/* ------------------------------------------------------------------ * 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++; } } } }