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FFmpeg/libavcodec/pngdec.c
Reinhard Tartler 737eb5976f Merge libavcore into libavutil 
It is pretty hopeless that other considerable projects will adopt
libavutil alone in other projects. Projects that need small footprint
are better off with more specialized libraries such as gnulib or rather
just copy the necessary parts that they need. With this in mind, nobody
is helped by having libavutil and libavcore split. In order to ease
maintenance inside and around FFmpeg and to reduce confusion where to
put common code, avcore's functionality is merged (back) to avutil.

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
2011-02-15 16:18:21 +01:00

674 lines
22 KiB
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/*
* PNG image format
* Copyright (c) 2003 Fabrice Bellard
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/imgutils.h"
#include "avcodec.h"
#include "bytestream.h"
#include "png.h"
#include "dsputil.h"
/* TODO:
* - add 2, 4 and 16 bit depth support
*/
#include <zlib.h>
//#define DEBUG
typedef struct PNGDecContext {
DSPContext dsp;
const uint8_t *bytestream;
const uint8_t *bytestream_start;
const uint8_t *bytestream_end;
AVFrame picture1, picture2;
AVFrame *current_picture, *last_picture;
int state;
int width, height;
int bit_depth;
int color_type;
int compression_type;
int interlace_type;
int filter_type;
int channels;
int bits_per_pixel;
int bpp;
uint8_t *image_buf;
int image_linesize;
uint32_t palette[256];
uint8_t *crow_buf;
uint8_t *last_row;
uint8_t *tmp_row;
int pass;
int crow_size; /* compressed row size (include filter type) */
int row_size; /* decompressed row size */
int pass_row_size; /* decompress row size of the current pass */
int y;
z_stream zstream;
} PNGDecContext;
/* Mask to determine which y pixels can be written in a pass */
static const uint8_t png_pass_dsp_ymask[NB_PASSES] = {
0xff, 0xff, 0x0f, 0xcc, 0x33, 0xff, 0x55,
};
/* Mask to determine which pixels to overwrite while displaying */
static const uint8_t png_pass_dsp_mask[NB_PASSES] = {
0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff
};
/* NOTE: we try to construct a good looking image at each pass. width
is the original image width. We also do pixel format conversion at
this stage */
static void png_put_interlaced_row(uint8_t *dst, int width,
int bits_per_pixel, int pass,
int color_type, const uint8_t *src)
{
int x, mask, dsp_mask, j, src_x, b, bpp;
uint8_t *d;
const uint8_t *s;
mask = ff_png_pass_mask[pass];
dsp_mask = png_pass_dsp_mask[pass];
switch(bits_per_pixel) {
case 1:
/* we must initialize the line to zero before writing to it */
if (pass == 0)
memset(dst, 0, (width + 7) >> 3);
src_x = 0;
for(x = 0; x < width; x++) {
j = (x & 7);
if ((dsp_mask << j) & 0x80) {
b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1;
dst[x >> 3] |= b << (7 - j);
}
if ((mask << j) & 0x80)
src_x++;
}
break;
default:
bpp = bits_per_pixel >> 3;
d = dst;
s = src;
if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
for(x = 0; x < width; x++) {
j = x & 7;
if ((dsp_mask << j) & 0x80) {
*(uint32_t *)d = (s[3] << 24) | (s[0] << 16) | (s[1] << 8) | s[2];
}
d += bpp;
if ((mask << j) & 0x80)
s += bpp;
}
} else {
for(x = 0; x < width; x++) {
j = x & 7;
if ((dsp_mask << j) & 0x80) {
