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Diffstat (limited to 'media/libstagefright/codecs/aacdec/intensity_right.cpp')
| -rw-r--r-- | media/libstagefright/codecs/aacdec/intensity_right.cpp | 457 |
1 files changed, 0 insertions, 457 deletions
diff --git a/media/libstagefright/codecs/aacdec/intensity_right.cpp b/media/libstagefright/codecs/aacdec/intensity_right.cpp deleted file mode 100644 index 106298a..0000000 --- a/media/libstagefright/codecs/aacdec/intensity_right.cpp +++ /dev/null @@ -1,457 +0,0 @@ -/* ------------------------------------------------------------------ - * 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: intensity_right.c - ------------------------------------------------------------------------------- - REVISION HISTORY - - Description: Modified per review comments. - - Description: Noticed that the code could be more efficient by - using some other method for storing the sign. The code was changed to - use a signed Int to store the table, and an adjustment of the q-format to - reflect the difference between the data being shifted by 16 and the table - being stored in q-15 format. - - Description: Updated pseudocode - - Description: When the multiplication of two 16-bits variables is stored in - an 32-bits variable, the result should be typecasted explicitly - to Int32 before it is stored. - *(pCoefRight++) = (Int32) tempInt2 * multiplier; - - Description: ------------------------------------------------------------------------------- - INPUT AND OUTPUT DEFINITIONS - - Inputs: - - scalefactor = Multiplier used to scale the data extracted from the left - channel for use on the right. - [const Int] - - coef_per_win = Number of coefficients per window. - (128 for short, 1024 for long) - [const Int] - - sfb_per_win = Number of scalefactor bands per window. This should be - a number divisible by four. - [const Int] - - wins_in_group = The number of windows in the group being decoded. - This number falls within the range 1-8. - [const Int] - - band_length = The length of the scalefactor band being decoded. - This value is divisible by 4. - [const Int] - - codebook = Value that denotes which Huffman codebook was used for - the encoding of this grouped scalefactor band. - [const Int] - - ms_used = Flag that denotes whether M/S is active for this band. - [const Bool] - - q_formatLeft = The Q-format for the left channel's fixed-point spectral - coefficients, on a per-scalefactor band, non-grouped basis. - [const Int *, length MAXBANDS] - - q_formatRight = The Q-format for the right channel's fixed-point spectral - coefficients, on a per-scalefactor band, non-grouped basis. - [Int *, length MAXBANDS] - - coefLeft = Array containing the fixed-point spectral coefficients - for the left channel. - [const Int32 *, length 1024] - - coefRight = Array containing the fixed-point spectral coefficients - for the right channel. - [Int32 *, length 1024] - - Local Stores/Buffers/Pointers Needed: - intensity_factor = Table which stores the values of - 0.5^(0), 0.5^(1/4), 0.5^(2/4) and 0.5^(3/4) - [UInt, length 4] - - Global Stores/Buffers/Pointers Needed: - None - - Outputs: - None - - Pointers and Buffers Modified: - coefRight[] Contains the new spectral information - - q_formatRight[] Q-format may be updated with changed fixed-point - data in coefRight. - - Local Stores Modified: - None - - Global Stores Modified: - None - ------------------------------------------------------------------------------- - FUNCTION DESCRIPTION - - This function applies Intensity Stereo, generating data on the right channel - that is derived from data on the Left. A scalefactor is applied using the - following formula... - - RightCh = LeftCh*0.5^(scalefactor/4) - - This function works for one scalefactor band, which may belong to a group. - (i.e. the same scalefactor band repeated across multiple windows belonging - to one group.) - ------------------------------------------------------------------------------- - REQUIREMENTS - - codebook must be either INTENSITY_HCB or INTENSITY_HCB2 when this function - is called. - - ms_used must be 1 when TRUE, 0 when FALSE. - - wins_in_group falls within the range [1-8] - ------------------------------------------------------------------------------- - REFERENCES - - (1) ISO/IEC 14496-3:1999(E) - Part 3 - Subpart 4.6.7.2.3 Decoding Process (Intensity Stereo) - - (2) 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. - ------------------------------------------------------------------------------- - PSEUDO-CODE - multiplier = codebook AND 0x1; - - multiplier = multiplier XOR ms_used; - - multiplier = multiplier << 1; - - multiplier = multiplier - 1; - - multiplier = multiplier * intensity_factor[scalefactor & 0x3]; - - scf_div_4 = (scalefactor >> 2); - - nextWinPtrUpdate = (coef_per_win - band_length); - - FOR (win_indx = wins_in_group; win_indx > 0; win_indx--) - - *(pQformatRight) = scf_div_4 + *(pQformatLeft) - 1; - - FOR (tempInt = band_length; tempInt > 0; tempInt--) - tempInt2 = (Int)(*(pCoefLeft) >> 16); - - *(pCoefRight) = tempInt2 * multiplier; - - pCoefRight = pCoefRight + 1; - pCoefLeft = pCoefLeft + 1; - - ENDFOR - - pCoefRight = pCoefRight + nextWinPtrUpdate; - pCoefLeft = pCoefLeft + nextWinPtrUpdate; - - pQformatRight = pQformatRight + sfb_per_win; - pQformatLeft = pQformatLeft + sfb_per_win; - ENDFOR - ------------------------------------------------------------------------------- - RESOURCES USED - When the code is written for a specific target processor 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 "intensity_right.h" -#include "e_huffmanconst.h" - -#include "fxp_mul32.h" -#include "aac_mem_funcs.