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FFmpeg/libavcodec/pcx.c
Andreas Rheinhardt 20f9727018 avcodec/codec_internal: Add FFCodec, hide internal part of AVCodec 
Up until now, codec.h contains both public and private parts
of AVCodec. This exposes the internals of AVCodec to users
and leads them into the temptation of actually using them
and forces us to forward-declare structures and types that
users can't use at all.

This commit changes this by adding a new structure FFCodec to
codec_internal.h that extends AVCodec, i.e. contains the public
AVCodec as first member; the private fields of AVCodec are moved
to this structure, leaving codec.h clean.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-03-21 01:33:09 +01:00

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/*
* PC Paintbrush PCX (.pcx) image decoder
* Copyright (c) 2007, 2008 Ivo van Poorten
*
* This decoder does not support CGA palettes. I am unable to find samples
* and Netpbm cannot generate them.
*
* 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 "codec_internal.h"
#include "get_bits.h"
#include "internal.h"
#define PCX_HEADER_SIZE 128
static int pcx_rle_decode(GetByteContext *gb,
uint8_t *dst,
unsigned int bytes_per_scanline,
int compressed)
{
unsigned int i = 0;
unsigned char run, value;
if (bytestream2_get_bytes_left(gb) < 1)
return AVERROR_INVALIDDATA;
if (compressed) {
while (i < bytes_per_scanline && bytestream2_get_bytes_left(gb)>0) {
run = 1;
value = bytestream2_get_byte(gb);
if (value >= 0xc0 && bytestream2_get_bytes_left(gb)>0) {
run = value & 0x3f;
value = bytestream2_get_byte(gb);
}
while (i < bytes_per_scanline && run--)
dst[i++] = value;
}
} else {
bytestream2_get_buffer(gb, dst, bytes_per_scanline);
}
return 0;
}
static void pcx_palette(GetByteContext *gb, uint32_t *dst, int pallen)
{
int i;
pallen = FFMIN(pallen, bytestream2_get_bytes_left(gb) / 3);
for (i = 0; i < pallen; i++)
*dst++ = 0xFF000000 | bytestream2_get_be24u(gb);
if (pallen < 256)
memset(dst, 0, (256 - pallen) * sizeof(*dst));
}
static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
AVPacket *avpkt)
{
GetByteContext gb;
AVFrame * const p = data;
int compressed, xmin, ymin, xmax, ymax;
int ret;
unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
bytes_per_scanline;
uint8_t *ptr, *scanline;
if (avpkt->size < PCX_HEADER_SIZE) {
av_log(avctx, AV_LOG_ERROR, "Packet too small\n");
return AVERROR_INVALIDDATA;
}
bytestream2_init(&gb, avpkt->data, avpkt->size);
if (bytestream2_get_byteu(&gb) != 0x0a || bytestream2_get_byteu(&gb) > 5) {
av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
return AVERROR_INVALIDDATA;
}
compressed = bytestream2_get_byteu(&gb);
bits_per_pixel = bytestream2_get_byteu(&gb);
xmin = bytestream2_get_le16u(&gb);
ymin = bytestream2_get_le16u(&gb);
xmax = bytestream2_get_le16u(&gb);
ymax = bytestream2_get_le16u(&gb);
avctx->sample_aspect_ratio.num = bytestream2_get_le16u(&gb);
avctx->sample_aspect_ratio.den = bytestream2_get_le16u(&gb);
if (xmax < xmin || ymax < ymin) {
av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
return AVERROR_INVALIDDATA;
}
w = xmax - xmin + 1;
h = ymax - ymin + 1;
bytestream2_skipu(&gb, 49);
nplanes = bytestream2_get_byteu(&gb);
bytes_per_line = bytestream2_get_le16u(&gb);
bytes_per_scanline = nplanes * bytes_per_line;
