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Diffstat (limited to 'media/libstagefright/codecs/aacdec/hufffac.cpp')
| -rw-r--r-- | media/libstagefright/codecs/aacdec/hufffac.cpp | 550 |
1 files changed, 550 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/aacdec/hufffac.cpp b/media/libstagefright/codecs/aacdec/hufffac.cpp new file mode 100644 index 0000000..e5a9c59 --- /dev/null +++ b/media/libstagefright/codecs/aacdec/hufffac.cpp @@ -0,0 +1,550 @@ +/* ------------------------------------------------------------------ + * 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. + * ------------------------------------------------------------------- + */ +/* + + Pathname: ./src/hufffac.c + Funtions: + hufffac + +------------------------------------------------------------------------------ + REVISION HISTORY + + Description: Modified from original shareware code + + Description: Modified to pass variables by reference to eliminate use + of global variables. + + Description: (1) Modified with new templates, + (2) Modified variable names for clarity + (3) adjusted variables of "for loop" + (4) eliminated multiple returns, use return valid + + Description: (1) Change return logic: 0 if success, 1 if error + (2) Define SectInfo structure to store section codebook index + and section boundary + (3) Substitute "switch" with "if- else if" + (4) move BITS *pInputStream to second pass-in parameter + (5) pass in huffBookUsed[] to save stack size + + Description: (1) Remove pass in parameter Hcb pBook + + Description: Use binary tree search in decode_huff_cw_binary + + Description: Use decode_huff_scl function. + + Who: Date: MM/DD/YYYY + Description: + +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + Inputs: + + *pFrameInfo = pointer to structure that holds information + of each Frame. type FrameInfo + + *pInputStream = pointer to input bitstream. type BITS + + *pGroup = pointer to array that contains the index of the first + window in each group, type UChar + + nsect = number of sections to be decoded. type Int + + *pSect = pointer to structure array that contains the huffman + codebook index and section boundary for each section, + type SectInfo + + global_gain = initial value for "DPCM encoded" scalefactors and noise + energy, type Int + + *pFactors = pointer to array that stores the decoded scalefactors, + intensity position or noise energy, type Int + + huffBookUsed = array that will hold the huffman codebook index for + each sfb, type Int + + *pBook = pointer to structure that contains the huffman codebook + information, such as dimension, Largest Absolute Value + (LAV) of each huffman codebook, etc. type Hcb + + + Local Stores/Buffers/Pointers Needed: None + + Global Stores/Buffers/Pointers Needed: None + + Outputs: + 0 if success + 1 if error + + Pointers and Buffers Modified: + + Int *pFactors contains the newly decoded scalefactors and/or + intensity position and/or noise energy level + + Local Stores Modified: + + Global Stores Modified: + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + This function first reads the Huffman codebook index of all sections within + one Frame. Then, depending on the huffman codebook index of each section, + the function decodes the scalefactors, and/or intensity positions + (INTENSITY_HCB, INTENSITY_HCB2), and/or noise energy (NOISE_HCB) + for every scalefactor band in each section. + The function returns 0 upon successful decoding, returns 1 if error. + +------------------------------------------------------------------------------ + REQUIREMENTS + + This function should replace the content of the array pFactors with the + decoded scalefactors and/or intensity positions and/or noise energy + +------------------------------------------------------------------------------ + REFERENCES + + (1) MPEG-2 NBC Audio Decoder + "This software module was originally developed by AT&T, Dolby + Laboratories, Fraunhofer Gesellschaft IIS in the course of development + of the MPEG-2 NBC/MPEG-4 Audio standard ISO/IEC 13818-7, 14496-1,2 and + 3. This software module is an implementation of a part of one or more + MPEG-2 NBC/MPEG-4 Audio tools as specified by the MPEG-2 NBC/MPEG-4 + Audio standard. ISO/IEC gives users of the MPEG-2 NBC/MPEG-4 Audio + standards free license to this software module or modifications thereof + for use in hardware or software products claiming conformance to the + MPEG-2 NBC/MPEG-4 Audio standards. Those intending to use this software + module in hardware or