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
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
|
// Copyright (C) 2020 Natanael Mojica <neithanmo@gmail.com>
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use std::{io, io::Write, sync::Arc};
use glib::subclass::prelude::*;
use gst::prelude::*;
use gst::subclass::prelude::*;
use gst::{gst_debug, gst_error};
use gst_video::prelude::*;
use gst_video::subclass::prelude::*;
use atomic_refcell::AtomicRefCell;
use once_cell::sync::Lazy;
use parking_lot::Mutex;
use super::CompressionLevel;
use super::FilterType;
const DEFAULT_COMPRESSION_LEVEL: CompressionLevel = CompressionLevel::Default;
const DEFAULT_FILTER_TYPE: FilterType = FilterType::NoFilter;
static CAT: Lazy<gst::DebugCategory> = Lazy::new(|| {
gst::DebugCategory::new(
"rspngenc",
gst::DebugColorFlags::empty(),
Some("PNG encoder"),
)
});
// Inner buffer where the result of frame encoding is written
// before relay them downstream
struct CacheBuffer {
buffer: AtomicRefCell<Vec<u8>>,
}
impl CacheBuffer {
pub fn new() -> Self {
Self {
buffer: AtomicRefCell::new(Vec::new()),
}
}
pub fn clear(&self) {
self.buffer.borrow_mut().clear();
}
pub fn write(&self, buf: &[u8]) {
let mut buffer = self.buffer.borrow_mut();
buffer.extend_from_slice(buf);
}
pub fn consume(&self) -> Vec<u8> {
let mut buffer = self.buffer.borrow_mut();
std::mem::replace(&mut *buffer, Vec::new())
}
}
// The Encoder requires a Writer, so we use here and intermediate structure
// for caching encoded frames
struct CacheWriter {
cache: Arc<CacheBuffer>,
}
impl CacheWriter {
pub fn new(cache: Arc<CacheBuffer>) -> Self {
Self { cache }
}
}
impl Write for CacheWriter {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.cache.write(buf);
Ok(buf.len())
}
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
#[derive(Debug, Clone, Copy)]
struct Settings {
compression: CompressionLevel,
filter: FilterType,
}
impl Default for Settings {
fn default() -> Self {
Settings {
compression: DEFAULT_COMPRESSION_LEVEL,
filter: DEFAULT_FILTER_TYPE,
}
}
}
struct State {
video_info: gst_video::VideoInfo,
cache: Arc<CacheBuffer>,
writer: Option<png::Writer<CacheWriter>>,
}
impl State {
fn new(video_info: gst_video::VideoInfo) -> Self {
let cache = Arc::new(CacheBuffer::new());
Self {
video_info,
cache,
writer: None,
}
}
fn reset(&mut self, settings: Settings) -> Result<(), gst::LoggableError> {
// clear the cache
self.cache.clear();
let width = self.video_info.width();
let height = self.video_info.height();
let mut encoder = png::Encoder::new(CacheWriter::new(self.cache.clone()), width, height);
let color = match self.video_info.format() {
gst_video::VideoFormat::Gray8 | gst_video::VideoFormat::Gray16Be => {
png::ColorType::Grayscale
}
gst_video::VideoFormat::Rgb => png::ColorType::RGB,
gst_video::VideoFormat::Rgba => png::ColorType::RGBA,
_ => {
gst_error!(CAT, "format is not supported yet");
unreachable!()
}
};
let depth = if self.video_info.format() == gst_video::VideoFormat::Gray16Be {
png::BitDepth::Sixteen
} else {
png::BitDepth::Eight
};
encoder.set_color(color);
encoder.set_depth(depth);
encoder.set_compression(png::Compression::from(settings.compression));
encoder.set_filter(png::FilterType::from(settings.filter));
// Write the header for this video format into our inner buffer
let writer = encoder.write_header().map_err(|e| {
gst::loggable_error!(CAT, "Failed to create encoder error: {}", e.to_string())
})?;
self.writer = Some(writer);
Ok(())
}
fn write_data(&mut self, data: &[u8]) -> Result<(), png::EncodingError> {
if let Some(writer) = self.writer.as_mut() {
writer.write_image_data(data)
} else {
unreachable!()
}
}
}
#[derive(Default)]
pub struct PngEncoder {
state: Mutex<Option<State>>,
settings: Mutex<Settings>,
}
#[glib::object_subclass]
impl ObjectSubclass for PngEncoder {
const NAME: &'static str = "PngEncoder";
type Type = super::PngEncoder;
type ParentType = gst_video::VideoEncoder;
type Instance = gst::subclass::ElementInstanceStruct<Self>;
}
impl ObjectImpl for PngEncoder {
fn properties() -> &'static [glib::ParamSpec] {
static PROPERTIES: Lazy<Vec<glib::ParamSpec>> = Lazy::new(|| {
vec![
glib::ParamSpec::enum_(
"compression-level",
"Compression level",
"Selects the compression algorithm to use",
