[cli] Add tests for save-qp command

scenedetect.cfg

@@ -291,6 +291,9 @@
 # Folder to output QP file to. Overrides [global] output option.
 #output = /usr/tmp/images
 
+# Disable shifting frame numbers by start time (yes/no).
+#disable-shift = no
+
 
 #
 # BACKEND OPTIONS

scenedetect/_cli/__init__.py

@@ -1467,6 +1467,15 @@ def save_images_command(
     help="Output directory to save QP file to. Overrides global option -o/--output.%s"
     % (USER_CONFIG.get_help_string("save-qp", "output", show_default=False)),
 )
+@click.option(
+    "--disable-shift",
+    "-d",
+    is_flag=True,
+    flag_value=True,
+    default=None,
+    help="Disable shifting frame numbers by start time.%s"
+    % (USER_CONFIG.get_help_string("save-qp", "disable-shift")),
+)
 @click.pass_context
 def save_qp_command(
     ctx: click.Context,
@@ -1483,7 +1492,7 @@ def save_qp_command(
     save_qp_args = {
         "filename_format": ctx.config.get_value("save-qp", "filename", filename),
         "output_dir": ctx.config.get_value("save-qp", "output", output),
-        "disable_shift": ctx.config.get_value("save-qp", "disable_shift", disable_shift),
+        "shift_start": not ctx.config.get_value("save-qp", "disable-shift", disable_shift),
     }
     ctx.add_command(cli_commands.save_qp, save_qp_args)
 

scenedetect/_cli/commands.py

@@ -70,21 +70,19 @@ def save_qp(
     cuts: CutList,
     output_dir: str,
     filename_format: str,
-    disable_shift: bool,
+    shift_start: bool,
 ):
     """Handler for the `save-qp` command."""
     del scenes  # We only use cuts for this handler.
-
     qp_path = get_and_create_path(
         Template(filename_format).safe_substitute(VIDEO_NAME=context.video_stream.name),
         output_dir,
     )
-    # We assume that if a start time was set, the user will encode the video starting from that
-    # point, so we shift all frame numbers such that the QP file always starts from frame 0.
+    start_frame = context.start_time.frame_num if context.start_time else 0
+    offset = start_frame if shift_start else 0
     with open(qp_path, "wt") as qp_file:
-        qp_file.write("0 I -1\n")
+        qp_file.write(f"{0 if shift_start else start_frame} I -1\n")
         # Place another I frame at each detected cut.
-        offset = 0 if context.start_time is None else context.start_time.frame_num
         qp_file.writelines(f"{cut.frame_num - offset} I -1\n" for cut in cuts)
     logger.info(f"QP file written to: {qp_path}")
 

scenedetect/_cli/config.py

@@ -301,10 +301,6 @@ def format(self, timecode: FrameTimecode) -> str:
         "image-width": 0,
         "no-images": False,
     },
-    "save-qp": {
-        "filename": "$VIDEO_NAME.qp",
-        "output": None,
-    },
     "list-scenes": {
         "cut-format": "timecode",
         "display-cuts": True,
@@ -340,6 +336,11 @@ def format(self, timecode: FrameTimecode) -> str:
         "scale-method": "linear",
         "width": 0,
     },
+    "save-qp": {
+        "disable-shift": False,
+        "filename": "$VIDEO_NAME.qp",
+        "output": None,
+    },
     "split-video": {
         "args": DEFAULT_FFMPEG_ARGS,
         "copy": False,

tests/test_cli.py

@@ -450,7 +450,7 @@ def test_cli_save_qp(tmp_path: Path):
         assert output_path.read_text() == EXPECTED_QP_CONTENTS[1:]
 
 
-def test_cli_save_qp_start_shift(tmp_path: Path):
+def test_cli_save_qp_start_offset(tmp_path: Path):
     """Test `save-qp` command but using a shifted start time."""
     # The QP file should always start from frame 0, so we expect a similar result to the above, but
     # with the frame numbers shifted by the start frame. Note that on the command-line, the first
@@ -473,6 +473,24 @@ def test_cli_save_qp_start_shift(tmp_path: Path):
     assert output_path.read_text() == EXPECTED_QP_CONTENTS[1:]
 
 
+def test_cli_save_qp_no_shift(tmp_path: Path):
+    """Test `save-qp` command with start time shifting disabled."""
+    EXPECTED_QP_CONTENTS = """
+50 I -1
+90 I -1
+"""
+    assert (
+        invoke_scenedetect(
+            "-i {VIDEO} time -s 51 -e 95 {DETECTOR} save-qp --disable-shift",
+            output_dir=tmp_path,
+        )
+        == 0
+    )
+    output_path = tmp_path.joinpath(f"{DEFAULT_VIDEO_NAME}.qp")
+    assert os.path.exists(output_path)
+    assert output_path.read_text() == EXPECTED_QP_CONTENTS[1:]
+
+
 @pytest.mark.parametrize("backend_type", ALL_BACKENDS)
 def test_cli_backend(backend_type: str):
     """Test setting the `-b`/`--backend` argument."""