Merge branch 'main' into lua-volume

1 files changed, 115 insertions, 0 deletions

diff --git a/src/codecs/dr_flac.cpp b/src/codecs/dr_flac.cpp
new file mode 100644
index 00000000..2f9acf8c
--- /dev/null
+++ b/src/codecs/dr_flac.cpp
@@ -0,0 +1,115 @@
+/*
+ * Copyright 2023 jacqueline <me@jacqueline.id.au>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#include "dr_flac.hpp"
+
+#include <cstdint>
+#include <cstdlib>
+
+#include "codec.hpp"
+#include "dr_flac.h"
+#include "esp_heap_caps.h"
+#include "esp_log.h"
+#include "result.hpp"
+#include "sample.hpp"
+
+namespace codecs {
+
+[[maybe_unused]] static const char kTag[] = "flac";
+
+static void* onMalloc(size_t sz, void* pUserData) {
+  return heap_caps_malloc(sz, MALLOC_CAP_SPIRAM);
+}
+
+static void* onRealloc(void* p, size_t sz, void* pUserData) {
+  return heap_caps_realloc(p, sz, MALLOC_CAP_SPIRAM);
+}
+
+static void onFree(void* p, void* pUserData) {
+  heap_caps_free(p);
+}
+
+static drflac_allocation_callbacks kAllocCallbacks{
+    .pUserData = nullptr,
+    .onMalloc = onMalloc,
+    .onRealloc = onRealloc,
+    .onFree = onFree,
+};
+
+static size_t readProc(void* pUserData, void* pBufferOut, size_t bytesToRead) {
+  IStream* stream = reinterpret_cast<IStream*>(pUserData);
+  ssize_t res =
+      stream->Read({reinterpret_cast<std::byte*>(pBufferOut), bytesToRead});
+  return res < 0 ? 0 : res;
+}
+
+static drflac_bool32 seekProc(void* pUserData,
+                              int offset,
+                              drflac_seek_origin origin) {
+  IStream* stream = reinterpret_cast<IStream*>(pUserData);
+  if (!stream->CanSeek()) {
+    return DRFLAC_FALSE;
+  }
+
+  IStream::SeekFrom seek_from;
+  switch (origin) {
+    case drflac_seek_origin_start:
+      seek_from = IStream::SeekFrom::kStartOfStream;
+      break;
+    case drflac_seek_origin_current:
+      seek_from = IStream::SeekFrom::kCurrentPosition;
+      break;
+    default:
+      return DRFLAC_FALSE;
+  }
+  stream->SeekTo(offset, seek_from);
+
+  // FIXME: Detect falling off the end of the file.
+  return DRFLAC_TRUE;
+}
+
+DrFlacDecoder::DrFlacDecoder() : input_(), flac_() {}
+
+DrFlacDecoder::~DrFlacDecoder() {
+  if (flac_) {
+    drflac_free(flac_, &kAllocCallbacks);
+  }
+}
+
+auto DrFlacDecoder::OpenStream(std::shared_ptr<IStream> input, uint32_t offset)
+    -> cpp::result<OutputFormat, Error> {
+  input_ = input;
+
+  flac_ = drflac_open(readProc, seekProc, input_.get(), &kAllocCallbacks);
+  if (!flac_) {
+    return cpp::fail(Error::kMalformedData);
+  }
+
+  if (offset && !drflac_seek_to_pcm_frame(flac_, offset * flac_->sampleRate)) {
+    return cpp::fail(Error::kMalformedData);
+  }
+
+  OutputFormat format{
+      .num_channels = static_cast<uint8_t>(flac_->channels),
+      .sample_rate_hz = static_cast<uint32_t>(flac_->sampleRate),
+      .total_samples = flac_->totalPCMFrameCount * flac_->channels,
+  };
+  return format;
+}
+
+auto DrFlacDecoder::DecodeTo(cpp::span<sample::Sample> output)
+    -> cpp::result<OutputInfo, Error> {
+  size_t frames_to_read = output.size() / flac_->channels / 2;
+
+  auto frames_written = drflac_read_pcm_frames_s16(
+      flac_, output.size() / flac_->channels, output.data());
+
+  return OutputInfo{
+      .samples_written = static_cast<size_t>(frames_written * flac_->channels),
+      .is_stream_finished = frames_written < frames_to_read};
+}
+
+}  // namespace codecs