feat: Add --list-tracks option to list media file tracks

docs/CHANGES.TXT

@@ -1,5 +1,6 @@
 0.95 (2025-09-15)
 -----------------
+- New: Added --list-tracks (-L) option to list all tracks in media files without processing
 - Fix: Garbled captions from HDHomeRun and I/P-only H.264 streams (#1109)
 - Fix: Enable stdout output for CEA-708 captions on Windows (#1693)
 - Fix: McPoodle DVD raw format read/write - properly handle loop markers (#1524)

src/rust/lib_ccxr/src/common/options.rs

@@ -424,6 +424,8 @@ pub struct Options {
     pub mp4vidtrack: bool,
     /// If true, extracts chapters (if present), from MP4 files.
     pub extract_chapters: bool,
+    /// If true, only list tracks in the input file without processing
+    pub list_tracks_only: bool,
     /* General settings */
     /// Force the use of pic_order_cnt_lsb in AVC/H.264 data streams
     pub usepicorder: bool,
@@ -562,6 +564,7 @@ impl Default for Options {
             auto_myth: None,
             mp4vidtrack: Default::default(),
             extract_chapters: Default::default(),
+            list_tracks_only: Default::default(),
             usepicorder: Default::default(),
             xmltv: Default::default(),
             xmltvliveinterval: Timestamp::from_millis(10000),

src/rust/src/args.rs

@@ -353,6 +353,10 @@ pub struct Args {
     /// Uses multiple programs from the same input stream.
     #[arg(long, verbatim_doc_comment, help_heading=OPTIONS_AFFECTING_INPUT_FILES)]
     pub multiprogram: bool,
+    /// List all tracks found in the input file and exit without
+    /// processing. Useful for exploring media files before extraction.
+    #[arg(long = "list-tracks", short = 'L', verbatim_doc_comment, help_heading=OPTIONS_AFFECTING_INPUT_FILES)]
+    pub list_tracks: bool,
     /// Don't try to find out the stream for caption/teletext
     /// data, just use this one instead.
     #[arg(long, verbatim_doc_comment, help_heading=OPTIONS_AFFECTING_INPUT_FILES)]

src/rust/src/lib.rs

@@ -27,6 +27,7 @@ pub mod hardsubx;
 pub mod hlist;
 pub mod libccxr_exports;
 pub mod parser;
+pub mod track_lister;
 pub mod utils;
 
 #[cfg(windows)]
@@ -420,6 +421,36 @@ pub unsafe extern "C" fn ccxr_parse_parameters(argc: c_int, argv: *mut *mut c_ch
         &mut _capitalization_list,
         &mut _profane,
     );
+
+    // Handle --list-tracks mode: list tracks and exit early
+    if opt.list_tracks_only {
+        use std::path::Path;
+        use track_lister::list_tracks;
+
+        let files = match &opt.inputfile {
+            Some(f) if !f.is_empty() => f,
+            _ => {
+                eprintln!("Error: No input files specified for --list-tracks");
+                return ExitCause::NoInputFiles.exit_code();
+            }
+        };
+
+        let mut had_errors = false;
+        for file in files {
+            if let Err(e) = list_tracks(Path::new(file)) {
+                eprintln!("Error listing tracks for '{}': {}", file, e);
+                had_errors = true;
+            }
+        }
+
+        // Exit with appropriate code - we don't want to continue to C processing
+        return if had_errors {
+            ExitCause::Failure.exit_code()
+        } else {
+            ExitCause::WithHelp.exit_code() // Reuse this code to indicate successful early exit
+        };
+    }
+
     tlt_config = _tlt_config.to_ctype(&opt);
 
     // Convert the rust struct (CcxOptions) to C struct (ccx_s_options), so that it can be used by the C code

src/rust/src/parser.rs

@@ -942,6 +942,10 @@ impl OptionsExt for Options {
             self.demux_cfg.ts_allprogram = true;
         }
 
+        if args.list_tracks {
+            self.list_tracks_only = true;
+        }
+
         if let Some(ref stream) = args.stream {
             self.live_stream = Some(Timestamp::from_millis(
                 1000 * get_atoi_hex::<i64>(stream.as_str()),