audio_format_handler Struct Reference

Data Fields
const char *const *	suffixes
int(*	get_file_info )(char *map, size_t numbytes, 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)

Detailed Description

Definition of an audio format handler.

Each audio format defines a constant instance of this structure, and this is usually the only non-static symbol of the corresponding _afh.c file.

Field Documentation

suffixes

const char* const* suffixes

Typical file endings, often only one.

get_file_info

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

Check if this audio format handler can handle the file.

A negative return value indicates that this audio format handler is unable to handle the file. On success, the function must fill in the given afh_info structure.

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)

Write audio file with altered tags.

This function shall create a copy of the memory-mapped file, but with altered metadata tags according to the tags argument. 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