pngdec.c File Reference

#include "libavutil/avassert.h"
#include "libavutil/bprint.h"
#include "libavutil/imgutils.h"
#include "libavutil/stereo3d.h"
#include "libavutil/mastering_display_metadata.h"
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
#include "apng.h"
#include "png.h"
#include "pngdsp.h"
#include "thread.h"
#include <zlib.h>

Go to the source code of this file.

Data Structures
struct	PNGDecContext

Macros
#define	UNROLL1(bpp, op)
#define	UNROLL_FILTER(op)
#define	OP_SUB(x, s, l)   ((x) + (s))
#define	OP_AVG(x, s, l)   (((((x) + (l)) >> 1) + (s)) & 0xff)
#define	YUV2RGB(NAME, TYPE)
#define	FAST_DIV255(x)   ((((x) + 128) * 257) >> 16)

Enumerations
enum	PNGHeaderState { PNG_IHDR = 1 << 0, PNG_PLTE = 1 << 1 }
enum	PNGImageState { PNG_IDAT = 1 << 0, PNG_ALLIMAGE = 1 << 1 }

Functions
static void	png_put_interlaced_row (uint8_t *dst, int width, int bits_per_pixel, int pass, int color_type, const uint8_t *src)
void	ff_add_png_paeth_prediction (uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp)
static void	png_filter_row (PNGDSPContext *dsp, uint8_t *dst, int filter_type, uint8_t *src, uint8_t *last, int size, int bpp)
static void	png_handle_row (PNGDecContext *s)
static int	png_decode_idat (PNGDecContext *s, int length)
static int	decode_zbuf (AVBPrint *bp, const uint8_t *data, const uint8_t *data_end)
static uint8_t *	iso88591_to_utf8 (const uint8_t *in, size_t size_in)
static int	decode_text_chunk (PNGDecContext *s, uint32_t length, int compressed, AVDictionary **dict)
static int	decode_ihdr_chunk (AVCodecContext *avctx, PNGDecContext *s, uint32_t length)
static int	decode_phys_chunk (AVCodecContext *avctx, PNGDecContext *s)
static int	decode_idat_chunk (AVCodecContext *avctx, PNGDecContext *s, uint32_t length, AVFrame *p)
static int	decode_plte_chunk (AVCodecContext *avctx, PNGDecContext *s, uint32_t length)
static int	decode_trns_chunk (AVCodecContext *avctx, PNGDecContext *s, uint32_t length)
static int	decode_iccp_chunk (PNGDecContext *s, int length, AVFrame *f)
static void	handle_small_bpp (PNGDecContext *s, AVFrame *p)
static int	decode_fctl_chunk (AVCodecContext *avctx, PNGDecContext *s, uint32_t length)
static void	handle_p_frame_png (PNGDecContext *s, AVFrame *p)
static int	handle_p_frame_apng (AVCodecContext *avctx, PNGDecContext *s, AVFrame *p)
static int	decode_frame_common (AVCodecContext *avctx, PNGDecContext *s, AVFrame *p, AVPacket *avpkt)
static av_cold int	png_dec_init (AVCodecContext *avctx)
static av_cold int	png_dec_end (AVCodecContext *avctx)

Variables
static const uint8_t	png_pass_mask [NB_PASSES]
static const uint8_t	png_pass_dsp_ymask [NB_PASSES]
static const uint8_t	png_pass_dsp_mask [NB_PASSES]

Macro Definition Documentation

UNROLL1

#define UNROLL1	(		bpp,
			op
	)

Value:

    {                                                                         \
        r = dst[0];                                                           \
        if (bpp >= 2)                                                         \
            g = dst[1];                                                       \
        if (bpp >= 3)                                                         \
            b = dst[2];                                                       \
        if (bpp >= 4)                                                         \
            a = dst[3];                                                       \
        for (; i <= size - bpp; i += bpp) {                                   \
            dst[i + 0] = r = op(r, src[i + 0], last[i + 0]);                  \
            if (bpp == 1)                                                     \
                continue;                                                     \
            dst[i + 1] = g = op(g, src[i + 1], last[i + 1]);                  \
            if (bpp == 2)                                                     \
                continue;                                                     \
            dst[i + 2] = b = op(b, src[i + 2], last[i + 2]);                  \
            if (bpp == 3)                                                     \
                continue;                                                     \
            dst[i + 3] = a = op(a, src[i + 3], last[i + 3]);                  \
        }                                                                     \
    }

Definition at line 213 of file pngdec.c.

UNROLL_FILTER

#define UNROLL_FILTER

(

op

)

Value:

    if (bpp == 1) {                                                           \
        UNROLL1(1, op)                                                        \
    } else if (bpp == 2) {                                                    \
        UNROLL1(2, op)                                                        \
    } else if (bpp == 3) {                                                    \
        UNROLL1(3, op)                                                        \
    } else if (bpp == 4) {                                                    \
        UNROLL1(4, op)                                                        \
    }                                                                         \
    for (; i < size; i++) {                                                   \
        dst[i] = op(dst[i - bpp], src[i], last[i]);                           \
    }

Definition at line 236 of file pngdec.c.

OP_SUB

#define OP_SUB	(		x,
			s,
			l
	)		((x) + (s))

OP_AVG

#define OP_AVG	(		x,
			s,
			l
	)		(((((x) + (l)) >> 1) + (s)) & 0xff)

YUV2RGB

#define YUV2RGB	(		NAME,
			TYPE
	)

Value:

static void deloco_ ## NAME(TYPE *dst, int size, int alpha) \
{ \
    int i; \
    for (i = 0; i < size; i += 3 + alpha) { \
        int g = dst [i + 1]; \
        dst[i + 0] += g; \
        dst[i + 2] += g; \
    } \
}

Definition at line 308 of file pngdec.c.

FAST_DIV255

#define FAST_DIV255

(

x

)

((((x) + 128) * 257) >> 16)

Definition at line 1059 of file pngdec.c.

Enumeration Type Documentation

PNGHeaderState

enum PNGHeaderState

Enumerator
PNG_IHDR
PNG_PLTE

Definition at line 40 of file pngdec.c.

PNGImageState

enum PNGImageState

Enumerator
PNG_IDAT
PNG_ALLIMAGE

Definition at line 45 of file pngdec.c.

Function Documentation

png_put_interlaced_row()

static void png_put_interlaced_row ( uint8_t *  dst, int  width, int  bits_per_pixel, int  pass, int  color_type, const uint8_t *  src  )

static

Definition at line 115 of file pngdec.c.

Referenced by png_handle_row().

ff_add_png_paeth_prediction()

void ff_add_png_paeth_prediction	(	uint8_t *	dst,
		uint8_t *	src,
		uint8_t *	top,
		int	w,
		int	bpp
	)

Definition at line 185 of file pngdec.c.

Referenced by ff_pngdsp_init(), and png_filter_row().

png_filter_row()

static void png_filter_row ( PNGDSPContext *  dsp, uint8_t *  dst, int  filter_type, uint8_t *  src, uint8_t *  last, int  size, int  bpp  )

static

Definition at line 251 of file pngdec.c.

Referenced by png_handle_row().

png_handle_row()

static void png_handle_row ( PNGDecContext *  s )

static

Definition at line 323 of file pngdec.c.

Referenced by png_decode_idat().

png_decode_idat()

static int png_decode_idat ( PNGDecContext *  s, int  length  )

static

Definition at line 404 of file pngdec.c.

Referenced by decode_idat_chunk().

decode_zbuf()

static int decode_zbuf ( AVBPrint *  bp, const uint8_t *  data, const uint8_t *  data_end  )

static

Definition at line 434 of file pngdec.c.

Referenced by decode_iccp_chunk(), and decode_text_chunk().

iso88591_to_utf8()

static uint8_t* iso88591_to_utf8 ( const uint8_t *  in, size_t  size_in  )

static

Definition at line 478 of file pngdec.c.

Referenced by decode_text_chunk().

decode_text_chunk()

static int decode_text_chunk ( PNGDecContext *  s, uint32_t  length, int  compressed, AVDictionary **  dict  )

static

Definition at line 502 of file pngdec.c.

Referenced by decode_frame_common().

decode_ihdr_chunk()

static int decode_ihdr_chunk ( AVCodecContext *  avctx, PNGDecContext *  s, uint32_t  length  )

static

Definition at line 550 of file pngdec.c.

Referenced by decode_frame_common().

decode_phys_chunk()

static int decode_phys_chunk ( AVCodecContext *  avctx, PNGDecContext *  s  )

static

Definition at line 602 of file pngdec.c.

Referenced by decode_frame_common().

decode_idat_chunk()

static int decode_idat_chunk ( AVCodecContext *  avctx, PNGDecContext *  s, uint32_t  length, AVFrame *  p  )

static

Definition at line 618 of file pngdec.c.

Referenced by decode_frame_common().

decode_plte_chunk()

static int decode_plte_chunk ( AVCodecContext *  avctx, PNGDecContext *  s, uint32_t  length  )

static

Definition at line 773 of file pngdec.c.

Referenced by decode_frame_common().

decode_trns_chunk()

static int decode_trns_chunk ( AVCodecContext *  avctx, PNGDecContext *  s, uint32_t  length  )

static

Definition at line 796 of file pngdec.c.

Referenced by decode_frame_common().

decode_iccp_chunk()

static int decode_iccp_chunk ( PNGDecContext *  s, int  length, AVFrame *  f  )

static

Definition at line 844 of file pngdec.c.

Referenced by decode_frame_common().

handle_small_bpp()

static void handle_small_bpp ( PNGDecContext *  s, AVFrame *  p  )

static

Definition at line 889 of file pngdec.c.

Referenced by decode_frame_common().

decode_fctl_chunk()

static int decode_fctl_chunk ( AVCodecContext *  avctx, PNGDecContext *  s, uint32_t  length  )

static

Definition at line 962 of file pngdec.c.

Referenced by decode_frame_common().

handle_p_frame_png()

static void handle_p_frame_png ( PNGDecContext *  s, AVFrame *  p  )

static

Definition at line 1041 of file pngdec.c.

Referenced by decode_frame_common().

handle_p_frame_apng()

static int handle_p_frame_apng ( AVCodecContext *  avctx, PNGDecContext *  s, AVFrame *  p  )

static

Definition at line 1061 of file pngdec.c.

Referenced by decode_frame_common().

decode_frame_common()

static int decode_frame_common ( AVCodecContext *  avctx, PNGDecContext *  s, AVFrame *  p, AVPacket *  avpkt  )

static

Definition at line 1174 of file pngdec.c.

png_dec_init()

static av_cold int png_dec_init ( AVCodecContext *  avctx )

static

Definition at line 1726 of file pngdec.c.

png_dec_end()

static av_cold int png_dec_end ( AVCodecContext *  avctx )

static

Definition at line 1754 of file pngdec.c.

Variable Documentation

png_pass_mask

const uint8_t png_pass_mask[NB_PASSES]

static

Initial value:

= {
    0x01, 0x01, 0x11, 0x11, 0x55, 0x55, 0xff,
}

Definition at line 98 of file pngdec.c.

Referenced by png_put_interlaced_row().

png_pass_dsp_ymask

const uint8_t png_pass_dsp_ymask[NB_PASSES]

static

Initial value:

= {
    0xff, 0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
}

Definition at line 103 of file pngdec.c.

Referenced by png_handle_row().

png_pass_dsp_mask

const uint8_t png_pass_dsp_mask[NB_PASSES]

static

Initial value:

= {
    0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff
}

Definition at line 108 of file pngdec.c.

Referenced by png_put_interlaced_row().