/****************************************************************************** Copyright (c) 2006 Analog Devices, Inc. All Rights Reserved. This software is proprietary and confidential to Analog Devices, Inc. and its licensors. ******************************************************************************* $Revision: 1.1 $ $Date: 2008/03/17 14:50:34 $ $LastChangedBy: dpowell $ Project: HE-AAC Decoder Title: riff_header.c Author: DWP Description: This file is an aid to the riff_header.c functions to provide a common set of methods to access riff headers. References: riff_header.c Wave File Format [http://www.sonicspot.com/guide/wavefiles.html] ******************************************************************************/ #ifndef RIFF_HEADER_H #define RIFF_HEADER_H #include #include #include /****************************************************************************** ** #defines ******************************************************************************/ #define RIFF_ID_SZ (4) #define RIFF_TYPE_SZ (4) #define CHUNK_ID_SZ (4) #define MAX_CH 6 /****************************************************************************** ** Typedefs/Enumerations ******************************************************************************/ typedef struct { char riffid[RIFF_ID_SZ]; unsigned int riffsize; char rifftype[RIFF_TYPE_SZ]; } riffheader_t; // common to all chunks typedef struct { char chunkid[CHUNK_ID_SZ+1]; unsigned int chunksize; void *chunkdata; } chunkheader_t; typedef struct { unsigned short audioformat; unsigned short numchannels; unsigned int samplerate; unsigned int byterate; unsigned short blockalign; unsigned short bitspersample; unsigned short extraformatsize; char *extraformatdata; } chunkformat_t; typedef struct { FILE *fp; unsigned char *temporary_buffer; int buffer_len; chunkheader_t metadata; chunkformat_t wavedata; } wavefile_t; typedef struct { int buffer_count; void **buffer; int buffer_size; int element_step; } generic_buffers; /****************************************************************************** ** Structure Declarations ******************************************************************************/ /****************************************************************************** ** Function Declarations ******************************************************************************/ /* ** ** Function: parse_riff_header ** ** Description: Examines the given file to ensure that it contains the ** expected RIFF container header ** ** Arguments: ** fd file descriptor of the RIFF file ** rh Structure to hold parsed RIFF header data ** ** Outputs: ** rh parsed RIFF header data is stored in the rh Structure ** on success the file descriptor is advanced beyond the header ** DEBUG MODE ** prints descriptive text to stdout ** ** Return value: ** 0 Success ** -1 Indicates that the first four bytes did not contain the ** characters 'R','I','F','F' ** -2 Indicates that the file size did not agree with that ** stated in the container header ** -3 Indicates that the four bytes at offset 8 did not contain the ** characters 'W','A','V','E' ** ** Assumptions: ** sizeof(unsigned int) == 4 bytes ** fd can successfully perform fseek(fd,0,SEEK_END) call ** fd is currently pointing to RIFF header in file ** ** */ int parse_riff_header(FILE *fd, riffheader_t *rh); /* ** ** Function: parse_chunk_header ** ** Description: Examines the file and parses the next chunk header. If a chunk is ** recognized it is parsed by the helper function and and saved into ** memory from the heap and can be located via the chunkdata pointer ** in the chunkheader_t structure. ** Currently this function recognizes the following chunks and parses ** those with accompanying helper functions ** [data] ** [fmt ] parse_chunk_format() ** ** Arguments: ** fd file descriptor of the RIFF file ** ch Structure to hold parsed RIFF Chunk data ** ** Outputs: Fills the chunkheader_t structure and, if recognized, allocates further ** memory on the heap to hold the chunk specific header data. ** ** Return value: ** 0 Successful Parse ** return > 0 Return code of helper function ** -1 EOF, if unable to read first eight bytes of expected chunk header ** -2 Source Code modified incorrectly ** -255 Insufficient memory to allocate for chunk header data. ** ** Assumptions: ** sizeof(unsigned int) == 4 bytes ** fd can successfully perform fseek rewind call ** fd is currently pointing to Chunk header start in file ** */ int parse_chunk_header(FILE *fd, chunkheader_t *ch); /* ** ** Function: parse_chunk_format ** ** Description: Helper Function to parse and fill the Chunk Header Data for ** a "fmt " chunk. Also allocates any extra memory required for ** the optional ExtraFormatBytes at the end of the header. ** ** Arguments: ** fd file descriptor of the RIFF file ** cf Structure to hold parsed RIFF Chunk fmt ** ** Outputs: fills the chunkformat_t structure with the data from the file ** and advances the file descriptor beyond the header information. ** ** Return value: ** 0 Successful Parse ** -1 EOF, if unable to read full expected chunk header ** -255 Insufficient memory to allocate for chunk header data. ** ** Assumptions: ** Intel Big-Endian byte ordering ** fd is currently pointing to Chunk start + 8 bytes ** User will free heap memory allocated for ExtraFormatData if exists ** ** */ int parse_chunk_format(FILE *fd, chunkformat_t *cf); /* ** ** Function: SkipChunk ** ** Description: Advance the File Descriptor to the beginning of the next chunk, ** assuming that the current position is currently offset 8 bytes from ** the beginning of the current chunk. This is necessary as chunks ** must be aligned on word boundaries, and so '\0' bytes are inserted ** after chunks in bitstream to achieve this. ** Assumes word size of 4; ** ** Arguments: ** fd file descriptor of the RIFF file ** ch RIFF Chunk Header containing size of chunk to skip ** ** Outputs: Advanced file descriptor ** ** Assumptions: ** alignment of RIFF file at 4 bytes ** fd is currently pointing to Chunk start + 8 bytes ** */ void SkipChunk(FILE *fd, chunkheader_t *ch); // other functions that need documentation int write_generic_buffer16(wavefile_t *riff, generic_buffers *data, int num_elements); void write_riff_header(wavefile_t *riff); void init_riff_file(wavefile_t *riff, FILE *fp, unsigned char *buffer, int buffer_len); #endif /* RIFF_HEADER_H */ /* ** ** EOF: $HeadURL: svn://dingofiles.spd.analog.com/audio/trunk/common/components/riff/public/riff_header.h $ ** */