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added progressive PNG support (both reading and writing) 

Originally committed as revision 1797 to svn://svn.ffmpeg.org/ffmpeg/trunk
tags/v0.5
Fabrice Bellard 22 years ago
parent
3b1a27e04c
commit
cff5e386bf
1 changed files with 378 additions and 121 deletions
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  1. +378
    -121
      libavformat/png.c

+ 378
- 121
libavformat/png.c View File

@@ -18,6 +18,11 @@
*/
#include "avformat.h"

/* TODO:
* - add 2, 4 and 16 bit depth support
* - use filters when generating a png (better compression)
*/

#ifdef CONFIG_ZLIB
#include <zlib.h>

@@ -44,6 +49,8 @@
#define PNG_ALLIMAGE 0x0004
#define PNG_PLTE 0x0008

#define NB_PASSES 7

#define IOBUF_SIZE 4096

typedef struct PNGDecodeState {
@@ -62,16 +69,48 @@ typedef struct PNGDecodeState {
int image_linesize;
uint32_t palette[256];
uint8_t *crow_buf;
uint8_t *empty_row;
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;
} PNGDecodeState;

static const uint8_t pngsig[8] = {137, 80, 78, 71, 13, 10, 26, 10};

/* Mask to determine which y pixels are valid in a pass */
static const uint8_t png_pass_ymask[NB_PASSES] = {
0x80, 0x80, 0x08, 0x88, 0x22, 0xaa, 0x55,
};

/* 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,
};

/* minimum x value */
static const uint8_t png_pass_xmin[NB_PASSES] = {
0, 4, 0, 2, 0, 1, 0
};

/* x shift to get row width */
static const uint8_t png_pass_xshift[NB_PASSES] = {
3, 3, 2, 2, 1, 1, 0
};

/* Mask to determine which pixels are valid in a pass */
static const uint8_t png_pass_mask[NB_PASSES] = {
0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff
};

/* 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
};

static int png_probe(AVProbeData *pd)
{
if (pd->buf_size >= 8 &&
@@ -91,6 +130,127 @@ static void png_zfree(void *opaque, void *ptr)
av_free(ptr);
}

static int png_get_nb_channels(int color_type)
{
int channels;
channels = 1;
if ((color_type & (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)) ==
PNG_COLOR_MASK_COLOR)
channels = 3;
if (color_type & PNG_COLOR_MASK_ALPHA)
channels++;
return channels;
}

/* compute the row size of an interleaved pass */
static int png_pass_row_size(int pass, int bits_per_pixel, int width)
{
int shift, xmin, pass_width;

xmin = png_pass_xmin[pass];
if (width <= xmin)
return 0;
shift = png_pass_xshift[pass];
pass_width = (width - xmin + (1 << shift) - 1) >> shift;
return (pass_width * bits_per_pixel + 7) >> 3;
}

/* NOTE: we try to construct a good looking image at each pass. width
is the original image width. We also do pixel format convertion 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 = png_pass_mask[pass];
dsp_mask = png_pass_dsp_mask[pass];
switch(bits_per_pixel) {
case 1:
/* we must intialize 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;
}
}

static void png_get_interlaced_row(uint8_t *dst, int row_size,
int bits_per_pixel, int pass,
const uint8_t *src, int width)
{
int x, mask, dst_x, j, b, bpp;
uint8_t *d;
const uint8_t *s;

mask = png_pass_mask[pass];
switch(bits_per_pixel) {
case 1:
memset(dst, 0, row_size);
dst_x = 0;
for(x = 0; x < width; x++) {
j = (x & 7);
if ((mask << j) & 0x80) {
b = (src[x >> 3] >> (7 - j)) & 1;
dst[dst_x >> 3] |= b << (7 - (dst_x & 7));
dst_x++;
}
}
break;
default:
bpp = bits_per_pixel >> 3;
d = dst;
s = src;
for(x = 0; x < width; x++) {
j = x & 7;
if ((mask << j) & 0x80) {
memcpy(d, s, bpp);
d += bpp;
}
s += bpp;
}
break;
}
}

/* XXX: optimize */
/* NOTE: 'dst' can be equal to 'last' */
static void png_filter_row(uint8_t *dst, int filter_type,
@@ -158,43 +318,107 @@ static void png_filter_row(uint8_t *dst, int filter_type,
}
}

static void convert_from_rgba32(uint8_t *dst, const uint8_t *src, int width)
{
uint8_t *d;
int j;
unsigned int v;
d = dst;
for(j = 0; j < width; j++) {
v = ((uint32_t *)src)[j];
d[0] = v >> 16;
d[1] = v >> 8;
d[2] = v;
d[3] = v >> 24;
d += 4;
}
}

static void convert_to_rgba32(uint8_t *dst, const uint8_t *src, int width)
{
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];
*(uint32_t *)dst = (a << 24) | (r << 16) | (g << 8) | b;
dst += 4;
src += 4;
}
}

/* process exactly one decompressed row */
static void png_handle_row(PNGDecodeState *s)
{
uint8_t *ptr, *last_row;

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) {
int j, w;
unsigned int r, g, b, a;
const uint8_t *src;

png_filter_row(s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
s->empty_row, s->row_size, s->bpp);
memcpy(s->empty_row, s->tmp_row, s->row_size);

src = s->tmp_row;
w = s->width;
for(j = 0;j < w; j++) {
r = src[0];
g = src[1];
b = src[2];
a = src[3];
*(uint32_t *)ptr = (a << 24) | (r << 16) | (g << 8) | b;
ptr += 4;
src += 4;
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->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_rgba32(ptr, s->tmp_row, s->width);
} 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(ptr, s->crow_buf[0], s->crow_buf + 1,
last_row, s->row_size, s->bpp);
}
s->y++;
if (s->y == s->height) {
s->state |= PNG_ALLIMAGE;
}
} else {
/* in normal case, we avoid one copy */

if (s->y == 0)
last_row = s->empty_row;
else
last_row = ptr - s->image_linesize;
png_filter_row(ptr, s->crow_buf[0], s->crow_buf + 1,
last_row, s->row_size, s->bpp);
got_line = 0;
for(;;) {
ptr = s->image_buf + s->image_linesize * s->y;
if ((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->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);
got_line = 1;
}
if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
/* NOTE: rgba32 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 = 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: ;
}
}

@@ -220,11 +444,8 @@ static int png_decode_idat(PNGDecodeState *s, ByteIOContext *f, int length)
return -1;
}
if (s->zstream.avail_out == 0) {
if (s->y < s->height) {
if (!(s->state & PNG_ALLIMAGE)) {
png_handle_row(s);
s->y++;
if (s->y == s->height)
s->state |= PNG_ALLIMAGE;
}
s->zstream.avail_out = s->crow_size;
s->zstream.next_out = s->crow_buf;
@@ -298,47 +519,44 @@ static int png_read(ByteIOContext *f,
/* init image info */
info->width = s->width;
info->height = s->height;
info->progressive = (s->interlace_type != 0);

s->channels = 1;
if ((s->color_type & (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)) ==
PNG_COLOR_MASK_COLOR)
s->channels = 3;
if (s->color_type & PNG_COLOR_MASK_ALPHA)
s->channels++;
s->channels = 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 = (info->width * s->bits_per_pixel + 7) >> 3;

if (s->bit_depth == 8 &&
s->color_type == PNG_COLOR_TYPE_RGB) {
info->pix_fmt = PIX_FMT_RGB24;
s->row_size = s->width * 3;
} else if (s->bit_depth == 8 &&
s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
info->pix_fmt = PIX_FMT_RGBA32;
s->row_size = s->width * 4;
} else if (s->bit_depth == 8 &&
s->color_type == PNG_COLOR_TYPE_GRAY) {
info->pix_fmt = PIX_FMT_GRAY8;
s->row_size = s->width;
} else if (s->bit_depth == 1 &&
s->color_type == PNG_COLOR_TYPE_GRAY) {
info->pix_fmt = PIX_FMT_MONOBLACK;
s->row_size = (s->width + 7) >> 3;
} else if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
info->pix_fmt = PIX_FMT_PAL8;
s->row_size = s->width;
} else {
goto fail;
}
ret = alloc_cb(opaque, info);
if (ret)
goto the_end;

/* compute the compressed row size */
if (!s->interlace_type) {
s->crow_size = s->row_size + 1;
} else {
/* XXX: handle interlacing */
goto fail;
s->pass = 0;
s->pass_row_size = png_pass_row_size(s->pass,
s->bits_per_pixel,
s->width);
s->crow_size = s->pass_row_size + 1;
}
ret = alloc_cb(opaque, info);
if (ret)
goto the_end;
#ifdef DEBUG
printf("row_size=%d crow_size =%d\n",
s->row_size, s->crow_size);
@@ -349,16 +567,17 @@ static int png_read(ByteIOContext *f,
if (s->color_type == PNG_COLOR_TYPE_PALETTE)
memcpy(info->pict.data[1], s->palette, 256 * sizeof(uint32_t));
/* empty row is used if differencing to the first row */
s->empty_row = av_mallocz(s->row_size);
if (!s->empty_row)
s->last_row = av_mallocz(s->row_size);
if (!s->last_row)
goto fail;
if (s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
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 */
s->crow_buf = av_malloc(s->crow_size);
s->crow_buf = av_malloc(s->row_size + 1);
if (!s->crow_buf)
goto fail;
s->zstream.avail_out = s->crow_size;
@@ -424,7 +643,7 @@ static int png_read(ByteIOContext *f,
the_end:
inflateEnd(&s->zstream);
av_free(s->crow_buf);
av_free(s->empty_row);
av_free(s->last_row);
av_free(s->tmp_row);
return ret;
fail:
@@ -462,66 +681,99 @@ static void to_be32(uint8_t *p, uint32_t v)
p[3] = v;
}

typedef struct PNGEncodeState {
ByteIOContext *f;
z_stream zstream;
uint8_t buf[IOBUF_SIZE];
} PNGEncodeState;


/* XXX: do filtering */
static int png_write_row(PNGEncodeState *s, const uint8_t *data, int size)
{
int ret;

s->zstream.avail_in = size;
s->zstream.next_in = (uint8_t *)data;
while (s->zstream.avail_in > 0) {
ret = deflate(&s->zstream, Z_NO_FLUSH);
if (ret != Z_OK)
return -1;
if (s->zstream.avail_out == 0) {
png_write_chunk(s->f, MKTAG('I', 'D', 'A', 'T'), s->buf, IOBUF_SIZE);
s->zstream.avail_out = IOBUF_SIZE;
s->zstream.next_out = s->buf;
}
}
return 0;
}

static int png_write(ByteIOContext *f, AVImageInfo *info)
{
int bit_depth, color_type, y, len, row_size, ret;
PNGEncodeState s1, *s = &s1;
int bit_depth, color_type, y, len, row_size, ret, is_progressive;
int bits_per_pixel, pass_row_size;
uint8_t *ptr;
uint8_t buf[IOBUF_SIZE];
uint8_t *crow_buf = NULL;
z_stream zstream;
uint8_t *tmp_buf = NULL;
s->f = f;
is_progressive = info->progressive;
switch(info->pix_fmt) {
case PIX_FMT_RGBA32:
bit_depth = 8;
color_type = PNG_COLOR_TYPE_RGB_ALPHA;
row_size = info->width * 4;
break;
case PIX_FMT_RGB24:
bit_depth = 8;
color_type = PNG_COLOR_TYPE_RGB;
row_size = info->width * 3;
break;
case PIX_FMT_GRAY8:
bit_depth = 8;
color_type = PNG_COLOR_TYPE_GRAY;
row_size = info->width;
break;
case PIX_FMT_MONOBLACK:
bit_depth = 1;
color_type = PNG_COLOR_TYPE_GRAY;
row_size = (info->width + 7) >> 3;
break;
case PIX_FMT_PAL8:
bit_depth = 8;
color_type = PNG_COLOR_TYPE_PALETTE;
row_size = info->width;
break;
default:
return -1;
}
zstream.zalloc = png_zalloc;
zstream.zfree = png_zfree;
zstream.opaque = NULL;
ret = deflateInit2(&zstream, Z_DEFAULT_COMPRESSION,
bits_per_pixel = png_get_nb_channels(color_type) * bit_depth;
row_size = (info->width * bits_per_pixel + 7) >> 3;

s->zstream.zalloc = png_zalloc;
s->zstream.zfree = png_zfree;
s->zstream.opaque = NULL;
ret = deflateInit2(&s->zstream, Z_DEFAULT_COMPRESSION,
Z_DEFLATED, 15, 8, Z_DEFAULT_STRATEGY);
if (ret != Z_OK)
return -1;
crow_buf = av_malloc(row_size + 1);
if (!crow_buf)
goto fail;
if (is_progressive) {
tmp_buf = av_malloc(row_size + 1);
if (!tmp_buf)
goto fail;
}

/* write png header */
put_buffer(f, pngsig, 8);
to_be32(buf, info->width);
to_be32(buf + 4, info->height);
buf[8] = bit_depth;
buf[9] = color_type;
buf[10] = 0; /* compression type */
buf[11] = 0; /* filter type */
buf[12] = 0; /* interlace type */
to_be32(s->buf, info->width);
to_be32(s->buf + 4, info->height);
s->buf[8] = bit_depth;
s->buf[9] = color_type;
s->buf[10] = 0; /* compression type */
s->buf[11] = 0; /* filter type */
s->buf[12] = is_progressive; /* interlace type */
png_write_chunk(f, MKTAG('I', 'H', 'D', 'R'), buf, 13);
png_write_chunk(f, MKTAG('I', 'H', 'D', 'R'), s->buf, 13);

/* put the palette if needed */
if (color_type == PNG_COLOR_TYPE_PALETTE) {
@@ -531,8 +783,8 @@ static int png_write(ByteIOContext *f, AVImageInfo *info)
uint8_t *alpha_ptr;
palette = (uint32_t *)info->pict.data[1];
ptr = buf;
alpha_ptr = buf + 256 * 3;
ptr = s->buf;
alpha_ptr = s->buf + 256 * 3;
has_alpha = 0;
for(i = 0; i < 256; i++) {
v = palette[i];
@@ -545,60 +797,63 @@ static int png_write(ByteIOContext *f, AVImageInfo *info)
ptr[2] = v;
ptr += 3;
}
png_write_chunk(f, MKTAG('P', 'L', 'T', 'E'), buf, 256 * 3);
png_write_chunk(f, MKTAG('P', 'L', 'T', 'E'), s->buf, 256 * 3);
if (has_alpha) {
png_write_chunk(f, MKTAG('t', 'R', 'N', 'S'), buf + 256 * 3, 256);
png_write_chunk(f, MKTAG('t', 'R', 'N', 'S'), s->buf + 256 * 3, 256);
}
}

/* now put each row */
zstream.avail_out = IOBUF_SIZE;
zstream.next_out = buf;
for(y = 0;y < info->height; y++) {
/* XXX: do filtering */
ptr = info->pict.data[0] + y * info->pict.linesize[0];
if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
uint8_t *d;
int j, w;
unsigned int v;

w = info->width;
d = crow_buf + 1;
for(j = 0; j < w; j++) {
v = ((uint32_t *)ptr)[j];
d[0] = v >> 16;
d[1] = v >> 8;
d[2] = v;
d[3] = v >> 24;
d += 4;
s->zstream.avail_out = IOBUF_SIZE;
s->zstream.next_out = s->buf;
if (is_progressive) {
uint8_t *ptr1;
int pass;

for(pass = 0; pass < NB_PASSES; pass++) {
/* NOTE: a pass is completely omited if no pixels would be
output */
pass_row_size = png_pass_row_size(pass, bits_per_pixel, info->width);
if (pass_row_size > 0) {
for(y = 0; y < info->height; y++) {
if ((png_pass_ymask[pass] << (y & 7)) & 0x80) {
ptr = info->pict.data[0] + y * info->pict.linesize[0];
if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
convert_from_rgba32(tmp_buf, ptr, info->width);
ptr1 = tmp_buf;
} else {
ptr1 = ptr;
}
png_get_interlaced_row(crow_buf + 1, pass_row_size,
bits_per_pixel, pass,
ptr1, info->width);
crow_buf[0] = PNG_FILTER_VALUE_NONE;
png_write_row(s, crow_buf, pass_row_size + 1);
}
}
}
} else {
memcpy(crow_buf + 1, ptr, row_size);
}
crow_buf[0] = PNG_FILTER_VALUE_NONE;
zstream.avail_in = row_size + 1;
zstream.next_in = crow_buf;
while (zstream.avail_in > 0) {
ret = deflate(&zstream, Z_NO_FLUSH);
if (ret != Z_OK)
goto fail;
if (zstream.avail_out == 0) {
png_write_chunk(f, MKTAG('I', 'D', 'A', 'T'), buf, IOBUF_SIZE);
zstream.avail_out = IOBUF_SIZE;
zstream.next_out = buf;
}
} else {
for(y = 0; y < info->height; y++) {
ptr = info->pict.data[0] + y * info->pict.linesize[0];
if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
convert_from_rgba32(crow_buf + 1, ptr, info->width);
else
memcpy(crow_buf + 1, ptr, row_size);
crow_buf[0] = PNG_FILTER_VALUE_NONE;
png_write_row(s, crow_buf, row_size + 1);
}
}
/* compress last bytes */
for(;;) {
ret = deflate(&zstream, Z_FINISH);
ret = deflate(&s->zstream, Z_FINISH);
if (ret == Z_OK || ret == Z_STREAM_END) {
len = IOBUF_SIZE - zstream.avail_out;
len = IOBUF_SIZE - s->zstream.avail_out;
if (len > 0) {
png_write_chunk(f, MKTAG('I', 'D', 'A', 'T'), buf, len);
png_write_chunk(f, MKTAG('I', 'D', 'A', 'T'), s->buf, len);
}
zstream.avail_out = IOBUF_SIZE;
zstream.next_out = buf;
s->zstream.avail_out = IOBUF_SIZE;
s->zstream.next_out = s->buf;
if (ret == Z_STREAM_END)
break;
} else {
@@ -611,7 +866,8 @@ static int png_write(ByteIOContext *f, AVImageInfo *info)
ret = 0;
the_end:
av_free(crow_buf);
deflateEnd(&zstream);
av_free(tmp_buf);
deflateEnd(&s->zstream);
return ret;
fail:
ret = -1;
@@ -626,5 +882,6 @@ AVImageFormat png_image_format = {
(1 << PIX_FMT_RGBA32) | (1 << PIX_FMT_RGB24) | (1 << PIX_FMT_GRAY8) |
(1 << PIX_FMT_MONOBLACK) | (1 << PIX_FMT_PAL8),
png_write,
AVIMAGE_PROGRESSIVE,
};
#endif

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