feat: enhance SaveVideo with DynamicCombo for codec-specific options

Major changes:
- SaveVideo now uses DynamicCombo to show codec-specific encoding options
- When selecting h264 or vp9, quality and speed inputs appear dynamically
- Each codec has unique ADVANCED options (shown in 'Show Advanced' section):
  - h264: Profile (baseline/main/high), Tune (film/animation/grain/etc.)
  - vp9: Row Multi-threading, Tile Columns
- Quality maps to CRF internally with codec-appropriate ranges
- Speed presets map to FFmpeg presets

New types:
- VideoSpeedPreset enum with user-friendly names
- quality_to_crf() helper function

This demonstrates both DynamicCombo (codec-specific inputs) and advanced
widgets (profile/tune/row_mt/tile_columns hidden by default).

Amp-Thread-ID: https://ampcode.com/threads/T-019bce44-e743-7349-8bad-d3027d456fb1
Co-authored-by: Amp <amp@ampcode.com>

comfy_api/latest/__init__.py

@@ -7,7 +7,7 @@ from comfy_api.internal.singleton import ProxiedSingleton
 from comfy_api.internal.async_to_sync import create_sync_class
 from ._input import ImageInput, AudioInput, MaskInput, LatentInput, VideoInput
 from ._input_impl import VideoFromFile, VideoFromComponents
-from ._util import VideoCodec, VideoContainer, VideoComponents, MESH, VOXEL
+from ._util import VideoCodec, VideoContainer, VideoComponents, VideoSpeedPreset, MESH, VOXEL
 from . import _io_public as io
 from . import _ui_public as ui
 from comfy_execution.utils import get_executing_context
@@ -103,6 +103,7 @@ class Types:
     VideoCodec = VideoCodec
     VideoContainer = VideoContainer
     VideoComponents = VideoComponents
+    VideoSpeedPreset = VideoSpeedPreset
     MESH = MESH
     VOXEL = VOXEL
 

comfy_api/latest/_input_impl/video_types.py

@@ -10,7 +10,7 @@ import json
 import numpy as np
 import math
 import torch
-from .._util import VideoContainer, VideoCodec, VideoComponents
+from .._util import VideoContainer, VideoCodec, VideoComponents, VideoSpeedPreset, quality_to_crf
 
 
 def container_to_output_format(container_format: str | None) -> str | None:
@@ -250,10 +250,16 @@ class VideoFromFile(VideoInput):
         path: str | io.BytesIO,
         format: VideoContainer = VideoContainer.AUTO,
         codec: VideoCodec = VideoCodec.AUTO,
-        metadata: Optional[dict] = None
+        metadata: Optional[dict] = None,
+        quality: Optional[int] = None,
+        speed: Optional[VideoSpeedPreset] = None,
+        profile: Optional[str] = None,
+        tune: Optional[str] = None,
+        row_mt: bool = True,
+        tile_columns: Optional[int] = None,
     ):
         if isinstance(self.__file, io.BytesIO):
-            self.__file.seek(0)  # Reset the BytesIO object to the beginning
+            self.__file.seek(0)
         with av.open(self.__file, mode='r') as container:
             container_format = container.format.name
             video_encoding = container.streams.video[0].codec.name if len(container.streams.video) > 0 else None
@@ -262,6 +268,10 @@ class VideoFromFile(VideoInput):
                 reuse_streams = False
             if codec != VideoCodec.AUTO and codec != video_encoding and video_encoding is not None:
                 reuse_streams = False
+            if quality is not None or speed is not None:
+                reuse_streams = False
+            if profile is not None or tune is not None or tile_columns is not None:
+                reuse_streams = False
 
             if not reuse_streams:
                 components = self.get_components_internal(container)
@@ -270,7 +280,13 @@ class VideoFromFile(VideoInput):
                     path,
                     format=format,
                     codec=codec,
-                    metadata=metadata
+                    metadata=metadata,
+                    quality=quality,
+                    speed=speed,
+                    profile=profile,
+                    tune=tune,
+                    row_mt=row_mt,
+                    tile_columns=tile_columns,
                 )
 