CompressionLevel::static_type(),
DEFAULT_COMPRESSION_LEVEL as i32,
glib::ParamFlags::READWRITE | gst::PARAM_FLAG_MUTABLE_READY,
),
glib::ParamSpec::enum_(
"filter",
"Filter",
"Selects the filter type to applied",
FilterType::static_type(),
DEFAULT_FILTER_TYPE as i32,
glib::ParamFlags::READWRITE | gst::PARAM_FLAG_MUTABLE_READY,
),
]
});
PROPERTIES.as_ref()
}
fn set_property(
&self,
_obj: &Self::Type,
_id: usize,
value: &glib::Value,
pspec: &glib::ParamSpec,
) {
match pspec.get_name() {
"compression-level" => {
let mut settings = self.settings.lock();
settings.compression = value
.get_some::<CompressionLevel>()
.expect("type checked upstream");
}
"filter" => {
let mut settings = self.settings.lock();
settings.filter = value
.get_some::<FilterType>()
.expect("type checked upstream");
}
_ => unreachable!(),
}
}
fn get_property(&self, _obj: &Self::Type, _id: usize, pspec: &glib::ParamSpec) -> glib::Value {
match pspec.get_name() {
"compression-level" => {
let settings = self.settings.lock();
settings.compression.to_value()
}
"filter" => {
let settings = self.settings.lock();
settings.filter.to_value()
}
_ => unimplemented!(),
}
}
}
impl ElementImpl for PngEncoder {
fn metadata() -> Option<&'static gst::subclass::ElementMetadata> {
static ELEMENT_METADATA: Lazy<gst::subclass::ElementMetadata> = Lazy::new(|| {
gst::subclass::ElementMetadata::new(
"PNG encoder",
"Encoder/Video",
"PNG encoder",
"Natanael Mojica <neithanmo@gmail>",
)
});
Some(&*ELEMENT_METADATA)
}
fn pad_templates() -> &'static [gst::PadTemplate] {
static PAD_TEMPLATES: Lazy<Vec<gst::PadTemplate>> = Lazy::new(|| {
let sink_caps = gst::Caps::new_simple(
"video/x-raw",
&[
(
"format",
&gst::List::new(&[
&gst_video::VideoFormat::Gray8.to_str(),
&gst_video::VideoFormat::Gray16Be.to_str(),
&gst_video::VideoFormat::Rgb.to_str(),
&gst_video::VideoFormat::Rgba.to_str(),
]),
),
("width", &gst::IntRange::<i32>::new(1, std::i32::MAX)),
("height", &gst::IntRange::<i32>::new(1, std::i32::MAX)),
(
"framerate",
&gst::FractionRange::new(
gst::Fraction::new(1, 1),
gst::Fraction::new(std::i32::MAX, 1),
),
),
],
);
let sink_pad_template = gst::PadTemplate::new(
"sink",
gst::PadDirection::Sink,
gst::PadPresence::Always,
&sink_caps,
)
.unwrap();
let src_caps = gst::Caps::new_simple("image/png", &[]);
let src_pad_template = gst::PadTemplate::new(
"src",
gst::PadDirection::Src,
gst::PadPresence::Always,
&src_caps,
)
.unwrap();
vec![sink_pad_template, src_pad_template]
});
PAD_TEMPLATES.as_ref()
}
}
impl VideoEncoderImpl for PngEncoder {
fn stop(&self, _element: &Self::Type) -> Result<(), gst::ErrorMessage> {
*self.state.lock() = None;
Ok(())
}
fn set_format(
&self,
element: &Self::Type,
state: &gst_video::VideoCodecState<'static, gst_video::video_codec_state::Readable>,
) -> Result<(), gst::LoggableError> {
let video_info = state.get_info();
gst_debug!(CAT, obj: element, "Setting format {:?}", video_info);
{
let settings = self.settings.lock();
let mut state = State::new(video_info);
state.reset(*settings)?;
*self.state.lock() = Some(state);
}
let output_state = element
.set_output_state(gst::Caps::new_simple("image/png", &[]), Some(state))
.map_err(|_| gst::loggable_error!(CAT, "Failed to set output state"))?;
element
.negotiate(output_state)
.map_err(|_| gst::loggable_error!(CAT, "Failed to negotiate"))
}
fn handle_frame(
&self,
element: &Self::Type,
mut frame: gst_video::VideoCodecFrame,
) -> Result<gst::FlowSuccess, gst::FlowError> {
let mut state_guard = self.state.lock();
let state = state_guard.as_mut().ok_or(gst::FlowError::NotNegotiated)?;
gst_debug!(
CAT,
obj: element,
"Sending frame {}",
frame.get_system_frame_number()
);
{
let input_buffer = frame
.get_input_buffer()
.expect("frame without input buffer");
let input_map = input_buffer.map_readable().unwrap();
let data = input_map.as_slice();
state.write_data(data).map_err(|e| {
gst::element_error!(element, gst::CoreError::Failed, [&e.to_string()]);
gst::FlowError::Error
})?;
}
let buffer = state.cache.consume();
drop(state_guard);
let output_buffer = gst::Buffer::from_mut_slice(buffer);
// There are no such incremental frames in the png format
frame.set_flags(gst_video::VideoCodecFrameFlags::SYNC_POINT);
frame.set_output_buffer(output_buffer);
element.finish_frame(Some(frame))
}
}
|