| /* ------------------------------------------------------------------ |
| * 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_mpeg2_get_scale_data.cpp |
| |
| Date: 09/21/2007 |
| |
| ------------------------------------------------------------------------------ |
| REVISION HISTORY |
| |
| |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Input |
| mp3SideInfo *si, side information |
| int32 gr, granule |
| int32 ch, channel |
| mp3Header *info, mp3 header information |
| uint32 *scalefac_buffer, |
| uint32 *scalefac_IIP_buffer, |
| tbits *pMainData bit stream Data |
| |
| Returns |
| |
| uint32 *scalefac_buffer, acquired scale band data |
| uint32 *scalefac_IIP_buffer, auxiliary scale data |
| |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| get scale data for mpeg2 layer III LSF extension |
| |
| ------------------------------------------------------------------------------ |
| 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_mpeg2_get_scale_data.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 |
| ----------------------------------------------------------------------------*/ |
| |
| const uint32 nr_of_sfb_block[6][3][4] = |
| { {{ 6, 5, 5, 5}, { 9, 9, 9, 9}, { 6, 9, 9, 9}}, |
| {{ 6, 5, 7, 3}, { 9, 9, 12, 6}, { 6, 9, 12, 6}}, |
| {{11, 10, 0, 0}, { 18, 18, 0, 0}, {15, 18, 0, 0}}, |
| {{ 7, 7, 7, 0}, { 12, 12, 12, 0}, { 6, 15, 12, 0}}, |
| {{ 6, 6, 6, 3}, { 12, 9, 9, 6}, { 6, 12, 9, 6}}, |
| {{ 8, 8, 5, 0}, { 15, 12, 9, 0}, { 6, 18, 9, 0}} |
| }; |
| |
| /*---------------------------------------------------------------------------- |
| ; 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 |
| ----------------------------------------------------------------------------*/ |
| |
| void pvmp3_mpeg2_get_scale_data(mp3SideInfo *si, |
| int32 gr, |
| int32 ch, |
| mp3Header *info, |
| uint32 *scalefac_buffer, |
| uint32 *scalefac_IIP_buffer, |
| tmp3Bits *pMainData) |
| { |
| int16 i; |
| int16 j; |
| int16 k; |
| int16 blocktypenumber = 0; |
| int16 blocknumber = 0; |
| |
| granuleInfo *gr_info = &(si->ch[ch].gran[gr]); |
| uint32 scalefac_comp, int_scalefac_comp, new_slen[4] = { 0,0,0,0 }; |
| |
| scalefac_comp = gr_info->scalefac_compress; |
| |
| |
| |
| if ((((info->mode_ext &1)) && (ch == 1))) |
| { |
| /* intensity_scale = scalefac_comp %2; */ |
| int_scalefac_comp = scalefac_comp >> 1; |
| |
| if (int_scalefac_comp < 180) |
| { |
| new_slen[0] = int_scalefac_comp / 36; |
| new_slen[1] = (int_scalefac_comp % 36) / 6; |
| new_slen[2] = int_scalefac_comp % 6; |
| blocknumber = 3; |
| } |
| else if (int_scalefac_comp < 244) |
| { |
| int_scalefac_comp -= 180; |
| new_slen[0] = (int_scalefac_comp & 63) >> 4; |
| new_slen[1] = (int_scalefac_comp & 15) >> 2; |
| new_slen[2] = int_scalefac_comp & 3; |
| blocknumber = 4; |
| } |
| else if (int_scalefac_comp <= 255) |
| { |
| int_scalefac_comp -= 244; |
| new_slen[0] = (int_scalefac_comp) / 3; |
| new_slen[1] = (int_scalefac_comp) % 3; |
| new_slen[2] = 0; |
| blocknumber = 5; |
| } |
| new_slen[3] = 0; |
| si->ch[ch].gran[gr].preflag = 0; |
| } |
| else |
| { |
| if (scalefac_comp < 400) |
| { |
| new_slen[0] = (scalefac_comp >> 4) / 5; |
| new_slen[1] = (scalefac_comp >> 4) % 5; |
| new_slen[2] = (scalefac_comp & 15) >> 2 ; |
| new_slen[3] = (scalefac_comp & 3); |
| si->ch[ch].gran[gr].preflag = 0; |
| |
| blocknumber = 0; |
| } |
| else if (scalefac_comp < 500) |
| { |
| scalefac_comp -= 400; |
| new_slen[0] = (scalefac_comp >> 2) / 5; |
| new_slen[1] = (scalefac_comp >> 2) % 5; |
| new_slen[2] = scalefac_comp & 3; |
| new_slen[3] = 0; |
| si->ch[ch].gran[gr].preflag = 0; |
| blocknumber = 1; |
| } |
| else if (scalefac_comp < 512) |
| { |
| scalefac_comp -= 500; |
| new_slen[0] = scalefac_comp / 3; |
| new_slen[1] = scalefac_comp % 3; |
| new_slen[2] = 0 ; |
| new_slen[3] = 0; |
| si->ch[ch].gran[gr].preflag = 1; |
| blocknumber = 2; |
| } |
| } |
| |
| if (gr_info->block_type == 2) |
| { |
| if (gr_info->mixed_block_flag) |
| { |
| blocktypenumber = 2; |
| } |
| else |
| { |
| blocktypenumber = 1; |
| } |
| } |
| |
| k = 0; |
| for (i = 0; i < 4; i++) |
| { |
| if (new_slen[i]) |
| { |
| for (j = 0; j < (int16)nr_of_sfb_block[blocknumber][blocktypenumber][i]; j++) |
| { |
| scalefac_buffer[k] = getNbits(pMainData, new_slen[i]); |
| scalefac_IIP_buffer[k] = (1L << new_slen[i]) - 1; |
| k++; |
| } |
| } |
| else |
| { |
| for (j = 0; j < (int16)nr_of_sfb_block[blocknumber][blocktypenumber][i]; j++) |
| { |
| scalefac_buffer[k] = 0; |
| scalefac_IIP_buffer[k] = 0; |
| k++; |
| } |
| } |
| } |
| } |
