Add basic cue sheet handling

The cue sheet is printed to stdout.

src/cue_sheet/mod.rs

@@ -0,0 +1,78 @@
+//! Module to extract the cue sheet from the NRG metadata.
+
+use ::error::NrgError;
+use ::metadata::metadata::NrgMetadata;
+
+
+pub fn write_cue_sheet(image_name: &String, nm: &NrgMetadata)
+                       -> Result<(), NrgError> {
+    if nm.cuex_chunk.is_none() {
+        return Err(NrgError::NoNrgCue);
+    }
+    let cuex_tracks = &nm.cuex_chunk.as_ref().unwrap().tracks;
+
+    let file_name = try!(make_cue_sheet_name(image_name));
+
+    println!("FILE \"{}\" RAW", image_name);
+
+    let mut index0_pos = -1;
+    for track in cuex_tracks {
+        // Ignore lead-in and lead-out areas
+        if track.track_number == 0 || track.track_number == 0xAA {
+            continue;
+        }
+
+        // Ignore negative positions
+        if track.position_sectors < 0 {
+            continue;
+        }
+
+        // Store/skip index0
+        if track.index_number == 0 {
+            index0_pos = track.position_sectors;
+            continue;
+        }
+
+        // Write track info
+        println!("  TRACK {:02} AUDIO", track.track_number);
+
+        // Write index0 if we stored it and it's before the current index's
+        // position (i.e., it indicates a pre-gap)
+        if index0_pos >= 0 && index0_pos < track.position_sectors {
+            try!(write_cue_index(0, index0_pos));
+            index0_pos = -1;
+        }
+
+        // Write current index
+        try!(write_cue_index(track.index_number, track.position_sectors));
+    }
+
+    Ok(())
+}
+
+
+/// Generates the cue sheet's name from the NRG image's name.
+///
+/// If `image_name`'s extension is `.nrg` (case-insensitive), the cue sheet's
+/// name will be the same as `image_name` with a `.cue` extension instead of
+/// `.nrg`. Otherwise, the cue sheet's name will be `image_name.cue`.
+fn make_cue_sheet_name(image_name: &String) -> Result<String, NrgError> {
+    Ok("image.cue".to_string())
+}
+
+
+fn write_cue_index(index: u8, position_sectors: i32)
+                   -> Result<(), NrgError> {
+    assert!(position_sectors >= 0);
+
+    // Audio CDs are played at a 75 sectors per second rate:
+    let mut seconds: u32 = position_sectors as u32 / 75;
+    let remaining_sectors = position_sectors % 75;
+    let minutes = seconds / 60;
+    seconds %= 60;
+
+    println!("    INDEX {:02} {:02}:{:02}:{:02}",
+             index, minutes, seconds, remaining_sectors);
+
+    Ok(())
+}

src/error.rs

@@ -11,6 +11,7 @@ pub enum NrgError {
     NrgFormat,
     NrgFormatV1,
     NrgChunkId,
+    NoNrgCue,
 }
 
 impl fmt::Display for NrgError {
@@ -20,6 +21,7 @@ impl fmt::Display for NrgError {
             NrgError::NrgFormat => write!(f, "NRG format unknown."),
             NrgError::NrgFormatV1 => write!(f, "NRG v1 format is not handled."),
             NrgError::NrgChunkId => write!(f, "NRG chunk ID unknown."),
+            NrgError::NoNrgCue => write!(f, "NRG cue sheet chunk absent."),
         }
     }
 }
@@ -31,6 +33,7 @@ impl Error for NrgError {
             NrgError::NrgFormat => "NRG format",
             NrgError::NrgFormatV1 => "NRG format v1",
             NrgError::NrgChunkId => "NRG chunk ID",
+            NrgError::NoNrgCue => "No NRG cue",
         }
     }
 
@@ -40,6 +43,7 @@ impl Error for NrgError {
             NrgError::NrgFormat => None,
             NrgError::NrgFormatV1 => None,
             NrgError::NrgChunkId => None,
+            NrgError::NoNrgCue => None,
         }
     }
 }

src/lib.rs

@@ -1,4 +1,5 @@
 //! Extracts audio data and metadata from an NRG image of an audio CD.
 
-pub mod metadata;
 pub mod error;
+pub mod metadata;
+pub mod cue_sheet;

src/main.rs

@@ -21,7 +21,7 @@ fn main() {
         exit_usage(&prog_name);
     }
 
-    println!("NRG image name: {}", img_name);
+    println!("NRG image name: \"{}\"", img_name);
 
     // We don't support more than one input file
     if argv.next().is_some() {
@@ -31,18 +31,25 @@ fn main() {
     // Open the image file
     let fd = File::open(&img_name);
     if fd.is_err() {
-        println!("Can't open \"{}\": {}",
+        println!("Can't open image file \"{}\": {}",
                  img_name, fd.unwrap_err().to_string());
         process::exit(1);
     }
     let mut fd = fd.unwrap();
 
-    // Read the image's metadata
-    match nrgrip::metadata::read_nrg_metadata(&mut fd) {
-        Err(err) => println!("Error reading \"{}\": {}",
-                             img_name, err.to_string()),
-        Ok(metadata) => println!("\n\
-                                  *** Metadata ***\n\
-                                  {}", metadata),
+    // Read and display the image's metadata
+    let metadata = nrgrip::metadata::read_nrg_metadata(&mut fd);
+    if metadata.is_err() {
+        println!("Error reading \"{}\": {}",
+                 img_name, metadata.unwrap_err().to_string());
+        process::exit(1);
+    }
+    let metadata = metadata.unwrap();
+    println!("\n{}", metadata);
+
+    // Read and write the cue sheet
+    if let Err(err) = nrgrip::cue_sheet::write_cue_sheet(&img_name, &metadata) {
+        println!("Error writing cue sheet: {}", err.to_string());
+        process::exit(1);
     }
 }

src/metadata/mod.rs

@@ -5,7 +5,7 @@ use std::io::{Seek, SeekFrom};
 
 use ::error::NrgError;
 
-mod metadata;
+pub mod metadata;
 mod cuex;
 mod daox;
 mod sinf;