nihed-cros-libva/src/context.rs

   1 // Copyright 2022 The ChromiumOS Authors
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 use std::rc::Rc;
   6
   7 use crate::bindings;
   8 use crate::buffer::Buffer;
   9 use crate::buffer::BufferType;
  10 use crate::display::Display;
  11 use crate::status::*;
  12 use crate::Config;
  13 use crate::Surface;
  14
  15 /// A VA context for a particular [`Display`].
  16 pub struct Context {
  17     display: Rc<Display>,
  18     id: bindings::VAContextID,
  19 }
  20
  21 impl Context {
  22     /// Creates a Context by wrapping around a `vaCreateContext` call. This is just a helper for
  23     /// [`Display::create_context`].
  24     pub(crate) fn new(
  25         display: Rc<Display>,
  26         config: &Config,
  27         coded_width: i32,
  28         coded_height: i32,
  29         surfaces: Option<&Vec<Surface>>,
  30         progressive: bool,
  31     ) -> VAResult<Rc<Self>> {
  32         let mut context_id = 0;
  33         let flags = if progressive {
  34             bindings::constants::VA_PROGRESSIVE as i32
  35         } else {
  36             0
  37         };
  38
  39         let mut render_targets = match surfaces {
  40             Some(surfaces) => Surface::as_id_vec(surfaces),
  41             None => Default::default(),
  42         };
  43
  44         // Safe because `self` represents a valid VADisplay and render_targets
  45         // and ntargets are properly initialized. Note that render_targets==NULL
  46         // is valid so long as ntargets==0.
  47         (unsafe {
  48             bindings::vaCreateContext(
  49                 display.handle(),
  50                 config.id(),
  51                 coded_width,
  52                 coded_height,
  53                 flags,
  54                 render_targets.as_mut_ptr(),
  55                 render_targets.len() as i32,
  56                 &mut context_id,
  57             )
  58         })
  59         .check()?;
  60
  61         Ok(Rc::new(Self {
  62             display,
  63             id: context_id,
  64         }))
  65     }
  66
  67     /// Returns a shared reference to the [`Display`] used by this context.
  68     pub fn display(&self) -> &Rc<Display> {
  69         &self.display
  70     }
  71
  72     /// Returns the ID of this context.
  73     pub(crate) fn id(&self) -> bindings::VAContextID {
  74         self.id
  75     }
  76
  77     /// Create a new buffer of type `type_`.
  78     pub fn create_buffer(self: &Rc<Self>, type_: BufferType) -> VAResult<Buffer> {
  79         Buffer::new(Rc::clone(self), type_)
  80     }
  81 }
  82
  83 impl Drop for Context {
  84     fn drop(&mut self) {
  85         // Safe because `self` represents a valid VAContext.
  86         let status =
  87             (unsafe { bindings::vaDestroyContext(self.display.handle(), self.id) }).check();
  88         if status.is_err() {
  89             println!("vaDestroyContext failed: {}", status.unwrap_err());
  90         }
  91     }
  92 }