- - int sf_command (SNDFILE *sndfile, int cmd, void *data, int datasize) ; --
- This function allows the caller to retrieve information from or change aspects of the - library behaviour. - Examples include retrieving a string containing the library version or changing the - scaling applied to floating point sample data during read and write. - Most of these operations are performed on a per-file basis. -
-- The cmd parameter is an integer identifier which is defined in <sndfile.h>. - All of the valid command identifiers have names beginning with "SFC_". - Data is passed to and returned from the library by use of a void pointer. - The library will not read or write more than datasize bytes from the void pointer. - For some calls no data is required in which case data should be NULL and datasize - may be used for some other purpose. -
-- The available commands are as follows: -
- -| SFC_GET_LIB_VERSION | -Retrieve the version of the library. | -
| SFC_GET_LOG_INFO | -Retrieve the internal per-file operation log. | -
| SFC_CALC_SIGNAL_MAX | -Calculate the measured maximum signal value. | -
| SFC_CALC_NORM_SIGNAL_MAX | -Calculate the measured normalised maximum signal value. | -
| SFC_CALC_MAX_ALL_CHANNELS | -Calculate the peak value for each channel. | -
| SFC_CALC_NORM_MAX_ALL_CHANNELS | -Calculate the normalised peak for each channel. | -
| SFC_GET_SIGNAL_MAX | -Retrieve the peak value for the file (as stored in the file header). | -
| SFC_GET_MAX_ALL_CHANNELS | -Retrieve the peak value for each channel (as stored in the file header). | -
| SFC_SET_NORM_FLOAT | -Modify the normalisation behaviour of the floating point reading and writing functions. | -
| SFC_SET_NORM_DOUBLE | -Modify the normalisation behaviour of the double precision floating point reading and writing functions. | -
| SFC_GET_NORM_FLOAT | -Retrieve the current normalisation behaviour of the floating point reading and writing functions. | -
| SFC_GET_NORM_DOUBLE | -Retrieve the current normalisation behaviour of the double precision floating point reading and writing functions. | -
| SFC_SET_SCALE_FLOAT_INT_READ | -Set/clear the scale factor when integer (short/int) data is read from a file - containing floating point data. | -
| SFC_SET_SCALE_INT_FLOAT_WRITE | -Set/clear the scale factor when integer (short/int) data is written to a file - as floating point data. | -
| SFC_GET_SIMPLE_FORMAT_COUNT | -Retrieve the number of simple formats supported by libsndfile. | -
| SFC_GET_SIMPLE_FORMAT | -Retrieve information about a simple format. | -
| SFC_GET_FORMAT_INFO | -Retrieve information about a major or subtype format. | -
| SFC_GET_FORMAT_MAJOR_COUNT | -Retrieve the number of major formats. | -
| SFC_GET_FORMAT_MAJOR | -Retrieve information about a major format type. | -
| SFC_GET_FORMAT_SUBTYPE_COUNT | -Retrieve the number of subformats. | -
| SFC_GET_FORMAT_SUBTYPE | -Retrieve information about a subformat. | -
| SFC_SET_ADD_PEAK_CHUNK | -Switch the code for adding the PEAK chunk to WAV and AIFF files on or off. | -
| SFC_UPDATE_HEADER_NOW | -Used when a file is open for write, this command will update the file - header to reflect the data written so far. | -
| SFC_SET_UPDATE_HEADER_AUTO | -Used when a file is open for write, this command will cause the file header - to be updated after each write to the file. | -
| SFC_FILE_TRUNCATE | -Truncate a file open for write or for read/write. | -
| SFC_SET_RAW_START_OFFSET | -Change the data start offset for files opened up as SF_FORMAT_RAW. | -
| SFC_SET_CLIPPING | -Turn on/off automatic clipping when doing floating point to integer - conversion. | -
