BlankClip

Revision as of 13:32, 24 August 2014

BlankClip([clip clip, int length, int width, int height, string pixel_type, int fps, int fps_denominator, int audio_rate, bool stereo, bool sixteen_bit, int color, int color_yuv])
BlankClip([clip clip, int length, int width, int height, string pixel_type, int fps, int fps_denominator, int audio_rate, int channels, string sample_type, 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 -- see script variables. 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", "YV12", "YV16" (v2.60), "YV24" (v2.60), "YV411" (v2.60) or "Y8" (v2.60).

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 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 and false give both 16 bit, except when a template is used where a different bit is set. Deprecated! Use the sample_type parameter instead.

color: specifies the color of the clip, black (= $000000) by default. See color presets for preset colors. See Colors 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 one of the YUV formats, otherwise it doesn't do anything.

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

When supplying a template you get identical clip properties to the template. If it's audio only you get a blank audio only clip, and if it's video only you get a blank video only clip. If you start to modify the parameters to force a video track (for width, height or pixel_type) or audio track (for audio_rate, channels or sample_type), the remaining parameters will be the default parameters. (added in v2.60)

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: