, tmp1, diff; + int32_t i; + + // upper allpass filter (generates odd output samples) + for (i = 0; i < len; i++) + { + tmp0 = in[i]; + diff = tmp0 - state[5]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[4] + diff * kResampleAllpass[0][0]; + state[4] = tmp0; + diff = tmp1 - state[6]; + // scale down and round + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[5] + diff * kResampleAllpass[0][1]; + state[5] = tmp1; + diff = tmp0 - state[7]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[7] = state[6] + diff * kResampleAllpass[0][2]; + state[6] = tmp0; + + // scale down, saturate and store + tmp1 = state[7] >> 15; + if (tmp1 > (int32_t)0x00007FFF) + tmp1 = 0x00007FFF; + if (tmp1 < (int32_t)0xFFFF8000) + tmp1 = 0xFFFF8000; + out[i << 1] = (int16_t)tmp1; + } + + out++; + + // lower allpass filter (generates even output samples) + for (i = 0; i < len; i++) + { + tmp0 = in[i]; + diff = tmp0 - state[1]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[0] + diff * kResampleAllpass[1][0]; + state[0] = tmp0; + diff = tmp1 - state[2]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[1] + diff * kResampleAllpass[1][1]; + state[1] = tmp1; + diff = tmp0 - state[3]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[3] = state[2] + diff * kResampleAllpass[1][2]; + state[2] = tmp0; + + // scale down, saturate and store + tmp1 = state[3] >> 15; + if (tmp1 > (int32_t)0x00007FFF) + tmp1 = 0x00007FFF; + if (tmp1 < (int32_t)0xFFFF8000) + tmp1 = 0xFFFF8000; + out[i << 1] = (int16_t)tmp1; + } +} + +// lowpass filter +// input: int16_t +// output: int32_t (normalized, not saturated) +// state: filter state array; length = 8 +void WebRtcSpl_LPBy2ShortToInt(const int16_t* in, int32_t len, int32_t* out, + int32_t* state) +{ + int32_t tmp0, tmp1, diff; + int32_t i; + + len >>= 1; + + // lower allpass filter: odd input -> even output samples + in++; + // initial state of polyphase delay element + tmp0 = state[12]; + for (i = 0; i < len; i++) + { + diff = tmp0 - state[1]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[0] + diff * kResampleAllpass[1][0]; + state[0] = tmp0; + diff = tmp1 - state[2]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[1] + diff * kResampleAllpass[1][1]; + state[1] = tmp1; + diff = tmp0 - state[3]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[3] = state[2] + diff * kResampleAllpass[1][2]; + state[2] = tmp0; + + // scale down, round and store + out[i << 1] = state[3] >> 1; + tmp0 = ((int32_t)in[i << 1] << 15) + (1 << 14); + } + in--; + + // upper allpass filter: even input -> even output samples + for (i = 0; i < len; i++) + { + tmp0 = ((int32_t)in[i << 1] << 15) + (1 << 14); + diff = tmp0 - state[5]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[4] + diff * kResampleAllpass[0][0]; + state[4] = tmp0; + diff = tmp1 - state[6]; + // scale down and round + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[5] + diff * kResampleAllpass[0][1]; + state[5] = tmp1; + diff = tmp0 - state[7]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[7] = state[6] + diff * kResampleAllpass[0][2]; + state[6] = tmp0; + + // average the two allpass outputs, scale down and store + out[i << 1] = (out[i << 1] + (state[7] >> 1)) >> 15; + } + + // switch to odd output samples + out++; + + // lower allpass filter: even input -> odd output samples + for (i = 0; i < len; i++) + { + tmp0 = ((int32_t)in[i << 1] << 15) + (1 << 14); + diff = tmp0 - state[9]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[8] + diff * kResampleAllpass[1][0]; + state[8] = tmp0; + diff = tmp1 - state[10]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[9] + diff * kResampleAllpass[1][1]; + state[9] = tmp1; + diff = tmp0 - state[11]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[11] = state[10] + diff * kResampleAllpass[1][2]; + state[10] = tmp0; + + // scale down, round and store + out[i << 1] = state[11] >> 1; + } + + // upper allpass filter: odd input -> odd output samples + in++; + for (i = 0; i < len; i++) + { + tmp0 = ((int32_t)in[i << 1] << 15) + (1 << 14); + diff = tmp0 - state[13]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[12] + diff * kResampleAllpass[0][0]; + state[12] = tmp0; + diff = tmp1 - state[14]; + // scale down and round + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[13] + diff * kResampleAllpass[0][1]; + state[13] = tmp1; + diff = tmp0 - state[15]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[15] = state[14] + diff * kResampleAllpass[0][2]; + state[14] = tmp0; + + // average the two allpass outputs, scale down and store + out[i << 1] = (out[i << 1] + (state[15] >> 1)) >> 15; + } +} + +// lowpass filter +// input: int32_t (shifted 15 positions to the left, + offset 16384) +// output: int32_t (normalized, not saturated) +// state: filter state array; length = 8 +void RTC_NO_SANITIZE("signed-integer-overflow") // bugs.webrtc.org/5486 +WebRtcSpl_LPBy2IntToInt(const int32_t* in, int32_t len, int32_t* out, + int32_t* state) +{ + int32_t tmp0, tmp1, diff; + int32_t i; + + len >>= 1; + + // lower allpass filter: odd input -> even output samples + in++; + // initial state of polyphase delay element + tmp0 = state[12]; + for (i = 0; i < len; i++) + { + diff = tmp0 - state[1]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[0] + diff * kResampleAllpass[1][0]; + state[0] = tmp0; + diff = tmp1 - state[2]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[1] + diff * kResampleAllpass[1][1]; + state[1] = tmp1; + diff = tmp0 - state[3]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[3] = state[2] + diff * kResampleAllpass[1][2]; + state[2] = tmp0; + + // scale down, round and store + out[i << 1] = state[3] >> 1; + tmp0 = in[i << 1]; + } + in--; + + // upper allpass filter: even input -> even output samples + for (i = 0; i < len; i++) + { + tmp0 = in[i << 1]; + diff = tmp0 - state[5]; + // UBSan: -794814117 - 1566149201 cannot be represented in type 'int' + + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[4] + diff * kResampleAllpass[0][0]; + state[4] = tmp0; + diff = tmp1 - state[6]; + // scale down and round + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[5] + diff * kResampleAllpass[0][1]; + state[5] = tmp1; + diff = tmp0 - state[7]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[7] = state[6] + diff * kResampleAllpass[0][2]; + state[6] = tmp0; + + // average the two allpass outputs, scale down and store + out[i << 1] = (out[i << 1] + (state[7] >> 1)) >> 15; + } + + // switch to odd output samples + out++; + + // lower allpass filter: even input -> odd output samples + for (i = 0; i < len; i++) + { + tmp0 = in[i << 1]; + diff = tmp0 - state[9]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[8] + diff * kResampleAllpass[1][0]; + state[8] = tmp0; + diff = tmp1 - state[10]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[9] + diff * kResampleAllpass[1][1]; + state[9] = tmp1; + diff = tmp0 - state[11]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[11] = state[10] + diff * kResampleAllpass[1][2]; + state[10] = tmp0; + + // scale down, round and store + out[i << 1] = state[11] >> 1; + } + + // upper allpass filter: odd input -> odd output samples + in++; + for (i = 0; i < len; i++) + { + tmp0 = in[i << 1]; + diff = tmp0 - state[13]; + // scale down and round + diff = (diff + (1 << 13)) >> 14; + tmp1 = state[12] + diff * kResampleAllpass[0][0]; + state[12] = tmp0; + diff = tmp1 - state[14]; + // scale down and round + diff = diff >> 14; + if (diff < 0) + diff += 1; + tmp0 = state[13] + diff * kResampleAllpass[0][1]; + state[13] = tmp1; + diff = tmp0 - state[15]; + // scale down and truncate + diff = diff >> 14; + if (diff < 0) + diff += 1; + state[15] = state[14] + diff * kResampleAllpass[0][2]; + state[14] = tmp0; + + // average the two allpass outputs, scale down and store + out[i << 1] = (out[i << 1] + (state[15] >> 1)) >> 15; + } +} |