Line data    Source code

       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           0 : int WebRtcIsac_GetCrc(const int16_t* bitstream,
      84             :                       int 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           0 :   if (bitstream == NULL) {
      94           0 :     return -1;
      95             :   }
      96             :   /* cast to UWord8 pointer */
      97           0 :   bitstream_ptr_uw8 = (uint8_t *)bitstream;
      98             : 
      99             :   /* initialize */
     100           0 :   crc_state = 0xFFFFFFFF;
     101             : 
     102           0 :   for (byte_cntr = 0; byte_cntr < len_bitstream_in_bytes; byte_cntr++) {
     103           0 :     crc_tbl_indx = (WEBRTC_SPL_RSHIFT_U32(crc_state, 24) ^
     104           0 :                        bitstream_ptr_uw8[byte_cntr]) & 0xFF;
     105           0 :     crc_state = (crc_state << 8) ^ kCrcTable[crc_tbl_indx];
     106             :   }
     107             : 
     108           0 :   *crc = ~crc_state;
     109           0 :   return 0;
     110             : }