Transloadit

Transcode, resize, or watermark videos

🤖/video/encode encodes, resizes, applies watermarks to videos and animated GIFs.

Usage example

Transcode uploaded video to HEVC (H.265):

{
  "steps": {
    "hevc_encoded": {
      "robot": "/video/encode",
      "use": ":original",
      "preset": "hevc"
    }
  }
}

Parameters

  • output_meta

    Record<string, boolean> | boolean

    Allows you to specify a set of metadata that is more expensive on CPU power to calculate, and thus is disabled by default to keep your Assemblies processing fast.

    For images, you can add "has_transparency": true in this object to extract if the image contains transparent parts and "dominant_colors": true to extract an array of hexadecimal color codes from the image.

    For videos, you can add the "colorspace: true" parameter to extract the colorspace of the output video.

    For audio, you can add "mean_volume": true to get a single value representing the mean average volume of the audio file.

    You can also set this to false to skip metadata extraction and speed up transcoding.

  • result

    boolean (default: false)

    Whether the results of this Step should be present in the Assembly Status JSON

  • queue

    "batch"

    Setting the queue to 'batch', manually downgrades the priority of jobs for this step to avoid consuming Priority job slots for jobs that don't need zero queue waiting times

  • force_accept

    boolean (default: false)
      Force a Robot to accept a file type it would have ignored.
    

    By default Robots ignore files they are not familiar with. 🤖/video/encode, for example, will happily ignore input images.

    With the force_accept parameter set to true you can force Robots to accept all files thrown at them. This will typically lead to errors and should only be used for debugging or combatting edge cases.

  • use

    string | Array<string> | Array<object> | object

    Specifies which Step(s) to use as input.

    • You can pick any names for Steps except ":original" (reserved for user uploads handled by Transloadit)
    • You can provide several Steps as input with arrays:
      {
        "use": [
          ":original",
          "encoded",
          "resized"
        ]
      }
      
  • ffmpeg

    object

    A parameter object to be passed to FFmpeg. If a preset is used, the options specified are merged on top of the ones from the preset. For available options, see the FFmpeg documentation. Options specified here take precedence over the preset options.

  • ffmpeg_stack

    "v5" | "v6" | "v7" | string (default: "v5.0.0")

    Selects the FFmpeg stack version to use for encoding. These versions reflect real FFmpeg versions. We currently recommend to use "v6.0.0".

  • width

    string | number | null

    Width of the new video, in pixels.

    If the value is not specified and the preset parameter is available, the preset's supplied width will be implemented.

  • height

    string | number | null

    Height of the new video, in pixels.

    If the value is not specified and the preset parameter is available, the preset's supplied height will be implemented.

  • preset

    Converts a video according to pre-configured settings.

    If you specify your own FFmpeg parameters using the Robot's and/or do not not want Transloadit to set any encoding setting, starting ffmpeg_stack: "v6", you can use the value 'empty' here.

  • resize_strategy

    (default: "pad")
  • zoom

    boolean (default: true)

    If this is set to false, smaller videos will not be stretched to the desired width and height. For details about the impact of zooming for your preferred resize strategy, see the list of available resize strategies.

  • crop

    object | string

    Specify an object containing coordinates for the top left and bottom right corners of the rectangle to be cropped from the original video(s). Values can be integers for absolute pixel values or strings for percentage based values.

    For example:

    
    {
      "x1": 80,
      "y1": 100,
      "x2": "60%",
      "y2": "80%"
    }
    
    

    This will crop the area from (80, 100) to (600, 800) from a 1000×1000 pixels video, which is a square whose width is 520px and height is 700px. If crop is set, the width and height parameters are ignored, and the resize_strategy is set to crop automatically.

    You can also use a JSON string of such an object with coordinates in similar fashion: "{ "x1": <Integer>, "y1": <Integer>, "x2": <Integer>, "y2": <Integer> }"

  • background

    string (default: "#00000000")

    The background color of the resulting video the "rrggbbaa" format (red, green, blue, alpha) when used with the "pad" resize strategy. The default color is black.

  • rotate

    Forces the video to be rotated by the specified degree integer. Currently, only multiples of 90 are supported. We automatically correct the orientation of many videos when the orientation is provided by the camera. This option is only useful for videos requiring rotation because it was not detected by the camera. If you set rotate to false no rotation is performed, even if the metadata contains such instructions.

