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Diffstat (limited to 'media/libstagefright/codecs/aacdec/pns_corr.cpp')
| -rw-r--r-- | media/libstagefright/codecs/aacdec/pns_corr.cpp | 342 |
1 files changed, 0 insertions, 342 deletions
diff --git a/media/libstagefright/codecs/aacdec/pns_corr.cpp b/media/libstagefright/codecs/aacdec/pns_corr.cpp deleted file mode 100644 index 4cfe720..0000000 --- a/media/libstagefright/codecs/aacdec/pns_corr.cpp +++ /dev/null @@ -1,342 +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: pns_corr.c - ------------------------------------------------------------------------------- - REVISION HISTORY - - Description: Made changes per review comments, the most major of which - being the change of the scaling into a 16 x 16 multiply. - - 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; - - Who: Date: - Description: ------------------------------------------------------------------------------- - INPUT AND OUTPUT DEFINITIONS - - Inputs: - - scale = Multiplier used to scale the noise 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 scalefactors per window. - [const Int] - - wins_in_group = The number of windows in the group being decoded. - [const Int] - - band_length = The length of the scalefactor band being decoded. - [const Int] - - sfb_prediction_used = Flag that denotes the activation of long term - prediction on a per-scalefactor band, - non-grouped basis. - [const Int *, length MAX_SFB] - - q_formatLeft = The Q-format for the left channel's fixed-point spectral - coefficients, on a per-scalefactor band, non-grouped basis. - [const Int] - - q_formatRight = The Q-format for the right channel's fixed-point spectral - coefficients, on a per-scalefactor band, non-grouped basis. - [Int *, length MAX_SFB] - - 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: - - Global Stores/Buffers/Pointers Needed: - - Outputs: - - Pointers and Buffers Modified: - pcoefRight Contains the new spectral information - - q_formatRight Q-format may be updated with changed to fixed-point - data in coefRight. - - sfb_prediction_used LTP may be disabled by presence of PNS tool on the - same scalefactor band. - - Local Stores Modified: - - Global Stores Modified: - ------------------------------------------------------------------------------- - FUNCTION DESCRIPTION - - This function derives noise from the left channel. The PNS tool is assumed - to have been used on the same scalefactor band on the left channel. The - noise on the left/right channels are not necessarily of the same amplitude, - and therefore have separate scalefactors. The noise is thus scaled by the - difference between the two transmitted scalefactors. This scaling is done - in fixed-point using a constant 4-element table. - ------------------------------------------------------------------------------- - REQUIREMENTS - - ------------------------------------------------------------------------------- - REFERENCES - - (1) ISO/IEC 14496-3:1999(E) - Part 3 - Subpart 4.6.7.1 M/S stereo - Subpart 4.6.12.3 Decoding Process (PNS) - Subpart 4.6.2 ScaleFactors - - (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 - - q_format = q_formatLeft - (scale >> 2); - q_format = q_format - 1; - q_formatRight = q_format; - - multiplier = hcb2_scale_mod_4[scale & 0x3]; - - pCoefLeft = coefLeft; - pCoefRight = coefRight; - - start_indx = 0; - - FOR (win_indx = wins_in_group; win_indx > 0; win_indx--) - - q_formatRight[start_indx] = q_format; - - sfb_prediction_used[start_indx] = FALSE; - - start_indx = start_indx + sfb_per_win; - - FOR (tempInt = band_length; tempInt > 0; tempInt--) - - *(pCoefRight) = (*(pCoefLeft) >> 9) * multiplier; - pCoefRight = pCoefRight + 1; - pCoefLeft = pCoefLeft + 1; - - ENDFOR - - tempInt = (coef_per_win - band_length); - pCoefRight = pCoefRight + tempInt; - pCoefLeft = pCoefLeft + tempInt; - - 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 "pns_corr.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 UInt hcb2_scale_mod_4[4] = -{ - 32768, /* (2.0^0.00)*2^15 */ - 38968, /* (2.0^0.25)*2^15 */ - 46341, /* (2.0^0.50)*2^15 */ - 55109 -}; /* (2.0^0.75)*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 pns_corr( - const Int scale, - const Int coef_per_win, - const Int sfb_per_win, - const Int wins_in_group, - const Int band_length, - const Int q_formatLeft, - Int q_formatRight[], - const Int32 coefLeft[], - Int32 coefRight[]) -{ - Int tempInt; - Int nextWinPtrUpdate; - - Int q_format; - - Int start_indx; - Int win_indx; - - const Int32 *pCoefLeft; - Int32 *pCoefRight; - - UInt multiplier; - - /* - * Generate noise correlated with the noise on the left channel - * - */ - - /* - * scale is interpreted as 2^(scale/4) - * Therefore, we can adjust the q-format by floor(scale/4) - * and save some complexity in the multiplier. - */ - q_format = q_formatLeft - (scale >> 2); - - /* - * Reduce the q-format by 1 to guard against overflow. - * This must be done because the hcb2_scale_mod_4 table - * must be stored in a common q-format, and we must shift - * by 16 to get *pCoefLeft into a 16-bit value, but we - * cannot store 2^0*2^16 and 2^0.75*2^16 in a table. - */ - q_format--; - - multiplier = hcb2_scale_mod_4[scale & 0x3]; - - pCoefLeft = coefLeft; - pCoefRight = coefRight; - - nextWinPtrUpdate = (coef_per_win - band_length); - - /* - * Step through all the windows in this group, replacing this - * band in each window's spectrum with correlated random noise - */ - - start_indx = 0; - - for (win_indx = wins_in_group; win_indx > 0; win_indx--) - { - /* - * Set the q-format for all scalefactor bands in the group. - * Normally, we could not assume that grouped scalefactors - * share the same q-format. - * However, here we can make this assumption. The reason - * being -- if this function is called, it is assumed - * PNS was used on the left channel. When PNS is used, - * all scalefactors in a group share the same q-format. - * - */ - q_formatRight[start_indx] = q_format; - - start_indx += sfb_per_win; - - /* reconstruct right noise values */ - for (tempInt = band_length; tempInt > 0; tempInt--) - { - *(pCoefRight++) = (Int32)(*(pCoefLeft++) >> 16) * multiplier; - } - - pCoefRight += nextWinPtrUpdate; - pCoefLeft += nextWinPtrUpdate; - - } /* for (win_indx) */ - - return; - -} /* void pns_corr */ |