#include "avcodec.h"
#include "bytestream.h"
#include "png.h"
+#include "dsputil.h"
/* TODO:
* - add 2, 4 and 16 bit depth support
//#define DEBUG
typedef struct PNGDecContext {
- uint8_t *bytestream;
- uint8_t *bytestream_start;
- uint8_t *bytestream_end;
+ DSPContext dsp;
+
+ const uint8_t *bytestream;
+ const uint8_t *bytestream_start;
+ const uint8_t *bytestream_end;
AVFrame picture;
int state;
}
}
-/* XXX: optimize */
+void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp)
+{
+ int i;
+ for(i = 0; i < w; i++) {
+ int a, b, c, p, pa, pb, pc;
+
+ a = dst[i - bpp];
+ b = top[i];
+ c = top[i - bpp];
+
+ p = b - c;
+ pc = a - c;
+
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+
+ if (pa <= pb && pa <= pc)
+ p = a;
+ else if (pb <= pc)
+ p = b;
+ else
+ p = c;
+ dst[i] = p + src[i];
+ }
+}
+
+#define UNROLL1(bpp, op) {\
+ r = dst[0];\
+ if(bpp >= 2) g = dst[1];\
+ if(bpp >= 3) b = dst[2];\
+ if(bpp >= 4) a = dst[3];\
+ for(; i < size; 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]);\
+ }\
+}
+
+#define UNROLL_FILTER(op)\
+ 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)\
+
/* NOTE: 'dst' can be equal to 'last' */
-static void png_filter_row(uint8_t *dst, int filter_type,
+static void png_filter_row(DSPContext *dsp, uint8_t *dst, int filter_type,
uint8_t *src, uint8_t *last, int size, int bpp)
{
- int i, p;
+ int i, p, r, g, b, a;
switch(filter_type) {
case PNG_FILTER_VALUE_NONE:
for(i = 0; i < bpp; i++) {
dst[i] = src[i];
}
- for(i = bpp; i < size; i++) {
- p = dst[i - bpp];
- dst[i] = p + src[i];
+ if(bpp == 4) {
+ p = *(int*)dst;
+ for(; i < size; i+=bpp) {
+ int s = *(int*)(src+i);
+ p = ((s&0x7f7f7f7f) + (p&0x7f7f7f7f)) ^ ((s^p)&0x80808080);
+ *(int*)(dst+i) = p;
+ }
+ } else {
+#define OP_SUB(x,s,l) x+s
+ UNROLL_FILTER(OP_SUB);
}
break;
case PNG_FILTER_VALUE_UP:
- for(i = 0; i < size; i++) {
- p = last[i];
- dst[i] = p + src[i];
- }
+ dsp->add_bytes_l2(dst, src, last, size);
break;
case PNG_FILTER_VALUE_AVG:
for(i = 0; i < bpp; i++) {
p = (last[i] >> 1);
dst[i] = p + src[i];
}
- for(i = bpp; i < size; i++) {
- p = ((dst[i - bpp] + last[i]) >> 1);
- dst[i] = p + src[i];
- }
+#define OP_AVG(x,s,l) (((x + l) >> 1) + s) & 0xff
+ UNROLL_FILTER(OP_AVG);
break;
case PNG_FILTER_VALUE_PAETH:
for(i = 0; i < bpp; i++) {
p = last[i];
dst[i] = p + src[i];
}
- for(i = bpp; i < size; i++) {
- int a, b, c, pa, pb, pc;
-
- a = dst[i - bpp];
- b = last[i];
- c = last[i - bpp];
-
- p = b - c;
- pc = a - c;
-
- pa = abs(p);
- pb = abs(pc);
- pc = abs(p + pc);
-
- if (pa <= pb && pa <= pc)
- p = a;
- else if (pb <= pc)
- p = b;
- else
- p = c;
- dst[i] = p + src[i];
+ if(bpp > 1 && size > 4) {
+ // would write off the end of the array if we let it process the last pixel with bpp=3
+ int w = bpp==4 ? size : size-3;
+ dsp->add_png_paeth_prediction(dst+i, src+i, last+i, w-i, bpp);
+ i = w;
}
+ ff_add_png_paeth_prediction(dst+i, src+i, last+i, size-i, bpp);
break;
}
}
-static void convert_to_rgb32(uint8_t *dst, const uint8_t *src, int width)
+static av_always_inline void convert_to_rgb32_loco(uint8_t *dst, const uint8_t *src, int width, int loco)
{
int j;
unsigned int r, g, b, a;
g = src[1];
b = src[2];
a = src[3];
+ if(loco) {
+ r = (r+g)&0xff;
+ b = (b+g)&0xff;
+ }
*(uint32_t *)dst = (a << 24) | (r << 16) | (g << 8) | b;
dst += 4;
src += 4;
}
}