software products are advised that this use may + infringe existing patents. The original developer of this software + module and his/her company, the subsequent editors and their companies, + and ISO/IEC have no liability for use of this software module or + modifications thereof in an implementation. Copyright is not released + for non MPEG-2 NBC/MPEG-4 Audio conforming products.The original + developer retains full right to use the code for his/her own purpose, + assign or donate the code to a third party and to inhibit third party + from using the code for non MPEG-2 NBC/MPEG-4 Audio conforming products. + This copyright notice must be included in all copies or derivative + works." + Copyright(c)1996. + + (2) ISO/IEC 14496-3: 1999(E) + Subpart 4 p72-73 (scalefactors) + p76 (decoding) + p78 (Table 4.6.1, Table 4.6.2) + p93-94 (INTENSITY_HCB) + p123 (NOISE_HCB) + +------------------------------------------------------------------------------ + PSEUDO-CODE + + status = SUCCESS; + + CALL pv_memset(pHuffBookUsed, ZERO_HCB, MAXBANDS*sizeof(*pHuffBookUsed)); + + CALL pv_memset(pFactors, ZERO_HCB, MAXBANDS*sizeof(*pFactors)); + + sect_start = 0; + + FOR(sect_idx = nsect; sect_idx > 0; sect_idx--) + { + sect_cb = pSect->sect_cb; + sect_end = pSect->sect_end; + pSect++; + + CALL pv_memset( + &pHuffBookUsed[sect_start], + sect_cb, + (sect_end - sect_start)); + + } + ENDFOR + + fac = global_gain; + is_pos = 0; + noise_nrg = global_gain - NOISE_OFFSET; + + pTable = pBook[BOOKSCL].pTable; + group_win = 0; + group_end = 0; + + WHILE((group_end < pFrameInfo->num_win)&&(status == SUCCESS)) + { + nsfb_win = pFrameInfo->sfb_per_win[group_end]; + group_end = *pGroup++; + + FOR(sfb = 0; sfb < nsfb_win; sfb++) + { + IF ((pHuffBookUsed[sfb] > 0)&&(pHuffBookUsed[sfb] < BOOKSCL)) + { + cw_index = CALL decode_huff_cw_binary(pTable, pInputStream); + + fac += cw_index - MIDFAC; + + IF((fac >= 2*TEXP) || (fac < 0)) + { + status = 1; + } + ELSE + { + pFactors[sfb] = fac; + } + ENDIF (fac) + + } + ELSE IF (pHuffBookUsed[sfb] == ZERO_HCB) + { + do nothing; + } + + ELSE IF ((pHuffBookUsed[sfb] == INTENSITY_HCB)|| + (pHuffBookUsed[sfb] == INTENSITY_HCB2)) + { + cw_index = CALL decode_huff_cw_binary(pTable, pInputStream); + + is_pos += cw_index - MIDFAC; + pFactors[sfb] = is_pos; + } + + ELSE IF (pHuffBookUsed[sfb] == NOISE_HCB) + { + IF (noise_pcm_flag == TRUE) + { + noise_pcm_flag = FALSE; + dpcm_noise_nrg = CALL getbits( + NOISE_PCM_BITS, + pInputStream); + + dpcm_noise_nrg -= NOISE_PCM_OFFSET; + } + ELSE + { + dpcm_noise_nrg = CALL decode_huff_cw_binary( + pTable, + pInputStream); + + dpcm_noise_nrg -= MIDFAC; + } + ENDIF (noise_pcm_flag) + + noise_nrg += dpcm_noise_nrg; + pFactors[sfb] = noise_nrg; + } + + ELSE IF (pHuffBookUsed[sfb] == BOOKSCL) + { + status = 1; + } + ENDIF (pHuffBookUsed[sfb]) + + } + ENDFOR (sfb) + + IF (pFrameInfo->islong == FALSE) + { + + FOR(group_win++; group_win < group_end; group_win++) + { + FOR (sfb=0; sfb < nsfb_win; sfb++) + { + pFactors[sfb + nsfb_win] = pFactors[sfb]; + } + ENDFOR + + pFactors += nsfb_win; + } + ENDFOR + + } + ENDIF (pFrameInfo) + + pHuffBookUsed += nsfb_win; + pFactors += nsfb_win; + + } + ENDWHILE (group_end) + + return status; + +------------------------------------------------------------------------------ + RESOURCES USED + When the code is written for a specific target processor the + the resources used should be documented below. + + STACK USAGE: [stack count for this module] + [variable to represent + stack usage for each subroutine called] + + where: [stack usage variable] = stack usage for [subroutine + name] (see [filename].ext) + + DATA MEMORY USED: x words + + PROGRAM MEMORY USED: x words + + CLOCK CYCLES: [cycle count equation for this module] + [variable + used to represent cycle count for each subroutine + called] + + where: [cycle count variable] = cycle count for [subroutine + name] (see [filename].ext) + +------------------------------------------------------------------------------ +*/ + + +/*---------------------------------------------------------------------------- +; INCLUDES +----------------------------------------------------------------------------*/ +#include "pv_audio_type_defs.h" +#include "aac_mem_funcs.h" /* pv_memset */ +#include "s_frameinfo.h" +#include "s_bits.h" +#include "s_sectinfo.h" +#include "s_huffman.h" +#include "ibstream.h" + +#include "hcbtables.h" +#include "e_huffmanconst.h" +#include "e_infoinitconst.h" +#include "huffman.