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FFmpeg/libavcodec/pcxenc.c

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/*
* PC Paintbrush PCX (.pcx) image encoder
* Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
*
* 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
*/
/**
* PCX image encoder
* @file libavcodec/pcxenc.c
* @author Daniel Verkamp
* @sa http://www.qzx.com/pc-gpe/pcx.txt
*/
#include "avcodec.h"
#include "bytestream.h"
typedef struct PCXContext {
AVFrame picture;
} PCXContext;
static const uint32_t monoblack_pal[] = { 0x000000, 0xFFFFFF };
static av_cold int pcx_encode_init(AVCodecContext *avctx)
{
PCXContext *s = avctx->priv_data;
avcodec_get_frame_defaults(&s->picture);
avctx->coded_frame = &s->picture;
return 0;
}
/**
* PCX run-length encoder
* @param dst output buffer
* @param dst_size size of output buffer
* @param src input buffer
* @param src_plane_size size of one plane of input buffer in bytes
* @param nplanes number of planes in input buffer
* @return number of bytes written to dst or -1 on error
* @bug will not work for nplanes != 1 && bpp != 8
*/
static int pcx_rle_encode( uint8_t *dst, int dst_size,
const uint8_t *src, int src_plane_size, int nplanes)
{
int p;
const uint8_t *dst_start = dst;
// check worst-case upper bound on dst_size
if (dst_size < 2LL * src_plane_size * nplanes || src_plane_size <= 0)
return -1;
for (p = 0; p < nplanes; p++) {
int count = 1;
const uint8_t *src_plane = src + p;
const uint8_t *src_plane_end = src_plane + src_plane_size * nplanes;
uint8_t prev = *src_plane;
src_plane += nplanes;
for (; ; src_plane += nplanes) {
if (src_plane < src_plane_end && *src_plane == prev && count < 0x3F) {
// current byte is same as prev
++count;
} else {
// output prev * count
if (count != 1 || prev >= 0xC0)
*dst++ = 0xC0 | count;
*dst++ = prev;
if (src_plane == src_plane_end)
break;
// start new run
count = 1;
prev = *src_plane;
}
}
}
return dst - dst_start;
}
static int pcx_encode_frame(AVCodecContext *avctx,
unsigned char *buf, int buf_size, void *data)
{
PCXContext *s = avctx->priv_data;
AVFrame *const pict = &s->picture;
const uint8_t *buf_start = buf;
const uint8_t *buf_end = buf + buf_size;
int bpp, nplanes, i, y, line_bytes, written;
const uint32_t *pal = NULL;
const uint8_t *src;
*pict = *(AVFrame *)data;
pict->pict_type = FF_I_TYPE;
pict->key_frame = 1;
if (avctx->width > 65535 || avctx->height > 65535) {
av_log(avctx, AV_LOG_ERROR, "image dimensions do not fit in 16 bits\n");
return -1;
}
switch (avctx->pix_fmt) {
case PIX_FMT_RGB24:
bpp = 8;
nplanes = 3;
break;
case PIX_FMT_RGB8:
case PIX_FMT_BGR8:
case PIX_FMT_RGB4_BYTE:
case PIX_FMT_BGR4_BYTE:
case PIX_FMT_GRAY8:
case PIX_FMT_PAL8:
bpp = 8;
nplanes = 1;
pal = (uint32_t *)pict->data[1];
break;
case PIX_FMT_MONOBLACK:
bpp = 1;
nplanes = 1;
pal = monoblack_pal;
break;
default:
av_log(avctx, AV_LOG_ERROR, "unsupported pixfmt\n");
return -1;
}
line_bytes = (avctx->width * bpp + 7) >> 3;
line_bytes = (line_bytes + 1) & ~1;
bytestream_put_byte(&buf, 10); // manufacturer
bytestream_put_byte(&buf, 5); // version
bytestream_put_byte(&buf, 1); // encoding
bytestream_put_byte(&buf, bpp); // bits per pixel per plane
bytestream_put_le16(&buf, 0); // x min
bytestream_put_le16(&buf, 0); // y min
bytestream_put_le16(&buf, avctx->width - 1); // x max
bytestream_put_le16(&buf, avctx->height - 1); // y max
bytestream_put_le16(&buf, 0); // horizontal DPI
bytestream_put_le16(&buf, 0); // vertical DPI
for (i = 0; i < 16; i++)
bytestream_put_be24(&buf, pal ? pal[i] : 0);// palette (<= 16 color only)
bytestream_put_byte(&buf, 0); // reserved
bytestream_put_byte(&buf, nplanes); // number of planes
bytestream_put_le16(&buf, line_bytes); // scanline plane size in bytes
while (buf - buf_start < 128)
*buf++= 0;
src = pict->data[0];
for (y = 0; y < avctx->height; y++) {
if ((written = pcx_rle_encode(buf, buf_end - buf,
src, line_bytes, nplanes)) < 0) {
av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
return -1;
}
buf += written;
src += pict->linesize[0];
}
if (nplanes == 1 && bpp == 8) {
if (buf_end - buf < 257) {
av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
return -1;
}
bytestream_put_byte(&buf, 12);
for (i = 0; i < 256; i++) {
bytestream_put_be24(&buf, pal[i]);
}
}
return buf - buf_start;
}
AVCodec pcx_encoder = {
"pcx",
CODEC_TYPE_VIDEO,
CODEC_ID_PCX,
sizeof(PCXContext),
pcx_encode_init,
pcx_encode_frame,
NULL,
.pix_fmts = (const enum PixelFormat[]){
PIX_FMT_RGB24,
PIX_FMT_RGB8, PIX_FMT_BGR8, PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE, PIX_FMT_GRAY8, PIX_FMT_PAL8,
PIX_FMT_MONOBLACK,
PIX_FMT_NONE},
.long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
};