1 files changed, 161 insertions, 0 deletions
diff --git a/src/codecs/wavpack.cpp b/src/codecs/wavpack.cpp
new file mode 100644
index 00000000..fa168d32
--- /dev/null
+++ b/src/codecs/wavpack.cpp
@@ -0,0 +1,161 @@
+/*
+ * Copyright 2025 ayumi <ayumi@noreply.codeberg.org>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#include "wavpack.hpp"
+
+#include <cstdint>
+#include <cstring>
+#include <algorithm>
+#include <optional>
+
+#include "esp_heap_caps.h"
+#include "codec.hpp"
+#include "esp_log.h"
+#include "result.hpp"
+#include "sample.hpp"
+#include "types.hpp"
+
+namespace codecs {
+
+[[maybe_unused]] static constexpr const char kTag[] = "wavpack";
+// kBufSize and audio::kCodecBufferLength must be equal
+static constexpr const size_t kBufSize = 2048;
+
+static inline constexpr auto loadLe16(std::byte* data) -> uint16_t {
+  return *reinterpret_cast<uint16_t*>(data);
+}
+
+static inline constexpr auto loadLe32(std::byte* data) -> uint32_t {
+  return *reinterpret_cast<uint32_t*>(data);
+}
+
+static auto readProc(void* data, void* buf, long size) -> long {
+  IStream* stream = static_cast<IStream*>(data);
+  const int32_t res = stream->Read({
+      static_cast<std::byte*>(buf),
+      static_cast<std::span<std::byte>::size_type>(size)
+  });
+  return res < 0 ? 0 : res;
+}
+
+WavPackDecoder::WavPackDecoder() : input_(), buf_() {
+  buf_ = static_cast<int32_t*>(
+      heap_caps_malloc(
+          kBufSize * sizeof(int32_t),
+          MALLOC_CAP_INTERNAL | MALLOC_CAP_CACHE_ALIGNED
+  ));
+}
+
+WavPackDecoder::~WavPackDecoder() {
+  heap_caps_free(buf_);
+}
+
+auto WavPackDecoder::OpenStream(std::shared_ptr<IStream> input, uint32_t offset)
+    -> cpp::result<OutputFormat, ICodec::Error> {
+  char error[80];
+  input_ = input;
+  wavpack_ = {};
+  if (!WavpackOpenFileInput(&wavpack_, readProc, input_.get(), error)) {
+    ESP_LOGE(kTag, "WavpackOpenFileInput: %s", error);
+    return cpp::fail(Error::kMalformedData);
+  }
+
+  channels_ = WavpackGetReducedChannels(&wavpack_);
+  bitdepth_ = WavpackGetBitsPerSample(&wavpack_);
+  size_ = kBufSize / channels_;
+  const std::optional total = WavpackGetNumSamples(&wavpack_) == -1
+      ? std::nullopt
+      : std::optional(
+          static_cast<uint64_t>(WavpackGetNumSamples(&wavpack_)) * channels_
+        );
+  const auto rate = WavpackGetSampleRate(&wavpack_);
+  if (offset && total && input_.get()->CanSeek()) {
+    const uint32_t want = offset * rate - 1;
+    if (total < want) {
+      ESP_LOGE(kTag, "seeking: offset points beyond the end of the file");
+      return cpp::fail(Error::kInternalError);
+    }
+
+    uint32_t target;
+    input_->SeekTo(0, IStream::SeekFrom::kStartOfStream);
+    while (true) {
+      std::byte header[32];
+      input_->Read(header);
+      if (memcmp(header, "wvpk", 4) != 0) {
+        ESP_LOGE(kTag, "seeking: header expected, but not found");
+        return cpp::fail(Error::kMalformedData);
+      }
+      const uint32_t size = loadLe32(header + 4);
+      const uint16_t version = loadLe16(header + 8);
+      if (version < 0x402 || version > 0x410) {
+        ESP_LOGE(kTag, "seeking: bad WavPack version (%x)", version);
+        return cpp::fail(Error::kMalformedData);
+      }
+      const uint32_t blockIndex = loadLe32(header + 16);
+      const uint32_t blockSamples = loadLe32(header + 20);
+      if (want >= blockIndex && want <= blockIndex + blockSamples) {
+        input_->SeekTo(-32, IStream::SeekFrom::kCurrentPosition);
+        target = want - blockIndex;
+        break;
+      }
+      input_->SeekTo(size - 24, IStream::SeekFrom::kCurrentPosition);
+    }
+
+    wavpack_ = {};
+    if (!WavpackOpenFileInput(&wavpack_, readProc, input_.get(), error)) {
+      ESP_LOGE(kTag, "WavpackOpenFileInput: %s", error);
+      return cpp::fail(Error::kMalformedData);
+    }
+
+    uint32_t samples = 0;
+    for (size_t i = 0, n = target / size_; i < n; i++)
+      samples += WavpackUnpackSamples(&wavpack_, buf_, size_);
+    samples += WavpackUnpackSamples(&wavpack_, buf_, target % size_);
+    if (WavpackGetNumErrors(&wavpack_) != 0) {
+      ESP_LOGE(kTag, "CRC error");
+      return cpp::fail(Error::kMalformedData);
+    } else if (samples != target || WavpackGetSampleIndex(&wavpack_) != want) {
+      ESP_LOGE(kTag, "seeking: seeking unsuccessful: want %lu, got %lu",
+          target, samples
+      );
+      return cpp::fail(Error::kInternalError);
+    }
+  } else if (offset && (!total || !input_.get()->CanSeek())) {
+    ESP_LOGE(kTag, "seeking: can’t seek");
+    return cpp::fail(Error::kInternalError);
+  }
+
+  const auto size = input->Size();
+  return OutputFormat{
+      .num_channels = channels_,
+      .sample_rate_hz = rate,
+      .total_samples = total,
+      .bitrate_kbps = size && total
+          ? std::optional(
+              ((double)size.value() * 8.0)
+              / ((double)total.value() / channels_ / rate) / 1000
+            )
+          : std::nullopt,
+  };
+}
+
+auto WavPackDecoder::DecodeTo(std::span<sample::Sample> output)
+    -> cpp::result<OutputInfo, Error> {
+  const auto size = std::min(size_, output.size() / channels_);
+  const auto samples = WavpackUnpackSamples(&wavpack_, buf_, size) * channels_;
+  if (WavpackGetNumErrors(&wavpack_) != 0) {
+    ESP_LOGE(kTag, "CRC error");
+    return cpp::fail(Error::kMalformedData);
+  }
+  for (size_t i = 0; i < samples; i++)
+    output[i] = sample::FromSigned(buf_[i], bitdepth_);
+  return OutputInfo{
+      .samples_written = samples,
+      .is_stream_finished = samples == 0,
+  };
+}
+
+}  // namespace codecs