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 +----------------------------------------------------------------------------*/ +Int hufffac( + FrameInfo *pFrameInfo, + BITS *pInputStream, + Int *pGroup, /* may be changed to Int */ + Int nsect, + SectInfo *pSect, /* may be changed to Int */ + Int global_gain, + Int *pFactors, + Int huffBookUsed[]) +{ + Int sect_idx; + Int group_end; /* index of 1st window in next group */ + Int group_win; /* window index within group */ + Int cw_index; /* huff codeword index */ + Int nsfb_win; /* # of scfbands per window */ + Int sfb; /* scalefactor band index */ + Int sect_cb; /* huff codebook # for each section */ + Int fac; /* decoded scf */ + Int is_pos; /* intensity stereo position */ + Int noise_pcm_flag = TRUE; /* first PNS sfb */ + Int dpcm_noise_nrg; /* dpcm noise energy */ + Int noise_nrg; /* noise energy */ + Int status = SUCCESS; /* status of decoding */ + Int *pHuffBookUsed = &huffBookUsed[0]; + + + pv_memset(pFactors, + ZERO_HCB, + MAXBANDS*sizeof(*pFactors)); + + + if (nsect) + { + /* read section length and codebook */ + + if (nsect == 1) /* long window */ + { + sect_cb = pSect->sect_cb; /* codebook for this section */ + + /* all sfbs in one section share the same codebook */ + + for (sfb = pSect->sect_end >> 2; sfb != 0; sfb--) + { + *(pHuffBookUsed++) = sect_cb; + *(pHuffBookUsed++) = sect_cb; + *(pHuffBookUsed++) = sect_cb; + *(pHuffBookUsed++) = sect_cb; + } + for (sfb = pSect->sect_end & 3; sfb != 0; sfb--) + { + *(pHuffBookUsed++) = sect_cb; + } + + } + else /* short */ + { + Int sect_start = 0; /* start index of sfb for each section */ + for (sect_idx = nsect; sect_idx > 0; sect_idx--) + { + sect_cb = pSect->sect_cb; /* codebook for this section */ + + /* all sfbs in one section share the same codebook */ + for (sfb = sect_start; sfb < pSect->sect_end; sfb++) + { + pHuffBookUsed[sfb] = sect_cb; + } + + pSect++; + sect_start = sfb; + + } /* for (sect_idx) */ + } + } + else + { + /* clear array for the case of max_sfb == 0 */ + pv_memset(pHuffBookUsed, + ZERO_HCB, + MAXBANDS*sizeof(*pHuffBookUsed)); + } + + pHuffBookUsed = &huffBookUsed[0]; + + /* scale factors and noise energy are dpcm relative to global gain + * intensity positions are dpcm relative to zero + */ + fac = global_gain; + is_pos = 0; + noise_nrg = global_gain - NOISE_OFFSET; + + /* get scale factors, + * use reserved Table entry = 12, see reference (2) p78 Table 4.6.2 + */ + group_win = 0; + group_end = 0; + + + /* group by group decoding scalefactors and/or noise energy + * and/or intensity position + */ + while ((group_end < pFrameInfo->num_win) && (status == SUCCESS)) + { + nsfb_win = pFrameInfo->sfb_per_win[group_end]; + group_end = *pGroup++; /* index of 1st window in next group */ + + /* decode scf in first window of each group */ + + for (sfb = 0; sfb < nsfb_win; sfb++) + { + + switch (pHuffBookUsed[sfb]) + { + case ZERO_HCB: + break; + case INTENSITY_HCB: + case INTENSITY_HCB2: + /* intensity books */ + /* decode intensity position */ + cw_index = decode_huff_scl(pInputStream); + + is_pos += cw_index - MIDFAC; + pFactors[sfb] = is_pos; + break; + case NOISE_HCB: + /* noise books */ + /* decode noise energy */ + if (noise_pcm_flag == TRUE) + { + noise_pcm_flag = FALSE; + dpcm_noise_nrg = get9_n_lessbits(NOISE_PCM_BITS, + pInputStream); + + dpcm_noise_nrg -= NOISE_PCM_OFFSET; + } + else + { + dpcm_noise_nrg = decode_huff_scl(pInputStream); + + dpcm_noise_nrg -= MIDFAC; + } /* if (noise_pcm_flag) */ + + noise_nrg += dpcm_noise_nrg; + pFactors[sfb] = noise_nrg; + break; + case BOOKSCL: + status = 1; /* invalid books */ + sfb = nsfb_win; /* force out */ + break; + default: + /* spectral books */ + /* decode scale factors */ + cw_index = decode_huff_scl(pInputStream); + + fac += cw_index - MIDFAC; /* 1.5 dB */ + if ((fac >= 2*TEXP) || (fac < 0)) + { + status = 1; /* error, MUST 0<=scf<256, Ref. p73 */ + } + else + { + pFactors[sfb] = fac; /* store scf */ + } /* if (fac) */ + } + + } /* for (sfb=0), first window decode ends */ + + /* expand scf to other windows in the same group */ + if (pFrameInfo->islong == FALSE) + { + + for (group_win++; group_win < group_end; group_win++) + { + for (sfb = 0; sfb < nsfb_win; sfb++) + { + pFactors[sfb + nsfb_win] = pFactors[sfb]; + } + pFactors += nsfb_win; + } + + } /* if (pFrameInfo->islong), one group decode ends */ + + + /* points to next group */ + pHuffBookUsed += nsfb_win; + pFactors += nsfb_win; + + } /* while (group_end), all groups decode end */ + + return status; + +} /* hufffac */ + |