## BlankClip / Blackness

`BlankClip` (clip clip, int "length", int "width", int "height", string "pixel_type",
float "fps", int "fps_denominator", int "audio_rate", int "channels",
string "sample_type", int "color", int "color_yuv")

`BlankClip` (clip clip, int "length", int "width", int "height", string "pixel_type",
float "fps", int "fps_denominator", int "audio_rate", bool "stereo",
bool "sixteen_bit", int "color", int "color_yuv")

`Blackness` ()

The `BlankClip` filter produces a solid color, silent video clip of the specified length (in frames). The clip passed as an argument is used as a template for frame rate, image size, and so on, but you can specify all clip properties without having to provide a template. color should be given as hexadecimal RGB values. Without any argument, `BlankClip` will produce a pitch-black 10 seconds clip (RGB32), 640x480, 24 fps, 16 bit 44100 Hz mono.

clip: if present, the resulting clip will have the clip-properties of the template, except for the properties you define explicitly.

length: length of the resulting clip (in frames).

width, height: width and height of the resulting clip.

pixel_type: pixel type of the resulting clip, it can be "RGB24", "RGB32", "YUY2" or "YV12".

fps: the framerate of the resulting clip.

fps_denominator: you can use this option if "fps" is not accurate enough. For example: fps = 30000, fps_denominator = 1001 (ratio = 29.97) or fps = 24000, fps_denominator = 1001 (ratio = 23.976). It is 1 by default.

audio_rate: samplerate of the silent audio of the clip.

channels: specifies the number of audio channels of silent audio added to the blank clip ( added in v2.58).

stereo: (boolean) when set to true the silent audio is in stereo, when set to false a silent mono track is added. Deprecated! Use should the channels parameter instead.

sample_type: specifies the audio sample type of the resulting clip. It can be "8bit", "16bit", "24bit", "32bit" or "float" ( added in v2.58).

sixteen_bit: (boolean) true give 16 bit, false gives ieee float. Deprecated! Use the sample_type parameter instead.

color: specifies the color of the clip, black (= $000000) by default. See ColorPresets for preset colors. See here for more information on specifying colors.
color_yuv: is added in v2.55, and it lets you specify the color of the clip using YUV values. It requires setting pixel_type to "YUY2" or "YV12", otherwise it doesn't do anything.

`Blackness` is an alias for `BlankClip`, provided for backward compatibility.

Examples:

    # produces a black clip (3000 frames, width 720, height 576, framerate 25), with a silent audio track (16 bit 44.1 kHz stereo):
    BlankClip(length=3000, width=720, height=576, fps=25, color=$000000)

    # produces a black clip (3000 frames) with the remaining clip properties of the avi:
    video = AviSource("E:\pdwork\DO-Heaven.AVI")
    BlankClip(video, length=3000, color=$000000)

    # adds a silent audio stream (with a samplerate of 48 kHz) to a video clip:
    video = AviSource("E:\pdwork\DO-Heaven.AVI")
    audio = BlankClip(video, audio_rate=48000)
    AudioDub(video, audio)

Changes:

v2.55 | added color_yuv
v2.58 | added channels and sample_type

`$Date: 2011/04/29 20:09:50 $`