memcpy(d, s, bpp);
}
d += bpp;
if ((mask << j) & 0x80)
s += bpp;
}
}
break;
}
}
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)\
else {\
for (; i < size; i += bpp) {\
int j;\
for (j = 0; j < bpp; j++)\
dst[i+j] = op(dst[i+j-bpp], src[i+j], last[i+j]);\
}\
}
/* NOTE: 'dst' can be equal to 'last' */
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, r, g, b, a;
switch(filter_type) {
case PNG_FILTER_VALUE_NONE:
memcpy(dst, src, size);
break;
case PNG_FILTER_VALUE_SUB:
for(i = 0; i < bpp; i++) {
dst[i] = 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:
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];
}
#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];
}
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 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;
for(j = 0;j < width; j++) {
r = src[0];
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)
{
uint8_t *ptr, *last_row;
int got_line;
if (!s->interlace_type) {
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->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
s->last_row, s->row_size, s->bpp);
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)
last_row = s->last_row;
else
last_row = ptr - s->image_linesize;
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;
for(;;) {
ptr = s->image_buf + s->image_linesize * s->y;
if ((ff_png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) {
/* if we already read one row, it is time to stop to
wait for the next one */
if (got_line)
break;
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);
FFSWAP(uint8_t*, s->last_row, s->tmp_row);
got_line = 1;
}
if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
/* NOTE: RGB32 is handled directly in png_put_interlaced_row */
png_put_interlaced_row(ptr, s->width, s->bits_per_pixel, s->pass,
s->color_type, s->last_row);
}
s->y++;
if (s->y == s->height) {
for(;;) {
if (s->pass == NB_PASSES - 1) {
s->state |= PNG_ALLIMAGE;
goto the_end;
} else {
s->pass++;
s->y = 0;
s->pass_row_size = ff_png_pass_row_size(s->pass,
s->bits_per_pixel,
s->width);
s->crow_size = s->pass_row_size + 1;
if (s->pass_row_size != 0)
break;
/* skip pass if empty row */
}
}
}
}
the_end: ;
}
}
static int png_decode_idat(PNGDecContext *s, int length)
{
int ret;
s->zstream.avail_in = length;
s->zstream.next_in = s->bytestream;
s->bytestream += length;
if(s->bytestream > s->bytestream_end)
return -1;
/* decode one line if possible */
while (s->zstream.avail_in > 0) {
ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
if (ret != Z_OK && ret != Z_STREAM_END) {
return -1;
}
if (s->zstream.avail_out == 0) {
if (!(s->state & PNG_ALLIMAGE)) {
png_handle_row(s);
}
s->zstream.avail_out = s->crow_size;
s->zstream.next_out = s->crow_buf;
}
}
return 0;
}
static int decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
PNGDecContext * const s = avctx->priv_data;
AVFrame *picture = data;
AVFrame *p;
uint8_t *crow_buf_base = NULL;
uint32_t tag, length;
int ret, crc;
FFSWAP(AVFrame *, s->current_picture, s->last_picture);
avctx->coded_frame= s->current_picture;
p = s->current_picture;
s->bytestream_start=
s->bytestream= buf;
s->bytestream_end= buf + buf_size;
/* check signature */
if (memcmp(s->bytestream, ff_pngsig, 8) != 0 &&
memcmp(s->bytestream, ff_mngsig, 8) != 0)
return -1;
s->bytestream+= 8;
s->y=
s->state=0;
// memset(s, 0, sizeof(PNGDecContext));
/* init the zlib */
s->zstream.zalloc = ff_png_zalloc;
s->zstream.zfree = ff_png_zfree;
s->zstream.opaque = NULL;
ret = inflateInit(&s->zstream);
if (ret != Z_OK)
return -1;
for(;;) {
int tag32;
if (s->bytestream >= s->bytestream_end)
goto fail;
length = bytestream_get_be32(&s->bytestream);
if (length > 0x7fffffff)
goto fail;
tag32 = bytestream_get_be32(&s->bytestream);
tag = av_bswap32(tag32);
av_dlog(avctx, "png: tag=%c%c%c%c length=%u\n",
(tag & 0xff),
((tag >> 8) & 0xff),
((tag >> 16) & 0xff),
((tag >> 24) & 0xff), length);
switch(tag) {
case MKTAG('I', 'H', 'D', 'R'):
if (length != 13)
goto fail;
s->width = bytestream_get_be32(&s->bytestream);
s->height = bytestream_get_be32(&s->bytestream);
if(av_image_check_size(s->width, s->height, 0, avctx)){
s->width= s->height= 0;
goto fail;
}
s->bit_depth = *s->bytestream++;
s->color_type = *s->bytestream++;
s->compression_type = *s->bytestream++;
s->filter_type = *s->bytestream++;
s->interlace_type = *s->bytestream++;
crc = bytestream_get_be32(&s->bytestream);
s->state |= PNG_IHDR;
av_dlog(avctx, "width=%d height=%d depth=%d color_type=%d compression_type=%d filter_type=%d interlace_type=%d\n",
s->width, s->height, s->bit_depth, s->color_type,
s->compression_type, s->filter_type, s->interlace_type);
break;
case MKTAG('I', 'D', 'A', 'T'):
if (!(s->state & PNG_IHDR))
goto fail;
if (!(s->state & PNG_IDAT)) {
/* init image info */
avctx->width = s->width;
avctx->height = s->height;
s->channels = ff_png_get_nb_channels(s->color_type);
s->bits_per_pixel = s->bit_depth * s->channels;
s->bpp = (s->bits_per_pixel + 7) >> 3;
s->row_size = (avctx->width * s->bits_per_pixel + 7) >> 3;
if (s->bit_depth == 8 &&
s->color_type == PNG_COLOR_TYPE_RGB) {
avctx->pix_fmt = PIX_FMT_RGB24;
} else if (s->bit_depth == 8 &&
s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
avctx->pix_fmt = PIX_FMT_RGB32;
} else if (s->bit_depth == 8 &&
s->color_type == PNG_COLOR_TYPE_GRAY) {
avctx->pix_fmt = PIX_FMT_GRAY8;
} else if (s->bit_depth == 16 &&
s->color_type == PNG_COLOR_TYPE_GRAY) {
avctx->pix_fmt = PIX_FMT_GRAY16BE;
} else if (s->bit_depth == 16 &&
s->color_type == PNG_COLOR_TYPE_RGB) {
avctx->pix_fmt = PIX_FMT_RGB48BE;
} else if (s->bit_depth == 1 &&
s->color_type == PNG_COLOR_TYPE_GRAY) {
avctx->pix_fmt = PIX_FMT_MONOBLACK;
} else if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
avctx->pix_fmt = PIX_FMT_PAL8;
} else if (s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
avctx->pix_fmt = PIX_FMT_Y400A;
} else {
goto fail;
}
if(p->data[0])
avctx->release_buffer(avctx, p);
p->reference= 0;
if(avctx->get_buffer(avctx, p) < 0){
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
goto fail;
}
p->pict_type= FF_I_TYPE;
p->key_frame= 1;
p->interlaced_frame = !!s->interlace_type;
/* compute the compressed row size */
if (!s->interlace_type) {
s->crow_size = s->row_size + 1;
} else {
s->pass = 0;
s->pass_row_size = ff_png_pass_row_size(s->pass,
s->bits_per_pixel,
s->width);
s->crow_size = s->pass_row_size + 1;
}
av_dlog(avctx, "row_size=%d crow_size =%d\n",
s->row_size, s->crow_size);
s->image_buf = p->data[0];
s->image_linesize = p->linesize[0];
/* copy the palette if needed */
if (s->color_type == PNG_COLOR_TYPE_PALETTE)
memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
/* empty row is used if differencing to the first row */
s->last_row = av_mallocz(s->row_size);
if (!s->last_row)
goto fail;
if (s->interlace_type ||
s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
s->tmp_row = av_malloc(s->row_size);
if (!s->tmp_row)
goto fail;
}
/* compressed row */
crow_buf_base = av_malloc(s->row_size + 16);
if (!crow_buf_base)
goto fail;
/* we want crow_buf+1 to be 16-byte aligned */
s->crow_buf = crow_buf_base + 15;
s->zstream.avail_out = s->crow_size;
s->zstream.next_out = s->crow_buf;
}
s->state |= PNG_IDAT;
if (png_decode_idat(s, length) < 0)
goto fail;
/* skip crc */
crc = bytestream_get_be32(&s->bytestream);
break;
case MKTAG('P', 'L', 'T', 'E'):
{
int n, i, r, g, b;
if ((length % 3) != 0 || length > 256 * 3)
goto skip_tag;
/* read the palette */
n = length / 3;
for(i=0;i<n;i++) {
r = *s->bytestream++;
g = *s->bytestream++;
b = *s->bytestream++;
s->palette[i] = (0xff << 24) | (r << 16) | (g << 8) | b;
}
for(;i<256;i++) {
s->palette[i] = (0xff << 24);
}
s->state |= PNG_PLTE;
crc = bytestream_get_be32(&s->bytestream);
}
break;
case MKTAG('t', 'R', 'N', 'S'):
{
int v, i;
/* read the transparency. XXX: Only palette mode supported */
if (s->color_type != PNG_COLOR_TYPE_PALETTE ||
length > 256 ||
!(s->state & PNG_PLTE))
goto skip_tag;
for(i=0;i<length;i++) {
v = *s->bytestream++;
s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
}
crc = bytestream_get_be32(&s->bytestream);
}
break;
case MKTAG('I', 'E', 'N', 'D'):
if (!(s->state & PNG_ALLIMAGE))
goto fail;
crc = bytestream_get_be32(&s->bytestream);
goto exit_loop;
default:
/* skip tag */
skip_tag:
s->bytestream += length + 4;
break;
}
}
exit_loop:
/* handle p-frames only if a predecessor frame is available */
if(s->last_picture->data[0] != NULL) {
if(!(avpkt->flags & AV_PKT_FLAG_KEY)) {
int i, j;
uint8_t *pd = s->current_picture->data[0];
uint8_t *pd_last = s->last_picture->data[0];
for(j=0; j < s->height; j++) {
for(i=0; i < s->width * s->bpp; i++) {
pd[i] += pd_last[i];
}
pd += s->image_linesize;
pd_last += s->image_linesize;
}
}
}
*picture= *s->current_picture;
*data_size = sizeof(AVFrame);
ret = s->bytestream - s->bytestream_start;
the_end:
inflateEnd(&s->zstream);
av_free(crow_buf_base);
s->crow_buf = NULL;
av_freep(&s->last_row);
av_freep(&s->tmp_row);
return ret;
fail:
ret = -1;
goto the_end;
}
static av_cold int png_dec_init(AVCodecContext *avctx){
PNGDecContext *s = avctx->priv_data;
s->current_picture = &s->picture1;
s->last_picture = &s->picture2;
avcodec_get_frame_defaults(&s->picture1);
avcodec_get_frame_defaults(&s->picture2);
dsputil_init(&s->dsp, avctx);
return 0;
}
static av_cold int png_dec_end(AVCodecContext *avctx)
{
PNGDecContext *s = avctx->priv_data;
if (s->picture1.data[0])
avctx->release_buffer(avctx, &s->picture1);
if (s->picture2.data[0])
avctx->release_buffer(avctx, &s->picture2);
return 0;
}
AVCodec ff_png_decoder = {
"png",
AVMEDIA_TYPE_VIDEO,
CODEC_ID_PNG,
sizeof(PNGDecContext),
png_dec_init,
NULL,
png_dec_end,
decode_frame,
CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
NULL,
.max_lowres = 5,
.long_name = NULL_IF_CONFIG_SMALL("PNG image"),
};
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