diff options
Diffstat (limited to 'media/libstagefright/codecs/mp3dec/src/pvmp3_mpeg2_get_scale_data.cpp')
| -rw-r--r-- | media/libstagefright/codecs/mp3dec/src/pvmp3_mpeg2_get_scale_data.cpp | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/mp3dec/src/pvmp3_mpeg2_get_scale_data.cpp b/media/libstagefright/codecs/mp3dec/src/pvmp3_mpeg2_get_scale_data.cpp new file mode 100644 index 0000000..ee42dc5 --- /dev/null +++ b/media/libstagefright/codecs/mp3dec/src/pvmp3_mpeg2_get_scale_data.cpp @@ -0,0 +1,247 @@ +/* ------------------------------------------------------------------ + * 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]; + + 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++; + } + } + } +} |