From a2c1dfbabddc2b4abaf8bf27c9ed9d1b99594859 Mon Sep 17 00:00:00 2001
From: jacqueline <me@jacqueline.id.au>
Date: Thu, 15 Jun 2023 10:33:46 +1000
Subject: Add vorbis and flac decoders, flesh out codec interface

vorbis doesn't quite work yet, not sure why. will pick it up again
later.
---
 src/codecs/foxenflac.cpp | 80 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 src/codecs/foxenflac.cpp

(limited to 'src/codecs/foxenflac.cpp')

diff --git a/src/codecs/foxenflac.cpp b/src/codecs/foxenflac.cpp
new file mode 100644
index 00000000..a2d6f000
--- /dev/null
+++ b/src/codecs/foxenflac.cpp
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2023 jacqueline <me@jacqueline.id.au>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#include "foxenflac.hpp"
+#include <stdint.h>
+
+#include <cstdlib>
+
+#include "esp_log.h"
+#include "foxen/flac.h"
+
+namespace codecs {
+
+FoxenFlacDecoder::FoxenFlacDecoder()
+    : flac_(FX_FLAC_ALLOC(FLAC_MAX_BLOCK_SIZE, 2)) {}
+
+FoxenFlacDecoder::~FoxenFlacDecoder() {
+  free(flac_);
+}
+
+auto FoxenFlacDecoder::BeginStream(const cpp::span<const std::byte> input)
+    -> Result<OutputFormat> {
+  uint32_t bytes_used = input.size_bytes();
+  fx_flac_state_t state =
+      fx_flac_process(flac_, reinterpret_cast<const uint8_t*>(input.data()),
+                      &bytes_used, NULL, NULL);
+  if (state != FLAC_END_OF_METADATA) {
+    return {bytes_used, cpp::fail(Error::kMalformedData)};
+  }
+
+  int64_t channels = fx_flac_get_streaminfo(flac_, FLAC_KEY_N_CHANNELS);
+  int64_t fs = fx_flac_get_streaminfo(flac_, FLAC_KEY_SAMPLE_RATE);
+  if (channels == FLAC_INVALID_METADATA_KEY ||
+      fs == FLAC_INVALID_METADATA_KEY) {
+    return {bytes_used, cpp::fail(Error::kMalformedData)};
+  }
+
+  return {bytes_used,
+          OutputFormat{
+              .num_channels = static_cast<uint8_t>(channels),
+              .bits_per_sample = 32,  // libfoxenflac output is fixed-size.
+              .sample_rate_hz = static_cast<uint32_t>(fs),
+          }};
+}
+
+auto FoxenFlacDecoder::ContinueStream(cpp::span<const std::byte> input,
+                                      cpp::span<std::byte> output)
+    -> Result<OutputInfo> {
+  cpp::span<int32_t> output_as_samples{
+      reinterpret_cast<int32_t*>(output.data()), output.size_bytes() / 4};
+  uint32_t bytes_read = input.size_bytes();
+  uint32_t samples_written = output_as_samples.size();
+
+  fx_flac_state_t state =
+      fx_flac_process(flac_, reinterpret_cast<const uint8_t*>(input.data()),
+                      &bytes_read, output_as_samples.data(), &samples_written);
+  if (state == FLAC_ERR) {
+    return {bytes_read, cpp::fail(Error::kMalformedData)};
+  }
+
+  if (samples_written > 0) {
+    return {bytes_read,
+            OutputInfo{.bytes_written = samples_written * 4,
+                       .is_finished_writing = state == FLAC_END_OF_FRAME}};
+  }
+
+  // No error, but no samples written. We must be out of data.
+  return {bytes_read, cpp::fail(Error::kOutOfInput)};
+}
+
+auto FoxenFlacDecoder::SeekStream(cpp::span<const std::byte> input,
+                                  std::size_t target_sample) -> Result<void> {
+  // TODO(jacqueline): Implement me.
+  return {0, {}};
+}
+
+}  // namespace codecs
-- 
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