picoware.gui.jpeg.JPEG

class documentation

class JPEG(jpegdec.JPEGDecoder):

Constructor: JPEG(screen_width, screen_height, buffer_size, buffer_num)

JPEG decoder for Picoware.

Method	`__del__`	Clean up decoder resources.
Method	`__init__`	Initialize the JPEG decoder with display and buffer settings.
Method	`draw`	Draw a JPEG file at position (x, y) on the display.
Method	`draw_buffer`	Draw a JPEG image from bytes data into a BytesIO buffer.
Method	`_cleanup`	Wait for the decoder core and reset the running flag.
Method	`_decode_split`	Decode a JPEG from a file, streaming buffers as needed.
Method	`_get_option`	Return the decoder option for the given scale factor.
Method	`_get_scale`	Return (scale, (auto_x, auto_y)) so the image fits the display.
Method	`_init_buffers`	Allocate the file buffer and split it into decode buffers.
Method	`_read_into_buf`	Read data from the file into a buffer.
Method	`_start_split`	Start decoding a JPEG from the given buffer.
Method	`_test_buffer`	Check which buffers cover the requested data range.
Instance Variable	`_buffer_num`	Undocumented
Instance Variable	`_buffer_size`	Undocumented
Instance Variable	`_buffers`	Undocumented
Instance Variable	`_buffers_len`	Undocumented
Instance Variable	`_buffers_pos`	Undocumented
Instance Variable	`_decoder_running`	Undocumented
Instance Variable	`_filebuffer`	Undocumented
Instance Variable	`_max_height`	Undocumented
Instance Variable	`_max_width`	Undocumented

def __del__(self): ¶

Clean up decoder resources.

def __init__(self, screen_width: int = 320, screen_height: int = 320, buffer_size: int = 1024 * 8, buffer_num: int = 2): ¶

Initialize the JPEG decoder with display and buffer settings.

Parameters
screen_width:`int`	Maximum display width. Defaults to 320.
screen_height:`int`	Maximum display height. Defaults to 320.
buffer_size:`int`	Size of each decode buffer. Defaults to 1024 * 8.
buffer_num:`int`	Number of decode buffers. Defaults to 2.

def draw(self, x: int, y: int, file_path, storage=None) -> bool: ¶

Draw a JPEG file at position (x, y) on the display.

Parameters
x:`int`	Horizontal draw position in pixels.
y:`int`	Vertical draw position in pixels.
file_path:`str`	Path to the .jpg / .jpeg file.
storage	Storage class instance. Defaults to None.

Returns
`bool`	True on success, False on failure.

def draw_buffer(self, x: int, y: int, buf) -> bool: ¶

Draw a JPEG image from bytes data into a BytesIO buffer.

Parameters
x:`int`	Horizontal draw position in pixels.
y:`int`	Vertical draw position in pixels.
buf	Bytes data containing the JPEG image.

Returns
`bool`	True on success, False on failure.

def _cleanup(self): ¶

Wait for the decoder core and reset the running flag.

def _decode_split(self, fi, fsize, x, y) -> bool: ¶

Decode a JPEG from a file, streaming buffers as needed.

Parameters
fi	The file object to read from.
fsize	The total file size.
x:`int`	Horizontal draw position.
y:`int`	Vertical draw position.

Returns
`bool`	True on success, False on failure.

def _get_option(self, scale) -> int: ¶

Return the decoder option for the given scale factor.

Parameters
scale	The scale factor (1, 0.5, 0.25, or 0.125).

Returns
`int`	The decoder option value.

def _get_scale(self, w, h) -> tuple[float, tuple[int, int]]: ¶

Return (scale, (auto_x, auto_y)) so the image fits the display.

Parameters
w:`int`	The image width.
h:`int`	The image height.

Returns
`tuple[float, tuple[int, int]]`	The scale and auto offset.

def _init_buffers(self): ¶

Allocate the file buffer and split it into decode buffers.

def _read_into_buf(self, fi, buf): ¶

Read data from the file into a buffer.

Parameters
fi	The file object to read from.
buf	The buffer to fill.

def _start_split(self, fsize, buf, x, y) -> bool: ¶

Start decoding a JPEG from the given buffer.

Parameters
fsize	The total file size.
buf	The initial buffer data.
x:`int`	Horizontal draw position.
y:`int`	Vertical draw position.

Returns
`bool`	True if decoding started successfully.

def _test_buffer(self, ipos, ilen) -> tuple[int, int]: ¶

Check which buffers cover the requested data range.

Parameters
ipos	The requested start position.
ilen	The requested length.

Returns
`tuple[int, int]`	The matching buffer index and free buffer mask.

_buffer_num = ¶

Undocumented

_buffer_size = ¶

Undocumented

_buffers = ¶

Undocumented

_buffers_len = ¶

Undocumented

_buffers_pos = ¶

Undocumented

_decoder_running: bool = ¶

Undocumented

_filebuffer = ¶

Undocumented

_max_height = ¶

Undocumented

_max_width = ¶

Undocumented