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
|
#include "audio_decoder.hpp"
#include <string.h>
#include <cstddef>
#include <cstdint>
#include <memory>
#include "freertos/FreeRTOS.h"
#include "esp_heap_caps.h"
#include "freertos/message_buffer.h"
#include "freertos/portmacro.h"
#include "audio_element.hpp"
#include "chunk.hpp"
#include "fatfs_audio_input.hpp"
#include "stream_info.hpp"
namespace audio {
static const std::size_t kSamplesPerChunk = 256;
AudioDecoder::AudioDecoder() : IAudioElement(), stream_info_({}) {}
AudioDecoder::~AudioDecoder() {}
auto AudioDecoder::HasUnprocessedInput() -> bool {
return !needs_more_input_ || has_samples_to_send_;
}
auto AudioDecoder::ProcessStreamInfo(const StreamInfo& info)
-> cpp::result<void, AudioProcessingError> {
stream_info_ = info;
if (info.ChunkSize()) {
chunk_reader_.emplace(info.ChunkSize().value());
} else {
// TODO.
}
// Reuse the existing codec if we can. This will help with gapless playback,
// since we can potentially just continue to decode as we were before,
// without any setup overhead.
if (current_codec_->CanHandleFile(info.Path().value_or(""))) {
current_codec_->ResetForNewStream();
return {};
}
auto result = codecs::CreateCodecForFile(info.Path().value());
if (result.has_value()) {
current_codec_ = std::move(result.value());
} else {
return cpp::fail(UNSUPPORTED_STREAM);
}
// TODO: defer until first header read, so we can give better info about
// sample rate, chunk size, etc.
auto downstream_info = StreamEvent::CreateStreamInfo(
input_events_, std::make_unique<StreamInfo>(info));
downstream_info->stream_info->BitsPerSample(32);
downstream_info->stream_info->SampleRate(48'000);
chunk_size_ = 128;
downstream_info->stream_info->ChunkSize(chunk_size_);
SendOrBufferEvent(std::move(downstream_info));
return {};
}
auto AudioDecoder::ProcessChunk(const cpp::span<std::byte>& chunk)
-> cpp::result<size_t, AudioProcessingError> {
if (current_codec_ == nullptr || !chunk_reader_) {
// Should never happen, but fail explicitly anyway.
return cpp::fail(UNSUPPORTED_STREAM);
}
current_codec_->SetInput(chunk_reader_->HandleNewData(chunk));
return {};
}
auto AudioDecoder::Process() -> cpp::result<void, AudioProcessingError> {
if (has_samples_to_send_) {
// Writing samples is relatively quick (it's just a bunch of memcopy's), so
// do them all at once.
while (has_samples_to_send_ && !IsOverBuffered()) {
auto buffer = StreamEvent::CreateChunkData(input_events_, chunk_size_);
auto write_res =
current_codec_->WriteOutputSamples(buffer->chunk_data.bytes);
buffer->chunk_data.bytes =
buffer->chunk_data.bytes.first(write_res.first);
has_samples_to_send_ = !write_res.second;
if (!SendOrBufferEvent(std::move(buffer))) {
return {};
}
}
// We will process the next frame during the next call to this method.
return {};
}
if (!needs_more_input_) {
auto res = current_codec_->ProcessNextFrame();
if (res.has_error()) {
// todo
return {};
}
needs_more_input_ = res.value();
has_samples_to_send_ = true;
if (needs_more_input_) {
chunk_reader_->HandleLeftovers(current_codec_->GetInputPosition());
}
}
return {};
}
} // namespace audio
|
