servo_media_audio/
offline_sink.rs

1use crate::block::{Chunk, FRAMES_PER_BLOCK_USIZE};
2use crate::render_thread::AudioRenderThreadMsg;
3use servo_media_streams::MediaSocket;
4use crate::sink::{AudioSink, AudioSinkError};
5use std::cell::{Cell, RefCell};
6use std::sync::mpsc::Sender;
7
8pub struct ProcessedAudio(Box<[f32]>);
9
10impl AsRef<[f32]> for ProcessedAudio {
11    fn as_ref(&self) -> &[f32] {
12        &self.0
13    }
14}
15
16pub struct OfflineAudioSink {
17    buffer: RefCell<Option<Vec<f32>>>,
18    channel_count: usize,
19    has_enough_data: Cell<bool>,
20    length: usize,
21    rendered_blocks: Cell<usize>,
22    eos_callback: RefCell<Option<Box<dyn Fn(Box<dyn AsRef<[f32]>>) + Send + Sync + 'static>>>,
23}
24
25impl OfflineAudioSink {
26    pub fn new(channel_count: usize, length: usize) -> Self {
27        Self {
28            buffer: RefCell::new(None),
29            channel_count,
30            has_enough_data: Cell::new(false),
31            length,
32            rendered_blocks: Cell::new(0),
33            eos_callback: RefCell::new(None),
34        }
35    }
36}
37
38impl AudioSink for OfflineAudioSink {
39    fn init(&self, _: f32, _: Sender<AudioRenderThreadMsg>) -> Result<(), AudioSinkError> {
40        Ok(())
41    }
42    fn init_stream(&self, _: u8, _: f32, _: Box<dyn MediaSocket>) -> Result<(), AudioSinkError> {
43        unreachable!("OfflineAudioSink should never be used for MediaStreamDestinationNode")
44    }
45    fn play(&self) -> Result<(), AudioSinkError> {
46        self.has_enough_data.set(false);
47        Ok(())
48    }
49
50    fn stop(&self) -> Result<(), AudioSinkError> {
51        self.has_enough_data.set(true);
52        Ok(())
53    }
54
55    fn has_enough_data(&self) -> bool {
56        self.has_enough_data.get()
57            || (self.rendered_blocks.get() * FRAMES_PER_BLOCK_USIZE >= self.length)
58    }
59
60    fn push_data(&self, mut chunk: Chunk) -> Result<(), AudioSinkError> {
61        let offset = self.rendered_blocks.get() * FRAMES_PER_BLOCK_USIZE;
62        let (last, copy_len) = if self.length - offset <= FRAMES_PER_BLOCK_USIZE {
63            (true, self.length - offset)
64        } else {
65            (false, FRAMES_PER_BLOCK_USIZE)
66        };
67        let mut buffer = self.buffer.borrow_mut();
68        if buffer.is_none() {
69            *buffer = Some(vec![0.; self.channel_count * self.length]);
70        }
71        if chunk.len() == 0 {
72            chunk.blocks.push(Default::default());
73        }
74        if chunk.blocks[0].is_empty() {
75            chunk.blocks[0].explicit_silence();
76        }
77        if let Some(ref mut buffer) = *buffer {
78            for channel_number in 0..self.channel_count {
79                let channel_offset = offset + (channel_number * self.length);
80                let channel_data = &mut buffer[channel_offset..channel_offset + copy_len];
81                channel_data
82                    .copy_from_slice(&chunk.blocks[0].data_chan(channel_number as u8)[0..copy_len]);
83            }
84        };
85        self.rendered_blocks.set(self.rendered_blocks.get() + 1);
86
87        if last {
88            if let Some(callback) = self.eos_callback.borrow_mut().take() {
89                let processed_audio = ProcessedAudio(buffer.take().unwrap().into_boxed_slice());
90                callback(Box::new(processed_audio));
91            }
92        }
93
94        Ok(())
95    }
96
97    fn set_eos_callback(
98        &self,
99        callback: Box<dyn Fn(Box<dyn AsRef<[f32]>>) + Send + Sync + 'static>,
100    ) {
101        *self.eos_callback.borrow_mut() = Some(callback);
102    }
103}
servo_media_audio/offline_sink.rs

servo_media_audio/
offline_sink.rs
