audio_format_handler Struct Reference

Data Fields
const char *const *	suffixes
int(*	get_file_info )(char *map, size_t numbytes, int fd, struct afh_info *afhi)
void(*	get_header )(void *map, size_t mapsize, char **buf, size_t *len)
int(*	open )(const void *map, size_t mapsize, void **afh_context)
int(*	get_chunk )(uint32_t chunk_num, void *afh_context, const char **buf, uint32_t *len)
void(*	close )(void *afh_context)
int(*	rewrite_tags )(const char *map, size_t mapsize, struct taginfo *tags, int output_fd, const char *filename)

Detailed Description

There's one such struct for each supported audio format. Initially, only name and init are defined. During the startup process, para_server calls the init function of each audio format handler which is expected to fill in the other part of this struct.

Field Documentation

suffixes

const char* const* suffixes

Typical file endings for files that can be handled by this afh.

Referenced by guess_audio_format().

get_file_info

int(* get_file_info) (char *map, size_t numbytes, int fd, struct afh_info *afhi)

Check if this audio format handler can handle the file.

This is a pointer to a function returning whether a given file is valid for this audio format. A negative return value indicates that this audio format handler is unable to decode the given file. On success, the function must return a positive value and fill in the given struct afh_info.

See also

struct afh_info.

get_header

void(* get_header) (void *map, size_t mapsize, char **buf, size_t *len)

Optional, used for header-rewriting.

See afh_get_header().

Referenced by afh_free_header(), and afh_get_header().

open

int(* open) (const void *map, size_t mapsize, void **afh_context)

An audio format handler may signify support for dynamic chunks by defining ->get_chunk below.

In this case the vss calls ->open() at BOS, ->get_chunk() for each chunk while streaming, and ->close() at EOS. The chunk table is not accessed at all.

The function may return its (opaque) context through the last argument. The returned pointer is passed to subsequent calls to ->get_chunk() and ->close().

Referenced by afh_get_chunk().

get_chunk

int(* get_chunk) (uint32_t chunk_num, void *afh_context, const char **buf, uint32_t *len)

Return a reference to one chunk.

The returned pointer points to a portion of the memory mapped audio file. The caller must not call free() on it.

Referenced by afh_get_chunk(), and afh_supports_dynamic_chunks().

close

void(* close) (void *afh_context)

Deallocate the resources occupied by ->open().

Referenced by afh_close(), and afh_get_chunk().

rewrite_tags

int(* rewrite_tags) (const char *map, size_t mapsize, struct taginfo *tags, int output_fd, const char *filename)

Write audio file with altered tags, optional.

The output file descriptor has been opened by the caller and must not be closed in this function.

Referenced by afh_rewrite_tags().

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The documentation for this struct was generated from the following file:

• afh.h