| SFC_GET_CLIPPING | -Retrieve current clipping setting. | -
| SFC_GET_EMBED_FILE_INFO | -Retrieve information about audio files embedded inside other files. | -
| SFC_GET_AMBISONIC | -Test a WAVEX file for Ambisonic format | -
| SFC_SET_AMBISONIC | -Modify a WAVEX header for Ambisonic format | -
| SFC_SET_VBR_ENCODING_QUALITY | -Set the the Variable Bit Rate encoding quality | -
| SFC_RAW_NEEDS_ENDSWAP | -Determine if raw data needs endswapping | -
| SFC_GET_BROADCAST_INFO | -Retrieve the Broadcast Chunk info | -
| SFC_SET_BROADCAST_INFO | -Set the Broadcast Chunk info | -
| SFC_GET_LOOP_INFO | -Get loop info | -
| SFC_GET_INSTRUMENT | -Get instrument info | -
| SFC_SET_INSTRUMENT | -Set instrument info | -
| SFC_SET_VBR_ENCODING_QUALITY | -Set variable bit rate encoding quality | -
-Retrieve the version of the library as a string. -
--Parameters: -
- sndfile : Not used - cmd : SFC_GET_LIB_VERSION - data : A pointer to a char buffer - datasize : The size of the the buffer --
-Example: -
-- char buffer [128] ; - sf_command (NULL, SFC_GET_LIB_VERSION, buffer, sizeof (buffer)) ; -- -
-Retrieve the log buffer generated when opening a file as a string. This log -buffer can often contain a good reason for why libsndfile failed to open a -particular file. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_GET_LOG_INFO - data : A pointer to a char buffer - datasize : The size of the the buffer --
-Example: -
-- char buffer [2048] ; - sf_command (sndfile, SFC_GET_LOG_INFO, buffer, sizeof (buffer)) ; -- -
-Retrieve the measured maximum signal value. This involves reading through -the whole file which can be slow on large files. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_CALC_SIGNAL_MAX - data : A pointer to a double - datasize : sizeof (double) --
-Example: -
-- double max_val ; - sf_command (sndfile, SFC_CALC_SIGNAL_MAX, &max_val, sizeof (max_val)) ; -- -
-Retrieve the measured normalised maximum signal value. This involves reading -through the whole file which can be slow on large files. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_CALC_NORM_SIGNAL_MAX - data : A pointer to a double - datasize : sizeof (double) --
-Example: -
-- double max_val ; - sf_command (sndfile, SFC_CALC_NORM_SIGNAL_MAX, &max_val, sizeof (max_val)) ; -- -
-Calculate the peak value (ie a single number) for each channel. -This involves reading through the whole file which can be slow on large files. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_CALC_MAX_ALL_CHANNELS - data : A pointer to a double - datasize : sizeof (double) * number_of_channels --
-Example: -
-- double peaks [number_of_channels] ; - sf_command (sndfile, SFC_CALC_MAX_ALL_CHANNELS, peaks, sizeof (peaks)) ; --
-Calculate the normalised peak for each channel. -This involves reading through the whole file which can be slow on large files. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_CALC_NORM_MAX_ALL_CHANNELS - data : A pointer to a double - datasize : sizeof (double) * number_of_channels --
-Example: -
-- double peaks [number_of_channels] ; - sf_command (sndfile, SFC_CALC_NORM_MAX_ALL_CHANNELS, peaks, sizeof (peaks)) ; --
-Retrieve the peak value for the file as stored in the file header. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_GET_SIGNAL_MAX - data : A pointer to a double - datasize : sizeof (double) --
-Example: -
-- double max_peak ; - sf_command (sndfile, SFC_GET_SIGNAL_MAX, &max_peak, sizeof (max_peak)) ; --
-Retrieve the peak value for the file as stored in the file header. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_GET_SIGNAL_MAX - data : A pointer to an array of doubles - datasize : sizeof (double) * number_of_channels --
