esphome::snapshot::GifWriter Class Reference

Writes an animated GIF a frame at a time, so a long recording is never held in memory. More...

#include <gif.h>

Data Structures
struct	ColorBin
	How many pixels of one colour there are in the frame, and the sum of their red, green and blue. More...

Public Member Functions
	GifWriter (FILE *file, int width, int height)
bool	write_header ()
	Write the start of the file. This must come first. The animation repeats forever.
bool	write_frame (const uint8_t *bgr, size_t row_stride, unsigned delay_centiseconds)
	Add a frame from three bytes per pixel in blue, green, red order, topmost row first, with row_stride bytes from the start of one row to the start of the next.
bool	write_trailer ()
	Write the end of the file. This must come last.

Protected Member Functions
size_t	build_palette_ (uint8_t *palette)
	Choose up to 256 colours for the frame in bins_, storing them as red, green, blue triples in palette and which one each colour is nearest in palette_index_.

Protected Attributes
FILE *	file_
int	width_
int	height_
std::vector< ColorBin >	bins_
std::vector< uint16_t >	used_colors_
std::vector< uint8_t >	palette_index_
std::vector< uint8_t >	indices_
std::vector< uint8_t >	output_

Detailed Description

Writes an animated GIF a frame at a time, so a long recording is never held in memory.

A GIF frame can use at most 256 colours. Each frame gets its own colour table, chosen from what is in that frame, so a frame with 256 colours or fewer is stored exactly.

Definition at line 15 of file gif.h.

Constructor & Destructor Documentation

GifWriter()

esphome::snapshot::GifWriter::GifWriter	(	FILE *	file,
		int	width,
		int	height )

Definition at line 124 of file gif.cpp.

Member Function Documentation

build_palette_()

size_t esphome::snapshot::GifWriter::build_palette_ ( uint8_t * palette )

protected

Choose up to 256 colours for the frame in bins_, storing them as red, green, blue triples in palette and which one each colour is nearest in palette_index_.

Returns how many were chosen.

Definition at line 149 of file gif.cpp.

write_frame()

bool esphome::snapshot::GifWriter::write_frame	(	const uint8_t *	bgr,
		size_t	row_stride,
		unsigned	delay_centiseconds )

Add a frame from three bytes per pixel in blue, green, red order, topmost row first, with row_stride bytes from the start of one row to the start of the next.

The frame is shown for delay_centiseconds hundredths of a second.

Definition at line 224 of file gif.cpp.

write_header()

bool esphome::snapshot::GifWriter::write_header

(

)

Write the start of the file. This must come first. The animation repeats forever.

Definition at line 132 of file gif.cpp.

write_trailer()

bool esphome::snapshot::GifWriter::write_trailer

(

)

Write the end of the file. This must come last.

Definition at line 277 of file gif.cpp.

Field Documentation

bins_

std::vector<ColorBin> esphome::snapshot::GifWriter::bins_

protected

Definition at line 42 of file gif.h.

file_

FILE* esphome::snapshot::GifWriter::file_

protected

Definition at line 39 of file gif.h.

height_

int esphome::snapshot::GifWriter::height_

protected

Definition at line 41 of file gif.h.

indices_

std::vector<uint8_t> esphome::snapshot::GifWriter::indices_

protected

Definition at line 45 of file gif.h.

output_

std::vector<uint8_t> esphome::snapshot::GifWriter::output_

protected

Definition at line 46 of file gif.h.

palette_index_

std::vector<uint8_t> esphome::snapshot::GifWriter::palette_index_

protected

Definition at line 44 of file gif.h.

used_colors_

std::vector<uint16_t> esphome::snapshot::GifWriter::used_colors_

protected

Definition at line 43 of file gif.h.

width_

int esphome::snapshot::GifWriter::width_

protected

Definition at line 40 of file gif.h.

---

The documentation for this class was generated from the following files:

• esphome/components/snapshot/gif.h
• esphome/components/snapshot/gif.cpp