| /* ------------------------------------------------------------------ |
| * 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; |
| |
| } |
| } |
| |