# Save Video Encodes a frame batch to the output folder and shows the result on the node. The current workflow is embedded in the file, so a saved video can be dragged back into ComfyUI to restore the graph that made it. The responsive player is owned by AusBoss rather than stacked on top of a core preview. It reports encoded dimensions, fps, frame count, and duration, keeps portrait video contained, and has a **LOOP** control. There is exactly one saved-video surface per node. `gif` and `webp` are shown as images, since a video element cannot play either. ## Controls - **frames**: BHWC frame batch to encode. For the subsampled formats, odd dimensions are cropped down one pixel to the even sizes they require. Optional only because a connected `video` brings its own frames — connect one or the other. - **fps**: Playback frame rate. Wire Load Video's `fps` output to keep the source timing. It steps in whole frames but stays a float, because the real broadcast rates are 23.976, 29.97 and 59.94 — those can be typed in, and an integer input would refuse Load Video's `fps` link entirely. - **Prefix** (`filename_prefix`): Path under the output folder; subfolders are created automatically. - **crf**: Quality — lower is better and larger. `19` is visually lossless for h264. What it means locally depends on the codec; see the format table. - **format**: Container and codec, see below. - **pingpong**: Plays the clip forward then backward so it loops seamlessly. Roughly doubles the frame count and the encode time. The first and last frames are not repeated at the turnaround, so the loop does not hitch. - **Metadata** (`save_metadata`): On by default. Turn it off to share a file without your prompt and node graph embedded in it. - **audio** (optional): A track to mux into the file, e.g. Load Video's `audio` output. - **video** (optional): A core `VIDEO` handle, e.g. Load Video's `video` output. Connecting it supersedes the `frames` and `audio` inputs — the video's own frames and track are encoded instead. Core decodes it in one uninterruptible step; see *The one phase Cancel cannot reach* below. ## Frame rate precedence A connected `video` brings the rate its frames were cut at, and that rate wins over the `fps` widget: replaying those frames at a stale widget rate would drift the picture away from the audio muxed beside it. When the two differ, one line naming the rate actually used is written to the ComfyUI console. With nothing connected to `video`, the widget is the only source and the console stays quiet. ## Formats | format | what it is | audio | crf means | | --- | --- | --- | --- | | `mp4 h264` | the default; plays everywhere | AAC | `crf` | | `mp4 h265` | about half the size at the same quality, where supported | AAC | `crf` | | `mp4 h264 nvenc` | h264 encoded on an NVIDIA GPU — much faster, slightly larger | AAC | `cq` | | `mp4 h265 nvenc` | h265 on the GPU | AAC | `cq` | | `webm vp9` | web delivery | Opus | `crf` | | `webm av1` | newer, smaller than vp9 | Opus | `crf` | | `mov prores` | ProRes HQ editing master; large | PCM | ignored | | `mkv ffv1` | bit-exact lossless; very large | FLAC | ignored | | `gif` | short silent loop, per-frame adaptive palette | none | ignored | | `webp` | short silent loop, much smaller than gif | none | quality | The nvenc formats need an NVIDIA GPU with a working driver, and refuse frames below roughly 145x49. If the encoder cannot start, the node says so and names a software format to use instead rather than failing with a driver stack trace. `gif` and `webp` have no streaming encoder, so every frame is held in memory before the first byte is written — keep those to short clips. Neither carries metadata, so an embedded workflow is not available for them. The node's face follows the table: widgets the chosen format ignores are hidden rather than left to look meaningful. The CRF field leaves the **FPS · CRF** row for `mov prores`, `mkv ffv1` and `gif` (their rows read *ignored* above), and the **Metadata** row disappears for `gif` and `webp`, which cannot carry it. Hidden is not removed: the widget keeps its position and its value, saved workflows store and restore it exactly as before, and switching the format back brings it back with the number it had. ## Output One file per run. Audio and video land in a single file — there is no separate audio-less copy. The embedded workflow survives in mp4, mov, webm and mkv; matroska uppercases the tag names, which is only visible to tools that read them directly. The node also has a **file_path** output: the absolute path of the file it just wrote, for wiring into downstream nodes that want the file itself. Leaving it unconnected changes nothing — the node saves either way. ## While it runs Encoding happens off ComfyUI's execution thread, so the server keeps answering while a long batch is written. The node fills its progress bar frame by frame, and **Cancel** stops the encode within a frame instead of at the end of the batch. Muxed audio is encoded after the picture, so the bar restarts and counts that track's AAC frames; **Cancel** stops there within one of them. ### The one phase Cancel cannot reach Connecting `video` adds a step this node does not control. ComfyUI core reads the whole file — every frame, decoded to float32 — before the first frame reaches this pack, and the core call that does it, `VideoInput.get_components()`, takes no progress or interrupt argument to pass one in. So that phase shows no progress and does not stop on **Cancel**: the cancel is registered right away (the decode runs off the execution thread, so the server still answers) and takes effect at the first frame of the encode, once control returns here. How long that lasts scales with pixels, not with file size. Measured on one desktop: ten seconds of 832x480 at 16 fps came back in about 0.6 s, while ten seconds of 1080p at 30 fps took about 7 s and held 7.5 GB of frames in memory. Minutes of high-resolution footage are the case to avoid — RAM runs out before the wait does. Wiring Load Video's `frames` output instead of `video` keeps the whole run interruptible and progress-tracked, since that decode is this pack's own loop.