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 a integer identifier which is defined in <sndfile.h>. Chris@40: All of the valid command identifiers have names begining 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:| SFC_GET_LIB_VERSION | Chris@40:Retrieve the version of the library. | Chris@40:
| SFC_GET_LOG_INFO | Chris@40:Retrieve the internal per-file operation log. | Chris@40:
| SFC_CALC_SIGNAL_MAX | Chris@40:Retrieve the measured maximum signal value. | Chris@40:
| SFC_CALC_NORM_SIGNAL_MAX | Chris@40:Retrieve the measured normalised maximum signal value. | Chris@40:
| SFC_CALC_MAX_ALL_CHANNELS | Chris@40:Calculate peaks for all channels. | Chris@40:
| SFC_CALC_NORM_MAX_ALL_CHANNELS | Chris@40:Calculate normalised peaks for all channels. | Chris@40:
| SFC_SET_NORM_FLOAT | Chris@40:Modify the normalisation behaviour of the floating point reading and writing functions. | Chris@40:
| SFC_SET_NORM_DOUBLE | Chris@40:Modify the normalisation behaviour of the double precision floating point reading and writing functions. | Chris@40:
| SFC_GET_NORM_FLOAT | Chris@40:Retrieve the current normalisation behaviour of the floating point reading and writing functions. | Chris@40:
| SFC_GET_NORM_DOUBLE | Chris@40:Retrieve the current normalisation behaviour of the double precision floating point reading and writing functions. | Chris@40:
| SFC_GET_SIMPLE_FORMAT_COUNT | Chris@40:Retrieve the number of simple formats supported by libsndfile. | Chris@40:
| SFC_GET_SIMPLE_FORMAT | Chris@40:Retrieve information about a simple format. | Chris@40:
| SFC_GET_FORMAT_INFO | Chris@40:Retrieve information about a major or subtype format. | Chris@40:
| SFC_GET_FORMAT_MAJOR_COUNT | Chris@40:Retrieve the number of major formats. | Chris@40:
| SFC_GET_FORMAT_MAJOR | Chris@40:Retrieve information about a major format type. | Chris@40:
| SFC_GET_FORMAT_SUBTYPE_COUNT | Chris@40:Retrieve the number of subformats. | Chris@40:
| SFC_GET_FORMAT_SUBTYPE | Chris@40:Retrieve information about a subformat. | Chris@40:
| SFC_SET_ADD_PEAK_CHUNK | Chris@40:Switch the code for adding the PEAK chunk to WAV and AIFF files on or off. | Chris@40:
| SFC_UPDATE_HEADER_NOW | Chris@40:Used when a file is open for write, this command will update the file Chris@40: header to reflect the data written so far. | Chris@40:
| SFC_SET_UPDATE_HEADER_AUTO | Chris@40:Used 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. | Chris@40:
| SFC_FILE_TRUNCATE | Chris@40:Truncate a file open for write or for read/write. | Chris@40:
| SFC_SET_RAW_START_OFFSET | Chris@40:Change the data start offset for files opened up as SF_FORMAT_RAW. | 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: 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: 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: Retrieve the measured normailised 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: Calculate peaks for all channels. 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_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: Calculate normalised peaks for all channels. 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_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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: Retrieve information about a subformat. 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: 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: /* Retrieve all the subtypes supported by the WAV format. */
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 | 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: 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: 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: 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: 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: Truncate a file open for write or for 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: 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: The libsndfile home page is here :
Chris@40:
Chris@40: http://www.mega-nerd.com/libsndfile/.
Chris@40:
Chris@40: Version : 1.0.27
Chris@40: