wav_reader.h File Reference

#include <stdio.h>
#include <cstdint>

Include dependency graph for wav_reader.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Classes
struct	wav_metadata

Macros
#define	WAV_HDR_PARSE_INVALID_PARAM   4
#define	WAV_HDR_PARSE_NOT_PCM   3
#define	WAV_HDR_PARSE_OK   0
#define	WAV_HDR_PARSE_READ_ERROR   1
#define	WAV_HDR_PARSE_WRONG_FORMAT   2

Functions
const char *	get_wav_error (int errcode)
int	read_wav_header (FILE *wav_file, struct wav_metadata *metadata)
size_t	wav_read (void *buffer, size_t sample_count, FILE *wav_file, struct wav_metadata *metadata)
int	wav_seek (FILE *wav_file, long offset, int whence, struct wav_metadata *metadata)
	same as fseek but WAV header presence is respected (for SEEK SET)

Detailed Description

Author

Martin Pulec marti.nosp@m.n.pu.nosp@m.lec@c.nosp@m.esne.nosp@m.t.cz

Definition in file wav_reader.h.

Macro Definition Documentation

WAV_HDR_PARSE_INVALID_PARAM

#define WAV_HDR_PARSE_INVALID_PARAM   4

Definition at line 61 of file wav_reader.h.

Referenced by get_wav_error(), and read_fmt_chunk().

WAV_HDR_PARSE_NOT_PCM

#define WAV_HDR_PARSE_NOT_PCM   3

Definition at line 60 of file wav_reader.h.

Referenced by get_wav_error(), and read_fmt_chunk().

WAV_HDR_PARSE_OK

#define WAV_HDR_PARSE_OK   0

Definition at line 57 of file wav_reader.h.

Referenced by audio_testcard_read_wav(), get_wav_error(), init_audio(), read_fmt_chunk(), and read_wav_header().

WAV_HDR_PARSE_READ_ERROR

#define WAV_HDR_PARSE_READ_ERROR   1

Definition at line 58 of file wav_reader.h.

Referenced by get_wav_error(), read_fmt_chunk(), and read_wav_header().

WAV_HDR_PARSE_WRONG_FORMAT

#define WAV_HDR_PARSE_WRONG_FORMAT   2

Definition at line 59 of file wav_reader.h.

Referenced by get_wav_error(), read_fmt_chunk(), and read_wav_header().

Function Documentation

get_wav_error()

const char * get_wav_error

(

int

errcode

)

Definition at line 300 of file wav_reader.c.

{
        switch(errcode) {
                case WAV_HDR_PARSE_OK:
                        return "Wav header OK";
                case WAV_HDR_PARSE_READ_ERROR:
                        return "Premature end of WAV file";
                case WAV_HDR_PARSE_WRONG_FORMAT:
                        return "Wav header in wrong format";
                case WAV_HDR_PARSE_NOT_PCM:
                        return "Wav not in PCM";
                case WAV_HDR_PARSE_INVALID_PARAM:
                        return "Wrong/unsupported value in header";
                default:
                        log_msg(LOG_LEVEL_ERROR, MOD_NAME "Unknown error code %d passed!\n", errcode);
                        return "Unknown error";
        }
}

References LOG_LEVEL_ERROR, log_msg(), MOD_NAME, WAV_HDR_PARSE_INVALID_PARAM, WAV_HDR_PARSE_NOT_PCM, WAV_HDR_PARSE_OK, WAV_HDR_PARSE_READ_ERROR, and WAV_HDR_PARSE_WRONG_FORMAT.

Referenced by audio_testcard_read_wav(), and init_audio().

Here is the call graph for this function:

read_wav_header()

int read_wav_header	(	FILE *	wav_file,
		struct wav_metadata *	metadata )

This function reads wav header

If read successfully, it leaves read file position at the beginning of data. Currently, only interleaved PCM is supported.

Return values

WAV_HDR_PARSE_OK	if ok
WAV_HDR_PARSE_READ_ERROR	in case of file read error
WAV_HDR_PARSE_WRONG_FORMAT	if unsupported wav format
WAV_HDR_PARSE_NOT_PCM	non-PCM WAV detected

< RF64 or BW64

Definition at line 215 of file wav_reader.c.

{
        char buffer[16];
        uint32_t chunk_size;
        rewind(wav_file);
 
        _Bool rf64 = 0; 
        READ_N(buffer, 4);
        if (strncmp(buffer, "RF64", 4) == 0 || strncmp(buffer, "BW64", 4) == 0) {
                log_msg(LOG_LEVEL_VERBOSE, MOD_NAME "Using %4.4s WAV file.\n", buffer);
                rf64 = 1;
        } else if (strncmp(buffer, "RIFF", 4) != 0) {
                log_msg(LOG_LEVEL_ERROR, MOD_NAME "Expected RIFF or RF64/BW64 chunk, %.4s given.\n", buffer);
                return WAV_HDR_PARSE_WRONG_FORMAT;
        }
 
