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https://gitlab.uni-freiburg.de/opensourcevdi/spice-common
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258123318d
The error functions are supposed to not return. Using the attribute documents that in the interface, and is better for the compiler because most noreturn-related optimizations and spurious warning eliminations happen at the call site. Signed-off-by: Christophe de Dinechin <dinechin@redhat.com> Acked-by: Frediano Ziglio <fziglio@redhat.com>
83 lines
3.5 KiB
C
83 lines
3.5 KiB
C
/* -*- Mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
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/*
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dictionary compression for images based on fastlz (http://www.fastlz.org/)
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(Distributed under MIT license).
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*/
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#ifndef __LZ_H
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#define __LZ_H
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#include <spice/macros.h>
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#include "lz_common.h"
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#include "lz_config.h"
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#include "draw.h"
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#include "macros.h"
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SPICE_BEGIN_DECLS
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typedef void *LzContext;
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typedef struct LzUsrContext LzUsrContext;
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struct LzUsrContext {
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SPICE_ATTR_NORETURN
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SPICE_ATTR_PRINTF(2, 3) void (*error)(LzUsrContext *usr, const char *fmt, ...);
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SPICE_ATTR_PRINTF(2, 3) void (*warn)(LzUsrContext *usr, const char *fmt, ...);
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SPICE_ATTR_PRINTF(2, 3) void (*info)(LzUsrContext *usr, const char *fmt, ...);
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void *(*malloc)(LzUsrContext *usr, int size);
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void (*free)(LzUsrContext *usr, void *ptr);
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int (*more_space)(LzUsrContext *usr, uint8_t **io_ptr); // get the next chunk of the
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// compressed buffer. return
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// number of bytes in the chunk.
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int (*more_lines)(LzUsrContext *usr, uint8_t **lines); // get the next chunk of the
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// original image. If the image
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// is down to top, return it from
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// the last line to the first one
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// (stride should always be
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// positive)
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};
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/*
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assumes width is in pixels and stride is in bytes
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return: the number of bytes in the compressed data
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TODO : determine size limit for the first segment and each chunk. check validity
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of the segment or go to literal copy.
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TODO : currently support only rgb images in which width*bytes_per_pixel = stride OR
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palette images in which stride equals the min number of bytes to
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hold a line. stride is not necessary for now. just for sanity check.
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stride should be > 0
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*/
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int lz_encode(LzContext *lz, LzImageType type, int width, int height, int top_down,
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uint8_t *lines, unsigned int num_lines, int stride,
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uint8_t *io_ptr, unsigned int num_io_bytes);
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/*
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prepare encoder and read lz magic.
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out_n_pixels number of compressed pixels. May differ from Width*height in plt1/4.
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Use it for allocation the decompressed buffer.
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*/
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void lz_decode_begin(LzContext *lz, uint8_t *io_ptr, unsigned int num_io_bytes,
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LzImageType *out_type, int *out_width, int *out_height,
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int *out_n_pixels, int *out_top_down, const SpicePalette *palette);
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/*
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to_type = the image output type.
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We assume the buffer is consecutive. i.e. width = stride
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Important: if the image is plt1/4 and to_type is rgb32, the image
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will decompressed including the last bits in each line. This means buffer should be
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larger than width*height if needed and you should use stride to fix it.
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Note: If the image is down to top, set the stride in the sw surface to negative.
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use alloc_lz_image_surface create the surface.
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*/
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void lz_decode(LzContext *lz, LzImageType to_type, uint8_t *buf);
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LzContext *lz_create(LzUsrContext *usr);
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void lz_destroy(LzContext *lz);
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SPICE_END_DECLS
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#endif // __LZ_H
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