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Diffstat (limited to 'libMpegTPDec/src/tpdec_adts.h')
| -rw-r--r-- | libMpegTPDec/src/tpdec_adts.h | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/libMpegTPDec/src/tpdec_adts.h b/libMpegTPDec/src/tpdec_adts.h new file mode 100644 index 0000000..13c66a4 --- /dev/null +++ b/libMpegTPDec/src/tpdec_adts.h @@ -0,0 +1,174 @@ +/***************************** MPEG-4 AAC Decoder ************************** + + (C) Copyright Fraunhofer IIS (2004) + All Rights Reserved + + Please be advised that this software and/or program delivery is + Confidential Information of Fraunhofer and subject to and covered by the + + Fraunhofer IIS Software Evaluation Agreement + between Google Inc. and Fraunhofer + effective and in full force since March 1, 2012. + + You may use this software and/or program only under the terms and + conditions described in the above mentioned Fraunhofer IIS Software + Evaluation Agreement. Any other and/or further use requires a separate agreement. + + + $Id$ + Author(s): Josef Hoepfl + Description: ADTS interface + + This software and/or program is protected by copyright law and international + treaties. Any reproduction or distribution of this software and/or program, + or any portion of it, may result in severe civil and criminal penalties, and + will be prosecuted to the maximum extent possible under law. + +******************************************************************************/ + +#ifndef TPDEC_ADTS_H +#define TPDEC_ADTS_H + +#include "tpdec_lib.h" + + +#define ADTS_SYNCWORD ( 0xfff ) +#define ADTS_SYNCLENGTH ( 12 ) /* in bits */ +#define ADTS_HEADERLENGTH ( 56 ) /* minimum header size in bits */ +#define ADTS_FIXED_HEADERLENGTH ( 28 ) /* in bits */ +#define ADTS_VARIABLE_HEADERLENGTH ( ADTS_HEADERLENGTH - ADTS_FIXED_HEADERLENGTH ) + +#ifdef CHECK_TWO_SYNCS + #define ADTS_MIN_TP_BUF_SIZE ( 8191 + 2 ) +#else + #define ADTS_MIN_TP_BUF_SIZE ( 8191 ) +#endif + +#include "FDK_crc.h" + +typedef struct { + /* ADTS header fields */ + UCHAR mpeg_id; + UCHAR layer; + UCHAR protection_absent; + UCHAR profile; + UCHAR sample_freq_index; + UCHAR private_bit; + UCHAR channel_config; + UCHAR original; + UCHAR home; + UCHAR copyright_id; + UCHAR copyright_start; + USHORT frame_length; + USHORT adts_fullness; + UCHAR num_raw_blocks; + UCHAR num_pce_bits; +} STRUCT_ADTS_BS; + +struct STRUCT_ADTS { + + STRUCT_ADTS_BS bs; + + UCHAR decoderCanDoMpeg4; + UCHAR BufferFullnesStartFlag; + + FDK_CRCINFO crcInfo; /* CRC state info */ + USHORT crcReadValue; /* CRC value read from bitstream data */ + USHORT rawDataBlockDist[4]; /* distance between each raw data block. Not the same as found in the bitstream */ +} ; + +typedef struct STRUCT_ADTS *HANDLE_ADTS; + +/*! + \brief Initialize ADTS CRC + + The function initialzes the crc buffer and the crc lookup table. + + \return none +*/ +void adtsRead_CrcInit( HANDLE_ADTS pAdts ); + +/** + * \brief Starts CRC region with a maximum number of bits + * If mBits is positive zero padding will be used for CRC calculation, if there + * are less than mBits bits available. + * If mBits is negative no zero padding is done. + * If mBits is zero the memory for the buffer is allocated dynamically, the + * number of bits is not limited. + * + * \param pAdts ADTS data handle + * \param hBs bitstream handle, on which the CRC region referes to + * \param mBits max number of bits in crc region to be considered + * + * \return ID for the created region, -1 in case of an error + */ +int adtsRead_CrcStartReg( + HANDLE_ADTS pAdts, + HANDLE_FDK_BITSTREAM hBs, + int mBits + ); + +/** + * \brief Ends CRC region identified by reg + * + * \param pAdts ADTS data handle + * \param hBs bitstream handle, on which the CRC region referes to + * \param reg CRC regions ID returned by adtsRead_CrcStartReg() + * + * \return none + */ +void adtsRead_CrcEndReg( + HANDLE_ADTS pAdts, + HANDLE_FDK_BITSTREAM hBs, + int reg + ); + +/** + * \brief Check CRC + * + * Checks if the currently calculated CRC matches the CRC field read from the bitstream + * Deletes all CRC regions. + * + * \param pAdts ADTS data handle + * + * \return Returns 0 if they are identical otherwise 1 + */ +TRANSPORTDEC_ERROR adtsRead_CrcCheck( HANDLE_ADTS pAdts ); + + +/** + * \brief Check if we have a valid ADTS frame at the current bitbuffer position + * + * This function assumes enough bits in buffer for the current frame. + * It reads out the header bits to prepare the bitbuffer for the decode loop. + * In case the header bits show an invalid bitstream/frame, the whole frame is skipped. + * + * \param pAdts ADTS data handle which is filled with parsed ADTS header data + * \param bs handle of bitstream from whom the ADTS header is read + * + * \return error status + */ +TRANSPORTDEC_ERROR adtsRead_DecodeHeader( + HANDLE_ADTS pAdts, + CSAudioSpecificConfig *pAsc, + HANDLE_FDK_BITSTREAM bs, + const INT ignoreBufferFullness + ); + +/** + * \brief Get the raw data block length of the given block number. + * + * \param pAdts ADTS data handle + * \param blockNum current raw data block index + * \param pLength pointer to an INT where the length of the given raw data block is stored into + * the returned value might be -1, in which case the raw data block length is unknown. + * + * \return error status + */ +int adtsRead_GetRawDataBlockLength( + HANDLE_ADTS pAdts, + INT blockNum + ); + + +#endif /* TPDEC_ADTS_H */ |