结构体 AVHWFramesContext 

#[repr(C)]
pub struct AVHWFramesContext {
    pub av_class: *const AVClass,
    pub device_ref: *mut AVBufferRef,
    pub device_ctx: *mut AVHWDeviceContext,
    pub hwctx: *mut c_void,
    pub free: Option<unsafe extern "C" fn(ctx: *mut AVHWFramesContext)>,
    pub user_opaque: *mut c_void,
    pub pool: *mut AVBufferPool,
    pub initial_pool_size: c_int,
    pub format: AVPixelFormat,
    pub sw_format: AVPixelFormat,
    pub width: c_int,
    pub height: c_int,
}

This struct describes a set or pool of “hardware” frames (i.e. those with data not located in normal system memory). All the frames in the pool are assumed to be allocated in the same way and interchangeable.

This struct is reference-counted with the AVBuffer mechanism and tied to a given AVHWDeviceContext instance. The av_hwframe_ctx_alloc() constructor yields a reference, whose data field points to the actual AVHWFramesContext struct.

Fields

av_class: *const AVClass

A class for logging.

device_ref: *mut AVBufferRef

A reference to the parent AVHWDeviceContext. This reference is owned and managed by the enclosing AVHWFramesContext, but the caller may derive additional references from it.

device_ctx: *mut AVHWDeviceContext

The parent AVHWDeviceContext. This is simply a pointer to device_ref->data provided for convenience.

Set by libavutil in av_hwframe_ctx_init().

hwctx: *mut c_void

The format-specific data, allocated and freed automatically along with this context.

The user shall ignore this field if the corresponding format-specific header (hwcontext_*.h) does not define a context to be used as AVHWFramesContext.hwctx.

Otherwise, it should be cast by the user to said context and filled as described in the documentation before calling av_hwframe_ctx_init().

After any frames using this context are created, the contents of this struct should not be modified by the caller.

free: Option<unsafe extern "C" fn(ctx: *mut AVHWFramesContext)>

This field may be set by the caller before calling av_hwframe_ctx_init().

If non-NULL, this callback will be called when the last reference to this context is unreferenced, immediately before it is freed.

user_opaque: *mut c_void

Arbitrary user data, to be used e.g. by the free() callback.

pool: *mut AVBufferPool

A pool from which the frames are allocated by av_hwframe_get_buffer(). This field may be set by the caller before calling av_hwframe_ctx_init(). The buffers returned by calling av_buffer_pool_get() on this pool must have the properties described in the documentation in the corresponding hw type’s header (hwcontext_*.h). The pool will be freed strictly before this struct’s free() callback is invoked.

This field may be NULL, then libavutil will attempt to allocate a pool internally. Note that certain device types enforce pools allocated at fixed size (frame count), which cannot be extended dynamically. In such a case, initial_pool_size must be set appropriately.

initial_pool_size: c_int

Initial size of the frame pool. If a device type does not support dynamically resizing the pool, then this is also the maximum pool size.

May be set by the caller before calling av_hwframe_ctx_init(). Must be set if pool is NULL and the device type does not support dynamic pools.

format: AVPixelFormat

The pixel format identifying the underlying HW surface type.

Must be a hwaccel format, i.e. the corresponding descriptor must have the AV_PIX_FMT_FLAG_HWACCEL flag set.

Must be set by the user before calling av_hwframe_ctx_init().

sw_format: AVPixelFormat

The pixel format identifying the actual data layout of the hardware frames.

Must be set by the caller before calling av_hwframe_ctx_init().

@note when the underlying API does not provide the exact data layout, but only the colorspace/bit depth, this field should be set to the fully planar version of that format (e.g. for 8-bit 420 YUV it should be AV_PIX_FMT_YUV420P, not AV_PIX_FMT_NV12 or anything else).

width: c_int

The allocated dimensions of the frames in this pool.

Must be set by the user before calling av_hwframe_ctx_init().

height: c_int

The allocated dimensions of the frames in this pool.

Must be set by the user before calling av_hwframe_ctx_init().

trait 实现

impl Clone for AVHWFramesContext

fn clone(&self) -> AVHWFramesContext

Returns a duplicate of the value. 阅读更多

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

从 source 执行拷贝赋值。 阅读更多

impl Debug for AVHWFramesContext

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

使用给定的格式化器格式化该值。 阅读更多

impl PartialEq for AVHWFramesContext

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

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

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

测试 !=。默认实现几乎总是足够的，没有充分理由不应被重写。

impl Copy for AVHWFramesContext

impl Eq for AVHWFramesContext

impl StructuralPartialEq for AVHWFramesContext