             streams = container.streams
@@ -330,54 +346,128 @@ class VideoFromComponents(VideoInput):
         path: str,
         format: VideoContainer = VideoContainer.AUTO,
         codec: VideoCodec = VideoCodec.AUTO,
-        metadata: Optional[dict] = None
+        metadata: Optional[dict] = None,
+        quality: Optional[int] = None,
+        speed: Optional[VideoSpeedPreset] = None,
+        profile: Optional[str] = None,
+        tune: Optional[str] = None,
+        row_mt: bool = True,
+        tile_columns: Optional[int] = None,
     ):
-        if format != VideoContainer.AUTO and format != VideoContainer.MP4:
+        """
-            raise ValueError("Only MP4 format is supported for now")
+        Save video to file with optional encoding parameters.
-        if codec != VideoCodec.AUTO and codec != VideoCodec.H264:
+
-            raise ValueError("Only H264 codec is supported for now")
+        Args:
+            path: Output file path
+            format: Container format (mp4, webm, or auto)
+            codec: Video codec (h264, vp9, or auto)
+            metadata: Optional metadata dict to embed
+            quality: Quality percentage 0-100 (100=best). Maps to CRF internally.
+            speed: Encoding speed preset. Slower = better compression.
+            profile: H.264 profile (baseline, main, high)
+            tune: H.264 tune option (film, animation, grain, etc.)
+            row_mt: VP9 row-based multi-threading
+            tile_columns: VP9 tile columns (power of 2)
+        """
+        resolved_format = format
+        resolved_codec = codec
+
+        if resolved_format == VideoContainer.AUTO:
+            resolved_format = VideoContainer.MP4
+        if resolved_codec == VideoCodec.AUTO:
+            if resolved_format == VideoContainer.WEBM:
+                resolved_codec = VideoCodec.VP9
+            else:
+                resolved_codec = VideoCodec.H264
+
+        if resolved_format == VideoContainer.WEBM and resolved_codec == VideoCodec.H264:
+            raise ValueError("H264 codec is not supported with WebM container")
+        if resolved_format == VideoContainer.MP4 and resolved_codec == VideoCodec.VP9:
+            raise ValueError("VP9 codec is not supported with MP4 container")
+
+        codec_map = {
+            VideoCodec.H264: "libx264",
+            VideoCodec.VP9: "libvpx-vp9",
+        }
+        ffmpeg_codec = codec_map.get(resolved_codec, "libx264")
+
         extra_kwargs = {}
-        if isinstance(format, VideoContainer) and format != VideoContainer.AUTO:
+        if resolved_format != VideoContainer.AUTO:
-            extra_kwargs["format"] = format.value
+            extra_kwargs["format"] = resolved_format.value
-        with av.open(path, mode='w', options={'movflags': 'use_metadata_tags'}, **extra_kwargs) as output:
+
-            # Add metadata before writing any streams
+        container_options = {}
+        if resolved_format == VideoContainer.MP4:
+            container_options["movflags"] = "use_metadata_tags"
+
+        with av.open(path, mode='w', options=container_options, **extra_kwargs) as output:
             if metadata is not None:
                 for key, value in metadata.items():
                     output.metadata[key] = json.dumps(value)
 
             frame_rate = Fraction(round(self.__components.frame_rate * 1000), 1000)
-            # Create a video stream
+            video_stream = output.add_stream(ffmpeg_codec, rate=frame_rate)
-            video_stream = output.add_stream('h264', rate=frame_rate)
             video_stream.width = self.__components.images.shape[2]
             video_stream.height = self.__components.images.shape[1]
-            video_stream.pix_fmt = 'yuv420p'
 
-            # Create an audio stream
+            if resolved_codec == VideoCodec.VP9:
+                video_stream.pix_fmt = 'yuv420p'
+                video_stream.bit_rate = 0
+            else:
+                video_stream.pix_fmt = 'yuv420p'
+
+            if quality is not None:
+                crf = quality_to_crf(quality, ffmpeg_codec)
+                video_stream.options['crf'] = str(crf)
+
+            if speed is not None and speed != VideoSpeedPreset.AUTO:
+                if isinstance(speed, str):
+                    speed = VideoSpeedPreset(speed)
+                preset = speed.to_ffmpeg_preset(ffmpeg_codec)
+                if resolved_codec == VideoCodec.VP9:
+                    video_stream.options['cpu-used'] = preset
+                else:
+                    video_stream.options['preset'] = preset
+
+            # H.264-specific options
+            if resolved_codec == VideoCodec.H264:
+                if profile is not None:
+                    video_stream.options['profile'] = profile
+                if tune is not None:
+                    video_stream.options['tune'] = tune
+
+            # VP9-specific options
+            if resolved_codec == VideoCodec.VP9:
+                if row_mt:
+                    video_stream.options['row-mt'] = '1'
+                if tile_columns is not None:
+                    video_stream.options['tile-columns'] = str(tile_columns)
+
             audio_sample_rate = 1
             audio_stream: Optional[av.AudioStream] = None
             if self.__components.audio:
                 audio_sample_rate = int(self.__components.audio['sample_rate'])
-                audio_stream = output.add_stream('aac', rate=audio_sample_rate)
+                audio_codec = 'libopus' if resolved_format == VideoContainer.WEBM else 'aac'
+                audio_stream = output.add_stream(audio_codec, rate=audio_sample_rate)
 
-            # Encode video
             for i, frame in enumerate(self.__components.images):
-                img = (frame * 255).clamp(0, 255).byte().cpu().numpy() # shape: (H, W, 3)
+                img = (frame * 255).clamp(0, 255).byte().cpu().numpy()
-                frame = av.VideoFrame.from_ndarray(img, format='rgb24')
+                video_frame = av.VideoFrame.from_ndarray(img, format='rgb24')
-                frame = frame.reformat(format='yuv420p')  # Convert to YUV420P as required by h264
+                video_frame = video_frame.reformat(format='yuv420p')
-                packet = video_stream.encode(frame)
+                packet = video_stream.encode(video_frame)
                 output.mux(packet)
 
-            # Flush video
             packet = video_stream.encode(None)
             output.mux(packet)
 
             if audio_stream and self.__components.audio:
                 waveform = self.__components.audio['waveform']
                 waveform = waveform[:, :, :math.ceil((audio_sample_rate / frame_rate) * self.__components.images.shape[0])]
-                frame = av.AudioFrame.from_ndarray(waveform.movedim(2, 1).reshape(1, -1).float().numpy(), format='flt', layout='mono' if waveform.shape[1] == 1 else 'stereo')
+                audio_frame = av.AudioFrame.from_ndarray(
-                frame.sample_rate = audio_sample_rate
+                    waveform.movedim(2, 1).reshape(1, -1).float().numpy(),
-                frame.pts = 0
+                    format='flt',
-                output.mux(audio_stream.encode(frame))
+                    layout='mono' if waveform.shape[1] == 1 else 'stereo'
-
+                )
-                # Flush encoder
+                audio_frame.sample_rate = audio_sample_rate
+                audio_frame.pts = 0
+                output.mux(audio_stream.encode(audio_frame))
                 output.mux(audio_stream.encode(None))

comfy_api/latest/_util/__init__.py

@@ -1,4 +1,4 @@
-from .video_types import VideoContainer, VideoCodec, VideoComponents
+from .video_types import VideoContainer, VideoCodec, VideoComponents, VideoSpeedPreset, quality_to_crf
 from .geometry_types import VOXEL, MESH
 from .image_types import SVG
 
