src/third_party/webrtc/modules/audio_coding/codecs/isac/main/source/crc.c

   1 /*
   2  *  Copyright (c) 2011 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 "crc.h"
  12 #include <stdlib.h>
  13 #include "signal_processing_library.h"
  14
  15 #define POLYNOMIAL 0x04c11db7L
  16
  17
  18 static const uint32_t kCrcTable[256] = {
  19   0,          0x4c11db7,  0x9823b6e,  0xd4326d9,  0x130476dc, 0x17c56b6b,
  20   0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
  21   0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
  22   0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
  23   0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
  24   0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
  25   0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
  26   0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
  27   0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
  28   0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
  29   0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
  30   0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
  31   0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x18aeb13,  0x54bf6a4,
  32   0x808d07d,  0xcc9cdca,  0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
  33   0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
  34   0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
  35   0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
  36   0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
  37   0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
  38   0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
  39   0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
  40   0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
  41   0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
  42   0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
  43   0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
  44   0x3f9b762c, 0x3b5a6b9b,  0x315d626, 0x7d4cb91,  0xa97ed48,  0xe56f0ff,
  45   0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
  46   0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
  47   0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
  48   0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
  49   0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
  50   0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
  51   0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
  52   0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
  53   0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
  54   0x18197087, 0x1cd86d30, 0x29f3d35,  0x65e2082,  0xb1d065b,  0xfdc1bec,
  55   0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
  56   0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
  57   0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
  58   0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
  59   0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
  60   0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
  61   0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
  62 };
  63
  64
  65
  66
  67 /****************************************************************************
  68  * WebRtcIsac_GetCrc(...)
  69  *
  70  * This function returns a 32 bit CRC checksum of a bit stream
  71  *
  72  * Input:
  73  *  - bitstream              : payload bitstream
  74  *  - len_bitstream_in_bytes : number of 8-bit words in the bit stream
  75  *
  76  * Output:
  77  *  - crc                    : checksum
  78  *
  79  * Return value              :  0 - Ok
  80  *                             -1 - Error
  81  */
  82
  83 int16_t WebRtcIsac_GetCrc(const int16_t* bitstream,
  84                           int16_t        len_bitstream_in_bytes,
  85                           uint32_t*      crc)
  86 {
  87   uint8_t* bitstream_ptr_uw8;
  88   uint32_t crc_state;
  89   int byte_cntr;
  90   int crc_tbl_indx;
  91
  92   /* Sanity Check. */
  93   if (bitstream == NULL) {
  94     return -1;
  95   }
  96   /* cast to UWord8 pointer */
  97   bitstream_ptr_uw8 = (uint8_t *)bitstream;
  98
  99   /* initialize */
 100   crc_state = 0xFFFFFFFF;
 101
 102   for (byte_cntr = 0; byte_cntr < len_bitstream_in_bytes; byte_cntr++) {
 103     crc_tbl_indx = (WEBRTC_SPL_RSHIFT_U32(crc_state, 24) ^
 104                        bitstream_ptr_uw8[byte_cntr]) & 0xFF;
 105     crc_state = (crc_state << 8) ^ kCrcTable[crc_tbl_indx];
 106   }
 107
 108   *crc = ~crc_state;
 109   return 0;
 110 }