  • hint

    boolean (default: false)

    Enables hinting for mp4 files, for RTP/RTSP streaming.

  • turbo

    boolean (default: false)

    Splits the video into multiple chunks so that each chunk can be encoded in parallel before all encoded chunks are stitched back together to form the result video. This comes at the expense of extra Priority Job Slots and may prove to be counter-productive for very small video files.

  • chunk_duration

    string | number

    Allows you to specify the duration of each chunk when turbo is set to true. This means you can take advantage of that feature while using fewer Priority Job Slots. For instance, the longer each chunk is, the fewer Encoding Jobs will need to be used.

  • watermark_url

    string (default: "")

    A URL indicating a PNG image to be overlaid above this image. You can also supply the watermark via another Assembly Step.

  • watermark_position

    | Array<> (default: "center")

    The position at which the watermark is placed.

    An array of possible values can also be specified, in which case one value will be selected at random, such as [ "center", "left", "bottom-left", "bottom-right" ].

    This setting puts the watermark in the specified corner. To use a specific pixel offset for the watermark, you will need to add the padding to the image itself.

  • watermark_x_offset

    string | number (default: 0)

    The x-offset in number of pixels at which the watermark will be placed in relation to the position it has due to watermark_position.

    Values can be both positive and negative and yield different results depending on the watermark_position parameter. Positive values move the watermark closer to the image's center point, whereas negative values move the watermark further away from the image's center point.

  • watermark_y_offset

    string | number (default: 0)

    The y-offset in number of pixels at which the watermark will be placed in relation to the position it has due to watermark_position.

    Values can be both positive and negative and yield different results depending on the watermark_position parameter. Positive values move the watermark closer to the image's center point, whereas negative values move the watermark further away from the image's center point.

  • watermark_size

    string

    The size of the watermark, as a percentage, such as "50%". How the watermark is resized greatly depends on the watermark_resize_strategy.

  • watermark_resize_strategy

    "area" | "fit" | "stretch" (default: "fit")

    To explain how the resize strategies work, let's assume our target video size is 800×800 pixels and our watermark image is 400×300 pixels. Let's also assume, the watermark_size parameter is set to "25%".

    For the "fit" resize strategy, the watermark is scaled so that the longer side of the watermark takes up 25% of the corresponding video side. And the other side is scaled according to the aspect ratio of the watermark image. So with our watermark, the width is the longer side, and 25% of the video size would be 200px. Hence, the watermark would be resized to 200×150 pixels. If the watermark_size was set to "50%"", it would be resized to 400×300 pixels (so just left at its original size).

    For the "stretch" resize strategy, the watermark image is stretched (meaning, it is resized without keeping its aspect ratio in mind) so that both sides take up 25% of the corresponding video side. Since our video is 800×800 pixels, for a watermark size of 25% the watermark would be resized to 200×200 pixels. Its height would appear stretched, because keeping the aspect ratio in mind it would be resized to 200×150 pixels instead.

    For the "area" resize strategy, the watermark is resized (keeping its aspect ratio in check) so that it covers "xx%" of the video's surface area. The value from watermark_size is used for the percentage area size.

  • watermark_start_time

    string | number (default: 0)

    The delay in seconds from the start of the video for the watermark to appear. By default the watermark is immediately shown.

  • watermark_duration

    string | number (default: -1)

    The duration in seconds for the watermark to be shown. Can be used together with watermark_start_time to create nice effects. The default value is -1.0, which means that the watermark is shown for the entire duration of the video.

  • watermark_opacity

    string | number (default: 1)

    The opacity of the watermark. Valid values are between 0 (invisible) and 1.0 (full visibility).

  • segment

    boolean (default: false)

    Splits the file into multiple parts, to be used for Apple's HTTP Live Streaming.

  • segment_duration

    string | number (default: 10)

    Specifies the length of each HTTP segment. This is optional, and the default value as recommended by Apple is 10. Do not change this value unless you have a good reason.

  • segment_prefix

    string (default: "")

    The prefix used for the naming. For example, a prefix of "segment_" would produce files named "segment_0.ts", "segment_1.ts" and so on. This is optional, and defaults to the base name of the input file. Also see the related segment_name parameter.

  • segment_name

    string (default: "")

    The name used for the final segment. Available variables are ${segment_prefix}, ${segment_number} and ${segment_id} (which is a UUIDv4 without dashes).

Demos

Related blog posts