Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: libsndfile : the sf_command function. Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:

sf_command

Chris@40:
Chris@40: 
Chris@40:         int    sf_command (SNDFILE *sndfile, int cmd, void *data, int datasize) ;
Chris@40: 
Chris@40:

Chris@40: This function allows the caller to retrieve information from or change aspects of the Chris@40: library behaviour. Chris@40: Examples include retrieving a string containing the library version or changing the Chris@40: scaling applied to floating point sample data during read and write. Chris@40: Most of these operations are performed on a per-file basis. Chris@40:

Chris@40:

Chris@40: The cmd parameter is an integer identifier which is defined in <sndfile.h>. Chris@40: All of the valid command identifiers have names beginning with "SFC_". Chris@40: Data is passed to and returned from the library by use of a void pointer. Chris@40: The library will not read or write more than datasize bytes from the void pointer. Chris@40: For some calls no data is required in which case data should be NULL and datasize Chris@40: may be used for some other purpose. Chris@40:

Chris@40:

Chris@40: The available commands are as follows: Chris@40:

Chris@40: Chris@40:
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SFC_GET_LIB_VERSIONRetrieve the version of the library.
SFC_GET_LOG_INFORetrieve the internal per-file operation log.
SFC_CALC_SIGNAL_MAXCalculate the measured maximum signal value.
SFC_CALC_NORM_SIGNAL_MAXCalculate the measured normalised maximum signal value.
SFC_CALC_MAX_ALL_CHANNELSCalculate the peak value for each channel.
SFC_CALC_NORM_MAX_ALL_CHANNELSCalculate the normalised peak for each channel.
SFC_GET_SIGNAL_MAXRetrieve the peak value for the file (as stored in the file header).
SFC_GET_MAX_ALL_CHANNELSRetrieve the peak value for each channel (as stored in the file header).
SFC_SET_NORM_FLOATModify the normalisation behaviour of the floating point reading and writing functions.
SFC_SET_NORM_DOUBLEModify the normalisation behaviour of the double precision floating point reading and writing functions.
SFC_GET_NORM_FLOATRetrieve the current normalisation behaviour of the floating point reading and writing functions.
SFC_GET_NORM_DOUBLERetrieve the current normalisation behaviour of the double precision floating point reading and writing functions.
SFC_SET_SCALE_FLOAT_INT_READSet/clear the scale factor when integer (short/int) data is read from a file Chris@40: containing floating point data.
SFC_SET_SCALE_INT_FLOAT_WRITESet/clear the scale factor when integer (short/int) data is written to a file Chris@40: as floating point data.
SFC_GET_SIMPLE_FORMAT_COUNTRetrieve the number of simple formats supported by libsndfile.
SFC_GET_SIMPLE_FORMATRetrieve information about a simple format.
SFC_GET_FORMAT_INFORetrieve information about a major or subtype format.
SFC_GET_FORMAT_MAJOR_COUNTRetrieve the number of major formats.
SFC_GET_FORMAT_MAJORRetrieve information about a major format type.
SFC_GET_FORMAT_SUBTYPE_COUNTRetrieve the number of subformats.
SFC_GET_FORMAT_SUBTYPERetrieve information about a subformat.
SFC_SET_ADD_PEAK_CHUNKSwitch the code for adding the PEAK chunk to WAV and AIFF files on or off.
SFC_UPDATE_HEADER_NOWUsed when a file is open for write, this command will update the file Chris@40: header to reflect the data written so far.
SFC_SET_UPDATE_HEADER_AUTOUsed when a file is open for write, this command will cause the file header Chris@40: to be updated after each write to the file.
SFC_FILE_TRUNCATETruncate a file open for write or for read/write.
SFC_SET_RAW_START_OFFSETChange the data start offset for files opened up as SF_FORMAT_RAW.
SFC_SET_CLIPPINGTurn on/off automatic clipping when doing floating point to integer Chris@40: conversion.
SFC_GET_CLIPPINGRetrieve current clipping setting.
SFC_GET_EMBED_FILE_INFORetrieve information about audio files embedded inside other files.
SFC_GET_AMBISONICTest a WAVEX file for Ambisonic format
SFC_SET_AMBISONICModify a WAVEX header for Ambisonic format
SFC_SET_VBR_ENCODING_QUALITYSet the Variable Bit Rate encoding quality
SFC_SET_COMPRESSION_LEVELSet the compression level.
SFC_RAW_NEEDS_ENDSWAPDetermine if raw data needs endswapping
SFC_GET_BROADCAST_INFORetrieve the Broadcast Chunk info
SFC_SET_BROADCAST_INFOSet the Broadcast Chunk info
SFC_SET_CART_INFOSet the Cart Chunk info
SFC_GET_CART_INFORetrieve the Cart Chunk info
SFC_GET_LOOP_INFOGet loop info
SFC_GET_INSTRUMENTGet instrument info
SFC_SET_INSTRUMENTSet instrument info
SFC_GET_CUE_COUNTGet the cue marker count
SFC_GET_CUEGet cue marker info
SFC_SET_CUESet cue marker info
SFC_RF64_AUTO_DOWNGRADEEnable auto downgrade from RF64 to WAV
Chris@40:
Chris@40: Chris@40:

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SFC_GET_LIB_VERSION

Chris@40:

Chris@40: Retrieve the version of the library as a string. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : Not used
Chris@40:         cmd      : SFC_GET_LIB_VERSION
Chris@40:         data     : A pointer to a char buffer
Chris@40:         datasize : The size of the buffer
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         char  buffer [128] ;
Chris@40:         sf_command (NULL, SFC_GET_LIB_VERSION, buffer, sizeof (buffer)) ;
Chris@40: 
Chris@40: Chris@40:
Chris@40:
Return value:
Chris@40:
This call will return the length of the retrieved version string. Chris@40:
Chris@40:
Chris@40:
Notes:
Chris@40:
Chris@40: The string returned in the buffer passed to this function will not overflow Chris@40: the buffer and will always be null terminated . Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_LOG_INFO

Chris@40:

Chris@40: Retrieve the log buffer generated when opening a file as a string. This log Chris@40: buffer can often contain a good reason for why libsndfile failed to open a Chris@40: particular file. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_GET_LOG_INFO
Chris@40:         data     : A pointer to a char buffer
Chris@40:         datasize : The size of the buffer
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         char  buffer [2048] ;
Chris@40:         sf_command (sndfile, SFC_GET_LOG_INFO, buffer, sizeof (buffer)) ;
Chris@40: 
Chris@40: Chris@40:
Chris@40:
Return value:
Chris@40:
This call will return the length of the retrieved version string. Chris@40:
Chris@40:
Chris@40:
Notes:
Chris@40:
Chris@40: The string returned in the buffer passed to this function will not overflow Chris@40: the buffer and will always be null terminated . Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_CALC_SIGNAL_MAX

Chris@40:

Chris@40: Retrieve the measured maximum signal value. This involves reading through Chris@40: the whole file which can be slow on large files. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_CALC_SIGNAL_MAX
Chris@40:         data     : A pointer to a double
Chris@40:         datasize : sizeof (double)
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         double   max_val ;
Chris@40:         sf_command (sndfile, SFC_CALC_SIGNAL_MAX, &max_val, sizeof (max_val)) ;
Chris@40: 
Chris@40: Chris@40:
Chris@40:
Return value:
Chris@40:
Zero on success, non-zero otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_CALC_NORM_SIGNAL_MAX

Chris@40:

Chris@40: Retrieve the measured normalised maximum signal value. This involves reading Chris@40: through the whole file which can be slow on large files. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_CALC_NORM_SIGNAL_MAX
Chris@40:         data     : A pointer to a double
Chris@40:         datasize : sizeof (double)
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         double   max_val ;
Chris@40:         sf_command (sndfile, SFC_CALC_NORM_SIGNAL_MAX, &max_val, sizeof (max_val)) ;
Chris@40: 
Chris@40: Chris@40:
Chris@40:
Return value:
Chris@40:
Zero on success, non-zero otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_CALC_MAX_ALL_CHANNELS

Chris@40:

Chris@40: Calculate the peak value (ie a single number) for each channel. Chris@40: This involves reading through the whole file which can be slow on large files. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_CALC_MAX_ALL_CHANNELS
Chris@40:         data     : A pointer to a double
Chris@40:         datasize : sizeof (double) * number_of_channels
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         double   peaks [number_of_channels] ;
Chris@40:         sf_command (sndfile, SFC_CALC_MAX_ALL_CHANNELS, peaks, sizeof (peaks)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
Zero if peaks have been calculated successfully and non-zero otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:


SFC_CALC_NORM_MAX_ALL_CHANNELS

Chris@40:

Chris@40: Calculate the normalised peak for each channel. Chris@40: This involves reading through the whole file which can be slow on large files. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_CALC_NORM_MAX_ALL_CHANNELS
Chris@40:         data     : A pointer to a double
Chris@40:         datasize : sizeof (double) * number_of_channels
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         double   peaks [number_of_channels] ;
Chris@40:         sf_command (sndfile, SFC_CALC_NORM_MAX_ALL_CHANNELS, peaks, sizeof (peaks)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
Zero if peaks have been calculated successfully and non-zero otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_SIGNAL_MAX

Chris@40:

Chris@40: Retrieve the peak value for the file as stored in the file header. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_GET_SIGNAL_MAX
Chris@40:         data     : A pointer to a double
Chris@40:         datasize : sizeof (double)
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         double   max_peak ;
Chris@40:         sf_command (sndfile, SFC_GET_SIGNAL_MAX, &max_peak, sizeof (max_peak)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE if the file header contained the peak value. SF_FALSE otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_MAX_ALL_CHANNELS

Chris@40:

Chris@40: Retrieve the peak value for the file as stored in the file header. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_GET_SIGNAL_MAX
Chris@40:         data     : A pointer to an array of doubles
Chris@40:         datasize : sizeof (double) * number_of_channels
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         double   peaks [number_of_channels] ;
Chris@40:         sf_command (sndfile, SFC_GET_MAX_ALL_CHANNELS, peaks, sizeof (peaks)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE if the file header contains per channel peak values for the file. Chris@40: SF_FALSE otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:


SFC_SET_NORM_FLOAT

Chris@40:

Chris@40: This command only affects data read from or written to using the floating point functions: Chris@40:

Chris@40:
Chris@40: 	size_t    sf_read_float    (SNDFILE *sndfile, float *ptr, size_t items) ;
Chris@40: 	size_t    sf_readf_float   (SNDFILE *sndfile, float *ptr, size_t frames) ;
Chris@40: 
Chris@40: 	size_t    sf_write_float   (SNDFILE *sndfile, float *ptr, size_t items) ;
Chris@40: 	size_t    sf_writef_float  (SNDFILE *sndfile, float *ptr, size_t frames) ;
Chris@40: 
Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_SET_NORM_FLOAT
Chris@40:         data     : NULL
Chris@40:         datasize : SF_TRUE or SF_FALSE
Chris@40: 
Chris@40:

Chris@40: For read operations setting normalisation to SF_TRUE means that the data from all Chris@40: subsequent reads will be be normalised to the range [-1.0, 1.0]. Chris@40:

Chris@40:

Chris@40: For write operations, setting normalisation to SF_TRUE means than all data supplied Chris@40: to the float write functions should be in the range [-1.0, 1.0] and will be scaled Chris@40: for the file format as necessary. Chris@40:

Chris@40:

Chris@40: For both cases, setting normalisation to SF_FALSE means that no scaling will take place. Chris@40:

Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         sf_command (sndfile, SFC_SET_NORM_FLOAT, NULL, SF_TRUE) ;
Chris@40: 
Chris@40:         sf_command (sndfile, SFC_SET_NORM_FLOAT, NULL, SF_FALSE) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
Returns the previous float normalisation mode. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_SET_NORM_DOUBLE

Chris@40:

Chris@40: This command only affects data read from or written to using the double precision Chris@40: floating point functions: Chris@40:

