/* ------------------------------------------------------------------ * Copyright (C) 1998-2009 PacketVideo * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either * express or implied. * See the License for the specific language governing permissions * and limitations under the License. * ------------------------------------------------------------------- */ /* ------------------------------------------------------------------------------ PacketVideo Corp. MP3 Decoder Library Filename: pvmp3_get_side_info.cpp Date: 09/21/2007 ------------------------------------------------------------------------------ REVISION HISTORY Description: ------------------------------------------------------------------------------ INPUT AND OUTPUT DEFINITIONS Input mp3SideInfo *si, mp3Header *info, mp3 header information uint32 *crc initialized crc value (if enabled) Returns mp3SideInfo *si, side information ------------------------------------------------------------------------------ FUNCTION DESCRIPTION acquires side information ------------------------------------------------------------------------------ REQUIREMENTS ------------------------------------------------------------------------------ REFERENCES [1] ISO MPEG Audio Subgroup Software Simulation Group (1996) ISO 13818-3 MPEG-2 Audio Decoder - Lower Sampling Frequency Extension ------------------------------------------------------------------------------ PSEUDO-CODE ------------------------------------------------------------------------------ */ /*---------------------------------------------------------------------------- ; INCLUDES ----------------------------------------------------------------------------*/ #include "pvmp3_get_side_info.h" #include "pvmp3_crc.h" #include "pvmp3_getbits.h" /*---------------------------------------------------------------------------- ; MACROS ; Define module specific macros here ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; DEFINES ; Include all pre-processor statements here. Include conditional ; compile variables also. ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; LOCAL FUNCTION DEFINITIONS ; Function Prototype declaration ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; LOCAL STORE/BUFFER/POINTER DEFINITIONS ; Variable declaration - defined here and used outside this module ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; EXTERNAL FUNCTION REFERENCES ; Declare functions defined elsewhere and referenced in this module ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES ; Declare variables used in this module but defined elsewhere ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; FUNCTION CODE ----------------------------------------------------------------------------*/ ERROR_CODE pvmp3_get_side_info(tmp3Bits *inputStream, mp3SideInfo *si, mp3Header *info, uint32 *crc) { int32 ch, gr; uint32 tmp; int stereo = (info->mode == MPG_MD_MONO) ? 1 : 2; if (info->version_x == MPEG_1) { if (stereo == 1) { if (!bitsAvailable(inputStream, 14)) { return SIDE_INFO_ERROR; } tmp = getbits_crc(inputStream, 14, crc, info->error_protection); si->main_data_begin = (tmp << 18) >> 23; /* 9 */ si->private_bits = (tmp << 27) >> 27; /* 5 */ } else { if (!bitsAvailable(inputStream, 12)) { return SIDE_INFO_ERROR; } tmp = getbits_crc(inputStream, 12, crc, info->error_protection); si->main_data_begin = (tmp << 20) >> 23; /* 9 */ si->private_bits = (tmp << 29) >> 29; /* 3 */ } for (ch = 0; ch < stereo; ch++) { if (!bitsAvailable(inputStream, 4)) { return SIDE_INFO_ERROR; } tmp = getbits_crc(inputStream, 4, crc, info->error_protection); si->ch[ch].scfsi[0] = (tmp << 28) >> 31; /* 1 */ si->ch[ch].scfsi[1] = (tmp << 29) >> 31; /* 1 */ si->ch[ch].scfsi[2] = (tmp << 30) >> 31; /* 1 */ si->ch[ch].scfsi[3] = tmp & 1; /* 1 */ } for (gr = 0; gr < 2 ; gr++) { for (ch = 0; ch < stereo; ch++) { if (!bitsAvailable(inputStream, 34)) { return SIDE_INFO_ERROR; } si->ch[ch].gran[gr].part2_3_length = getbits_crc(inputStream, 12, crc, info->error_protection); tmp = getbits_crc(inputStream, 22, crc, info->error_protection); si->ch[ch].gran[gr].big_values = (tmp << 10) >> 23; /* 9 */ si->ch[ch].gran[gr].global_gain = (int32)((tmp << 19) >> 24) - 210; /* 8 */ si->ch[ch].gran[gr].scalefac_compress = (tmp << 27) >> 28; /* 4 */ si->ch[ch].gran[gr].window_switching_flag = tmp & 1; /* 1 */ if (si->ch[ch].gran[gr].window_switching_flag) { if (!bitsAvailable(inputStream, 22)) { return