Struct rsmpeg::ffi::AVRegionOfInterest [−][src]
#[repr(C)]pub struct AVRegionOfInterest { pub self_size: u32, pub top: i32, pub bottom: i32, pub left: i32, pub right: i32, pub qoffset: AVRational, }
Expand description
Structure describing a single Region Of Interest.
When multiple regions are defined in a single side-data block, they should be ordered from most to least important - some encoders are only capable of supporting a limited number of distinct regions, so will have to truncate the list.
When overlapping regions are defined, the first region containing a given area of the frame applies.
Fields
self_size: u32
Expand description
Must be set to the size of this data structure (that is, sizeof(AVRegionOfInterest)).
top: i32
Expand description
Distance in pixels from the top edge of the frame to the top and bottom edges and from the left edge of the frame to the left and right edges of the rectangle defining this region of interest.
The constraints on a region are encoder dependent, so the region actually affected may be slightly larger for alignment or other reasons.
bottom: i32
left: i32
right: i32
qoffset: AVRational
Expand description
Quantisation offset.
Must be in the range -1 to +1. A value of zero indicates no quality change. A negative value asks for better quality (less quantisation), while a positive value asks for worse quality (greater quantisation).
The range is calibrated so that the extreme values indicate the largest possible offset - if the rest of the frame is encoded with the worst possible quality, an offset of -1 indicates that this region should be encoded with the best possible quality anyway. Intermediate values are then interpolated in some codec-dependent way.
For example, in 10-bit H.264 the quantisation parameter varies between -12 and 51. A typical qoffset value of -1/10 therefore indicates that this region should be encoded with a QP around one-tenth of the full range better than the rest of the frame. So, if most of the frame were to be encoded with a QP of around 30, this region would get a QP of around 24 (an offset of approximately -1/10 * (51 - -12) = -6.3). An extreme value of -1 would indicate that this region should be encoded with the best possible quality regardless of the treatment of the rest of the frame - that is, should be encoded at a QP of -12.
Trait Implementations
impl Clone for AVRegionOfInterest
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impl Clone for AVRegionOfInterest
[src]pub fn clone(&self) -> AVRegionOfInterest
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pub fn clone(&self) -> AVRegionOfInterest
[src]Returns a copy of the value. Read more
fn clone_from(&mut self, source: &Self)
1.0.0[src]
fn clone_from(&mut self, source: &Self)
1.0.0[src]Performs copy-assignment from source
. Read more
impl Debug for AVRegionOfInterest
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impl Debug for AVRegionOfInterest
[src]impl Copy for AVRegionOfInterest
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Auto Trait Implementations
impl RefUnwindSafe for AVRegionOfInterest
impl Send for AVRegionOfInterest
impl Sync for AVRegionOfInterest
impl Unpin for AVRegionOfInterest
impl UnwindSafe for AVRegionOfInterest
Blanket Implementations
impl<T> BorrowMut<T> for T where
T: ?Sized,
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impl<T> BorrowMut<T> for T where
T: ?Sized,
[src]pub fn borrow_mut(&mut self) -> &mut T
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pub fn borrow_mut(&mut self) -> &mut T
[src]Mutably borrows from an owned value. Read more
impl<T> ToOwned for T where
T: Clone,
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impl<T> ToOwned for T where
T: Clone,
[src]type Owned = T
type Owned = T
The resulting type after obtaining ownership.
pub fn to_owned(&self) -> T
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pub fn to_owned(&self) -> T
[src]Creates owned data from borrowed data, usually by cloning. Read more
pub fn clone_into(&self, target: &mut T)
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pub fn clone_into(&self, target: &mut T)
[src]🔬 This is a nightly-only experimental API. (toowned_clone_into
)
recently added
Uses borrowed data to replace owned data, usually by cloning. Read more