ConvertBits

AVS+
This feature is specific to AviSynthPlus. It is not supported in other AviSynth versions.

ConvertBits

Changes bit depth while keeping color format the same, if possible.
If the conversion is not possible – for example, converting RGB32 to 16bit – an error is raised.

ConvertBits(clip, int bits [, bool truerange, int dither, float scale, int dither_bits, bool fulls, bool fulld ] )

(older bit-depth conversion filters – deprecated)

ConvertToFloat(clip, int bits [, bool truerange, int dither, float scale, int dither_bits, bool fulls, bool fulld ] )
ConvertTo16bit(clip, int bits [, bool truerange, int dither, float scale, int dither_bits, bool fulls, bool fulld ] )
ConvertTo8bit(clip, int bits [, bool truerange, int dither, float scale, int dither_bits, bool fulls, bool fulld ] )

clip   = (required)

Source clip.

bits   = (required)

Bit depth of output clip. Valid values: 8, 10, 12, 14, 16 (integer) or 32 (floating point).

bool  truerange = true

(TODO if false, seems to either do nothing or corrupt output)

Only allowed with Planar color formats.

If true (default), convert 10-16 bit formats without re-scaling underlying pixel data. For example,

  clip10bit.ConvertBits(16, truerange=false)

will leave pixel data in the 0..1023 range, but will change the color format from YUVxxxP10 to YUVxxxP16.

Current recommendation: do not specify a truerange argument – use the default value.

int  dither = -1

If 0, add ordered dither; if -1 (default), do not add dither.

Currently works only for 10-16bit → 8bit conversions.

float  scale = 1.0

(TODO no apparent change in output)

Only allowed for 32bit → 32bit.

Current recommendation: do not specify a scale argument – use the default value.

int  dither_bits = bits

Dither to a lower color depth than selected bits (default = bits)

No effect if dither=-1 (off).

• Must be an even number between 2 to bits, inclusive.
• In addition, dither_bits must be >= (clip.BitsPerComponent-8)

Examples

Conversion	Allowed Values
16 → 12bit	8, 10, 12
16 → 10bit	8, 10
16 →   8bit	8
14 → 10bit	6, 8, 10
14 →   8bit	6, 8
12 → 10bit	4, 6, 8, 10
12 →   8bit	4, 6, 8
10 →   8bit	2, 4, 6, 8

bool  fulls = (auto)

If true (rgb default), scale by multiplication: 0-255 → 0-65535;

if false (yuv default), scale by bit-shifting.

Use case: override greyscale conversion to fullscale instead of bit-shifts

Notes:

• Conversion from and to float is always full-scale
• Alpha plane is always treated as full scale
• At the moment, fulld must equal fulls.

Current recommendation: do not specify a fulls argument – use the default value.

bool  fulld = fulls

Current recommendation: do not specify a fulld argument – use the default value.

Changes

20170310 r2440	parameter dither_bits
20170202 r2420	parameters fulls, fulld