-Example: -
-- double peaks [number_of_channels] ; - sf_command (sndfile, SFC_GET_MAX_ALL_CHANNELS, peaks, sizeof (peaks)) ; --
-This command only affects data read from or written to using the floating point functions: -
-- size_t sf_read_float (SNDFILE *sndfile, float *ptr, size_t items) ; - size_t sf_readf_float (SNDFILE *sndfile, float *ptr, size_t frames) ; - - size_t sf_write_float (SNDFILE *sndfile, float *ptr, size_t items) ; - size_t sf_writef_float (SNDFILE *sndfile, float *ptr, size_t frames) ; --
-Parameters: -
-- sndfile : A valid SNDFILE* pointer - cmd : SFC_SET_NORM_FLOAT - data : NULL - datasize : SF_TRUE or SF_FALSE --
-For read operations setting normalisation to SF_TRUE means that the data from all -subsequent reads will be be normalised to the range [-1.0, 1.0]. -
--For write operations, setting normalisation to SF_TRUE means than all data supplied -to the float write functions should be in the range [-1.0, 1.0] and will be scaled -for the file format as necessary. -
--For both cases, setting normalisation to SF_FALSE means that no scaling will take place. -
--Example: -
-- sf_command (sndfile, SFC_SET_NORM_FLOAT, NULL, SF_TRUE) ; - - sf_command (sndfile, SFC_SET_NORM_FLOAT, NULL, SF_FALSE) ; --
-This command only affects data read from or written to using the double precision -floating point functions: -
-- size_t sf_read_double (SNDFILE *sndfile, double *ptr, size_t items) ; - size_t sf_readf_double (SNDFILE *sndfile, double *ptr, size_t frames) ; - - size_t sf_write_double (SNDFILE *sndfile, double *ptr, size_t items) ; - size_t sf_writef_double (SNDFILE *sndfile, double *ptr, size_t frames) ; --
-Parameters: -
-- sndfile : A valid SNDFILE* pointer - cmd : SFC_SET_NORM_DOUBLE - data : NULL - datasize : SF_TRUE or SF_FALSE --
-For read operations setting normalisation to SF_TRUE means that the data -from all subsequent reads will be be normalised to the range [-1.0, 1.0]. -
--For write operations, setting normalisation to SF_TRUE means than all data supplied -to the double write functions should be in the range [-1.0, 1.0] and will be scaled -for the file format as necessary. -
--For both cases, setting normalisation to SF_FALSE means that no scaling will take place. -
--Example: -
-- sf_command (sndfile, SFC_SET_NORM_DOUBLE, NULL, SF_TRUE) ; - - sf_command (sndfile, SFC_SET_NORM_DOUBLE, NULL, SF_FALSE) ; --
-Retrieve the current float normalisation mode. -
--Parameters: -
-- sndfile : A valid SNDFILE* pointer - cmd : SFC_GET_NORM_FLOAT - data : NULL - datasize : anything --
-Example: -
-- normalisation = sf_command (sndfile, SFC_GET_NORM_FLOAT, NULL, 0) ; --
-Retrieve the current float normalisation mode. -
--Parameters: -
-- sndfile : A valid SNDFILE* pointer - cmd : SFC_GET_NORM_DOUBLE - data : NULL - datasize : anything --
-Example: -
-- normalisation = sf_command (sndfile, SFC_GET_NORM_DOUBLE, NULL, 0) ; --
-Set/clear the scale factor when integer (short/int) data is read from a file -containing floating point data. -
--Parameters: -
-- sndfile : A valid SNDFILE* pointer - cmd : SFC_SET_SCALE_FLOAT_INT_READ - data : NULL - datasize : TRUE or FALSE --
-Example: -
-- sf_command (sndfile, SFC_SET_SCALE_FLOAT_INT_READ, NULL, SF_TRUE) ; --
-Set/clear the scale factor when integer (short/int) data is written to a file -as floating point data. -
--Parameters: -
-- sndfile : A valid SNDFILE* pointer - cmd : SFC_SET_SCALE_FLOAT_INT_READ - data : NULL - datasize : TRUE or FALSE --
-Example: -
-- sf_command (sndfile, SFC_SET_SCALE_INT_FLOAT_WRITE, NULL, SF_TRUE) ; --
-Retrieve the number of simple formats supported by libsndfile. -
