/* ------------------------------------------------------------------ * 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/set_mc_info.c ------------------------------------------------------------------------------ REVISION HISTORY Description: Modified per review comments Description: Change audioObjectType from Int to enum types Who: Date: Description: ------------------------------------------------------------------------------ INPUT AND OUTPUT DEFINITIONS Inputs: pMC_Info = pointer to structure MC_Info that holds information of multiple channels' configurations Data type pointer to MC_Info objectType = variable that holds the Audio Object Type of current file/bitstream. Data type Int sampling_rate_idx = variable that indicates the sampling rate of the source file being encoded Data Type Int tag = variable that stores the element instance tag of the first (front) channel element. Data type Int is_cpe = variable that indicates if a Channel Pair Element (CPE) or a Single Channel Element (SCE) is used. Data type Int (maybe Boolean) pWinSeqInfo = array of pointers that points to structures holding frame information of long and short window sequences. Data type FrameInfo pSfbwidth128 = array that will store the scalefactor bandwidth of short window sequence frame. Data type Int array Local Stores/Buffers/Pointers Needed: None Global Stores/Buffers/Pointers Needed: None Outputs: return SUCCESS Pointers and Buffers Modified: pMC_Info->nch contains the number of channels depending upon if CPE or SCE is used pMC_Info->objectType contents updated with the decoded Audio Object Type pMC_Info->ch_info.tag contents updated with the value of decoded channel element tag PMC_Info->ch_info.cpe contents updated depending upon if CPE or SCE is used pWinSeqInfo contents updated by calling infoinit if sampling_rate_idx is different from previous value pSfbWidth128 contents updated by calling infoinit if sampling_rate_idx is different from previous value Local Stores Modified: None Global Stores Modified: None ------------------------------------------------------------------------------ FUNCTION DESCRIPTION This function initializes the channel configuration information. The structure MC_Info stores the number of channels, channel element tag. If sampling rate index is different from the previous value, The frame information will be updated by calling infoinit.c ------------------------------------------------------------------------------ REQUIREMENTS This function shall update the relevant information on channel configs ------------------------------------------------------------------------------ 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 1 p20 Table 1.6.3 Subpart 4 p30 5.1.2.1 Subpart 4 p31 4.5.2.1.1 ------------------------------------------------------------------------------ PSEUDO-CODE pMC_Info->nch = 0; pMC_Info->profile = objectType; IF (pMC_Info->sampling_rate_idx != sampling_rate_idx) THEN pMC_Info->sampling_rate_idx = sampling_rate_idx; CALL infoinit( samp_rate_idx = sampling_rate_idx ppWin_seq_info= pWinSeqInfo pSfbwidth128 = pSfbwidth128) MODIFYING(pWinSeqInfo, pSfbwidth128) RETURNING(None) ENDIF pCh_Info = &pMC_Info->ch_info[0]; pCh_Info->tag = tag; IF (is_cpe == FALSE) THEN pCh_Info->cpe = FALSE; pMC_Info->nch = 1; ELSE pCh_Info->cpe = TRUE; pCh_Info = &pMC_Info->ch_info[1]; pCh_Info->tag = tag; pCh_Info->cpe = TRUE; pMC_Info->nch = 2; ENDIF RETURN(SUCCESS) ------------------------------------------------------------------------------ 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 "set_mc_info.h" #include "huffman.h" #include "s_ch_info.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 set_mc_info( MC_Info *pMC_Info, const tMP4AudioObjectType audioObjectType, /* used to be profile */ const Int sampling_rate_idx, const Int tag, /* always pass-in last element's value */ const Int is_cpe, FrameInfo *pWinSeqInfo[], Int sfbwidth128[] ) { Ch_Info *pCh_Info; /*optional task: eliminate this structure */ /* * audioObjectType and sampling rate * re-configure if new sampling rate * */ pMC_Info->audioObjectType = audioObjectType; if (pMC_Info->sampling_rate_idx != sampling_rate_idx) { pMC_Info->sampling_rate_idx = sampling_rate_idx; Int status; status = infoinit(sampling_rate_idx, pWinSeqInfo, sfbwidth128); if (SUCCESS != status) { return 1; } } /* * first setup values for mono config, Single Channel Element (SCE) * then if stereo, go inside if(is_cpe != FALSE) branch to setup * values for stereo. * set the channel counts * save tag for left channel */ pMC_Info->nch = 1 + is_cpe; pCh_Info = &pMC_Info->ch_info[0]; pCh_Info->tag = tag; pCh_Info->cpe = is_cpe; /* This if branch maybe deleted in the future */ if (is_cpe != FALSE) { /* Channel Pair Element (CPE) */ /* right channel*/ pCh_Info = &pMC_Info->ch_info[1]; pCh_Info->cpe = TRUE; } return(SUCCESS); /* possible future error checkings */ }