Struct AVClass

#[repr(C)]
pub struct AVClass {
    pub class_name: *const c_char,
    pub item_name: Option<unsafe extern "C" fn(ctx: *mut c_void) -> *const c_char>,
    pub option: *const AVOption,
    pub version: c_int,
    pub log_level_offset_offset: c_int,
    pub parent_log_context_offset: c_int,
    pub category: AVClassCategory,
    pub get_category: Option<unsafe extern "C" fn(ctx: *mut c_void) -> AVClassCategory>,
    pub query_ranges: Option<unsafe extern "C" fn(arg1: *mut *mut AVOptionRanges, obj: *mut c_void, key: *const c_char, flags: c_int) -> c_int>,
    pub child_next: Option<unsafe extern "C" fn(obj: *mut c_void, prev: *mut c_void) -> *mut c_void>,
    pub child_class_iterate: Option<unsafe extern "C" fn(iter: *mut *mut c_void) -> *const AVClass>,
}

Describe the class of an AVClass context structure. That is an arbitrary struct of which the first field is a pointer to an AVClass struct (e.g. AVCodecContext, AVFormatContext etc.).

Fields

class_name: *const c_char

The name of the class; usually it is the same name as the context structure type to which the AVClass is associated.

item_name: Option<unsafe extern "C" fn(ctx: *mut c_void) -> *const c_char>

A pointer to a function which returns the name of a context instance ctx associated with the class.

option: *const AVOption

a pointer to the first option specified in the class if any or NULL

@see av_set_default_options()

version: c_int

LIBAVUTIL_VERSION with which this structure was created. This is used to allow fields to be added without requiring major version bumps everywhere.

log_level_offset_offset: c_int

Offset in the structure where log_level_offset is stored. 0 means there is no such variable

parent_log_context_offset: c_int

Offset in the structure where a pointer to the parent context for logging is stored. For example a decoder could pass its AVCodecContext to eval as such a parent context, which an av_log() implementation could then leverage to display the parent context. The offset can be NULL.

category: AVClassCategory

Category used for visualization (like color) This is only set if the category is equal for all objects using this class. available since version (51 << 16 | 56 << 8 | 100)

get_category: Option<unsafe extern "C" fn(ctx: *mut c_void) -> AVClassCategory>

Callback to return the category. available since version (51 << 16 | 59 << 8 | 100)

query_ranges: Option<unsafe extern "C" fn(arg1: *mut *mut AVOptionRanges, obj: *mut c_void, key: *const c_char, flags: c_int) -> c_int>

Callback to return the supported/allowed ranges. available since version (52.12)

child_next: Option<unsafe extern "C" fn(obj: *mut c_void, prev: *mut c_void) -> *mut c_void>

Return next AVOptions-enabled child or NULL

child_class_iterate: Option<unsafe extern "C" fn(iter: *mut *mut c_void) -> *const AVClass>

Iterate over the AVClasses corresponding to potential AVOptions-enabled children.

@param iter pointer to opaque iteration state. The caller must initialize *iter to NULL before the first call. @return AVClass for the next AVOptions-enabled child or NULL if there are no more such children.

@note The difference between child_next and this is that child_next iterates over already existing objects, while child_class_iterate iterates over all possible children.

Trait Implementations

impl Clone for AVClass

fn clone(&self) -> AVClass

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AVClass

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for AVClass

fn eq(&self, other: &AVClass) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for AVClass

impl Eq for AVClass

impl StructuralPartialEq for AVClass