Chris@40:
Chris@40: 	size_t    sf_read_double    (SNDFILE *sndfile, double *ptr, size_t items) ;
Chris@40: 	size_t    sf_readf_double   (SNDFILE *sndfile, double *ptr, size_t frames) ;
Chris@40: 
Chris@40: 	size_t    sf_write_double   (SNDFILE *sndfile, double *ptr, size_t items) ;
Chris@40: 	size_t    sf_writef_double  (SNDFILE *sndfile, double *ptr, size_t frames) ;
Chris@40: 
Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_SET_NORM_DOUBLE
Chris@40:         data     : NULL
Chris@40:         datasize : SF_TRUE or SF_FALSE
Chris@40: 
Chris@40:

Chris@40: For read operations setting normalisation to SF_TRUE means that the data Chris@40: from all subsequent reads will be be normalised to the range [-1.0, 1.0]. Chris@40:

Chris@40:

Chris@40: For write operations, setting normalisation to SF_TRUE means than all data supplied Chris@40: to the double write functions should be in the range [-1.0, 1.0] and will be scaled Chris@40: for the file format as necessary. Chris@40:

Chris@40:

Chris@40: For both cases, setting normalisation to SF_FALSE means that no scaling will take place. Chris@40:

Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         sf_command (sndfile, SFC_SET_NORM_DOUBLE, NULL, SF_TRUE) ;
Chris@40: 
Chris@40:         sf_command (sndfile, SFC_SET_NORM_DOUBLE, NULL, SF_FALSE) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
Returns the previous double normalisation mode. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_NORM_FLOAT

Chris@40:

Chris@40: Retrieve the current float normalisation mode. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_GET_NORM_FLOAT
Chris@40:         data     : NULL
Chris@40:         datasize : anything
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         normalisation = sf_command (sndfile, SFC_GET_NORM_FLOAT, NULL, 0) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
Returns TRUE if normalisation is on and FALSE otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_NORM_DOUBLE

Chris@40:

Chris@40: Retrieve the current float normalisation mode. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_GET_NORM_DOUBLE
Chris@40:         data     : NULL
Chris@40:         datasize : anything
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         normalisation = sf_command (sndfile, SFC_GET_NORM_DOUBLE, NULL, 0) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
Returns TRUE if normalisation is on and FALSE otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:


SFC_SET_SCALE_FLOAT_INT_READ

Chris@40:

Chris@40: Set/clear the scale factor when integer (short/int) data is read from a file Chris@40: containing floating point data. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_SET_SCALE_FLOAT_INT_READ
Chris@40:         data     : NULL
Chris@40:         datasize : TRUE or FALSE
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         sf_command (sndfile, SFC_SET_SCALE_FLOAT_INT_READ, NULL, SF_TRUE) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
Returns the previous SFC_SET_SCALE_FLOAT_INT_READ setting for this file. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:


SFC_SET_SCALE_INT_FLOAT_WRITE

Chris@40:

Chris@40: Set/clear the scale factor when integer (short/int) data is written to a file Chris@40: as floating point data. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_SET_SCALE_FLOAT_INT_READ
Chris@40:         data     : NULL
Chris@40:         datasize : TRUE or FALSE
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         sf_command (sndfile, SFC_SET_SCALE_INT_FLOAT_WRITE, NULL, SF_TRUE) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
Returns the previous SFC_SET_SCALE_INT_FLOAT_WRITE setting for this file. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_SIMPLE_FORMAT_COUNT

Chris@40:

Chris@40: Retrieve the number of simple formats supported by libsndfile. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : Not used.
Chris@40:         cmd      : SFC_GET_SIMPLE_FORMAT_COUNT
Chris@40:         data     : a pointer to an int
Chris@40:         datasize : sizeof (int)
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         int  count ;
Chris@40:         sf_command (sndfile, SFC_GET_SIMPLE_FORMAT_COUNT, &count, sizeof (int)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
0 Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_SIMPLE_FORMAT

Chris@40:

Chris@40: Retrieve information about a simple format. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : Not used.
Chris@40:         cmd      : SFC_GET_SIMPLE_FORMAT
Chris@40:         data     : a pointer to an  SF_FORMAT_INFO struct
Chris@40:         datasize : sizeof (SF_FORMAT_INFO)
Chris@40: 
Chris@40:

Chris@40: The SF_FORMAT_INFO struct is defined in <sndfile.h> as: Chris@40:

Chris@40:
Chris@40:         typedef struct
Chris@40:         {   int         format ;
Chris@40:             const char  *name ;
Chris@40:             const char  *extension ;
Chris@40:         } SF_FORMAT_INFO ;
Chris@40: 
Chris@40:

Chris@40: When sf_command() is called with SF_GET_SIMPLE_FORMAT, the value of the format Chris@40: field should be the format number (ie 0 <= format <= count value obtained using Chris@40: SF_GET_SIMPLE_FORMAT_COUNT). Chris@40:

Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         SF_FORMAT_INFO	format_info ;
Chris@40:         int             k, count ;
Chris@40: 
Chris@40:         sf_command (sndfile, SFC_GET_SIMPLE_FORMAT_COUNT, &count, sizeof (int)) ;
Chris@40: 
Chris@40:         for (k = 0 ; k < count ; k++)
Chris@40:         {   format_info.format = k ;
Chris@40:             sf_command (sndfile, SFC_GET_SIMPLE_FORMAT, &format_info, sizeof (format_info)) ;
Chris@40:             printf ("%08x  %s %s\n", format_info.format, format_info.name, format_info.extension) ;
Chris@40:             } ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
0 on success and non-zero otherwise. Chris@40:
The value of the format field of the SF_FORMAT_INFO struct will be a value which Chris@40: can be placed in the format field of an SF_INFO struct when a file is to be opened Chris@40: for write. Chris@40:
The name field will contain a char* pointer to the name of the string, eg. "WAV (Microsoft 16 bit PCM)". Chris@40:
The extension field will contain the most commonly used file extension for that file type. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_FORMAT_INFO

Chris@40:

Chris@40: Retrieve information about a major or subtype format. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : Not used.
Chris@40:         cmd      : SFC_GET_FORMAT_INFO
Chris@40:         data     : a pointer to an SF_FORMAT_INFO struct
Chris@40:         datasize : sizeof (SF_FORMAT_INFO)
Chris@40: 
Chris@40:

