1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
// Copyright 2022 The ChromiumOS Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
use std::sync::Arc;
use crate::bindings;
use crate::va_check;
use crate::Display;
use crate::Surface;
use crate::SurfaceMemoryDescriptor;
use crate::VaError;
/// Wrapper around `VAImage` that is tied to the lifetime of a given `Picture`.
///
/// An image is used to either get the surface data to client memory, or to copy image data in
/// client memory to a surface.
pub struct Image<'a> {
/// The display from which the image was created, so we can unmap it upon destruction.
display: Arc<Display>,
/// The `VAImage` returned by libva.
image: bindings::VAImage,
/// The mapped surface data.
///
/// The lifetime also allows us to ensure that the `Surface` we have been created from
/// does not drop or get changed while we exist.
data: &'a mut [u8],
/// Whether the image was derived using the `vaDeriveImage` API or created using the
/// `vaCreateImage` API.
derived: bool,
/// The display resolution requested by the client. The implementation is
/// free to enlarge this value as needed. In any case, we guarantee that an
/// image at least as large is returned.
display_resolution: (u32, u32),
/// Tracks whether the underlying data has possibly been written to, i.e. an encoder will create
/// an image and map its buffer in order to write to it, so we must writeback later.
dirty: bool,
/// The ID of the `Surface` we have been created from.
surface_id: u32,
}
impl<'a> Image<'a> {
/// Helper method to map a `VAImage` using `vaMapBuffer` and return an `Image`.
///
/// Returns an error if the mapping failed.
fn new<D: SurfaceMemoryDescriptor>(
surface: &'a Surface<D>,
image: bindings::VAImage,
derived: bool,
display_resolution: (u32, u32),
) -> Result<Self, VaError> {
let mut addr = std::ptr::null_mut();
// Safe since `picture.inner.context` represents a valid `VAContext` and `image` has been
// successfully created at this point.
match va_check(unsafe { bindings::vaMapBuffer(surface.display().handle(), image.buf, &mut addr) }) {
Ok(_) => {
// Assert that libva provided us with a coded resolution that is
// at least as large as `display_resolution`.
assert!(u32::from(image.width) >= display_resolution.0);
assert!(u32::from(image.height) >= display_resolution.1);
// Safe since `addr` points to data mapped onto our address space since we called
// `vaMapBuffer` above, which also guarantees that the data is valid for
// `image.data_size`.
let data = unsafe { std::slice::from_raw_parts_mut(addr as _, image.data_size as usize) };
Ok(Image {
display: Arc::clone(surface.display()),
image,
data,
derived,
display_resolution,
dirty: false,
surface_id: surface.id(),
})
}
Err(e) => {
// Safe because `picture.inner.context` represents a valid `VAContext` and `image`
// represents a valid `VAImage`.
unsafe {
bindings::vaDestroyImage(surface.display().handle(), image.image_id);
}
Err(e)
}
}
}
/// Create a new derived image from this `surface` using `vaDeriveImage`.
///
/// Derived images are a direct view (i.e. without any copy) on the buffer content of
/// `surface`. On the other hand, not all `Surface`s can be derived.
///
/// `visible_rect` is the visible rectangle inside `surface` that we want to access.
pub fn derive_from<D: SurfaceMemoryDescriptor>(
surface: &'a Surface<D>,
visible_rect: (u32, u32),
) -> Result<Self, VaError> {
// An all-zero byte-pattern is a valid initial value for `VAImage`.
let mut image: bindings::VAImage = Default::default();
// Safe because `self` has a valid display handle and ID.
va_check(unsafe { bindings::vaDeriveImage(surface.display().handle(), surface.id(), &mut image) })?;
Self::new(surface, image, true, visible_rect)
}
/// Create new image from `surface` using `vaCreateImage` and `vaGetImage`.
///
/// `visible_rect` is the visible rectangle inside `surface` that we want to access.
///
/// The image will contain a copy of `surface`'s data' in the desired `format` and
/// `coded_resolution`, meaning the data can be scaled if `coded_resolution` and `visible_rect`
/// differ.
pub fn create_from<D: SurfaceMemoryDescriptor>(
surface: &'a Surface<D>,
mut format: bindings::VAImageFormat,
coded_resolution: (u32, u32),
visible_rect: (u32, u32),
) -> Result<Image<'a>, VaError> {
// An all-zero byte-pattern is a valid initial value for `VAImage`.
let mut image: bindings::VAImage = Default::default();
let dpy = surface.display().handle();
// Safe because `dpy` is a valid display handle.
va_check(unsafe {
bindings::vaCreateImage(
dpy,
&mut format,
coded_resolution.0 as i32,
coded_resolution.1 as i32,
&mut image,
)
})?;
// Safe because `dpy` is a valid display handle, `picture.surface` is a valid VASurface and
// `image` is a valid `VAImage`.
match va_check(unsafe {
bindings::vaGetImage(
dpy,
surface.id(),
0,
0,
coded_resolution.0,
coded_resolution.1,
image.image_id,
)
}) {
Ok(()) => Self::new(surface, image, false, visible_rect),
Err(e) => {
// Safe because `image` is a valid `VAImage`.
unsafe {
bindings::vaDestroyImage(dpy, image.image_id);
}
Err(e)
}
}
}
/// Get a reference to the underlying `VAImage` that describes this image.
pub fn image(&self) -> &bindings::VAImage {
&self.image
}
/// Returns whether this image is directly derived from its underlying `Picture`, as opposed to
/// being a view/copy of said `Picture` in a guaranteed pixel format.
pub fn is_derived(&self) -> bool {
self.derived
}
/// Returns the display resolution as passed in by the client. This is a
/// value that is less than or equal to the coded resolution.
pub fn display_resolution(&self) -> (u32, u32) {
self.display_resolution
}
/// Returns the coded resolution. This value can be larger than the value
/// passed in when the image was created if the driver needs to.
pub fn coded_resolution(&self) -> (u32, u32) {
(self.image.width.into(), self.image.height.into())
}
}
impl<'a> AsRef<[u8]> for Image<'a> {
fn as_ref(&self) -> &[u8] {
self.data
}
}
impl<'a> AsMut<[u8]> for Image<'a> {
fn as_mut(&mut self) -> &mut [u8] {
self.dirty = true;
self.data
}
}
impl<'a> Drop for Image<'a> {
fn drop(&mut self) {
if !self.derived && self.dirty {
// Safe because `picture.inner.context` represents a valid `VAContext`,
// `picture.surface` represents a valid `VASurface` and `image` represents a valid
// `VAImage`.
unsafe {
bindings::vaPutImage(
self.display.handle(),
self.surface_id,
self.image.image_id,
0,
0,
self.image.width as u32,
self.image.height as u32,
0,
0,
self.image.width as u32,
self.image.height as u32,
);
}
}
unsafe {
// Safe since the buffer is mapped in `Image::new`, so `self.image.buf` points to a
// valid `VABufferID`.
bindings::vaUnmapBuffer(self.display.handle(), self.image.buf);
// Safe since `self.image` represents a valid `VAImage`.
bindings::vaDestroyImage(self.display.handle(), self.image.image_id);
}
}
}