mcp-ffmpeg

Overview Schema Source Related Servers Discussions Admin

set_video_codec

Change a video's codec to a specified format such as libx264 or libx265 while preserving the audio stream by copying it. Specify the source video, destination path, and target codec.

Instructions

Sets the video codec of a video, attempting to copy the audio stream.

Args: input_video_path: Path to the source video file. output_video_path: Path to save the video with the new video codec. video_codec: Target video codec (e.g., 'libx264', 'libx265', 'vp9'). Returns: A status message indicating success or failure.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "input_video_path": "<input_video_path>",
      "output_video_path": "<output_video_path>",
      "video_codec": "<video_codec>"
    },
    "name": "set_video_codec"
  }
}

Input Schema

Name	Required	Description	Default
`video_codec`	Yes
`input_video_path`	Yes
`output_video_path`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Aug 11, 2026

TDQS

A3.5/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden. It mentions the audio copy attempt and a status message return, but does not disclose side effects like file overwriting, whether the input is modified, codec prerequisites, or failure conditions beyond 'success or failure'.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a compact docstring with a clear main sentence, an Args list, and a Returns note. Every sentence earns its place; there is no fluff or repetition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description covers the core operation and parameters well, but lacks usage context needed to choose among many video-related siblings. It does not clarify when to prefer this over more general converters, and the 'attempting' wording leaves important failure behavior unstated.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0%, but the description's Args section provides a one-line explanation for each of the three parameters and gives concrete examples for video_codec. This adds meaning beyond the bare schema field names.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the operation with a specific verb ('Sets') and resource ('the video codec of a video'), and adds a distinguishing nuance ('attempting to copy the audio stream'). This differentiates it from sibling tools like set_video_bitrate or convert_video_format.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance is provided on when to use this tool versus alternatives such as convert_video_properties or set_video_audio_track_codec. The description simply states the action without any context, exclusions, or mention of use cases.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.