@@ -7,6 +7,8 @@ __all__ = [
     "VideoContainer",
     "VideoCodec",
     "VideoComponents",
+    "VideoSpeedPreset",
+    "quality_to_crf",
     "VOXEL",
     "MESH",
     "SVG",

comfy_api/latest/_util/video_types.py

@@ -8,6 +8,7 @@ from .._input import ImageInput, AudioInput
 class VideoCodec(str, Enum):
     AUTO = "auto"
     H264 = "h264"
+    VP9 = "vp9"
 
     @classmethod
     def as_input(cls) -> list[str]:
@@ -16,9 +17,11 @@ class VideoCodec(str, Enum):
         """
         return [member.value for member in cls]
 
+
 class VideoContainer(str, Enum):
     AUTO = "auto"
     MP4 = "mp4"
+    WEBM = "webm"
 
     @classmethod
     def as_input(cls) -> list[str]:
@@ -36,8 +39,71 @@ class VideoContainer(str, Enum):
             value = cls(value)
         if value == VideoContainer.MP4 or value == VideoContainer.AUTO:
             return "mp4"
+        if value == VideoContainer.WEBM:
+            return "webm"
         return ""
 
+
+class VideoSpeedPreset(str, Enum):
+    """Encoding speed presets - slower = better compression at same quality."""
+    AUTO = "auto"
+    FASTEST = "Fastest"
+    FAST = "Fast"
+    BALANCED = "Balanced"
+    QUALITY = "Quality"
+    BEST = "Best"
+
+    @classmethod
+    def as_input(cls) -> list[str]:
+        return [member.value for member in cls]
+
+    def to_ffmpeg_preset(self, codec: str = "h264") -> str:
+        """Convert to FFmpeg preset string for the given codec."""
+        h264_map = {
+            VideoSpeedPreset.FASTEST: "ultrafast",
+            VideoSpeedPreset.FAST: "veryfast",
+            VideoSpeedPreset.BALANCED: "medium",
+            VideoSpeedPreset.QUALITY: "slow",
+            VideoSpeedPreset.BEST: "veryslow",
+            VideoSpeedPreset.AUTO: "medium",
+        }
+        vp9_map = {
+            VideoSpeedPreset.FASTEST: "0",
+            VideoSpeedPreset.FAST: "1",
+            VideoSpeedPreset.BALANCED: "2",
+            VideoSpeedPreset.QUALITY: "3",
+            VideoSpeedPreset.BEST: "4",
+            VideoSpeedPreset.AUTO: "2",
+        }
+        if codec in ("vp9", "libvpx-vp9"):
+            return vp9_map.get(self, "2")
+        return h264_map.get(self, "medium")
+
+
+def quality_to_crf(quality: int, codec: str = "h264") -> int:
+    """
+    Map 0-100 quality percentage to codec-appropriate CRF value.
+
+    Args:
+        quality: 0-100 where 100 is best quality
+        codec: The codec being used (h264, vp9, etc.)
+
+    Returns:
+        CRF value appropriate for the codec
+    """
+    quality = max(0, min(100, quality))
+
+    if codec in ("h264", "libx264"):
+        # h264: CRF 0-51 (lower = better), typical range 12-40
+        # quality 100 → CRF 12, quality 0 → CRF 40
+        return int(40 - (quality / 100) * 28)
+    elif codec in ("vp9", "libvpx-vp9"):
+        # vp9: CRF 0-63 (lower = better), typical range 15-50
+        # quality 100 → CRF 15, quality 0 → CRF 50
+        return int(50 - (quality / 100) * 35)
+    # Default fallback
+    return 23
+
 @dataclass
 class VideoComponents:
     """

