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/*
* Copyright 2023 jacqueline <me@jacqueline.id.au>
*
* SPDX-License-Identifier: GPL-3.0-only
*/
#include "opus.hpp"
#include <stdint.h>
#include <sys/_stdint.h>
#include <cstdint>
#include <cstring>
#include <optional>
#include "esp_heap_caps.h"
#include "mad.h"
#include "codec.hpp"
#include "esp_log.h"
#include "opus.h"
#include "opus_types.h"
#include "result.hpp"
#include "sample.hpp"
#include "types.hpp"
namespace codecs {
static constexpr char kTag[] = "opus";
// "If this is less than the maximum packet duration (120ms; 5760 for 48kHz),
// this function will not be capable of decoding some packets"
static constexpr size_t kSampleBufferSize = 5760;
XiphOpusDecoder::XiphOpusDecoder() {
int err;
opus_ = opus_decoder_create(48000, 2, &err);
assert(err == OPUS_OK);
pos_in_buffer_ = 0;
sample_buffer_ = {reinterpret_cast<opus_int16*>(
heap_caps_calloc(kSampleBufferSize, sizeof(opus_int16),
MALLOC_CAP_8BIT | MALLOC_CAP_SPIRAM)),
kSampleBufferSize};
}
XiphOpusDecoder::~XiphOpusDecoder() {
opus_decoder_destroy(opus_);
heap_caps_free(sample_buffer_.data());
}
auto XiphOpusDecoder::BeginStream(const cpp::span<const std::byte> input)
-> Result<OutputFormat> {
return {0, OutputFormat{
.num_channels = 2,
.sample_rate_hz = 48000,
}};
}
auto read_uint32(cpp::span<const std::byte> src) -> uint32_t {
return static_cast<uint32_t>(src[0] << 24) |
static_cast<uint32_t>(src[1] << 16) |
static_cast<uint32_t>(src[2] << 8) |
static_cast<uint32_t>(src[3] << 0);
}
auto XiphOpusDecoder::ContinueStream(cpp::span<const std::byte> input,
cpp::span<sample::Sample> output)
-> Result<OutputInfo> {
size_t bytes_used = 0;
if (pos_in_buffer_ >= samples_in_buffer_) {
ESP_LOGI(kTag, "sample buffer is empty. parsing more.");
if (input.size() < 4) {
return {0, cpp::fail(Error::kOutOfInput)};
}
uint32_t payload_length = read_uint32(input);
ESP_LOGI(kTag, "payload length is %lu", payload_length);
if (input.size() - 4 < payload_length) {
ESP_LOGI(kTag, "input too small for payload");
return {0, cpp::fail(Error::kOutOfInput)};
}
// Next 4 bytes are the 'final range'.
// uint32_t enc_final_range = read_uint32(input.subspan(4));
bytes_used = payload_length + 8;
pos_in_buffer_ = 0;
samples_in_buffer_ = opus_decode(
opus_, reinterpret_cast<const unsigned char*>(input.data() + 8),
payload_length, sample_buffer_.data(), sample_buffer_.size(), 0);
if (samples_in_buffer_ < 0) {
ESP_LOGE(kTag, "error decoding stream");
return {bytes_used, cpp::fail(Error::kMalformedData)};
}
}
size_t samples_written = 0;
while (pos_in_buffer_ < samples_in_buffer_ &&
samples_written < output.size()) {
output[samples_written++] =
sample::FromSigned(sample_buffer_[pos_in_buffer_++], 16);
}
return {bytes_used,
OutputInfo{
.samples_written = samples_written,
.is_finished_writing = pos_in_buffer_ >= samples_in_buffer_,
}};
}
auto XiphOpusDecoder::SeekStream(cpp::span<const std::byte> input,
std::size_t target_sample) -> Result<void> {
return {};
}
} // namespace codecs
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