+static void convert_to_rgb32(uint8_t *dst, const uint8_t *src, int width, int loco)
+{
+ if(loco)
+ convert_to_rgb32_loco(dst, src, width, 1);
+ else
+ convert_to_rgb32_loco(dst, src, width, 0);
+}
+
+static void deloco_rgb24(uint8_t *dst, int size)
+{
+ int i;
+ for(i=0; i<size; i+=3) {
+ int g = dst[i+1];
+ dst[i+0] += g;
+ dst[i+2] += g;
+ }
+}
+
/* process exactly one decompressed row */
static void png_handle_row(PNGDecContext *s)
{
ptr = s->image_buf + s->image_linesize * s->y;
/* need to swap bytes correctly for RGB_ALPHA */
if (s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
- png_filter_row(s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
+ png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
s->last_row, s->row_size, s->bpp);
- memcpy(s->last_row, s->tmp_row, s->row_size);
- convert_to_rgb32(ptr, s->tmp_row, s->width);
+ convert_to_rgb32(ptr, s->tmp_row, s->width, s->filter_type == PNG_FILTER_TYPE_LOCO);
+ FFSWAP(uint8_t*, s->last_row, s->tmp_row);
} else {
/* in normal case, we avoid one copy */
if (s->y == 0)
else
last_row = ptr - s->image_linesize;
- png_filter_row(ptr, s->crow_buf[0], s->crow_buf + 1,
+ png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1,
last_row, s->row_size, s->bpp);
}
+ /* loco lags by 1 row so that it doesn't interfere with top prediction */
+ if (s->filter_type == PNG_FILTER_TYPE_LOCO &&
+ s->color_type == PNG_COLOR_TYPE_RGB && s->y > 0)
+ deloco_rgb24(ptr - s->image_linesize, s->row_size);
s->y++;
if (s->y == s->height) {
s->state |= PNG_ALLIMAGE;
+ if (s->filter_type == PNG_FILTER_TYPE_LOCO &&
+ s->color_type == PNG_COLOR_TYPE_RGB)
+ deloco_rgb24(ptr, s->row_size);
}
} else {
got_line = 0;
wait for the next one */
if (got_line)
break;
- png_filter_row(s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
+ png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
s->last_row, s->pass_row_size, s->bpp);
- memcpy(s->last_row, s->tmp_row, s->pass_row_size);
+ FFSWAP(uint8_t*, s->last_row, s->tmp_row);
got_line = 1;
}
if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
static int decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
- uint8_t *buf, int buf_size)
+ const uint8_t *buf, int buf_size)
{
PNGDecContext * const s = avctx->priv_data;
AVFrame *picture = data;
- AVFrame * const p= (AVFrame*)&s->picture;
+ AVFrame * const p= &s->picture;
uint32_t tag, length;
int ret, crc;
s->bytestream_end= buf + buf_size;
/* check signature */
- if (memcmp(s->bytestream, ff_pngsig, 8) != 0)
+ if (memcmp(s->bytestream, ff_pngsig, 8) != 0 &&
+ memcmp(s->bytestream, ff_mngsig, 8) != 0)
return -1;
s->bytestream+= 8;
s->y=
}
}
exit_loop:
- *picture= *(AVFrame*)&s->picture;
- *data_size = sizeof(AVPicture);
+ *picture= s->picture;
+ *data_size = sizeof(AVFrame);
ret = s->bytestream - s->bytestream_start;
the_end:
goto the_end;
}
-static int png_dec_init(AVCodecContext *avctx){
+static av_cold int png_dec_init(AVCodecContext *avctx){
PNGDecContext *s = avctx->priv_data;
- avcodec_get_frame_defaults((AVFrame*)&s->picture);
- avctx->coded_frame= (AVFrame*)&s->picture;
+ avcodec_get_frame_defaults(&s->picture);
+ avctx->coded_frame= &s->picture;
+ dsputil_init(&s->dsp, avctx);
return 0;
}
NULL, //decode_end,
decode_frame,
0 /*CODEC_CAP_DR1*/ /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
- NULL
+ NULL,
+ .long_name = NULL_IF_CONFIG_SMALL("PNG image"),
};
projects / ffmpeg / blobdiff