Chris@40: The SF_FORMAT_INFO struct is defined in <sndfile.h> as: Chris@40:

Chris@40:
Chris@40:         typedef struct
Chris@40:         {   int         format ;
Chris@40:             const char  *name ;
Chris@40:             const char  *extension ;
Chris@40:         } SF_FORMAT_INFO ;
Chris@40: 
Chris@40:

Chris@40: When sf_command() is called with SF_GET_FORMAT_INFO, the format field is Chris@40: examined and if (format & SF_FORMAT_TYPEMASK) is a valid format then the struct Chris@40: is filled in with information about the given major type. Chris@40: If (format & SF_FORMAT_TYPEMASK) is FALSE and (format & SF_FORMAT_SUBMASK) is a Chris@40: valid subtype format then the struct is filled in with information about the given Chris@40: subtype. Chris@40:

Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         SF_FORMAT_INFO	format_info ;
Chris@40: 
Chris@40:         format_info.format = SF_FORMAT_WAV ;
Chris@40:         sf_command (sndfile, SFC_GET_FORMAT_INFO, &format_info, sizeof (format_info)) ;
Chris@40:         printf ("%08x  %s %s\n", format_info.format, format_info.name, format_info.extension) ;
Chris@40: 
Chris@40:         format_info.format = SF_FORMAT_ULAW ;
Chris@40:         sf_command (sndfile, SFC_GET_FORMAT_INFO, &format_info, sizeof (format_info)) ;
Chris@40:         printf ("%08x  %s\n", format_info.format, format_info.name) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
0 on success and non-zero otherwise. Chris@40:
Chris@40: Chris@40: Chris@40:


SFC_GET_FORMAT_MAJOR_COUNT

Chris@40:

Chris@40: Retrieve the number of major formats. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : Not used.
Chris@40:         cmd      : SFC_GET_FORMAT_MAJOR_COUNT
Chris@40:         data     : a pointer to an int
Chris@40:         datasize : sizeof (int)
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         int  count ;
Chris@40:         sf_command (sndfile, SFC_GET_FORMAT_MAJOR_COUNT, &count, sizeof (int)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
0 Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_FORMAT_MAJOR

Chris@40:

Chris@40: Retrieve information about a major format type. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : Not used.
Chris@40:         cmd      : SFC_GET_FORMAT_MAJOR
Chris@40:         data     : a pointer to an  SF_FORMAT_INFO struct
Chris@40:         datasize : sizeof (SF_FORMAT_INFO)
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         SF_FORMAT_INFO	format_info ;
Chris@40:         int             k, count ;
Chris@40: 
Chris@40:         sf_command (sndfile, SFC_GET_FORMAT_MAJOR_COUNT, &count, sizeof (int)) ;
Chris@40: 
Chris@40:         for (k = 0 ; k < count ; k++)
Chris@40:         {   format_info.format = k ;
Chris@40:             sf_command (sndfile, SFC_GET_FORMAT_MAJOR, &format_info, sizeof (format_info)) ;
Chris@40:             printf ("%08x  %s %s\n", format_info.format, format_info.name, format_info.extension) ;
Chris@40:             } ;
Chris@40: 
Chris@40:

Chris@40: For a more comprehensive example, see the program list_formats.c in the examples/ Chris@40: directory of the libsndfile source code distribution. Chris@40:

Chris@40:
Chris@40:
Return value:
Chris@40:
0 on success and non-zero otherwise. Chris@40:
The value of the format field will be one of the major format identifiers such as Chris@40: SF_FORMAT_WAV or SF_FORMAT_AIFF. Chris@40:
The name field will contain a char* pointer to the name of the string, eg. "WAV (Microsoft)". Chris@40:
The extension field will contain the most commonly used file extension for that file type. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_FORMAT_SUBTYPE_COUNT

Chris@40:

Chris@40: Retrieve the number of subformats. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : Not used.
Chris@40:         cmd      : SFC_GET_FORMAT_SUBTYPE_COUNT
Chris@40:         data     : a pointer to an int
Chris@40:         datasize : sizeof (int)
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         int   count ;
Chris@40:         sf_command (sndfile, SFC_GET_FORMAT_SUBTYPE_COUNT, &count, sizeof (int)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
0 Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_FORMAT_SUBTYPE

Chris@40:

Chris@40: Enumerate the subtypes (this function does not translate a subtype into Chris@40: a string describing that subtype). Chris@40: A typical use case might be retrieving a string description of all subtypes Chris@40: so that a dialog box can be filled in. Chris@40:

Chris@40:

Chris@40: Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : Not used.
Chris@40:         cmd      : SFC_GET_FORMAT_SUBTYPE
Chris@40:         data     : a pointer to an SF_FORMAT_INFO struct
Chris@40:         datasize : sizeof (SF_FORMAT_INFO)
Chris@40: 
Chris@40:

Chris@40: Example 1: Retrieve all sybtypes supported by the WAV format. Chris@40:

Chris@40:
Chris@40:         SF_FORMAT_INFO	format_info ;
Chris@40:         int             k, count ;
Chris@40: 
Chris@40:         sf_command (sndfile, SFC_GET_FORMAT_SUBTYPE_COUNT, &count, sizeof (int)) ;
Chris@40: 
Chris@40:         for (k = 0 ; k < count ; k++)
Chris@40:         {   format_info.format = k ;
Chris@40:             sf_command (sndfile, SFC_GET_FORMAT_SUBTYPE, &format_info, sizeof (format_info)) ;
Chris@40:             if (! sf_format_check (format_info.format | SF_FORMAT_WAV))
Chris@40:                continue ;
Chris@40:             printf ("%08x  %s\n", format_info.format, format_info.name) ;
Chris@40:             } ;
Chris@40: 
Chris@40:

Chris@40: Example 2: Print a string describing the SF_FORMAT_PCM_16 subtype. Chris@40:

Chris@40:
Chris@40:         SF_FORMAT_INFO	format_info ;
Chris@40:         int             k, count ;
Chris@40: 
Chris@40:         sf_command (sndfile, SFC_GET_FORMAT_SUBTYPE_COUNT, &count, sizeof (int)) ;
Chris@40: 
Chris@40:         for (k = 0 ; k < count ; k++)
Chris@40:         {   format_info.format = k ;
Chris@40:             sf_command (sndfile, SFC_GET_FORMAT_SUBTYPE, &format_info, sizeof (format_info)) ;
Chris@40:             if (format_info.format == SF_FORMAT_PCM_16)
Chris@40:             {   printf ("%08x  %s\n", format_info.format, format_info.name) ;
Chris@40:                 break ;
Chris@40:                 } ;
Chris@40:             } ;
Chris@40: 
Chris@40:

Chris@40: For a more comprehensive example, see the program list_formats.c in the examples/ Chris@40: directory of the libsndfile source code distribution. Chris@40:

Chris@40:
Chris@40:
Return value:
Chris@40:
0 on success and non-zero otherwise. Chris@40:
The value of the format field will be one of the major format identifiers such as Chris@40: SF_FORMAT_WAV or SF_FORMAT_AIFF. Chris@40:
The name field will contain a char* pointer to the name of the string; for instance Chris@40: "WAV (Microsoft)" or "AIFF (Apple/SGI)". Chris@40:
The extension field will be a NULL pointer. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_SET_ADD_PEAK_CHUNK

Chris@40:

Chris@40: By default, WAV and AIFF files which contain floating point data (subtype SF_FORMAT_FLOAT Chris@40: or SF_FORMAT_DOUBLE) have a PEAK chunk. Chris@40: By using this command, the addition of a PEAK chunk can be turned on or off. Chris@40:

Chris@40:

Chris@40: Note : This call must be made before any data is written to the file. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_SET_ADD_PEAK_CHUNK
Chris@40:         data     : Not used (should be NULL)
Chris@40:         datasize : TRUE or FALSE.
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         /* Turn on the PEAK chunk. */
Chris@40:         sf_command (sndfile, SFC_SET_ADD_PEAK_CHUNK, NULL, SF_TRUE) ;
Chris@40: 
Chris@40:         /* Turn off the PEAK chunk. */
Chris@40:         sf_command (sndfile, SFC_SET_ADD_PEAK_CHUNK, NULL, SF_FALSE) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
Returns SF_TRUE if the peak chunk will be written after this call. Chris@40:
Returns SF_FALSE if the peak chunk will not be written after this call. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_UPDATE_HEADER_NOW

Chris@40:

Chris@40: The header of an audio file is normally written by libsndfile when the file is Chris@40: closed using sf_close(). Chris@40:

Chris@40:

Chris@40: There are however situations where large files are being generated and it would Chris@40: be nice to have valid data in the header before the file is complete. Chris@40: Using this command will update the file header to reflect the amount of data written Chris@40: to the file so far. Chris@40: Other programs opening the file for read (before any more data is written) will Chris@40: then read a valid sound file header. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_UPDATE_HEADER_NOW
Chris@40:         data     : Not used (should be NULL)
Chris@40:         datasize : Not used.
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         /* Update the header now. */
Chris@40:         sf_command (sndfile, SFC_UPDATE_HEADER_NOW, NULL, 0) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
0 Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_SET_UPDATE_HEADER_AUTO

Chris@40:

Chris@40: Similar to SFC_UPDATE_HEADER_NOW but updates the header at the end of every call Chris@40: to the sf_write* functions. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_UPDATE_HEADER_NOW
Chris@40:         data     : Not used (should be NULL)
Chris@40:         datasize : SF_TRUE or SF_FALSE
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         /* Turn on auto header update. */
Chris@40:         sf_command (sndfile, SFC_SET_UPDATE_HEADER_AUTO, NULL, SF_TRUE) ;
Chris@40: 
Chris@40:         /* Turn off auto header update. */
Chris@40:         sf_command (sndfile, SFC_SET_UPDATE_HEADER_AUTO, NULL, SF_FALSE) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
TRUE if auto update header is now on; FALSE otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_FILE_TRUNCATE

Chris@40:

Chris@40: Truncate a file that was opened for write or read/write. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_FILE_TRUNCATE
Chris@40:         data     : A pointer to an sf_count_t.
Chris@40:         datasize : sizeof (sf_count_t)
Chris@40: 
Chris@40: Chris@40:

Chris@40: Truncate the file to the number of frames specified by the sf_count_t pointed Chris@40: to by data. Chris@40: After this command, both the read and the write pointer will be Chris@40: at the new end of the file. Chris@40: This command will fail (returning non-zero) if the requested truncate position Chris@40: is beyond the end of the file. Chris@40:

Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         /* Truncate the file to a length of 20 frames. */
Chris@40:         sf_count_t  frames = 20 ;
Chris@40:         sf_command (sndfile, SFC_FILE_TRUNCATE, &frames, sizeof (frames)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
Zero on sucess, non-zero otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_SET_RAW_START_OFFSET

Chris@40:

Chris@40: Change the data start offset for files opened up as SF_FORMAT_RAW. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_SET_RAW_START_OFFSET
Chris@40:         data     : A pointer to an sf_count_t.
Chris@40:         datasize : sizeof (sf_count_t)
Chris@40: 
Chris@40: Chris@40:

Chris@40: For a file opened as format SF_FORMAT_RAW, set the data offset to the value Chris@40: given by data. Chris@40:

Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         /* Reset the data offset to 5 bytes from the start of the file. */
Chris@40:         sf_count_t  offset = 5 ;
Chris@40:         sf_command (sndfile, SFC_SET_RAW_START_OFFSET, &offset, sizeof (offset)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
Zero on success, non-zero otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_SET_CLIPPING

Chris@40:

Chris@40: Turn on/off automatic clipping when doing floating point to integer conversion. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_SET_CLIPPING
Chris@40:         data     : NULL
Chris@40:         datasize : SF_TRUE or SF_FALSE.
Chris@40: 
Chris@40: Chris@40:

Chris@40: Turn on (datasize == SF_TRUE) or off (datasize == SF_FALSE) clipping. Chris@40:

Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         sf_command (sndfile, SFC_SET_CLIPPING, NULL, SF_TRUE) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
Clipping mode (SF_TRUE or SF_FALSE). Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_CLIPPING

Chris@40:

Chris@40: Turn on/off automatic clipping when doing floating point to integer conversion. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_GET_CLIPPING
Chris@40:         data     : NULL
Chris@40:         datasize : 0
Chris@40: 
Chris@40: Chris@40:

Chris@40: Retrieve the current cliiping setting. Chris@40:

Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:         sf_command (sndfile, SFC_GET_CLIPPING, NULL, 0) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
Clipping mode (SF_TRUE or SF_FALSE). Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_EMBED_FILE_INFO

Chris@40:

Chris@40: Get the file offset and file length of a file enbedded within another Chris@40: larger file. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_GET_CLIPPING
Chris@40:         data     : a pointer to an  SF_EMBED_FILE_INFO struct
Chris@40:         datasize : sizeof (SF_EMBED_FILE_INFO)
Chris@40: 
Chris@40:

Chris@40: The SF_EMBED_FILE_INFO struct is defined in <sndfile.h> as: Chris@40:

Chris@40:
Chris@40:         typedef struct
Chris@40:         {   sf_count_t	offset ;
Chris@40:             sf_count_t	length ;
Chris@40:         } SF_EMBED_FILE_INFO ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
0 on success and non-zero otherwise. Chris@40:
The value of the offset field of the SF_EMBED_FILE_INFO struct will be Chris@40: the offsets in bytes from the start of the outer file to the start of Chris@40: the audio file. Chris@40:
The value of the offset field of the SF_EMBED_FILE_INFO struct will be Chris@40: the length in bytes of the embedded file. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:


SFC_WAVEX_GET_AMBISONIC

Chris@40:

Chris@40: Test if the current file has the GUID of a WAVEX file for any of the Ambisonic Chris@40: formats. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_WAVEX_GET_AMBISONIC
Chris@40:         data     : NULL
Chris@40:         datasize : 0
Chris@40: 
Chris@40:

Chris@40: The Ambisonic WAVEX formats are defined here : Chris@40: Chris@40: http://dream.cs.bath.ac.uk/researchdev/wave-ex/bformat.html. Chris@40:

Chris@40:
Chris@40:
Return value:
Chris@40:
SF_AMBISONIC_NONE or SF_AMBISONIC_B_FORMAT or zero if the file format Chris@40: does not support ambisonic formats. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_WAVEX_SET_AMBISONIC

Chris@40:

Chris@40: Set the GUID of a new WAVEX file to indicate an Ambisonics format. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_WAVEX_SET_AMBISONIC
Chris@40:         data     : NULL
Chris@40:         datasize : SF_AMBISONIC_NONE or SF_AMBISONIC_B_FORMAT
Chris@40: 
Chris@40:

Chris@40: Turn on (SF_AMBISONIC_B_FORMAT) or off (SF_AMBISONIC_NONE) encoding. Chris@40: This command is currently only supported for files with SF_FORMAT_WAVEX format. Chris@40:

Chris@40:

Chris@40: The Ambisonic WAVEX formats are defined here : Chris@40: Chris@40: http://dream.cs.bath.ac.uk/researchdev/wave-ex/bformat.html. Chris@40:

Chris@40:
Chris@40:
Return value:
Chris@40:
Return the ambisonic value that has just been set or zero if the file Chris@40: format does not support ambisonic encoding. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_SET_VBR_ENCODING_QUALITY

Chris@40:

Chris@40: Set the Variable Bit Rate encoding quality. Chris@40: The encoding quality value should be between 0.0 (lowest quality) and 1.0 Chris@40: (highest quality). Chris@40: Currenly this command is only implemented for FLAC and Ogg/Vorbis files. Chris@40: It has no effect on un-compressed file formats. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_SET_VBR_ENCODING_QUALITY
Chris@40:         data     : A pointer to a double value
Chris@40:         datasize : sizeof (double)
Chris@40: 
Chris@40:

Chris@40: The command must be sent before any audio data is written to the file. Chris@40:

Chris@40:

Chris@40:

Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE if VBR encoding quality was set. Chris@40: SF_FALSE otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_SET_COMPRESSION_LEVEL

Chris@40:

Chris@40: Set the compression level. Chris@40: The compression level should be between 0.0 (minimum compression level) and 1.0 Chris@40: (highest compression level). Chris@40: Currenly this command is only implemented for FLAC and Ogg/Vorbis files. Chris@40: It has no effect on un-compressed file formats. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_SET_COMPRESSION_LEVEL
Chris@40:         data     : A pointer to a double value
Chris@40:         datasize : sizeof (double)
Chris@40: 
Chris@40:

Chris@40: The command must be sent before any audio data is written to the file. Chris@40:

Chris@40:

Chris@40:

Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE if compression level was set. Chris@40: SF_FALSE otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_RAW_NEEDS_ENDSWAP

Chris@40:

Chris@40: Determine if raw data read using Chris@40: Chris@40: sf_read_raw Chris@40: needs to be end swapped on the host CPU. Chris@40:

Chris@40:

Chris@40: For instance, will return SF_TRUE on when reading WAV containing Chris@40: SF_FORMAT_PCM_16 data on a big endian machine and SF_FALSE on a little endian Chris@40: machine. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_RAW_NEEDS_ENDSWAP
Chris@40:         data     : NULL
Chris@40:         datasize : 0
Chris@40: 
Chris@40: Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE or SF_FALSE Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_BROADCAST_INFO

Chris@40:

Chris@40: Retrieve the Broadcast Extension Chunk from WAV (and related) files. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_GET_BROADCAST_INFO
Chris@40:         data     : a pointer to an SF_BROADCAST_INFO struct
Chris@40:         datasize : sizeof (SF_BROADCAST_INFO)
Chris@40: 
Chris@40:

Chris@40: The SF_BROADCAST_INFO struct is defined in <sndfile.h> as: Chris@40:

