### FFmpeg Version Detection Feature Flags

Source: https://github.com/zmwangx/rust-ffmpeg-sys/blob/master/README.md

This section documents the compile-time feature flags used to detect the FFmpeg installation version. These flags are enabled if the linked FFmpeg library is at least the specified version, allowing for conditional compilation based on FFmpeg capabilities.

```APIDOC
- ffmpeg_<x>_<y>: Indicates the FFmpeg installation is at least version <x>.<y>.
  Examples:
    - ffmpeg_3_0
    - ffmpeg_3_1
    - ffmpeg_3_2
    - ffmpeg_3_3
    - ffmpeg_4_0
    - ffmpeg_4_1
    - ffmpeg_4_2
    - ffmpeg_4_3
    - ffmpeg_4_4
```

--------------------------------

### FFmpeg API Deprecation Guard Feature Flags

Source: https://github.com/zmwangx/rust-ffmpeg-sys/blob/master/README.md

These flags correspond to FFmpeg's uppercase deprecation guards. They allow developers to check whether a specific API feature is currently active or simply defined, aiding in managing compatibility with different FFmpeg versions.

```APIDOC
- ff_api_<feature>: Corresponds to FFmpeg's uppercase deprecation guards, enabled if the feature is active.
  Example:
    - ff_api_vaapi
- ff_api_<feature>_is_defined: Enabled if the corresponding deprecation guard is defined, regardless of its value.
  Example:
    - ff_api_vappi_is_defined
```

--------------------------------

### AVCodec Version Greater Than Feature Flags

Source: https://github.com/zmwangx/rust-ffmpeg-sys/blob/master/README.md

This flag indicates if the `avcodec` library version is greater than a specified major and minor version. It is useful for checking for specific `avcodec` API availability beyond a certain version.

```APIDOC
- avcodec_version_greater_than_<x>_<y>: Indicates the avcodec library version is greater than <x>.<y>.
  Example:
    - avcodec_version_greater_than_58_90
```

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