Use ffprobe to read meta-data if not compiled against libav

Closes #18

ChangeLog

@@ -11,8 +11,7 @@
    flags.
 6. Add option to write analysis results to files, and use for future scans.
 7. If log level set to 'trace' then set this level for the Bliss library too.
-8. Enable support for '.dsf' files, but only if compiled against ffmpeg
-   libraries.
+8. Enable support for '.dsf' files.
 
 0.2.3
 -----

src/analyse.rs

@@ -40,11 +40,7 @@ use bliss_audio::{decoder::Decoder, BlissResult, Song};
 const DONT_ANALYSE: &str = ".notmusic";
 const MAX_ERRORS_TO_SHOW: usize = 100;
 const MAX_TAG_ERRORS_TO_SHOW: usize = 50;
-
-#[cfg(feature = "libav")]
 const VALID_EXTENSIONS: [&str; 7] = ["m4a", "mp3", "ogg", "flac", "opus", "wv", "dsf"];
-#[cfg(not(feature = "libav"))]
-const VALID_EXTENSIONS: [&str; 6] = ["m4a", "mp3", "ogg", "flac", "opus", "wv"];
 
 fn get_file_list(db: &mut db::Db, mpath: &Path, path: &Path, track_paths: &mut Vec<String>, cue_tracks:&mut Vec<cue::CueTrack>, file_count:&mut usize, max_num_files: usize, use_tags: bool, tagged_file_count:&mut usize, dry_run: bool) {
     if !path.is_dir() {
@@ -285,7 +281,10 @@ fn analyse_new_files(db: &db::Db, mpath: &PathBuf, track_paths: Vec<String>, max
         match result {
             Ok(track) => {
                 let cpath = String::from(path.to_string_lossy());
-                let meta = tags::read(&cpath, false);
+                let mut meta = tags::read(&cpath, false);
+                if meta.is_empty() {
+                    meta = ffmpeg::read_tags(&cpath);
+                }
                 if meta.is_empty() {
                     tag_error.push(sname.clone());
                 }

src/ffmpeg.rs

@@ -6,6 +6,7 @@
  *
  **/
 
+use crate::db;
 use bliss_audio::decoder::Decoder as DecoderTrait;
 use bliss_audio::decoder::PreAnalyzedSong;
 use bliss_audio::{BlissError, BlissResult};
@@ -13,6 +14,8 @@ use std::path::Path;
 use std::process::{Child, Command, Stdio};
 use std::io;
 use std::io::Read;
+use std::io::BufRead;
+use std::io::BufReader;
 use std::time::Duration;
 
 pub const TIME_SEP:&str = "<TIME>";
@@ -41,6 +44,59 @@ fn handle_command(mut child: Child) -> BlissResult<PreAnalyzedSong> {
     Ok(decoded_song)
 }
 
+fn get_val(line: String) -> String {
+    let parts = line.split("=");
+    let mut resp:Vec<String> = Vec::new();
+    let mut first =true;
+    for part in parts {
+        if !first {
+            resp.push(String::from(part));
+        }
+        first = false
+    }
+    resp.join("=")
+}
+
+pub fn read_tags(path: &String) -> db::Metadata {
+    let mut meta = db::Metadata {
+        duration: 0,
+        ..db::Metadata::default()
+    };
+
+    if let Ok(child) = Command::new("ffprobe")
+                                .arg("-hide_banner")
+                                .arg("-v").arg("quiet")
+                                .arg("-show_entries").arg("format")
+                                .arg(path)
+                                .stdout(Stdio::piped())
+                                .spawn() {
+        let out = child.stdout.unwrap();
+        let lines = BufReader::new(out).lines().filter_map(|line| line.ok());
+        for line in lines {
+            if line.starts_with("duration=") {
+                let val = get_val(line);
+                match val.parse::<f32>() {
+                    Ok(v) => {
+                        meta.duration = v as u32;
+                    },
+                    Err(_) => { }
+                }
+            } else if line.starts_with("TAG:title=") {
+                meta.title = get_val(line);
+            } else if line.starts_with("TAG:artist=") {
+                meta.artist = get_val(line);
+            } else if line.starts_with("TAG:album=") {
+                meta.album = get_val(line);
+            } else if line.starts_with("TAG:album_artist=") {
+                meta.album_artist = get_val(line);
+            } else if line.starts_with("TAG:genre=") {
+                meta.genre = get_val(line);
+            }
+        }
+    }
+    meta
+}
+
 impl DecoderTrait for FFmpegCmdDecoder {
     fn decode(path: &Path) -> BlissResult<PreAnalyzedSong> {
         let binding = path.to_string_lossy();