ptttl_to_wav.h File Reference

Converts the output of ptttl_parse() into a WAV file. No dynamic memory allocation, and no loading the entire WAV file in memory. More...

#include "ptttl_parser.h"
#include "ptttl_sample_generator.h"

Go to the source code of this file.

Macros
#define	PTTTL_WAVFILE_GENERATION_STRATEGY   0

Functions
int	ptttl_to_wav (ptttl_parser_t *parser, FILE *fp, ptttl_sample_generator_config_t *config, ptttl_waveform_type_e wave_type)

Detailed Description

Converts the output of ptttl_parse() into a WAV file. No dynamic memory allocation, and no loading the entire WAV file in memory.

Requires ptttl_parser.c and ptttl_sample_generator.c

Requires stdint.h, and fopen/fseek/fwrite from stdio.h

See https://github.com/eriknyquist/ptttl for more details about PTTTL.

Author

Erik Nyquist

Macro Definition Documentation

PTTTL_WAVFILE_GENERATION_STRATEGY

#define PTTTL_WAVFILE_GENERATION_STRATEGY   0

Defines the strategy used by ptttl_to_wav to generate .wav files. The available options make various trade-offs between dynamic memory usage, performance, and composability:

• 0 (default): Seeking not allowed, dynamic memory allocation not allowed. This is the most portable and composable strategy. No dynamic/heap memory will be used, and no seek operations will be performed on the output file stream (allowing 'stdout' connected to a shell pipe to be used as the output stream, for example). Due to the fact that we need to know how many sample points / frames there will be in order to generate the first few .wav bytes containing the header, and no seeking is allowed, this strategy comes with a performance cost, since the parser & sample generator must make two full passes of the input text; once to determine the total number of sample points / frames the generated .wav file will contain, and again to obtain the sample point / frame values for writing to the output stream.
• 1: Seeking not allowed, dynamic memory allocation allowed. This option is more performant than 0, at the cost of dynamic memory allocation being required. Seek operations will not be performed on the output stream, but dynamic memory allocations will be performed.
• 2: Seeking allowed, dynamic memory allocation not allowed. This strategy is the most performant, at the cost of composability. Seek operations will be performed on the output file stream, so only one pass of the parser & sample generator are required. No dynamic memory allocation will be performed.

Function Documentation

ptttl_to_wav()

int ptttl_to_wav	(	ptttl_parser_t *	parser,
		FILE *	fp,
		ptttl_sample_generator_config_t *	config,
		ptttl_waveform_type_e	wave_type
	)

Convert PTTTL/RTTTL source to .wav file

Parameters

parser	Pointer to initialized parser object
fp	File stream that has already been opened for writing. Generated contents of .wav file will be written here.
config	Pointer to configuration for sample generator. May be NULL. If NULL, a default configuration will be used.
wave_type	Waveform type to use for all channels

Returns

0 if successful, -1 if an error occurred. Call ptttl_parser_error for an error description if -1 is returned.