gaConfig.cpp
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上传日期:2013-07-19
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- /* ***** BEGIN LICENSE BLOCK *****
- * Version: RCSL 1.0/RPSL 1.0
- *
- * Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved.
- *
- * The contents of this file, and the files included with this file, are
- * subject to the current version of the RealNetworks Public Source License
- * Version 1.0 (the "RPSL") available at
- * http://www.helixcommunity.org/content/rpsl unless you have licensed
- * the file under the RealNetworks Community Source License Version 1.0
- * (the "RCSL") available at http://www.helixcommunity.org/content/rcsl,
- * in which case the RCSL will apply. You may also obtain the license terms
- * directly from RealNetworks. You may not use this file except in
- * compliance with the RPSL or, if you have a valid RCSL with RealNetworks
- * applicable to this file, the RCSL. Please see the applicable RPSL or
- * RCSL for the rights, obligations and limitations governing use of the
- * contents of the file.
- *
- * This file is part of the Helix DNA Technology. RealNetworks is the
- * developer of the Original Code and owns the copyrights in the portions
- * it created.
- *
- * This file, and the files included with this file, is distributed and made
- * available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS
- * FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- *
- * Technology Compatibility Kit Test Suite(s) Location:
- * http://www.helixcommunity.org/content/tck
- *
- * Contributor(s):
- *
- * ***** END LICENSE BLOCK ***** */
- /* parse an MPEG-4 general audio specific config structure from a bitstream */
- #include "gaConfig.h"
- #include "bitstream.h"
- CGASpecificConfig::CGASpecificConfig()
- : mFrameLengthFlag (1)
- , mDependsOnCoreCoder(1)
- , mCoreCoderDelay (14,0)
- , mExtensionFlag (1)
- {
- }
- CGASpecificConfig::~CGASpecificConfig() {}
- HX_RESULT CGASpecificConfig::Read(struct BITSTREAM &bs,
- UINT32 samplingFrequency,
- UINT32 ChannelConfiguration,
- UINT32 AudioObjectType)
- {
- mFrameLengthFlag.Read(bs) ;
- mFrameLength = mFrameLengthFlag ? 960 : 1024 ;
- if (mDependsOnCoreCoder.Read(bs))
- mCoreCoderDelay.Read(bs) ;
- mExtensionFlag.Read(bs) ;
- if (ChannelConfiguration == 0)
- {
- mPCE.Read(bs) ;
- }
- else
- {
- HX_RESULT res = mPCE.SetChannelConfiguration(ChannelConfiguration) ;
- if (FAILED(res))
- return res ;
- }
- if (mExtensionFlag)
- {
- // to be defined in mpeg4 phase 2
- // should we return HXR_FAIL?
- }
- return HXR_OK ;
- }
- UINT32 CGASpecificConfig::GetFrameLength() const
- {
- return mFrameLength ;
- }
- CPCE::CPCE()
- : element_instance_tag (4)
- , object_type (2)
- , sampling_frequency_index (4)
- , num_front_channel_elements (4)
- , num_side_channel_elements (4)
- , num_back_channel_elements (4)
- , num_lfe_channel_elements (2)
- , num_assoc_data_elements (3)
- , num_valid_cc_elements (4)
- , mono_mixdown_present (1)
- , mono_mixdown_element_number (4,0)
- , stereo_mixdown_present (1)
- , stereo_mixdown_element_number(4,0)
- , matrix_mixdown_idx_present (1)
- , matrix_mixdown_idx (2)
- , pseudo_surround_enable (1)
- , comment_field_bytes (8)
- , comment_field_data (0)
- {
- }
- CPCE::~CPCE()
- {
- if (comment_field_data) delete[] comment_field_data ;
- }
- UINT32 CPCE::GetNChannels() const
- {
- return
- num_front_channels +
- num_side_channels +
- num_back_channels +
- num_lfe_channel_elements ;
- }
- const int CPCE::channelMapping[][4] =
- {
- {0,0,0,0},
- {1,0,0,0}, // center front speaker
- {2,0,0,0}, // left, right front speakers
- {3,0,0,0}, // center front speaker, left, right front speakers
- {3,0,1,0}, // center front speaker, left, right center front speakers, rear surround speakers
- {3,0,2,0}, // center front speaker, left, right front speakers, left surround, right surround rear speakers
- {3,0,2,1}, // center front speaker, left, right front speakers, left surround, right surround rear speakers, front low frequency effects speaker
- {5,0,2,1}, // center front speaker left, right center front speakers, left, right outside front speakers, left surround, right surround rear speakers, front low frequency effects speaker
- } ;
- /* Utility function for implizit channel config signalling.
- Initialize the channel pair information and return the number of channel elements. */
- static int initChannelPairs(int n, int isCpe[])
- {
- int nElem = (n+1)>>1 ;
- int i ;
- isCpe[0] = 0 ;
- for (i = (n & 1); i < nElem; i++)
- isCpe[i] = 1 ;
- return nElem ;
- }
- HX_RESULT CPCE::SetChannelConfiguration(UINT32 channelConfig)
- {
- if (channelConfig >= 8)
- return HXR_FAIL ;
- num_front_channels = channelMapping[channelConfig][0] ;
- num_side_channels = channelMapping[channelConfig][1] ;
- num_back_channels = channelMapping[channelConfig][2] ;
- num_lfe_channel_elements = channelMapping[channelConfig][3] ;
- num_front_channel_elements = initChannelPairs(num_front_channels, front_element_is_cpe) ;
- num_side_channel_elements = initChannelPairs(num_side_channels, side_element_is_cpe) ;
- num_back_channel_elements = initChannelPairs(num_back_channels, back_element_is_cpe) ;
- return HXR_OK ;
- }
- HX_RESULT CPCE::Read(struct BITSTREAM &bs)
- {
- UINT32 i ;
- num_front_channels = 0 ;
- num_side_channels = 0 ;
- num_back_channels = 0 ;
- /* should check here whether we have enough bits in the bitstream */
- element_instance_tag.Read(bs) ;
- object_type.Read(bs) ;
- sampling_frequency_index.Read(bs) ;
- num_front_channel_elements.Read(bs) ;
- num_side_channel_elements.Read(bs) ;
- num_back_channel_elements.Read(bs) ;
- num_lfe_channel_elements.Read(bs) ;
- num_assoc_data_elements.Read(bs) ;
- num_valid_cc_elements.Read(bs) ;
- if (mono_mixdown_present.Read(bs))
- mono_mixdown_element_number.Read(bs) ;
- if (stereo_mixdown_present.Read(bs))
- stereo_mixdown_element_number.Read(bs) ;
- if (matrix_mixdown_idx_present.Read(bs))
- {
- matrix_mixdown_idx.Read(bs) ;
- pseudo_surround_enable.Read(bs) ;
- }
- for ( i = 0; i < num_front_channel_elements; i++) {
- front_element_is_cpe[i] = readBits(&bs,1) ;
- num_front_channels += (1+front_element_is_cpe[i]) ;
- front_element_tag_select[i] = readBits(&bs,4) ;
- }
- for ( i = 0; i < num_side_channel_elements; i++) {
- side_element_is_cpe[i] = readBits(&bs,1) ;
- num_side_channels += (1+side_element_is_cpe[i]) ;
- side_element_tag_select[i] = readBits(&bs,4) ;
- }
- for ( i = 0; i < num_back_channel_elements; i++) {
- back_element_is_cpe[i] = readBits(&bs,1) ;
- num_back_channels += (1+back_element_is_cpe[i]) ;
- back_element_tag_select[i] = readBits(&bs,4) ;
- }
- for ( i = 0; i < num_lfe_channel_elements; i++)
- lfe_element_tag_select[i] = readBits(&bs,4) ;
- for ( i = 0; i < num_assoc_data_elements; i++)
- assoc_data_element_tag_select[i] = readBits(&bs,4) ;
- for ( i = 0; i < num_valid_cc_elements; i++) {
- cc_element_is_ind_sw[i] = readBits(&bs,1) ;
- valid_cc_element_tag_select[i] = readBits(&bs,4) ;
- }
- byteAlign(&bs) ;
- comment_field_bytes.Read(bs) ;
- if (comment_field_bytes)
- {
- // this is a slow way to read characters, but since we don't
- // parse many GAconfigs, I think that's OK
- CBitstreamInt t(8) ;
- comment_field_data = new char[(UINT32)comment_field_bytes] ;
