From e12ac1d9632856237388614bf393c7338500e00a Mon Sep 17 00:00:00 2001
From: jacqueline <me@jacqueline.id.au>
Date: Wed, 7 Jun 2023 15:39:28 +1000
Subject: Do some prep cleanup for multiple filetypes

---
 src/audio/fatfs_audio_input.cpp | 69 ++++++++++++++++++++++++++++++++++++-----
 1 file changed, 61 insertions(+), 8 deletions(-)

(limited to 'src/audio/fatfs_audio_input.cpp')

diff --git a/src/audio/fatfs_audio_input.cpp b/src/audio/fatfs_audio_input.cpp
index 9affcf1a..a89858ca 100644
--- a/src/audio/fatfs_audio_input.cpp
+++ b/src/audio/fatfs_audio_input.cpp
@@ -5,6 +5,7 @@
  */
 
 #include "fatfs_audio_input.hpp"
+#include <stdint.h>
 
 #include <algorithm>
 #include <cstdint>
@@ -23,10 +24,12 @@
 
 #include "audio_element.hpp"
 #include "chunk.hpp"
+#include "song.hpp"
 #include "stream_buffer.hpp"
 #include "stream_event.hpp"
 #include "stream_info.hpp"
 #include "stream_message.hpp"
+#include "tag_parser.hpp"
 #include "types.hpp"
 
 static const char* kTag = "SRC";
@@ -34,7 +37,11 @@ static const char* kTag = "SRC";
 namespace audio {
 
 FatfsAudioInput::FatfsAudioInput()
-    : IAudioElement(), current_file_(), is_file_open_(false) {}
+    : IAudioElement(),
+      current_file_(),
+      is_file_open_(false),
+      current_container_(),
+      current_format_() {}
 
 FatfsAudioInput::~FatfsAudioInput() {}
 
@@ -44,6 +51,36 @@ auto FatfsAudioInput::OpenFile(const std::string& path) -> bool {
     is_file_open_ = false;
   }
   ESP_LOGI(kTag, "opening file %s", path.c_str());
+
+  database::TagParserImpl tag_parser;
+  database::SongTags tags;
+  if (!tag_parser.ReadAndParseTags(path, &tags)) {
+    ESP_LOGE(kTag, "failed to read tags");
+    return false;
+  }
+
+  auto stream_type = ContainerToStreamType(tags.encoding);
+  if (!stream_type.has_value()) {
+    return false;
+  }
+
+  current_container_ = tags.encoding;
+
+  if (*stream_type == codecs::StreamType::kPcm && tags.channels &&
+      tags.bits_per_sample && tags.channels) {
+    // WAV files are a special case bc they contain raw PCM streams. These don't
+    // need decoding, but we *do* need to parse the PCM format from the header.
+    // TODO(jacqueline): Maybe we should have a decoder for this just to deal
+    // with endianness differences?
+    current_format_ = StreamInfo::Pcm{
+        .channels = static_cast<uint8_t>(*tags.channels),
+        .bits_per_sample = static_cast<uint8_t>(*tags.bits_per_sample),
+        .sample_rate = static_cast<uint32_t>(*tags.sample_rate),
+    };
+  } else {
+    current_format_ = StreamInfo::Encoded{*stream_type};
+  }
+
   FRESULT res = f_open(&current_file_, path.c_str(), FA_READ);
   if (res != FR_OK) {
     ESP_LOGE(kTag, "failed to open file! res: %i", res);
@@ -61,13 +98,10 @@ auto FatfsAudioInput::NeedsToProcess() const -> bool {
 auto FatfsAudioInput::Process(const std::vector<InputStream>& inputs,
                               OutputStream* output) -> void {
   if (!is_file_open_) {
-    // TODO(jacqueline): should we clear the stream format?
-    // output->prepare({});
     return;
   }
 
-  StreamInfo::Format format = StreamInfo::Encoded{codecs::STREAM_MP3};
-  if (!output->prepare(format)) {
+  if (!output->prepare(*current_format_)) {
     return;
   }
 
@@ -91,12 +125,31 @@ auto FatfsAudioInput::Process(const std::vector<InputStream>& inputs,
     f_close(&current_file_);
     is_file_open_ = false;
 
-    // TODO(jacqueline): MP3 only
-    std::fill_n(output->data().begin(), 8, std::byte(0));
-    output->add(8);
+    // HACK: libmad requires an 8 byte padding at the end of each file.
+    if (current_container_ == database::Encoding::kMp3) {
+      std::fill_n(output->data().begin(), 8, std::byte(0));
+      output->add(8);
+    }
 
     events::Dispatch<InputFileFinished, AudioState>({});
   }
 }
 
+auto FatfsAudioInput::ContainerToStreamType(database::Encoding enc)
+    -> std::optional<codecs::StreamType> {
+  switch (enc) {
+    case database::Encoding::kMp3:
+      return codecs::StreamType::kMp3;
+    case database::Encoding::kWav:
+      return codecs::StreamType::kPcm;
+    case database::Encoding::kFlac:
+      return codecs::StreamType::kFlac;
+    case database::Encoding::kOgg:
+      return codecs::StreamType::kOgg;
+    case database::Encoding::kUnsupported:
+    default:
+      return {};
+  }
+}
+
 }  // namespace audio
-- 
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