if (bytes_per_scanline < (w * bits_per_pixel * nplanes + 7) / 8 ||
(!compressed && bytes_per_scanline > bytestream2_get_bytes_left(&gb) / h)) {
av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
return AVERROR_INVALIDDATA;
}
switch ((nplanes << 8) + bits_per_pixel) {
case 0x0308:
avctx->pix_fmt = AV_PIX_FMT_RGB24;
break;
case 0x0108:
case 0x0104:
case 0x0102:
case 0x0101:
case 0x0401:
case 0x0301:
case 0x0201:
avctx->pix_fmt = AV_PIX_FMT_PAL8;
break;
default:
av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
return AVERROR_INVALIDDATA;
}
bytestream2_skipu(&gb, 60);
if ((ret = ff_set_dimensions(avctx, w, h)) < 0)
return ret;
if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
return ret;
p->pict_type = AV_PICTURE_TYPE_I;
ptr = p->data[0];
stride = p->linesize[0];
scanline = av_malloc(bytes_per_scanline + AV_INPUT_BUFFER_PADDING_SIZE);
if (!scanline)
return AVERROR(ENOMEM);
if (nplanes == 3 && bits_per_pixel == 8) {
for (y = 0; y < h; y++) {
ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
if (ret < 0)
goto end;
for (x = 0; x < w; x++) {
ptr[3 * x] = scanline[x];
ptr[3 * x + 1] = scanline[x + bytes_per_line];
ptr[3 * x + 2] = scanline[x + (bytes_per_line << 1)];
}
ptr += stride;
}
} else if (nplanes == 1 && bits_per_pixel == 8) {
int palstart = avpkt->size - 769;
if (avpkt->size < 769) {
av_log(avctx, AV_LOG_ERROR, "File is too short\n");
ret = avctx->err_recognition & AV_EF_EXPLODE ?
AVERROR_INVALIDDATA : avpkt->size;
goto end;
}
for (y = 0; y < h; y++, ptr += stride) {
ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
if (ret < 0)
goto end;
memcpy(ptr, scanline, w);
}
if (bytestream2_tell(&gb) != palstart) {
av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");
bytestream2_seek(&gb, palstart, SEEK_SET);
}
if (bytestream2_get_byte(&gb) != 12) {
av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");
ret = avctx->err_recognition & AV_EF_EXPLODE ?
AVERROR_INVALIDDATA : avpkt->size;
goto end;
}
} else if (nplanes == 1) { /* all packed formats, max. 16 colors */
GetBitContext s;
for (y = 0; y < h; y++) {
init_get_bits8(&s, scanline, bytes_per_scanline);
ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
if (ret < 0)
goto end;
for (x = 0; x < w; x++)
ptr[x] = get_bits(&s, bits_per_pixel);
ptr += stride;
}
} else { /* planar, 4, 8 or 16 colors */
int i;
for (y = 0; y < h; y++) {
ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
if (ret < 0)
goto end;
for (x = 0; x < w; x++) {
int m = 0x80 >> (x & 7), v = 0;
for (i = nplanes - 1; i >= 0; i--) {
v <<= 1;
v += !!(scanline[i * bytes_per_line + (x >> 3)] & m);
}
ptr[x] = v;
}
ptr += stride;
}
}
ret = bytestream2_tell(&gb);
if (nplanes == 1 && bits_per_pixel == 8) {
pcx_palette(&gb, (uint32_t *)p->data[1], 256);
ret += 256 * 3;
} else if (bits_per_pixel * nplanes == 1) {
AV_WN32A(p->data[1] , 0xFF000000);
AV_WN32A(p->data[1]+4, 0xFFFFFFFF);
} else if (bits_per_pixel < 8) {
bytestream2_seek(&gb, 16, SEEK_SET);
pcx_palette(&gb, (uint32_t *)p->data[1], 16);
}
*got_frame = 1;
end:
av_free(scanline);
return ret;
}
const FFCodec ff_pcx_decoder = {
.p.name = "pcx",
.p.long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_PCX,
.decode = pcx_decode_frame,
.p.capabilities = AV_CODEC_CAP_DR1,
};
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