- for (i = 0 ; i < comment_field_bytes ; i++)
- {
- comment_field_data[i] = (char)t.Read(bs) ;
- }
- }
- return HXR_OK ;
- }
- CAudioSpecificConfig::CAudioSpecificConfig()
- : AudioObjectType (5)
- , samplingFrequencyIndex (4)
- , samplingFrequency (24)
- , extensionSamplingFrequencyIndex (4)
- , extensionSamplingFrequency (24)
- , channelConfiguration (4)
- {
- }
- CAudioSpecificConfig::~CAudioSpecificConfig() {}
- const UINT32 CAudioSpecificConfig::aSampleRate[13] =
- {
- 96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000, 12000,
- 11025, 8000, 7350
- } ;
- HX_RESULT CAudioSpecificConfig::Read(struct BITSTREAM &bs)
- {
- HX_RESULT res = HXR_OK;
- AudioObjectType.Read(bs) ;
- samplingFrequencyIndex.Read(bs) ;
- extensionSamplingFrequencyIndex = samplingFrequencyIndex ;
- switch (samplingFrequencyIndex)
- {
- case 0xf: // ESC, read sr from bitstream
- samplingFrequency.Read(bs) ;
- break ;
- case 0xd: case 0xe: // these are reserved.
- return HXR_FAIL ;
- break ;
- default: // the normal case
- samplingFrequency = aSampleRate[samplingFrequencyIndex] ;
- }
- extensionSamplingFrequency = samplingFrequency ;
- channelConfiguration.Read(bs) ;
- m_bSBR = (AudioObjectType == AACSBR) ;
- if (m_bSBR)
- {
- extensionSamplingFrequencyIndex.Read(bs) ;
- switch (extensionSamplingFrequencyIndex)
- {
- case 0xf: // ESC, read sr from bitstream
- extensionSamplingFrequency.Read(bs) ;
- break ;
- case 0xd: case 0xe: // these are reserved.
- return HXR_FAIL ;
- break ;
- default: // the normal case
- extensionSamplingFrequency = aSampleRate[extensionSamplingFrequencyIndex] ;
- }
- AudioObjectType.Read(bs) ;
- }
- switch (AudioObjectType)
- {
- case AACMAIN: case AACLC: case AACLTP:
- res = GASpecificConfig.Read(bs,
- samplingFrequency,channelConfiguration,AudioObjectType) ;
- break ;
- default:
- // no other audio types supported
- return HXR_FAIL ;
- }
- if (!m_bSBR && bitsLeftInBitstream(&bs) >= 16)
- // if SBR info has not been read before, but there are more bytes to follow...
- {
- if (readBits(&bs,11) == 0x2b7)
- {
- if (readBits(&bs,5) == 5)
- {
- m_bSBR = readBits(&bs,1) ;
- if (m_bSBR)
- {
- extensionSamplingFrequencyIndex.Read(bs) ;
- switch (extensionSamplingFrequencyIndex)
- {
- case 0xf: // ESC, read sr from bitstream
- extensionSamplingFrequency.Read(bs) ;
- break ;
- case 0xd: case 0xe: // these are reserved.
- return HXR_FAIL ;
- break ;
- default: // the normal case
- extensionSamplingFrequency = aSampleRate[extensionSamplingFrequencyIndex] ;
- }
- }
- }
- }
- }
- return HXR_OK ;
- }
- UINT32 CAudioSpecificConfig::GetSampleRate() const
- {
- return extensionSamplingFrequency ;
- }
- UINT32 CAudioSpecificConfig::GetCoreSampleRate() const
- {
- return samplingFrequency ;
- }
- UINT32 CAudioSpecificConfig::GetCoreSamplingFrequencyIndex() const
- {
- return samplingFrequencyIndex;
- }
- UINT32 CAudioSpecificConfig::GetObjectType() const
- {
- return AudioObjectType ;
- }