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 Int16 intensity_factor[4] = -{ - 32767, /* (0.5^0.00)*2^15 - 1 (minus 1 for storage as type Int) */ - 27554, /* (0.5^0.25)*2^15 */ - 23170, /* (0.5^0.50)*2^15 */ - 19484 -}; /* (0.5^0.75)*2^15 */ - - -/*---------------------------------------------------------------------------- -; 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 intensity_right( - const Int scalefactor, - const Int coef_per_win, - const Int sfb_per_win, - const Int wins_in_group, - const Int band_length, - const Int codebook, - const Bool ms_used, - const Int q_formatLeft[], - Int q_formatRight[], - const Int32 coefLeft[], - Int32 coefRight[]) - -{ - const Int32 *pCoefLeft = coefLeft; - Int32 *pCoefRight = coefRight; - - const Int *pQformatLeft = q_formatLeft; - Int *pQformatRight = q_formatRight; - - Int multiplier; - Int scf_div_4; - Int nextWinPtrUpdate; - - /* - * The sign of the intensity multiplier obeys the following table... - * - * codebook | ms_used | multiplier - * -------------------------------------- - * INTENSITY_HCB | TRUE | -1 - * INTENSITY_HCB | FALSE | +1 - * INTENSITY_HCB2 | TRUE | +1 - * INTENSITY_HCB2 | FALSE | -1 - * - * In binary, the above table is represented as... - * - * codebook | ms_used | multiplier - * -------------------------------------- - * 1111b | 1 | -1 - * 1111b | 0 | +1 - * 1110b | 1 | +1 - * 1110b | 0 | -1 - * - */ - - /* - * Deriving the correct value for "multiplier" is illustrated - * below for all 4 possible combinations of codebook and ms_used - */ - - /* - * 1111b AND 0x1 = 1b - * 1111b AND 0x1 = 1b - * 1110b AND 0x1 = 0b - * 1110b AND 0x1 = 0b - */ - multiplier = (codebook & 0x1); - - /* - * 1b XOR 1 = 0b - * 1b XOR 0 = 1b - * 0b XOR 1 = 1b - * 0b XOR 0 = 0b - */ - multiplier ^= ms_used; - - /* - * 0b << 1 = 0 - * 1b << 1 = 2 - * 1b << 1 = 2 - * 0b << 1 = 0 - */ - multiplier <<= 1; - - /* - * 0 - 1 = -1 - * 2 - 1 = +1 - * 2 - 1 = +1 - * 0 - 1 = -1 - */ - multiplier--; - - multiplier *= intensity_factor[scalefactor & 0x3]; - - scf_div_4 = (scalefactor >> 2); - - /* - * Step through all the windows in this group, replacing this - * band in each window's spectrum with - * left-channel correlated data - */ - - nextWinPtrUpdate = (coef_per_win - band_length); - - for (Int win_indx = wins_in_group; win_indx > 0; win_indx--) - { - - /* - * Calculate q_formatRight - * - * q_formatLeft must be included, since the values - * on the right-channel are derived from the values - * on the left-channel. - * - * scalefactor/4 is included, since the intensity - * formula is RightCh = LeftCh*0.5^(scalefactor/4) - * - * powers of 0.5 increase the q_format by 1. - * (Another way to multiply something by 0.5^(x) - * is to increase its q-format by x.) - * - * Finally the q-format must be decreased by 1. - * The reason for this is because the table is stored - * in q-15 format, but we are shifting by 16 to do - * a 16 x 16 multiply. - */ - - *(pQformatRight) = scf_div_4 + *(pQformatLeft); - - /* - * reconstruct right intensity values - * - * to make things faster, this for loop - * can be partially unrolled, since band_length is a multiple - * of four. - */ - - - if (multiplier == 32767) - { - Int32 tempInt2 = *(pCoefLeft++); - Int32 tempInt22 = *(pCoefLeft++); - - for (Int tempInt = band_length >> 1; tempInt > 0; tempInt--) - { - *(pCoefRight++) = tempInt2; - *(pCoefRight++) = tempInt22; - tempInt2 = *(pCoefLeft++); - tempInt22 = *(pCoefLeft++); - } - - } - else - { - - Int32 tempInt2 = *(pCoefLeft++); - Int32 tempInt22 = *(pCoefLeft++); - for (Int tempInt = band_length >> 1; tempInt > 0; tempInt--) - { - *(pCoefRight++) = fxp_mul32_by_16(tempInt2, multiplier) << 1; - *(pCoefRight++) = fxp_mul32_by_16(tempInt22, multiplier) << 1; - tempInt2 = *(pCoefLeft++); - tempInt22 = *(pCoefLeft++); - } - } - - /* - * Set pCoefRight and pCoefLeft to the beginning of - * this sfb in the next window in the group. - */ - - pCoefRight += nextWinPtrUpdate; - pCoefLeft += (nextWinPtrUpdate - 2); - - /* - * Update pQformatRight and pQformatLeft to this sfb in - * in the next window in the group. - */ - - pQformatRight += sfb_per_win; - pQformatLeft += sfb_per_win; - - } /* for (win_indx) */ - - -} /* void intensity_right */ |