Add the codec option in list command to show only info about related

```
./fluster.py list --codec H.266

List of available test suites:

JVET-VVC_draft6
    Codec: H.266
    Description: JVET VVC draft6
    Test vectors: 282

List of available decoders:

H.266
    FFmpeg-H.266: FFmpeg H.266 SW decoder
    Fluendo-H.266-SW-Gst1.0: Fluendo H.266 SW decoder for GStreamer 1.0
    GStreamer-H.266-Libav-Gst1.0: GStreamer H.266 Libav decoder for GStreamer 1.0
    GStreamer-H.266-VVdeC-Gst1.0: GStreamer H.266 VVdeC decoder for GStreamer 1.0
    VVCSoftware_VTM-H266: VVCSoftware_VTM H.266/VVC reference decoder
    VVdeC-H266: VVdeC H.266/VVC decoder
```

fluster/codec.py

@@ -31,6 +31,9 @@ class Codec(Enum):
     AAC = "AAC"
     AV1 = "AV1"
 
+    def __str__(self) -> str:
+        return self.value
+
 
 class OutputFormat(Enum):
     """Output format"""

fluster/fluster.py

@@ -185,7 +185,9 @@ def _load_test_suites(self) -> None:
         if len(self.test_suites) == 0:
             raise Exception(f'No test suites found in "{self.test_suites_dir}"')
 
-    def list_decoders(self, check: bool, verbose: bool) -> None:
+    def list_decoders(
+        self, check: bool, verbose: bool, codec: Optional[Codec] = None
+    ) -> None:
         """List all the available decoders"""
         print("\nList of available decoders:")
         decoders_dict: Dict[Codec, List[Decoder]] = {}
@@ -194,8 +196,10 @@ def list_decoders(self, check: bool, verbose: bool) -> None:
                 decoders_dict[dec.codec] = []
             decoders_dict[dec.codec].append(dec)
 
-        for codec, decoder_list in decoders_dict.items():
-            print(f'\n{str(codec).split(".")[1]}')
+        for current_codec, decoder_list in decoders_dict.items():
+            if codec and codec != current_codec:
+                continue
+            print(f"\n{current_codec}")
             for decoder in decoder_list:
                 string = f"{decoder}"
                 if check:
@@ -210,16 +214,19 @@ def list_test_suites(
         self,
         show_test_vectors: bool = False,
         test_suites: Optional[List[str]] = None,
+        codec: Optional[Codec] = None,
     ) -> None:
         """List all test suites"""
         self._load_test_suites()
         print("\nList of available test suites:")
         if test_suites:
             test_suites = [x.lower() for x in test_suites]
+
         for test_suite in self.test_suites:
-            if test_suites:
-                if test_suite.name.lower() not in test_suites:
-                    continue
+            if test_suites and test_suite.name.lower() not in test_suites:
+                continue
+            if codec and test_suite.codec != codec:
+                continue
             print(test_suite)
             if show_test_vectors:
                 for test_vector in test_suite.test_vectors.values():

fluster/main.py

@@ -26,6 +26,7 @@
 from tempfile import gettempdir
 
 from fluster.fluster import Fluster, Context, SummaryFormat
+from fluster.codec import Codec
 from fluster import utils
 
 APPNAME = "fluster"
@@ -190,6 +191,13 @@ def _add_list_cmd(self, subparsers: Any) -> None:
             help="show stdout and stderr of commands executed",
             action="store_true",
         )
+        subparser.add_argument(
+            "-d",
+            "--codec",
+            help="show decoders and test suites of a codec",
+            type=Codec,
+            choices=list(Codec),
+        )
         subparser.set_defaults(func=self._list_cmd)
 
     def _add_run_cmd(self, subparsers: Any) -> None:
@@ -366,9 +374,15 @@ def _add_download_cmd(self, subparsers: Any) -> None:
     @staticmethod
     def _list_cmd(args: Any, fluster: Fluster) -> None:
         fluster.list_test_suites(
-            show_test_vectors=args.testvectors, test_suites=args.testsuites
+            show_test_vectors=args.testvectors,
+            test_suites=args.testsuites,
+            codec=args.codec,
+        )
+        fluster.list_decoders(
+            check=args.check,
+            verbose=args.verbose,
+            codec=args.codec,
         )
-        fluster.list_decoders(check=args.check, verbose=args.verbose)
 
     @staticmethod
     def _run_cmd(args: Any, fluster: Fluster) -> None: