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Diffstat (limited to 'media/libstagefright/codecs/mp3dec/src/pvmp3_get_scale_factors.cpp')
| -rw-r--r-- | media/libstagefright/codecs/mp3dec/src/pvmp3_get_scale_factors.cpp | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/mp3dec/src/pvmp3_get_scale_factors.cpp b/media/libstagefright/codecs/mp3dec/src/pvmp3_get_scale_factors.cpp new file mode 100644 index 0000000..f1a3ff8 --- /dev/null +++ b/media/libstagefright/codecs/mp3dec/src/pvmp3_get_scale_factors.cpp @@ -0,0 +1,226 @@ +/* ------------------------------------------------------------------ + * 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_get_scale_factors.cpp + + Date: 09/21/2007 + +------------------------------------------------------------------------------ + REVISION HISTORY + + + Description: + +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + Input + mp3ScaleFactors *scalefac, + mp3SideInfo *si, side info + int32 gr, granule + int32 ch, channel + tbits *pMainData bit stream + + Returns + + mp3ScaleFactors *scalefac, scale factors + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + get scale factors + +------------------------------------------------------------------------------ + 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_get_scale_factors.h" +#include "pvmp3_getbits.h" +#include "mp3_mem_funcs.h" + +/*---------------------------------------------------------------------------- +; MACROS +; Define module specific macros here +----------------------------------------------------------------------------*/ + + +/*---------------------------------------------------------------------------- +; DEFINES +; Include all pre-processor statements here. Include conditional +; compile variables also. +----------------------------------------------------------------------------*/ +#define Qfmt_28(a)(int32(double(0x10000000)*a)) + +/*---------------------------------------------------------------------------- +; LOCAL FUNCTION DEFINITIONS +; Function Prototype declaration +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; LOCAL STORE/BUFFER/POINTER DEFINITIONS +; Variable declaration - defined here and used outside this module +----------------------------------------------------------------------------*/ +const int32 slen[2][16] = +{ + {0, 0, 0, 0, 3, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4}, + {0, 1, 2, 3, 0, 1, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3} +}; + +const struct +{ + int32 l[5]; + int32 s[3]; +} sfbtable = +{ + {0, 6, 11, 16, 21}, + {0, 6, 12} +}; + +const int32 long_sfbtable[4] = { 6, 5, 5, 5}; + +/*---------------------------------------------------------------------------- +; 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_get_scale_factors(mp3ScaleFactors *scalefac, + mp3SideInfo *si, + int32 gr, + int32 ch, + tmp3Bits *pMainData) +{ + int32 sfb; + int32 i; + int32 window; + granuleInfo *gr_info = &(si->ch[ch].gran[gr]); + + if (gr_info->window_switching_flag && (gr_info->block_type == 2)) + { + if (gr_info->mixed_block_flag) + { /* MIXED */ + for (sfb = 0; sfb < 8; sfb++) + { + scalefac->l[sfb] = getNbits(pMainData, slen[0][gr_info->scalefac_compress]); + } + + for (sfb = 3; sfb < 6; sfb++) + { + for (window = 0; window < 3; window++) + { + scalefac->s[window][sfb] = getNbits(pMainData, slen[0][gr_info->scalefac_compress]); + } + } + for (sfb = 6; sfb < 12; sfb++) + { + for (window = 0; window < 3; window++) + { + scalefac->s[window][sfb] = getNbits(pMainData, slen[1][gr_info->scalefac_compress]); + } + } + } + else + { /* SHORT*/ + for (i = 0; i < 2; i++) + { + for (sfb = sfbtable.s[i]; sfb < sfbtable.s[i+1]; sfb++) + { + for (window = 0; window < 3; window++) + { + scalefac->s[window][sfb] = getNbits(pMainData, slen[i][gr_info->scalefac_compress]); + } + } + } + } + + scalefac->s[0][12] = 0; /* sfb = 12 win= 0 */ + scalefac->s[1][12] = 0; /* sfb = 12 win= 1 */ + scalefac->s[2][12] = 0; /* sfb = 12 win= 2 */ + } + else + { /* LONG types 0,1,3 */ + + int32 *ptr = &scalefac->l[0]; + + for (i = 0; i < 4; i++) + { + int32 tmp4 = long_sfbtable[i]; + + if ((si->ch[ch].scfsi[i] == 0) || (gr == 0)) + { + int32 tmp1 = slen[(i>>1)][gr_info->scalefac_compress]; + + if (tmp1) + { + int32 tmp2 = tmp1 * tmp4; + uint32 tmp3 = getNbits(pMainData, tmp2); + tmp4 = 32 - tmp1; + for (; tmp2 > 0; tmp2 -= tmp1) + { + *(ptr++) = (tmp3 << (32 - tmp2)) >> tmp4; + } + } + else + { + for (sfb = tmp4; sfb != 0; sfb--) + { + *(ptr++) = 0; + } + + } + } + else + { + ptr += tmp4; + } + } + scalefac->l[21] = 0; + scalefac->l[22] = 0; + } +} + |