78 lines
3.2 KiB
Plaintext
78 lines
3.2 KiB
Plaintext
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title: Video Operations
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---
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body:
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Just like [images](../imageops/), videos are separate files that are embedded into HTML files. Since they are media files, it's often desirable to read metadata or manipulate them in some way.
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!! Video metadata access is powered by [FFmpeg](https://ffmpeg.org/). In order to use it FFmpeg must be installed on your system and detected by Lektor. If Lektor is unable to find FFmpeg you will see the error message `Unable to locate ffmpeg or ffprobe executable. Is it installed?` in your console output if you try to use functionality that requires it.
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## Accessing videos
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```html+jinja
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{% for video in this.attachments.videos %}
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<div class="video"><video src="{{ video|url }}"></div>
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{% endfor %}
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```
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Just like images you can also access them using `site.get('/myfolder').attachments.videos` or `site.get('/myfolder').attachments.get('examplevideo.mp4')`. Note that not all formats are detected as videos (see [attachments](../../content/attachments/)). If your format is not in the list you may still be able to get it detected as a video by adding it to your [Lektor project file](../../project/file/#[attachment_types]).
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## Accessing metadata
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Video objects are sub-classes of Attachments but with a few extra properties.
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| Attribute | Description
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| - | -
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| `width` | Video height in pixels
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| `height` | Video height in pixels
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| `duration` | Video length as a [`datetime.timedelta`](https://docs.python.org/3/library/datetime.html) instance
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Example:
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```html+jinja
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{% set video = this.attachments.videos.first() %}
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<video src="{{ video|url }}">
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<dl>
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<dt>Width:</dt>
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<dd>{{ video.width }} px</dd>
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<dt>Height:</dt>
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<dd>{{ video.height }} px</dd>
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<dt>Duration:</dt>
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<dd>{{ video.duration.total_seconds() }} s</dd>
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</dl>
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```
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## Generating thumbnails
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The main difference between video and image attachments is how thumbnails are handled. Since a video basically is a long sequence of images you must first choose where in the video the thumbnail should be generated. This is done using the `.frame() method. There are multiple ways of calling it:
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| Method | Description
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| - | -
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| `frame()` | Use a frame from the middle of the video *(default)*
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| `frame(seek: float)` | Fraction between 0.0 and 1.0 of the video duration from where to extract the frame. The value `0.5` means that the middle of the video will be used. It can be seen as a shorthand for `video.frame(video.duration * seek)`.
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| `frame(seek: datetime.timedelta)` | Use a frame at the given seek distance from the beginning of the video. This is useful when you want to seek a fix time into a video.
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Calling this method will return a `VideoFrame` instance, which is not usable by itself. It does however just like an image have a thumbnail method.
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Example:
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```html+jinja
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{% set video = this.attachments.videos.first() %}
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<img src="{{ video.frame().thumbnail(300, 200, mode="crop")|url }}">
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<img src="{{ video.frame(0.1).thumbnail(300, 200, mode="crop")|url }}">
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```
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Note that unlike images it is not possible to get an URL to a video frame directly:
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```html+jinja
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{% set video = this.attachments.videos.first() %}
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<img src="{{ video.frame()|url }}"> <!-- This is not valid -->
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```
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---
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sort_key: 40
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---
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summary: Shows how templates can work with videos
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---
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version_added: 3.2
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