--Parameters: -
-- sndfile : Not used. - cmd : SFC_GET_SIMPLE_FORMAT_COUNT - data : a pointer to an int - datasize : sizeof (int) --
-Example: -
-- int count ; - sf_command (sndfile, SFC_GET_SIMPLE_FORMAT_COUNT, &count, sizeof (int)) ; --
-Retrieve information about a simple format. -
--Parameters: -
-- sndfile : Not used. - cmd : SFC_GET_SIMPLE_FORMAT - data : a pointer to an SF_FORMAT_INFO struct - datasize : sizeof (SF_FORMAT_INFO) --
-The SF_FORMAT_INFO struct is defined in <sndfile.h> as: -
-
- typedef struct
- { int format ;
- const char *name ;
- const char *extension ;
- } SF_FORMAT_INFO ;
-
--When sf_command() is called with SF_GET_SIMPLE_FORMAT, the value of the format -field should be the format number (ie 0 <= format <= count value obtained using -SF_GET_SIMPLE_FORMAT_COUNT). -
--Example: -
-
- SF_FORMAT_INFO format_info ;
- int k, count ;
-
- sf_command (sndfile, SFC_GET_SIMPLE_FORMAT_COUNT, &count, sizeof (int)) ;
-
- for (k = 0 ; k < count ; k++)
- { format_info.format = k ;
- sf_command (sndfile, SFC_GET_SIMPLE_FORMAT, &format_info, sizeof (format_info)) ;
- printf ("%08x %s %s\n", format_info.format, format_info.name, format_info.extension) ;
- } ;
-
--Retrieve information about a major or subtype format. -
--Parameters: -
-- sndfile : Not used. - cmd : SFC_GET_FORMAT_INFO - data : a pointer to an SF_FORMAT_INFO struct - datasize : sizeof (SF_FORMAT_INFO) --
-The SF_FORMAT_INFO struct is defined in <sndfile.h> as: -
-
- typedef struct
- { int format ;
- const char *name ;
- const char *extension ;
- } SF_FORMAT_INFO ;
-
--When sf_command() is called with SF_GET_FORMAT_INFO, the format field is -examined and if (format & SF_FORMAT_TYPEMASK) is a valid format then the struct -is filled in with information about the given major type. -If (format & SF_FORMAT_TYPEMASK) is FALSE and (format & SF_FORMAT_SUBMASK) is a -valid subtype format then the struct is filled in with information about the given -subtype. -
--Example: -
-
- SF_FORMAT_INFO format_info ;
-
- format_info.format = SF_FORMAT_WAV ;
- sf_command (sndfile, SFC_GET_FORMAT_INFO, &format_info, sizeof (format_info)) ;
- printf ("%08x %s %s\n", format_info.format, format_info.name, format_info.extension) ;
-
- format_info.format = SF_FORMAT_ULAW ;
- sf_command (sndfile, SFC_GET_FORMAT_INFO, &format_info, sizeof (format_info)) ;
- printf ("%08x %s\n", format_info.format, format_info.name) ;
-
--Retrieve the number of major formats. -
--Parameters: -
-- sndfile : Not used. - cmd : SFC_GET_FORMAT_MAJOR_COUNT - data : a pointer to an int - datasize : sizeof (int) --
-Example: -
-- int count ; - sf_command (sndfile, SFC_GET_FORMAT_MAJOR_COUNT, &count, sizeof (int)) ; --
-Retrieve information about a major format type. -
--Parameters: -
-- sndfile : Not used. - cmd : SFC_GET_FORMAT_MAJOR - data : a pointer to an SF_FORMAT_INFO struct - datasize : sizeof (SF_FORMAT_INFO) --
-Example: -
-
- SF_FORMAT_INFO format_info ;
- int k, count ;
-
- sf_command (sndfile, SFC_GET_FORMAT_MAJOR_COUNT, &count, sizeof (int)) ;
-
- for (k = 0 ; k < count ; k++)
- { format_info.format = k ;
- sf_command (sndfile, SFC_GET_FORMAT_MAJOR, &format_info, sizeof (format_info)) ;
- printf ("%08x %s %s\n", format_info.format, format_info.name, format_info.extension) ;
- } ;
-
--For a more comprehensive example, see the program list_formats.c in the examples/ -directory of the libsndfile source code distribution. -
--Retrieve the number of subformats. -
--Parameters: -
-- sndfile : Not used. - cmd : SFC_GET_FORMAT_SUBTYPE_COUNT - data : a pointer to an int - datasize : sizeof (int) --
-Example: -
-- int count ; - sf_command (sndfile, SFC_GET_FORMAT_SUBTYPE_COUNT, &count, sizeof (int)) ; --
-Enumerate the subtypes (this function does not translate a subtype into -a string describing that subtype). -A typical use case might be retrieving a string description of all subtypes -so that a dialog box can be filled in. -
-- -
--Parameters: -
-- sndfile : Not used. - cmd : SFC_GET_FORMAT_SUBTYPE - data : a pointer to an SF_FORMAT_INFO struct - datasize : sizeof (SF_FORMAT_INFO) --
-Example 1: Retrieve all sybtypes supported by the WAV format. -
-
- SF_FORMAT_INFO format_info ;
- int k, count ;
-
- sf_command (sndfile, SFC_GET_FORMAT_SUBTYPE_COUNT, &count, sizeof (int)) ;
-
- for (k = 0 ; k < count ; k++)
- { format_info.format = k ;
- sf_command (sndfile, SFC_GET_FORMAT_SUBTYPE, &format_info, sizeof (format_info)) ;
- if (! sf_format_check (format_info.format | SF_FORMAT_WAV))
- continue ;
- printf ("%08x %s\n", format_info.format, format_info.name) ;
- } ;
-
--Example 2: Print a string describing the SF_FORMAT_PCM_16 subtype. -
-
- SF_FORMAT_INFO format_info ;
- int k, count ;
-
- sf_command (sndfile, SFC_GET_FORMAT_SUBTYPE_COUNT, &count, sizeof (int)) ;
-
- for (k = 0 ; k < count ; k++)
- { format_info.format = k ;
- sf_command (sndfile, SFC_GET_FORMAT_SUBTYPE, &format_info, sizeof (format_info)) ;
- if (format_info.format == SF_FORMAT_PCM_16)
- { printf ("%08x %s\n", format_info.format, format_info.name) ;
- break ;
- } ;
- } ;
-
--For a more comprehensive example, see the program list_formats.c in the examples/ -directory of the libsndfile source code distribution. -
--By default, WAV and AIFF files which contain floating point data (subtype SF_FORMAT_FLOAT -or SF_FORMAT_DOUBLE) have a PEAK chunk. -By using this command, the addition of a PEAK chunk can be turned on or off. -
--Note : This call must be made before any data is written to the file. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_SET_ADD_PEAK_CHUNK - data : Not used (should be NULL) - datasize : TRUE or FALSE. --
-Example: -
-- /* Turn on the PEAK chunk. */ - sf_command (sndfile, SFC_SET_ADD_PEAK_CHUNK, NULL, SF_TRUE) ; - - /* Turn off the PEAK chunk. */ - sf_command (sndfile, SFC_SET_ADD_PEAK_CHUNK, NULL, SF_FALSE) ; --
-The header of an audio file is normally written by libsndfile when the file is -closed using sf_close(). -
--There are however situations where large files are being generated and it would -be nice to have valid data in the header before the file is complete. -Using this command will update the file header to reflect the amount of data written -to the file so far. -Other programs opening the file for read (before any more data is written) will -then read a valid sound file header. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_UPDATE_HEADER_NOW - data : Not used (should be NULL) - datasize : Not used. --
-Example: -
-- /* Update the header now. */ - sf_command (sndfile, SFC_UPDATE_HEADER_NOW, NULL, 0) ; --
-Similar to SFC_UPDATE_HEADER_NOW but updates the header at the end of every call -to the sf_write* functions. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_UPDATE_HEADER_NOW - data : Not used (should be NULL) - datasize : SF_TRUE or SF_FALSE --
-Example: -
-- /* Turn on auto header update. */ - sf_command (sndfile, SFC_SET_UPDATE_HEADER_AUTO, NULL, SF_TRUE) ; - - /* Turn off auto header update. */ - sf_command (sndfile, SFC_SET_UPDATE_HEADER_AUTO, NULL, SF_FALSE) ; --
-Truncate a file that was opened for write or read/write. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_FILE_TRUNCATE - data : A pointer to an sf_count_t. - datasize : sizeof (sf_count_t) -- -
-Truncate the file to the number of frames specified by the sf_count_t pointed -to by data. -After this command, both the read and the write pointer will be -at the new end of the file. -This command will fail (returning non-zero) if the requested truncate position -is beyond the end of the file. -
--Example: -
-- /* Truncate the file to a length of 20 frames. */ - sf_count_t frames = 20 ; - sf_command (sndfile, SFC_FILE_TRUNCATE, &frames, sizeof (frames)) ; --
-Change the data start offset for files opened up as SF_FORMAT_RAW. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_SET_RAW_START_OFFSET - data : A pointer to an sf_count_t. - datasize : sizeof (sf_count_t) -- -
-For a file opened as format SF_FORMAT_RAW, set the data offset to the value -given by data. -
--Example: -
-- /* Reset the data offset to 5 bytes from the start of the file. */ - sf_count_t offset = 5 ; - sf_command (sndfile, SFC_SET_RAW_START_OFFSET, &offset, sizeof (offset)) ; --
-Turn on/off automatic clipping when doing floating point to integer conversion. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_SET_CLIPPING - data : NULL - datasize : SF_TRUE or SF_FALSE. -- -
-Turn on (datasize == SF_TRUE) or off (datasize == SF_FALSE) clipping. -
--Example: -
-- sf_command (sndfile, SFC_SET_CLIPPING, NULL, SF_TRUE) ; --
-Turn on/off automatic clipping when doing floating point to integer conversion. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_GET_CLIPPING - data : NULL - datasize : 0 -- -
-Retrieve the current cliiping setting. -
--Example: -
-- sf_command (sndfile, SFC_GET_CLIPPING, NULL, 0) ; --
-Get the file offset and file length of a file enbedded within another -larger file. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_GET_CLIPPING - data : a pointer to an SF_EMBED_FILE_INFO struct - datasize : sizeof (SF_EMBED_FILE_INFO) --
-The SF_EMBED_FILE_INFO struct is defined in <sndfile.h> as: -
-
- typedef struct
- { sf_count_t offset ;
- sf_count_t length ;
- } SF_EMBED_FILE_INFO ;
-
--Test if the current file has the GUID of a WAVEX file for any of the Ambisonic -formats. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_WAVEX_GET_AMBISONIC - data : NULL - datasize : 0 --
- The Ambisonic WAVEX formats are defined here : - - http://dream.cs.bath.ac.uk/researchdev/wave-ex/bformat.html. -
--Set the GUID of a new WAVEX file to indicate an Ambisonics format. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_WAVEX_SET_AMBISONIC - data : NULL - datasize : SF_AMBISONIC_NONE or SF_AMBISONIC_B_FORMAT --
-Turn on (SF_AMBISONIC_B_FORMAT) or off (SF_AMBISONIC_NONE) encoding. -This command is currently only supported for files with SF_FORMAT_WAVEX format. -
-- The Ambisonic WAVEX formats are defined here : - - http://dream.cs.bath.ac.uk/researchdev/wave-ex/bformat.html. -
--Set the the Variable Bit Rate encoding quality. -The encoding quality value should be between 0.0 (lowest quality) and 1.0 -(highest quality). -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_SET_VBR_ENCODING_QUALITY - data : A pointer to a double value - datasize : sizeof (double) --
-The command must be sent before any audio data is written to the file. -
--
--Determine if raw data read using - - sf_read_raw -needs to be end swapped on the host CPU. -
--For instance, will return SF_TRUE on when reading WAV containing -SF_FORMAT_PCM_16 data on a big endian machine and SF_FALSE on a little endian -machine. -
--Parameters: -
- sndfile : A valid SNDFILE* pointer - cmd : SFC_RAW_NEEDS_ENDSWAP - data : NULL - datasize : 0 -- -
-Retrieve the Broadcast Extension Chunk from WAV (and related) files. -
--Parameters: -
-- sndfile : A valid SNDFILE* pointer - cmd : SFC_GET_BROADCAST_INFO - data : a pointer to an SF_BROADCAST_INFO struct - datasize : sizeof (SF_BROADCAST_INFO) --
-The SF_BROADCAST_INFO struct is defined in <sndfile.h> as: -
-
- typedef struct
- { char description [256] ;
- char originator [32] ;
- char originator_reference [32] ;
- char origination_date [10] ;
- char origination_time [8] ;
- unsigned int time_reference_low ;
- unsigned int time_reference_high ;
- short version ;
- char umid [64] ;
- char reserved [190] ;
- unsigned int coding_history_size ;
- char coding_history [256] ;
- } SF_BROADCAST_INFO ;
-
-
--Set the Broadcast Extension Chunk for WAV (and related) files. -
--Parameters: -
-- sndfile : A valid SNDFILE* pointer - cmd : SFC_SET_BROADCAST_INFO - data : a pointer to an SF_BROADCAST_INFO struct - datasize : sizeof (SF_BROADCAST_INFO) -- -
-Retrieve loop information for file including time signature, length in -beats and original MIDI base note -
--Parameters: -
-- sndfile : A valid SNDFILE* pointer - cmd : SFC_GET_LOOP_INFO - data : a pointer to an SF_LOOP_INFO struct - datasize : sizeof (SF_LOOP_INFO) --
-The SF_BROADCAST_INFO struct is defined in <sndfile.h> as: -
-
- typedef struct
- { short time_sig_num ; /* any positive integer > 0 */
- short time_sig_den ; /* any positive power of 2 > 0 */
- int loop_mode ; /* see SF_LOOP enum */
-
- int num_beats ; /* this is NOT the amount of quarter notes !!!*/
- /* a full bar of 4/4 is 4 beats */
- /* a full bar of 7/8 is 7 beats */
-
- float bpm ; /* suggestion, as it can be calculated using other fields:*/
- /* file's lenght, file's sampleRate and our time_sig_den*/
- /* -> bpms are always the amount of _quarter notes_ per minute */
-
- int root_key ; /* MIDI note, or -1 for None */
- int future [6] ;
- } SF_LOOP_INFO ;
-
--Example: -
-- SF_LOOP_INFO loop; - sf_command (sndfile, SFC_GET_LOOP_INFO, &loop, sizeof (loop)) ; --
-Retrieve instrument information from file including MIDI base note, -keyboard mapping and looping informations(start/stop and mode). -
--Parameters: -
-- sndfile : A valid SNDFILE* pointer - cmd : SFC_GET_INSTRUMENT - data : a pointer to an SF_INSTRUMENT struct - datasize : sizeof (SF_INSTRUMENT) -- -
-The SF_INSTRUMENT struct is defined in <sndfile.h> as: -
-
- enum
- { /*
- ** The loop mode field in SF_INSTRUMENT will be one of the following.
- */
- SF_LOOP_NONE = 800,
- SF_LOOP_FORWARD,
- SF_LOOP_BACKWARD,
- SF_LOOP_ALTERNATING
- } ;
-
- typedef struct
- { int gain ;
- char basenote, detune ;
- char velocity_lo, velocity_hi ;
- char key_lo, key_hi ;
- int loop_count ;
-
- struct
- { int mode ;
- unsigned int start ;
- unsigned int end ;
- unsigned int count ;
- } loops [16] ; /* make variable in a sensible way */
- } SF_INSTRUMENT ;
-
-
--Example: -
-- SF_INSTRUMENT inst ; - sf_command (sndfile, SFC_GET_INSTRUMENT, &inst, sizeof (inst)) ; --
-Set the instrument information for the file. -
--Parameters: -
-- sndfile : A valid SNDFILE* pointer - cmd : SFC_GET_INSTRUMENT - data : a pointer to an SF_INSTRUMENT struct - datasize : sizeof (SF_INSTRUMENT) --
-Example: -
-- SF_INSTRUMENT inst ; - sf_command (sndfile, SFC_SET_INSTRUMENT, &inst, sizeof (inst)) ; --
-Set the Variable Bite Rate encoding quality. -Currenly only implemented fro Ogg/Vorbis files. -
--Parameters: -
-- sndfile : A valid SNDFILE* pointer - cmd : SFC_SET_VBR_ENCODING_QUALITY - data : a pointer to double specifing VBR quality - datasize : sizeof (double) --
-Example: -
-- double quality = 0.5 ; - sf_command (sndfile, SFC_SET_VBR_ENCODING_QUALITY, &quality, sizeof (double)) ; --
- The libsndfile home page is here :
-
- http://www.mega-nerd.com/libsndfile/.
-
-Version : 1.0.25
-