        // this is the length of the rest of the file, we may ignore
        READ_N(&chunk_size, 4);
 
        READ_N(buffer, 4);
        if (strncmp(buffer, "WAVE", 4) != 0) {
                log_msg(LOG_LEVEL_ERROR, MOD_NAME "Expected WAVE chunk, %.4s given.\n", buffer);
                return WAV_HDR_PARSE_WRONG_FORMAT;
        }
 
        bool found_data_chunk = false;
        bool found_ds64_chunk = false;
        bool found_fmt_chunk = false;
        while (fread(buffer, 4, 1, wav_file) == 1) {
                READ_N(&chunk_size, 4);
                if (strncmp(buffer, "data", 4) == 0) {
                        if (!process_data_chunk(wav_file, chunk_size, metadata, found_ds64_chunk)) {
                                return WAV_HDR_PARSE_READ_ERROR;
                        }
                        found_data_chunk = true;
                        break;
                }
                if (strncmp(buffer, "ds64", 4) == 0) {
                        if (!read_ds64(wav_file, chunk_size, metadata)) {
                                return WAV_HDR_PARSE_WRONG_FORMAT;
                        }
                        found_ds64_chunk = true;
                } else if (strncmp(buffer, "fmt ", 4) == 0) {
                        found_fmt_chunk = true;
                        int rc = read_fmt_chunk(wav_file, metadata, chunk_size);
                        if (rc != WAV_HDR_PARSE_OK) {
                                return rc;
                        }
                } else { // other tags
                        const char *known_tags[] = { "JUNK", "LIST", "id3 ", NULL }; // "olym" ?
                        int level = is_member(buffer, known_tags) ? LOG_LEVEL_VERBOSE : LOG_LEVEL_WARNING;
                        log_msg(level, MOD_NAME "Skipping chunk \"%4.4s\" sized %" PRIu32 " B!\n", buffer, chunk_size);
                        CHECK(fskip(wav_file, chunk_size), WAV_HDR_PARSE_READ_ERROR);
                }
        }
 
        if (!found_data_chunk) {
                log_msg(LOG_LEVEL_ERROR, MOD_NAME "Data chunk not found!\n");
                return WAV_HDR_PARSE_READ_ERROR;
        }
 
        if (!found_fmt_chunk) {
                log_msg(LOG_LEVEL_ERROR, MOD_NAME "Fmt chunk not found!\n");
                return WAV_HDR_PARSE_READ_ERROR;
        }
 
        if (rf64 && !found_ds64_chunk) { // buggy, but we may try to continue witn implicit data size
                log_msg(LOG_LEVEL_WARNING, MOD_NAME "Broken WAV - a RF64 file detected but no ds64 chunk found!\n");
        }
 
        log_msg(LOG_LEVEL_VERBOSE, MOD_NAME "File parsed correctly - length %lld bytes, data offset %lld.\n",
                        metadata->data_size, metadata->data_offset);
 
        return WAV_HDR_PARSE_OK;
}

References CHECK, wav_metadata::data_offset, wav_metadata::data_size, fskip(), is_member(), LOG_LEVEL_ERROR, LOG_LEVEL_VERBOSE, LOG_LEVEL_WARNING, log_msg(), MOD_NAME, process_data_chunk(), read_ds64(), read_fmt_chunk(), READ_N, WAV_HDR_PARSE_OK, WAV_HDR_PARSE_READ_ERROR, and WAV_HDR_PARSE_WRONG_FORMAT.

Referenced by audio_testcard_read_wav(), and init_audio().

Here is the call graph for this function:

wav_read()

size_t wav_read	(	void *	buffer,
		size_t	sample_count,
		FILE *	wav_file,
		struct wav_metadata *	metadata )

Reads sample_count samples from wav_file according to metadata.

Note

conversion to signed is performed if wav sample type is u8

Definition at line 291 of file wav_reader.c.

{
        size_t samples = fread(buffer, metadata->ch_count * metadata->bits_per_sample / 8, sample_count, wav_file);
        if (metadata->bits_per_sample == 8) {
                signed2unsigned(buffer, buffer, samples * metadata->ch_count * metadata->bits_per_sample / 8);
        }
        return samples;
}

References wav_metadata::bits_per_sample, wav_metadata::ch_count, and signed2unsigned().

Referenced by audio_reading_thread(), and audio_testcard_read_wav().

Here is the call graph for this function:

wav_seek()

int wav_seek	(	FILE *	wav_file,
		long	offset,
		int	whence,
		struct wav_metadata *	metadata )

same as fseek but WAV header presence is respected (for SEEK SET)

Definition at line 319 of file wav_reader.c.

{
        if (whence == SEEK_CUR || whence == SEEK_END) {
                return fseek(wav_file, offset, whence);
        }
        assert(whence == SEEK_SET);
        return fseek(wav_file, metadata->data_offset + offset, SEEK_SET);
}

References wav_metadata::data_offset, and offset.

Referenced by audio_reading_thread(), and reset_import().