| /* ------------------------------------------------------------------ |
| * 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" |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; 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) |
| { |
| tmp = getbits_crc(inputStream, 14, crc, info->error_protection); |
| si->main_data_begin = (tmp << 18) >> 23; /* 9 */ |
| si->private_bits = (tmp << 23) >> 27; /* 5 */ |
| } |
| else |
| { |
| tmp = getbits_crc(inputStream, 12, crc, info->error_protection); |
| si->main_data_begin = (tmp << 20) >> 23; /* 9 */ |
| si->private_bits = (tmp << 23) >> 29; /* 3 */ |
| |
| } |
| |
| for (ch = 0; ch < stereo; ch++) |
| { |
| 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++) |
| { |
| 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 = ((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) |
| { |
| 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 |
| { |
| 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; |
| } |
| |
| 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 */ |
| { |
| 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++) |
| { |
| 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) |
| { |
| |
| 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 |
| { |
| 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; |
| } |
| |
| 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); |
| } |
| |