SIDE_INFO_ERROR; } tmp = getbits_crc(inputStream, 22, crc, info->error_protection); si->ch[ch].gran[gr].block_type = (tmp << 10) >> 30; /* 2 */; si->ch[ch].gran[gr].mixed_block_flag = (tmp << 12) >> 31; /* 1 */; si->ch[ch].gran[gr].table_select[0] = (tmp << 13) >> 27; /* 5 */; si->ch[ch].gran[gr].table_select[1] = (tmp << 18) >> 27; /* 5 */; si->ch[ch].gran[gr].subblock_gain[0] = (tmp << 23) >> 29; /* 3 */; si->ch[ch].gran[gr].subblock_gain[1] = (tmp << 26) >> 29; /* 3 */; si->ch[ch].gran[gr].subblock_gain[2] = (tmp << 29) >> 29; /* 3 */; /* Set region_count parameters since they are implicit in this case. */ if (si->ch[ch].gran[gr].block_type == 0) { return(SIDE_INFO_ERROR); } else if ((si->ch[ch].gran[gr].block_type == 2) && (si->ch[ch].gran[gr].mixed_block_flag == 0)) { si->ch[ch].gran[gr].region0_count = 8; /* MI 9; */ si->ch[ch].gran[gr].region1_count = 12; } else { si->ch[ch].gran[gr].region0_count = 7; /* MI 8; */ si->ch[ch].gran[gr].region1_count = 13; } } else { if (!bitsAvailable(inputStream, 22)) { return SIDE_INFO_ERROR; } tmp = getbits_crc(inputStream, 22, crc, info->error_protection); si->ch[ch].gran[gr].table_select[0] = (tmp << 10) >> 27; /* 5 */; si->ch[ch].gran[gr].table_select[1] = (tmp << 15) >> 27; /* 5 */; si->ch[ch].gran[gr].table_select[2] = (tmp << 20) >> 27; /* 5 */; si->ch[ch].gran[gr].region0_count = (tmp << 25) >> 28; /* 4 */; si->ch[ch].gran[gr].region1_count = (tmp << 29) >> 29; /* 3 */; si->ch[ch].gran[gr].block_type = 0; } if (!bitsAvailable(inputStream, 3)) { return SIDE_INFO_ERROR; } tmp = getbits_crc(inputStream, 3, crc, info->error_protection); si->ch[ch].gran[gr].preflag = (tmp << 29) >> 31; /* 1 */ si->ch[ch].gran[gr].scalefac_scale = (tmp << 30) >> 31; /* 1 */ si->ch[ch].gran[gr].count1table_select = tmp & 1; /* 1 */ } } } else /* Layer 3 LSF */ { if (!bitsAvailable(inputStream, 8 + stereo)) { return SIDE_INFO_ERROR; } si->main_data_begin = getbits_crc(inputStream, 8, crc, info->error_protection); si->private_bits = getbits_crc(inputStream, stereo, crc, info->error_protection); for (ch = 0; ch < stereo; ch++) { if (!bitsAvailable(inputStream, 39)) { return SIDE_INFO_ERROR; } tmp = getbits_crc(inputStream, 21, crc, info->error_protection); si->ch[ch].gran[0].part2_3_length = (tmp << 11) >> 20; /* 12 */ si->ch[ch].gran[0].big_values = (tmp << 23) >> 23; /* 9 */ tmp = getbits_crc(inputStream, 18, crc, info->error_protection); si->ch[ch].gran[0].global_gain = ((tmp << 14) >> 24) - 210; /* 8 */ si->ch[ch].gran[0].scalefac_compress = (tmp << 22) >> 23; /* 9 */ si->ch[ch].gran[0].window_switching_flag = tmp & 1; /* 1 */ if (si->ch[ch].gran[0].window_switching_flag) { if (!bitsAvailable(inputStream, 22)) { return SIDE_INFO_ERROR; } tmp = getbits_crc(inputStream, 22, crc, info->error_protection); si->ch[ch].gran[0].block_type = (tmp << 10) >> 30; /* 2 */; si->ch[ch].gran[0].mixed_block_flag = (tmp << 12) >> 31; /* 1 */; si->ch[ch].gran[0].table_select[0] = (tmp << 13) >> 27; /* 5 */; si->ch[ch].gran[0].table_select[1] = (tmp << 18) >> 27; /* 5 */; si->ch[ch].gran[0].subblock_gain[0] = (tmp << 23) >> 29; /* 3 */; si->ch[ch].gran[0].subblock_gain[1] = (tmp << 26) >> 29; /* 3 */; si->ch[ch].gran[0].subblock_gain[2] = (tmp << 29) >> 29; /* 3 */; /* Set region_count parameters since they are implicit in this case. */ if (si->ch[ch].gran[0].block_type == 0) { return(SIDE_INFO_ERROR); } else if ((si->ch[ch].gran[0].block_type == 2) && (si->ch[ch].gran[0].mixed_block_flag == 0)) { si->ch[ch].gran[0].region0_count = 8; /* MI 9; */ si->ch[ch].gran[0].region1_count = 12; } else { si->ch[ch].gran[0].region0_count = 7; /* MI 8; */ si->ch[ch].gran[0].region1_count = 13; } } else { if (!bitsAvailable(inputStream, 22)) { return SIDE_INFO_ERROR; } tmp = getbits_crc(inputStream, 22, crc, info->error_protection); si->ch[ch].gran[0].table_select[0] = (tmp << 10) >> 27; /* 5 */; si->ch[ch].gran[0].table_select[1] = (tmp << 15) >> 27; /* 5 */; si->ch[ch].gran[0].table_select[2] = (tmp << 20) >> 27; /* 5 */; si->ch[ch].gran[0].region0_count = (tmp << 25) >> 28; /* 4 */; si->ch[ch].gran[0].region1_count = (tmp << 29) >> 29; /* 3 */; si->ch[ch].gran[0].block_type = 0; } if (!bitsAvailable(inputStream, 2)) { return SIDE_INFO_ERROR; } tmp = getbits_crc(inputStream, 2, crc, info->error_protection); si->ch[ch].gran[0].scalefac_scale = tmp >> 1; /* 1 */ si->ch[ch].gran[0].count1table_select = tmp & 1; /* 1 */ } } return (NO_DECODING_ERROR); }