fitz/band-writer.h

Index

typedef

• fz_close_band_writer_fn
• fz_drop_band_writer_fn
• fz_write_band_fn
• fz_write_header_fn
• fz_write_trailer_fn

struct

• fz_band_writer

macro

• fz_new_band_writer

function

• fz_close_band_writer
• fz_drop_band_writer
• fz_new_band_writer_of_size
• fz_write_band
• fz_write_header

Band Writer

typedef fz_band_writer

typedef struct fz_band_writer fz_band_writer

A band writer is used to write image files incrementally. This is typically used when there isn’t enough memory to hold the full image at once; for example when rendering a high resolution page in bands.

function fz_write_header

void
fz_write_header (
        fz_context *ctx,
        fz_band_writer *writer,
        int w,
        int h,
        int n,
        int alpha,
        int xres,
        int yres,
        int pagenum,
        fz_colorspace *cs,
        fz_separations *seps
)

Cause a band writer to write the header for a banded image with the given properties/dimensions etc. This also configures the bandwriter for the format of the data to be passed in future calls.

w, h:

Width and Height of the entire page.

n:

Number of components (including spots and alphas).

alpha:

Number of alpha components.

xres, yres:

X and Y resolutions in dpi.

cs:

Colorspace (NULL for bitmaps)

seps:

Separation details (or NULL).

function fz_write_band

void
fz_write_band (
        fz_context *ctx,
        fz_band_writer *writer,
        int stride,
        int band_height,
        const unsigned char *samples
)

Cause a band writer to write the next band of data for an image.

stride:

The byte offset from the first byte of the data for a pixel to the first byte of the data for the same pixel on the row below.

band_height:

The number of lines in this band.

samples:

Pointer to first byte of the data.

function fz_close_band_writer

void
fz_close_band_writer (
        fz_context *ctx,
        fz_band_writer *writer
)

Finishes up the output and closes the band writer. After this call no more headers or bands may be written.

function fz_drop_band_writer

void
fz_drop_band_writer (
        fz_context *ctx,
        fz_band_writer *writer
)

Drop the reference to the band writer, causing it to be destroyed.

Never throws an exception.

Implementation details

Subject to change.

typedef fz_write_header_fn

typedef void (fz_write_header_fn)(
        fz_context *ctx,
        fz_band_writer *writer,
        fz_colorspace *cs
)

typedef fz_write_band_fn

typedef void (fz_write_band_fn)(
        fz_context *ctx,
        fz_band_writer *writer,
        int stride,
        int band_start,
        int band_height,
        const unsigned char *samples
)

typedef fz_write_trailer_fn

typedef void (fz_write_trailer_fn)(fz_context *ctx, fz_band_writer *writer)

typedef fz_close_band_writer_fn

typedef void (fz_close_band_writer_fn)(fz_context *ctx, fz_band_writer *writer)

typedef fz_drop_band_writer_fn

typedef void (fz_drop_band_writer_fn)(fz_context *ctx, fz_band_writer *writer)

struct fz_band_writer

struct fz_band_writer
{
        fz_drop_band_writer_fn *drop;
        fz_close_band_writer_fn *close;
        fz_write_header_fn *header;
        fz_write_band_fn *band;
        fz_write_trailer_fn *trailer;
        fz_output *out;
        int w;
        int h;
        int n;
        int s;
        int alpha;
        int xres;
        int yres;
        int pagenum;
        int line;
        fz_separations *seps;
}

function fz_new_band_writer_of_size

fz_band_writer *
fz_new_band_writer_of_size (
        fz_context *ctx,
        size_t size,
        fz_output *out
)

macro fz_new_band_writer

#define fz_new_band_writer(C,M,O)