0,0 → 1,508 |
/* |
* 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 "avcodec.h" |
#include "internal.h" |
#include "bytestream.h" |
#include "dsputil.h" |
#include "png.h" |
|
#include "libavutil/avassert.h" |
#include "libavutil/opt.h" |
|
#include <zlib.h> |
|
#define IOBUF_SIZE 4096 |
|
typedef struct PNGEncContext { |
AVClass *class; |
DSPContext dsp; |
|
uint8_t *bytestream; |
uint8_t *bytestream_start; |
uint8_t *bytestream_end; |
AVFrame picture; |
|
int filter_type; |
|
z_stream zstream; |
uint8_t buf[IOBUF_SIZE]; |
int dpi; ///< Physical pixel density, in dots per inch, if set |
int dpm; ///< Physical pixel density, in dots per meter, if set |
} PNGEncContext; |
|
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; |
static const int masks[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff}; |
|
mask = masks[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; |
} |
} |
|
static void sub_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 = src[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] = src[i] - p; |
} |
} |
|
static void png_filter_row(DSPContext *dsp, uint8_t *dst, int filter_type, |
uint8_t *src, uint8_t *top, int size, int bpp) |
{ |
int i; |
|
switch(filter_type) { |
case PNG_FILTER_VALUE_NONE: |
memcpy(dst, src, size); |
break; |
case PNG_FILTER_VALUE_SUB: |
dsp->diff_bytes(dst, src, src-bpp, size); |
memcpy(dst, src, bpp); |
break; |
case PNG_FILTER_VALUE_UP: |
dsp->diff_bytes(dst, src, top, size); |
break; |
case PNG_FILTER_VALUE_AVG: |
for(i = 0; i < bpp; i++) |
dst[i] = src[i] - (top[i] >> 1); |
for(; i < size; i++) |
dst[i] = src[i] - ((src[i-bpp] + top[i]) >> 1); |
break; |
case PNG_FILTER_VALUE_PAETH: |
for(i = 0; i < bpp; i++) |
dst[i] = src[i] - top[i]; |
sub_png_paeth_prediction(dst+i, src+i, top+i, size-i, bpp); |
break; |
} |
} |
|
static uint8_t *png_choose_filter(PNGEncContext *s, uint8_t *dst, |
uint8_t *src, uint8_t *top, int size, int bpp) |
{ |
int pred = s->filter_type; |
av_assert0(bpp || !pred); |
if(!top && pred) |
pred = PNG_FILTER_VALUE_SUB; |
if(pred == PNG_FILTER_VALUE_MIXED) { |
int i; |
int cost, bcost = INT_MAX; |
uint8_t *buf1 = dst, *buf2 = dst + size + 16; |
for(pred=0; pred<5; pred++) { |
png_filter_row(&s->dsp, buf1+1, pred, src, top, size, bpp); |
buf1[0] = pred; |
cost = 0; |
for(i=0; i<=size; i++) |
cost += abs((int8_t)buf1[i]); |
if(cost < bcost) { |
bcost = cost; |
FFSWAP(uint8_t*, buf1, buf2); |
} |
} |
return buf2; |
} else { |
png_filter_row(&s->dsp, dst+1, pred, src, top, size, bpp); |
dst[0] = pred; |
return dst; |
} |
} |
|
static void png_write_chunk(uint8_t **f, uint32_t tag, |
const uint8_t *buf, int length) |
{ |
uint32_t crc; |
uint8_t tagbuf[4]; |
|
bytestream_put_be32(f, length); |
crc = crc32(0, Z_NULL, 0); |
AV_WL32(tagbuf, tag); |
crc = crc32(crc, tagbuf, 4); |
bytestream_put_be32(f, av_bswap32(tag)); |
if (length > 0) { |
crc = crc32(crc, buf, length); |
memcpy(*f, buf, length); |
*f += length; |
} |
bytestream_put_be32(f, crc); |
} |
|
/* XXX: do filtering */ |
static int png_write_row(PNGEncContext *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) { |
if(s->bytestream_end - s->bytestream > IOBUF_SIZE + 100) |
png_write_chunk(&s->bytestream, 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 encode_frame(AVCodecContext *avctx, AVPacket *pkt, |
const AVFrame *pict, int *got_packet) |
{ |
PNGEncContext *s = avctx->priv_data; |
AVFrame * const p= &s->picture; |
int bit_depth, color_type, y, len, row_size, ret, is_progressive; |
int bits_per_pixel, pass_row_size, enc_row_size; |
int64_t max_packet_size; |
int compression_level; |
uint8_t *ptr, *top; |
uint8_t *crow_base = NULL, *crow_buf, *crow; |
uint8_t *progressive_buf = NULL; |
uint8_t *top_buf = NULL; |
|
*p = *pict; |
p->pict_type= AV_PICTURE_TYPE_I; |
p->key_frame= 1; |
|
is_progressive = !!(avctx->flags & CODEC_FLAG_INTERLACED_DCT); |
switch(avctx->pix_fmt) { |
case AV_PIX_FMT_RGBA64BE: |
bit_depth = 16; |
color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
break; |
case AV_PIX_FMT_RGB48BE: |
bit_depth = 16; |
color_type = PNG_COLOR_TYPE_RGB; |
break; |
case AV_PIX_FMT_RGBA: |
bit_depth = 8; |
color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
break; |
case AV_PIX_FMT_RGB24: |
bit_depth = 8; |
color_type = PNG_COLOR_TYPE_RGB; |
break; |
case AV_PIX_FMT_GRAY16BE: |
bit_depth = 16; |
color_type = PNG_COLOR_TYPE_GRAY; |
break; |
case AV_PIX_FMT_GRAY8: |
bit_depth = 8; |
color_type = PNG_COLOR_TYPE_GRAY; |
break; |
case AV_PIX_FMT_GRAY8A: |
bit_depth = 8; |
color_type = PNG_COLOR_TYPE_GRAY_ALPHA; |
break; |
case AV_PIX_FMT_MONOBLACK: |
bit_depth = 1; |
color_type = PNG_COLOR_TYPE_GRAY; |
break; |
case AV_PIX_FMT_PAL8: |
bit_depth = 8; |
color_type = PNG_COLOR_TYPE_PALETTE; |
break; |
default: |
return -1; |
} |
bits_per_pixel = ff_png_get_nb_channels(color_type) * bit_depth; |
row_size = (avctx->width * bits_per_pixel + 7) >> 3; |
|
s->zstream.zalloc = ff_png_zalloc; |
s->zstream.zfree = ff_png_zfree; |
s->zstream.opaque = NULL; |
compression_level = avctx->compression_level == FF_COMPRESSION_DEFAULT ? |
Z_DEFAULT_COMPRESSION : |
av_clip(avctx->compression_level, 0, 9); |
ret = deflateInit2(&s->zstream, compression_level, |
Z_DEFLATED, 15, 8, Z_DEFAULT_STRATEGY); |
if (ret != Z_OK) |
return -1; |
|
enc_row_size = deflateBound(&s->zstream, row_size); |
max_packet_size = avctx->height * (int64_t)(enc_row_size + |
((enc_row_size + IOBUF_SIZE - 1) / IOBUF_SIZE) * 12) |
+ FF_MIN_BUFFER_SIZE; |
if (max_packet_size > INT_MAX) |
return AVERROR(ENOMEM); |
if ((ret = ff_alloc_packet2(avctx, pkt, max_packet_size)) < 0) |
return ret; |
|
s->bytestream_start = |
s->bytestream = pkt->data; |
s->bytestream_end = pkt->data + pkt->size; |
|
crow_base = av_malloc((row_size + 32) << (s->filter_type == PNG_FILTER_VALUE_MIXED)); |
if (!crow_base) |
goto fail; |
crow_buf = crow_base + 15; // pixel data should be aligned, but there's a control byte before it |
if (is_progressive) { |
progressive_buf = av_malloc(row_size + 1); |
if (!progressive_buf) |
goto fail; |
} |
if (is_progressive) { |
top_buf = av_malloc(row_size + 1); |
if (!top_buf) |
goto fail; |
} |
|
/* write png header */ |
AV_WB64(s->bytestream, PNGSIG); |
s->bytestream += 8; |
|
AV_WB32(s->buf, avctx->width); |
AV_WB32(s->buf + 4, avctx->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 */ |
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png_write_chunk(&s->bytestream, MKTAG('I', 'H', 'D', 'R'), s->buf, 13); |
|
if (s->dpm) { |
AV_WB32(s->buf, s->dpm); |
AV_WB32(s->buf + 4, s->dpm); |
s->buf[8] = 1; /* unit specifier is meter */ |
} else { |
AV_WB32(s->buf, avctx->sample_aspect_ratio.num); |
AV_WB32(s->buf + 4, avctx->sample_aspect_ratio.den); |
s->buf[8] = 0; /* unit specifier is unknown */ |
} |
png_write_chunk(&s->bytestream, MKTAG('p', 'H', 'Y', 's'), s->buf, 9); |
|
/* put the palette if needed */ |
if (color_type == PNG_COLOR_TYPE_PALETTE) { |
int has_alpha, alpha, i; |
unsigned int v; |
uint32_t *palette; |
uint8_t *alpha_ptr; |
|
palette = (uint32_t *)p->data[1]; |
ptr = s->buf; |
alpha_ptr = s->buf + 256 * 3; |
has_alpha = 0; |
for(i = 0; i < 256; i++) { |
v = palette[i]; |
alpha = v >> 24; |
if (alpha != 0xff) |
has_alpha = 1; |
*alpha_ptr++ = alpha; |
bytestream_put_be24(&ptr, v); |
} |
png_write_chunk(&s->bytestream, MKTAG('P', 'L', 'T', 'E'), s->buf, 256 * 3); |
if (has_alpha) { |
png_write_chunk(&s->bytestream, MKTAG('t', 'R', 'N', 'S'), s->buf + 256 * 3, 256); |
} |
} |
|
/* now put each row */ |
s->zstream.avail_out = IOBUF_SIZE; |
s->zstream.next_out = s->buf; |
if (is_progressive) { |
int pass; |
|
for(pass = 0; pass < NB_PASSES; pass++) { |
/* NOTE: a pass is completely omitted if no pixels would be |
output */ |
pass_row_size = ff_png_pass_row_size(pass, bits_per_pixel, avctx->width); |
if (pass_row_size > 0) { |
top = NULL; |
for(y = 0; y < avctx->height; y++) { |
if ((ff_png_pass_ymask[pass] << (y & 7)) & 0x80) { |
ptr = p->data[0] + y * p->linesize[0]; |
FFSWAP(uint8_t*, progressive_buf, top_buf); |
png_get_interlaced_row(progressive_buf, pass_row_size, |
bits_per_pixel, pass, |
ptr, avctx->width); |
crow = png_choose_filter(s, crow_buf, progressive_buf, top, pass_row_size, bits_per_pixel>>3); |
png_write_row(s, crow, pass_row_size + 1); |
top = progressive_buf; |
} |
} |
} |
} |
} else { |
top = NULL; |
for(y = 0; y < avctx->height; y++) { |
ptr = p->data[0] + y * p->linesize[0]; |
crow = png_choose_filter(s, crow_buf, ptr, top, row_size, bits_per_pixel>>3); |
png_write_row(s, crow, row_size + 1); |
top = ptr; |
} |
} |
/* compress last bytes */ |
for(;;) { |
ret = deflate(&s->zstream, Z_FINISH); |
if (ret == Z_OK || ret == Z_STREAM_END) { |
len = IOBUF_SIZE - s->zstream.avail_out; |
if (len > 0 && s->bytestream_end - s->bytestream > len + 100) { |
png_write_chunk(&s->bytestream, MKTAG('I', 'D', 'A', 'T'), s->buf, len); |
} |
s->zstream.avail_out = IOBUF_SIZE; |
s->zstream.next_out = s->buf; |
if (ret == Z_STREAM_END) |
break; |
} else { |
goto fail; |
} |
} |
png_write_chunk(&s->bytestream, MKTAG('I', 'E', 'N', 'D'), NULL, 0); |
|
pkt->size = s->bytestream - s->bytestream_start; |
pkt->flags |= AV_PKT_FLAG_KEY; |
*got_packet = 1; |
ret = 0; |
|
the_end: |
av_free(crow_base); |
av_free(progressive_buf); |
av_free(top_buf); |
deflateEnd(&s->zstream); |
return ret; |
fail: |
ret = -1; |
goto the_end; |
} |
|
static av_cold int png_enc_init(AVCodecContext *avctx){ |
PNGEncContext *s = avctx->priv_data; |
|
switch(avctx->pix_fmt) { |
case AV_PIX_FMT_RGBA: |
avctx->bits_per_coded_sample = 32; |
break; |
case AV_PIX_FMT_RGB24: |
avctx->bits_per_coded_sample = 24; |
break; |
case AV_PIX_FMT_GRAY8: |
avctx->bits_per_coded_sample = 0x28; |
break; |
case AV_PIX_FMT_MONOBLACK: |
avctx->bits_per_coded_sample = 1; |
break; |
case AV_PIX_FMT_PAL8: |
avctx->bits_per_coded_sample = 8; |
} |
|
avcodec_get_frame_defaults(&s->picture); |
avctx->coded_frame= &s->picture; |
ff_dsputil_init(&s->dsp, avctx); |
|
s->filter_type = av_clip(avctx->prediction_method, PNG_FILTER_VALUE_NONE, PNG_FILTER_VALUE_MIXED); |
if(avctx->pix_fmt == AV_PIX_FMT_MONOBLACK) |
s->filter_type = PNG_FILTER_VALUE_NONE; |
|
if (s->dpi && s->dpm) { |
av_log(avctx, AV_LOG_ERROR, "Only one of 'dpi' or 'dpm' options should be set\n"); |
return AVERROR(EINVAL); |
} else if (s->dpi) { |
s->dpm = s->dpi * 10000 / 254; |
} |
|
return 0; |
} |
|
#define OFFSET(x) offsetof(PNGEncContext, x) |
#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM |
static const AVOption options[] = { |
{"dpi", "Set image resolution (in dots per inch)", OFFSET(dpi), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 0x10000, VE}, |
{"dpm", "Set image resolution (in dots per meter)", OFFSET(dpm), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 0x10000, VE}, |
{ NULL } |
}; |
|
static const AVClass pngenc_class = { |
.class_name = "PNG encoder", |
.item_name = av_default_item_name, |
.option = options, |
.version = LIBAVUTIL_VERSION_INT, |
}; |
|
AVCodec ff_png_encoder = { |
.name = "png", |
.long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"), |
.type = AVMEDIA_TYPE_VIDEO, |
.id = AV_CODEC_ID_PNG, |
.priv_data_size = sizeof(PNGEncContext), |
.init = png_enc_init, |
.encode2 = encode_frame, |
.capabilities = CODEC_CAP_FRAME_THREADS | CODEC_CAP_INTRA_ONLY, |
.pix_fmts = (const enum AVPixelFormat[]){ |
AV_PIX_FMT_RGB24, AV_PIX_FMT_RGBA, |
AV_PIX_FMT_RGB48BE, AV_PIX_FMT_RGBA64BE, |
AV_PIX_FMT_PAL8, |
AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY8A, |
AV_PIX_FMT_GRAY16BE, |
AV_PIX_FMT_MONOBLACK, AV_PIX_FMT_NONE |
}, |
.priv_class = &pngenc_class, |
}; |