comfy_extras/nodes_video.py

@@ -67,23 +67,134 @@ class SaveWEBM(io.ComfyNode):
 class SaveVideo(io.ComfyNode):
     @classmethod
     def define_schema(cls):
+        # H264-specific inputs
+        h264_quality = io.Int.Input(
+            "quality",
+            default=80,
+            min=0,
+            max=100,
+            step=1,
+            display_name="Quality",
+            tooltip="Output quality (0-100). Higher = better quality, larger files. "
+                    "Internally maps to CRF: 100→CRF 12, 50→CRF 23, 0→CRF 40.",
+        )
+        h264_speed = io.Combo.Input(
+            "speed",
+            options=Types.VideoSpeedPreset.as_input(),
+            default="auto",
+            display_name="Encoding Speed",
+            tooltip="Encoding speed preset. Slower = better compression at same quality. "
+                    "Maps to FFmpeg presets: Fastest=ultrafast, Balanced=medium, Best=veryslow.",
+        )
+        h264_profile = io.Combo.Input(
+            "profile",
+            options=["auto", "baseline", "main", "high"],
+            default="auto",
+            display_name="Profile",
+            tooltip="H.264 profile. 'baseline' for max compatibility (older devices), "
+                    "'main' for standard use, 'high' for best quality/compression.",
+            advanced=True,
+        )
+        h264_tune = io.Combo.Input(
+            "tune",
+            options=["auto", "film", "animation", "grain", "stillimage", "fastdecode", "zerolatency"],
+            default="auto",
+            display_name="Tune",
+            tooltip="Optimize encoding for specific content types. "
+                    "'film' for live action, 'animation' for cartoons/anime, 'grain' to preserve film grain.",
+            advanced=True,
+        )
+
+        # VP9-specific inputs
+        vp9_quality = io.Int.Input(
+            "quality",
+            default=80,
+            min=0,
+            max=100,
+            step=1,
+            display_name="Quality",
+            tooltip="Output quality (0-100). Higher = better quality, larger files. "
+                    "Internally maps to CRF: 100→CRF 15, 50→CRF 33, 0→CRF 50.",
+        )
+        vp9_speed = io.Combo.Input(
+            "speed",
+            options=Types.VideoSpeedPreset.as_input(),
+            default="auto",
+            display_name="Encoding Speed",
+            tooltip="Encoding speed. Slower = better compression. "
+                    "Maps to VP9 cpu-used: Fastest=0, Balanced=2, Best=4.",
+        )
+        vp9_row_mt = io.Boolean.Input(
+            "row_mt",
+            default=True,
+            display_name="Row Multi-threading",
+            tooltip="Enable row-based multi-threading for faster encoding on multi-core CPUs.",
+            advanced=True,
+        )
+        vp9_tile_columns = io.Combo.Input(
+            "tile_columns",
+            options=["auto", "0", "1", "2", "3", "4"],
+            default="auto",
+            display_name="Tile Columns",
+            tooltip="Number of tile columns (as power of 2). More tiles = faster encoding "
+                    "but slightly worse compression. 'auto' picks based on resolution.",
+            advanced=True,
+        )
+
         return io.Schema(
             node_id="SaveVideo",
             display_name="Save Video",
             category="image/video",
-            description="Saves the input images to your ComfyUI output directory.",
+            description="Saves video to the output directory. "
+                        "When format/codec/quality differ from source, the video is re-encoded.",
             inputs=[
                 io.Video.Input("video", tooltip="The video to save."),
-                io.String.Input("filename_prefix", default="video/ComfyUI", tooltip="The prefix for the file to save. This may include formatting information such as %date:yyyy-MM-dd% or %Empty Latent Image.width% to include values from nodes."),
+                io.String.Input(
-                io.Combo.Input("format", options=Types.VideoContainer.as_input(), default="auto", tooltip="The format to save the video as."),
+                    "filename_prefix",
-                io.Combo.Input("codec", options=Types.VideoCodec.as_input(), default="auto", tooltip="The codec to use for the video."),
+                    default="video/ComfyUI",
+                    tooltip="The prefix for the file to save. "
+                            "Supports formatting like %date:yyyy-MM-dd%.",
+                ),
+                io.DynamicCombo.Input("codec", options=[
+                    io.DynamicCombo.Option("auto", []),
+                    io.DynamicCombo.Option("h264", [h264_quality, h264_speed, h264_profile, h264_tune]),
+                    io.DynamicCombo.Option("vp9", [vp9_quality, vp9_speed, vp9_row_mt, vp9_tile_columns]),
+                ], tooltip="Video codec. 'auto' preserves source when possible. "
+                           "h264 outputs MP4, vp9 outputs WebM."),
             ],
             hidden=[io.Hidden.prompt, io.Hidden.extra_pnginfo],
             is_output_node=True,
         )
 
     @classmethod
-    def execute(cls, video: Input.Video, filename_prefix, format: str, codec) -> io.NodeOutput:
+    def execute(cls, video: Input.Video, filename_prefix: str, codec: dict) -> io.NodeOutput:
+        selected_codec = codec.get("codec", "auto")
+        quality = codec.get("quality")
+        speed_str = codec.get("speed", "auto")
+
+        # H264-specific options
+        profile = codec.get("profile", "auto")
+        tune = codec.get("tune", "auto")
+
+        # VP9-specific options
+        row_mt = codec.get("row_mt", True)
+        tile_columns = codec.get("tile_columns", "auto")
+
+        if selected_codec == "auto":
+            resolved_format = Types.VideoContainer.AUTO
+            resolved_codec = Types.VideoCodec.AUTO
+        elif selected_codec == "h264":
+            resolved_format = Types.VideoContainer.MP4
+            resolved_codec = Types.VideoCodec.H264
+        elif selected_codec == "vp9":
+            resolved_format = Types.VideoContainer.WEBM
+            resolved_codec = Types.VideoCodec.VP9
+        else:
+            resolved_format = Types.VideoContainer.AUTO
+            resolved_codec = Types.VideoCodec.AUTO
+
+        speed = Types.VideoSpeedPreset(speed_str) if speed_str else None
+
         width, height = video.get_dimensions()
         full_output_folder, filename, counter, subfolder, filename_prefix = folder_paths.get_save_image_path(
             filename_prefix,
@@ -91,6 +202,7 @@ class SaveVideo(io.ComfyNode):
             width,
             height
         )
+
         saved_metadata = None
         if not args.disable_metadata:
             metadata = {}
@@ -100,12 +212,20 @@ class SaveVideo(io.ComfyNode):
                 metadata["prompt"] = cls.hidden.prompt
             if len(metadata) > 0:
                 saved_metadata = metadata
-        file = f"{filename}_{counter:05}_.{Types.VideoContainer.get_extension(format)}"
+
+        extension = Types.VideoContainer.get_extension(resolved_format)
+        file = f"{filename}_{counter:05}_.{extension}"
         video.save_to(
             os.path.join(full_output_folder, file),
-            format=Types.VideoContainer(format),
+            format=resolved_format,
-            codec=codec,
+            codec=resolved_codec,
-            metadata=saved_metadata
+            metadata=saved_metadata,
+            quality=quality,
+            speed=speed,
+            profile=profile if profile != "auto" else None,
+            tune=tune if tune != "auto" else None,
+            row_mt=row_mt,
+            tile_columns=int(tile_columns) if tile_columns != "auto" else None,
         )
 
         return io.NodeOutput(ui=ui.PreviewVideo([ui.SavedResult(file, subfolder, io.FolderType.output)]))

tests-unit/comfy_api_test/video_types_test.py

@@ -6,7 +6,7 @@ import av
 import io
 from fractions import Fraction
 from comfy_api.input_impl.video_types import VideoFromFile, VideoFromComponents
-from comfy_api.util.video_types import VideoComponents
+from comfy_api.util.video_types import VideoComponents, VideoSpeedPreset, quality_to_crf
 from comfy_api.input.basic_types import AudioInput
 from av.error import InvalidDataError
 
@@ -237,3 +237,71 @@ def test_duration_consistency(video_components):
     manual_duration = float(components.images.shape[0] / components.frame_rate)
 
     assert duration == pytest.approx(manual_duration)
+
+
+class TestVideoSpeedPreset:
+    """Tests for VideoSpeedPreset enum and its methods."""
+
+    def test_as_input_returns_all_values(self):
+        """as_input() returns all preset values"""
+        values = VideoSpeedPreset.as_input()
+        assert values == ["auto", "Fastest", "Fast", "Balanced", "Quality", "Best"]
+
+    def test_to_ffmpeg_preset_h264(self):
+        """H.264 presets map correctly"""
+        assert VideoSpeedPreset.FASTEST.to_ffmpeg_preset("h264") == "ultrafast"
+        assert VideoSpeedPreset.FAST.to_ffmpeg_preset("h264") == "veryfast"
+        assert VideoSpeedPreset.BALANCED.to_ffmpeg_preset("h264") == "medium"
+        assert VideoSpeedPreset.QUALITY.to_ffmpeg_preset("h264") == "slow"
+        assert VideoSpeedPreset.BEST.to_ffmpeg_preset("h264") == "veryslow"
+        assert VideoSpeedPreset.AUTO.to_ffmpeg_preset("h264") == "medium"
+
+    def test_to_ffmpeg_preset_vp9(self):
+        """VP9 presets map correctly"""
+        assert VideoSpeedPreset.FASTEST.to_ffmpeg_preset("vp9") == "0"
+        assert VideoSpeedPreset.FAST.to_ffmpeg_preset("vp9") == "1"
+        assert VideoSpeedPreset.BALANCED.to_ffmpeg_preset("vp9") == "2"
+        assert VideoSpeedPreset.QUALITY.to_ffmpeg_preset("vp9") == "3"
+        assert VideoSpeedPreset.BEST.to_ffmpeg_preset("vp9") == "4"
+        assert VideoSpeedPreset.AUTO.to_ffmpeg_preset("vp9") == "2"
+
+    def test_to_ffmpeg_preset_libvpx_vp9(self):
+        """libvpx-vp9 codec string also maps to VP9 presets"""
+        assert VideoSpeedPreset.BALANCED.to_ffmpeg_preset("libvpx-vp9") == "2"
+
+    def test_to_ffmpeg_preset_default_to_h264(self):
+        """Unknown codecs default to H.264 mapping"""
+        assert VideoSpeedPreset.BALANCED.to_ffmpeg_preset("unknown") == "medium"
+
+
+class TestQualityToCrf:
+    """Tests for quality_to_crf helper function."""
+
+    def test_h264_quality_boundaries(self):
+        """H.264 quality maps to correct CRF range (12-40)"""
+        assert quality_to_crf(100, "h264") == 12
+        assert quality_to_crf(0, "h264") == 40
+        assert quality_to_crf(50, "h264") == 26
+
+    def test_h264_libx264_alias(self):
+        """libx264 codec string uses H.264 mapping"""
+        assert quality_to_crf(100, "libx264") == 12
+
+    def test_vp9_quality_boundaries(self):
+        """VP9 quality maps to correct CRF range (15-50)"""
+        assert quality_to_crf(100, "vp9") == 15
+        assert quality_to_crf(0, "vp9") == 50
+        assert quality_to_crf(50, "vp9") == 32
+
+    def test_vp9_libvpx_alias(self):
+        """libvpx-vp9 codec string uses VP9 mapping"""
+        assert quality_to_crf(100, "libvpx-vp9") == 15
+
+    def test_quality_clamping(self):
+        """Quality values outside 0-100 are clamped"""
+        assert quality_to_crf(150, "h264") == 12
+        assert quality_to_crf(-50, "h264") == 40
+
+    def test_unknown_codec_fallback(self):
+        """Unknown codecs return default CRF 23"""
+        assert quality_to_crf(50, "unknown_codec") == 23