Writting metadata

src/main.cpp

@@ -5,27 +5,34 @@
 #include <format>
 #include <fstream>
 #include <future>
+#include <regex>
 #include <string>
 #include <vector>
 
-// This may come in handy later
-// `yt-dlp` supports the following audio codecs:
-// `mp3`: MP3 (MPEG Audio Layer 3)
-// `m4a`: MPEG-4 Audio
-// `ogg`: Ogg Vorbis
-// `flac`: FLAC (Free Lossless Audio Codec)
-// `opus`: Opus
-// `aac`: AAC (Advanced Audio Coding)
-
 #define TMP_DOWNLOAD_FOLDER "tmp/download"
 #define MAX_THREADS 4
 
 // This runs in shell, if put through a website interface it would allow for injection
-auto ytdlp(std::string args) -> bool {
+auto ytdlp(const std::string& args) -> bool {
   system(std::format("bin/linux/yt-dlp {}", args).c_str());
   return true;
 }
 
+auto metadata(const std::string& file, const std::string& artist, const std::string& album, size_t index) {
+  std::string name = std::filesystem::path(file).filename().string();
+
+  system(std::format("bin/linux/ffmpeg "
+                     "-hide_banner -loglevel error "
+                     "-i \"{}\" -c copy "
+                     "-metadata title=\"{}\" "
+                     "-metadata artist=\"{}\" "
+                     "-metadata album=\"{}\" "
+                     "-metadata track=\"{}\" "
+                     "\"{}/{}_{}.mp3\"",
+                     file, name, artist, album, index, TMP_DOWNLOAD_FOLDER, index, name)
+             .c_str());
+}
+
 auto cleanTmpDownloadFolder() -> bool {
   for (const auto& entry : std::filesystem::directory_iterator(TMP_DOWNLOAD_FOLDER)) {
     std::filesystem::remove_all(entry.path());
@@ -61,6 +68,41 @@ auto urlsFromPlaylist(const std::string& url) -> std::vector<std::string> {
   return urls;
 }
 
+auto dataFromYtdlpPlaylist(const std::string& playlistUrl, const std::string& data) -> std::string {
+  ytdlp(
+      std::format("--quiet "
+                  "--no-warnings "
+                  "--flat-playlist "
+                  "--playlist-items 1 "
+                  "--print-to-file \"%({})s\" data.txt \"{}\"",
+                  data, playlistUrl));
+
+  std::ifstream f("data.txt");
+  if (!f.is_open()) {
+    printf("ERROR: Couldn't open data.txt\n");
+  }
+
+  std::string s;
+  std::string line;
+  while (std::getline(f, line)) {
+    s = line;
+  }
+
+  return s;
+};
+
+auto playlistTitle(const std::string& playlistUrl) {
+  std::string s = dataFromYtdlpPlaylist(playlistUrl, "playlist_title");
+  s = std::regex_replace(s, std::regex("Album - "), "");
+  return s;
+}
+
+auto channelName(const std::string& playlistUrl) {
+  std::string s = dataFromYtdlpPlaylist(playlistUrl, "channel");
+  s = std::regex_replace(s, std::regex(" - Topic"), "");
+  return s;
+}
+
 auto downloadVideo(const std::string& url) -> bool {
   if (url == "") {
     printf("ERROR: Cannot download video with empty url\n");
@@ -80,7 +122,7 @@ auto downloadVideo(const std::string& url) -> bool {
   return true;
 }
 
-auto downloadPlaylist(const std::string& playlistUrl) -> bool {
+auto downloadPlaylist(std::string playlistUrl) -> bool {
   std::vector<std::string> videoUrls = urlsFromPlaylist(playlistUrl);
 
   if (videoUrls.empty()) {
@@ -93,6 +135,8 @@ auto downloadPlaylist(const std::string& playlistUrl) -> bool {
     return false;
   }
 
+  playlistUrl = std::regex_replace(playlistUrl, std::regex("music.youtube"), "www.youtube");
+
   int count = 0;
 
   for (size_t i = 0; i < videoUrls.size(); i += MAX_THREADS) {
@@ -116,11 +160,31 @@ auto downloadPlaylist(const std::string& playlistUrl) -> bool {
   return true;
 }
 
+auto writeAlbumMetadataToTmpFolder(const std::string& playlistUrl) -> bool {
+  std::string artist = channelName(playlistUrl);
+  std::string album = playlistTitle(playlistUrl);
+  printf("Starting to write metadata for %s by %s.\n", album.c_str(), artist.c_str());
+
+  size_t index = 1;
+  for (const auto& entry : std::filesystem::directory_iterator(TMP_DOWNLOAD_FOLDER)) {
+    metadata(entry.path(), artist, album, index);
+    printf("Finished writting metadata for %s.\n", entry.path().c_str());
+    std::filesystem::remove(entry.path());
+    index++;
+  }
+
+  printf("Finished writing metadata for %s by %s.\n", album.c_str(), artist.c_str());
+
+  return true;
+}
+
 auto main(int argc, char* argv[]) -> int {
   auto musicDir = "/home/ethanscharlie/Downloads/tmp";
-  auto url = "https://music.youtube.com/playlist?list=OLAK5uy_kwG9Ln_fS_R-Oa8F-JIgs8PPBoRgDe8ok";
+  std::string url = "https://music.youtube.com/playlist?list=OLAK5uy_kwG9Ln_fS_R-Oa8F-JIgs8PPBoRgDe8ok";
 
   std::filesystem::create_directories(TMP_DOWNLOAD_FOLDER);
 
+  url = std::regex_replace(url, std::regex("music.youtube"), "www.youtube");
   downloadPlaylist(url);
+  writeAlbumMetadataToTmpFolder(url);
 }