/* ------------------------------------------------------------------ * 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_factors.cpp Date: 09/21/2007 ------------------------------------------------------------------------------ REVISION HISTORY Description: ------------------------------------------------------------------------------ INPUT AND OUTPUT DEFINITIONS Input mp3ScaleFactors *scalefac, mp3SideInfo *si, side information int32 gr, granule int32 ch, channel mp3Header *info, mp3 header information uint32 *scalefac_IIP_buffer, auxiliary scale data tbits *pMainData bit stream Data Returns III_scalefac_t *scalefac, scale factor ------------------------------------------------------------------------------ FUNCTION DESCRIPTION get scale factor for mpe2 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_factors.h" #include "pvmp3_mpeg2_get_scale_data.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 ----------------------------------------------------------------------------*/ void pvmp3_mpeg2_get_scale_factors(mp3ScaleFactors *scalefac, mp3SideInfo *si, int32 gr, int32 ch, mp3Header *info, uint32 *scalefac_IIP_buffer, tmp3Bits *pMainData) { int32 sfb; int32 k = 0; int32 window; uint32 *scalefac_buffer = &scalefac_IIP_buffer[56]; granuleInfo *gr_info = &(si->ch[ch].gran[gr]); pvmp3_mpeg2_get_scale_data(si, gr, ch, info, (uint32 *)scalefac_buffer, (uint32 *)scalefac_IIP_buffer, pMainData); if (gr_info->window_switching_flag && (gr_info->block_type == 2)) { if (gr_info->mixed_block_flag) { for (sfb = 0; sfb < 6; sfb++) { scalefac->l[sfb] = scalefac_buffer[sfb]; } k = 6; for (sfb = 3; sfb < 12; sfb++) { for (window = 0; window < 3; window++) { scalefac->s[window][sfb] = scalefac_buffer[k]; k++; } } /* adjust position of "illegal position" information in scalefac_IIP_buffer[] */ /* in mixed blocks mode for short sfb, move them 3 places up. efs 3002-07-04 */ for (sfb = 11; sfb >= 3; sfb--) { scalefac_IIP_buffer[3*sfb + 2] = scalefac_IIP_buffer[3*sfb - 1]; scalefac_IIP_buffer[3*sfb + 1] = scalefac_IIP_buffer[3*sfb - 2]; scalefac_IIP_buffer[3*sfb ] = scalefac_IIP_buffer[3*sfb - 3]; } } else { /* SHORT*/ for (sfb = 0; sfb < 12; sfb++) { for (window = 0; window < 3; window++) { scalefac->s[window][sfb] = scalefac_buffer[k]; k++; } } } scalefac->s[0][12] = 0; scalefac->s[1][12] = 0; scalefac->s[2][12] = 0; } else { /* LONG types 0,1,3 */ for (sfb = 0; sfb < 21; sfb++) { scalefac->l[sfb] = scalefac_buffer[sfb]; } scalefac->l[21] = 0; scalefac->l[22] = 0; } }