Chris@40:
Chris@40:     typedef struct
Chris@40:     {   char            description [256] ;
Chris@40:         char            originator [32] ;
Chris@40:         char            originator_reference [32] ;
Chris@40:         char            origination_date [10] ;
Chris@40:         char            origination_time [8] ;
Chris@40:         unsigned int    time_reference_low ;
Chris@40:         unsigned int    time_reference_high ;
Chris@40:         short           version ;
Chris@40:         char            umid [64] ;
Chris@40:         char            reserved [190] ;
Chris@40:         unsigned int    coding_history_size ;
Chris@40:         char            coding_history [256] ;
Chris@40:     } SF_BROADCAST_INFO ;
Chris@40: 
Chris@40: Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE if the file contained a Broadcast Extension chunk or SF_FALSE Chris@40: otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_SET_BROADCAST_INFO

Chris@40:

Chris@40: Set the Broadcast Extension Chunk for WAV (and related) files. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_SET_BROADCAST_INFO
Chris@40:         data     : a pointer to an SF_BROADCAST_INFO struct
Chris@40:         datasize : sizeof (SF_BROADCAST_INFO)
Chris@40: 
Chris@40: Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE if setting the Broadcast Extension chunk was successful and SF_FALSE Chris@40: otherwise. Chris@40: Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_CART_INFO

Chris@40:

Retrieve the Cart Chunk from WAV (and related) files. Based on AES46 standard for CartChunk (see CartChunk.org for more information. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_GET_CART_INFO
Chris@40:         data     : a pointer to an SF_CART_INFO struct
Chris@40:         datasize : sizeof (SF_CART_INFO)
Chris@40: 
Chris@40:

Chris@40: The SF_CART_INFO struct is defined in <sndfile.h> as: Chris@40:

Chris@40:
Chris@40: #define SF_CART_INFO_VAR(p_tag_text_size) \
Chris@40:                         struct
Chris@40:                         {       char            version [4] ;
Chris@40:                                 char            title [64] ;
Chris@40:                                 char            artist [64] ;
Chris@40:                                 char            cut_id [64] ;
Chris@40:                                 char            client_id [64] ;
Chris@40:                                 char            category [64] ;
Chris@40:                                 char            classification [64] ;
Chris@40:                                 char            out_cue [64] ;
Chris@40:                                 char            start_date [10] ;
Chris@40:                                 char            start_time [8] ;
Chris@40:                                 char            end_date [10] ;
Chris@40:                                 char            end_time [8] ;
Chris@40:                                 char            producer_app_id [64] ;
Chris@40:                                 char            producer_app_version [64] ;
Chris@40:                                 char            user_def [64] ;
Chris@40:                                 long    level_reference ;
Chris@40:                                 SF_CART_TIMER   post_timers [8] ;
Chris@40:                                 char            reserved [276] ;
Chris@40:                                 char            url [1024] ;
Chris@40:                                 unsigned int    tag_text_size ;
Chris@40:                                 char            tag_text[p_tag_text_size] ;
Chris@40:                         }
Chris@40: 
Chris@40: Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE if the file contained a Cart chunk or SF_FALSE Chris@40: otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_SET_CART_INFO

Chris@40:

Chris@40: Set the Cart Chunk for WAV (and related) files. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:         sndfile  : A valid SNDFILE* pointer
Chris@40:         cmd      : SFC_SET_CART_INFO
Chris@40:         data     : a pointer to an SF_CART_INFO struct
Chris@40:         datasize : sizeof (SF_CART_INFO)
Chris@40: 
Chris@40: Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE if setting the Cart chunk was successful and SF_FALSE Chris@40: otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_LOOP_INFO

Chris@40:

Chris@40: Retrieve loop information for file including time signature, length in Chris@40: beats and original MIDI base note Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:          sndfile  : A valid SNDFILE* pointer
Chris@40:          cmd      : SFC_GET_LOOP_INFO
Chris@40:          data     : a pointer to an SF_LOOP_INFO struct
Chris@40:          datasize : sizeof (SF_LOOP_INFO)
Chris@40: 
Chris@40:

Chris@40: The SF_BROADCAST_INFO struct is defined in <sndfile.h> as: Chris@40:

Chris@40:
Chris@40:         typedef struct
Chris@40:         {   short    time_sig_num ;   /* any positive integer    > 0  */
Chris@40:             short    time_sig_den ;   /* any positive power of 2 > 0  */
Chris@40:             int        loop_mode ;    /* see SF_LOOP enum             */
Chris@40: 
Chris@40:             int        num_beats ;    /* this is NOT the amount of quarter notes !!!*/
Chris@40:                                       /* a full bar of 4/4 is 4 beats */
Chris@40:                                       /* a full bar of 7/8 is 7 beats */
Chris@40: 
Chris@40:             float    bpm ;            /* suggestion, as it can be calculated using other fields:*/
Chris@40:                                       /* file's lenght, file's sampleRate and our time_sig_den*/
Chris@40:                                       /* -> bpms are always the amount of _quarter notes_ per minute */
Chris@40: 
Chris@40:             int    root_key ;         /* MIDI note, or -1 for None */
Chris@40:             int future [6] ;
Chris@40:         } SF_LOOP_INFO ;
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:          SF_LOOP_INFO loop;
Chris@40:          sf_command (sndfile, SFC_GET_LOOP_INFO, &loop, sizeof (loop)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE if the file header contains loop information for the file. Chris@40: SF_FALSE otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_INSTRUMENT

Chris@40:

Chris@40: Retrieve instrument information from file including MIDI base note, Chris@40: keyboard mapping and looping informations(start/stop and mode). Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:          sndfile  : A valid SNDFILE* pointer
Chris@40:          cmd      : SFC_GET_INSTRUMENT
Chris@40:          data     : a pointer to an SF_INSTRUMENT struct
Chris@40:          datasize : sizeof (SF_INSTRUMENT)
Chris@40: 
Chris@40: Chris@40:

Chris@40: The SF_INSTRUMENT struct is defined in <sndfile.h> as: Chris@40:

Chris@40:
Chris@40:         enum
Chris@40:         {    /*
Chris@40:             **    The loop mode field in SF_INSTRUMENT will be one of the following.
Chris@40:             */
Chris@40:             SF_LOOP_NONE = 800,
Chris@40:             SF_LOOP_FORWARD,
Chris@40:             SF_LOOP_BACKWARD,
Chris@40:             SF_LOOP_ALTERNATING
Chris@40:         } ;
Chris@40: 
Chris@40:         typedef struct
Chris@40:         {   int gain ;
Chris@40:             char basenote, detune ;
Chris@40:             char velocity_lo, velocity_hi ;
Chris@40:             char key_lo, key_hi ;
Chris@40:             int loop_count ;
Chris@40: 
Chris@40:             struct
Chris@40:             {   int mode ;
Chris@40:                 unsigned int start ;
Chris@40:                 unsigned int end ;
Chris@40:                 unsigned int count ;
Chris@40:             } loops [16] ; /* make variable in a sensible way */
Chris@40:         } SF_INSTRUMENT ;
Chris@40: 
Chris@40: Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:          SF_INSTRUMENT inst ;
Chris@40:          sf_command (sndfile, SFC_GET_INSTRUMENT, &inst, sizeof (inst)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE if the file header contains instrument information for the Chris@40: file. SF_FALSE otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:


SFC_SET_INSTRUMENT

Chris@40:

Chris@40: Set the instrument information for the file. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:          sndfile  : A valid SNDFILE* pointer
Chris@40:          cmd      : SFC_SET_INSTRUMENT
Chris@40:          data     : a pointer to an SF_INSTRUMENT struct
Chris@40:          datasize : sizeof (SF_INSTRUMENT)
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:          SF_INSTRUMENT inst ;
Chris@40:          sf_command (sndfile, SFC_SET_INSTRUMENT, &inst, sizeof (inst)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE if the file header contains instrument information for the Chris@40: file. SF_FALSE otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_CUE_COUNT

Chris@40:

Chris@40: Retrieve the number of cue markers available for retrieval using the Chris@40: SFC_GET_CUE command. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:          sndfile  : A valid SNDFILE* pointer
Chris@40:          cmd      : SFC_GET_CUE
Chris@40:          data     : a pointer to a uint32_t
Chris@40:          datasize : sizeof (uint32_t)
Chris@40: 
Chris@40: Chris@40: Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:          uint32_t cue_count ;
Chris@40:          sf_command (sndfile, SFC_GET_CUE_COUNT, &cue_count, sizeof (cue_count)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE if the file header contains cue marker information for the Chris@40: file. SF_FALSE otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:


SFC_GET_CUE

Chris@40:

Chris@40: Retrieve cue marker information from file. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:          sndfile  : A valid SNDFILE* pointer
Chris@40:          cmd      : SFC_GET_CUE
Chris@40:          data     : a pointer to an SF_CUES struct
Chris@40:          datasize : sizeof (SF_CUES)
Chris@40: 
Chris@40: Chris@40:

Chris@40: The SF_CUES struct is defined in <sndfile.h> as: Chris@40:

Chris@40:
Chris@40:     typedef struct
Chris@40:     {	int cue_count ;
Chris@40: 
Chris@40:     	struct
Chris@40:     	{	int32_t   indx ;
Chris@40:     		uint32_t  position ;
Chris@40:     		int32_t   fcc_chunk ;
Chris@40:     		int32_t   chunk_start ;
Chris@40:     		int32_t   block_start ;
Chris@40:     		uint32_t  sample_offset ;
Chris@40:     		char name [256] ;
Chris@40:     	} cue_points [100] ;
Chris@40:     } SF_CUES ;
Chris@40: 
Chris@40: Chris@40:

Chris@40: There is also an SF_CUES_VAR #define that allows reading/writing more than 100 Chris@40: cue markers. Chris@40:

Chris@40: Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:          SF_CUES cues ;
Chris@40:          sf_command (sndfile, SFC_GET_CUE, &cues, sizeof (cues)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE if the file header contains cue marker information for the Chris@40: file. SF_FALSE otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:


SFC_SET_CUE

Chris@40:

Chris@40: Set the cue marker information for the file. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:          sndfile  : A valid SNDFILE* pointer
Chris@40:          cmd      : SFC_SET_CUE
Chris@40:          data     : a pointer to an SF_CUES struct
Chris@40:          datasize : sizeof (SF_CUES)
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:          SF_CUES cues ;
Chris@40:          sf_command (sndfile, SFC_SET_CUE, &cues, sizeof (cues)) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
SF_TRUE if the file header contains cue marker information for the Chris@40: file. SF_FALSE otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:


SFC_RF64_AUTO_DOWNGRADE

Chris@40:

Chris@40: Enable auto downgrade from RF64 to WAV. Chris@40:

Chris@40:

Chris@40: The EBU recomendation is that when writing RF64 files and the resulting file is Chris@40: less than 4Gig in size, it should be downgraded to a WAV file (WAV files have a Chris@40: maximum size of 4Gig). Chris@40: libsndfile doesn't follow the EBU recommendations exactly, , mainly because the Chris@40: test suite needs to be able test reading/writing RF64 files without having to Chris@40: generate files larger than 4 gigabytes. Chris@40:

Chris@40:

Chris@40: Note: This command should be issued before the first bit of audio data has been Chris@40: written to the file. Chris@40: Calling this command after audio data has been written will return the current Chris@40: value of this setting, but will not allow it to be changed. Chris@40:

Chris@40:

Chris@40: Parameters: Chris@40:

Chris@40:
Chris@40:          sndfile  : A valid SNDFILE* pointer
Chris@40:          cmd      : SFC_RF64_AUTO_DOWNGRADE
Chris@40:          data     : NULL
Chris@40:          datasize : SF_TRUE or SF_FALSE
Chris@40: 
Chris@40:

Chris@40: Example: Chris@40:

Chris@40:
Chris@40:          /* Enable auto downgrade on file close. */
Chris@40:          sf_command (sndfile, SFC_RF64_AUTO_DOWNGRADE, NULL, SF_TRUE) ;
Chris@40: 
Chris@40:
Chris@40:
Return value:
Chris@40:
Returns SF_TRUE if SFC_RF64_AUTO_DOWNGRADE is set and SF_FALSE Chris@40: otherwise. Chris@40:
Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40: Chris@40:
Chris@40:

Chris@40: The libsndfile home page is here : Chris@40: Chris@40: http://www.mega-nerd.com/libsndfile/. Chris@40:
Chris@40: Version : 1.0.25 Chris@40:

Chris@40: Chris@40: Chris@40: