FFmpeg/libavcodec/targa.c
Michael Niedermayer eb3f81e4ef targadec: Simplify RLE out of packet check.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
2012-01-28 01:36:42 +01:00

300 lines
9.4 KiB
C

/*
* Targa (.tga) image decoder
* Copyright (c) 2006 Konstantin Shishkov
*
* 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/intreadwrite.h"
#include "libavutil/imgutils.h"
#include "avcodec.h"
#include "bytestream.h"
#include "targa.h"
typedef struct TargaContext {
AVFrame picture;
int width, height;
int bpp;
int color_type;
int compression_type;
} TargaContext;
#define CHECK_BUFFER_SIZE(buf, buf_end, needed, where) \
if(needed > buf_end - buf){ \
av_log(avctx, AV_LOG_ERROR, "Problem: unexpected end of data while reading " where "\n"); \
return -1; \
} \
static int targa_decode_rle(AVCodecContext *avctx, TargaContext *s, const uint8_t *src, int src_size, uint8_t *dst, int w, int h, int stride, int bpp)
{
int i, x, y;
int depth = (bpp + 1) >> 3;
int type, count;
int diff;
const uint8_t *src_end = src + src_size;
diff = stride - w * depth;
x = y = 0;
while(y < h){
CHECK_BUFFER_SIZE(src, src_end, 1, "image type");
type = *src++;
count = (type & 0x7F) + 1;
type &= 0x80;
if(x + count > (h - y) * w){
av_log(avctx, AV_LOG_ERROR, "Packet went out of bounds: position (%i,%i) size %i\n", x, y, count);
return -1;
}
if(type){
CHECK_BUFFER_SIZE(src, src_end, depth, "image data");
}else{
CHECK_BUFFER_SIZE(src, src_end, count * depth, "image data");
}
for(i = 0; i < count; i++){
switch(depth){
case 1:
*dst = *src;
break;
case 2:
AV_WN16A(dst, AV_RN16A(src));
break;
case 3:
dst[0] = src[0];
dst[1] = src[1];
dst[2] = src[2];
break;
case 4:
AV_WN32A(dst, AV_RN32A(src));
break;
}
dst += depth;
if(!type)
src += depth;
x++;
if(x == w){
x = 0;
y++;
dst += diff;
}
}
if(type)
src += depth;
}
return src_size;
}
static int decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
const uint8_t *buf_end = avpkt->data + avpkt->size;
TargaContext * const s = avctx->priv_data;
AVFrame *picture = data;
AVFrame * const p= (AVFrame*)&s->picture;
uint8_t *dst;
int stride;
int idlen, pal, compr, y, w, h, bpp, flags;
int first_clr, colors, csize;
/* parse image header */
CHECK_BUFFER_SIZE(buf, buf_end, 18, "header");
idlen = *buf++;
pal = *buf++;
compr = *buf++;
first_clr = bytestream_get_le16(&buf);
colors = bytestream_get_le16(&buf);
csize = *buf++;
if (!pal && (first_clr || colors || csize)) {
av_log(avctx, AV_LOG_WARNING, "File without colormap has colormap information set.\n");
// specification says we should ignore those value in this case
first_clr = colors = csize = 0;
}
buf += 2; /* x */
y = bytestream_get_le16(&buf);
w = bytestream_get_le16(&buf);
h = bytestream_get_le16(&buf);
bpp = *buf++;
flags = *buf++;
//skip identifier if any
CHECK_BUFFER_SIZE(buf, buf_end, idlen, "identifiers");
buf += idlen;
s->bpp = bpp;
s->width = w;
s->height = h;
switch(s->bpp){
case 8:
avctx->pix_fmt = ((compr & (~TGA_RLE)) == TGA_BW) ? PIX_FMT_GRAY8 : PIX_FMT_PAL8;
break;
case 15:
case 16:
avctx->pix_fmt = PIX_FMT_RGB555LE;
break;
case 24:
avctx->pix_fmt = PIX_FMT_BGR24;
break;
case 32:
avctx->pix_fmt = PIX_FMT_BGRA;
break;
default:
av_log(avctx, AV_LOG_ERROR, "Bit depth %i is not supported\n", s->bpp);
return -1;
}
if(s->picture.data[0])
avctx->release_buffer(avctx, &s->picture);
if(av_image_check_size(w, h, 0, avctx))
return -1;
if(w != avctx->width || h != avctx->height)
avcodec_set_dimensions(avctx, w, h);
if(avctx->get_buffer(avctx, p) < 0){
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
if(flags & 0x20){
dst = p->data[0];
stride = p->linesize[0];
}else{ //image is upside-down
dst = p->data[0] + p->linesize[0] * (h - 1);
stride = -p->linesize[0];
}
if(colors){
int pal_size, pal_sample_size;
if((colors + first_clr) > 256){
av_log(avctx, AV_LOG_ERROR, "Incorrect palette: %i colors with offset %i\n", colors, first_clr);
return -1;
}
switch (csize) {
case 24: pal_sample_size = 3; break;
case 16:
case 15: pal_sample_size = 2; break;
default:
av_log(avctx, AV_LOG_ERROR, "Palette entry size %i bits is not supported\n", csize);
return -1;
}
pal_size = colors * pal_sample_size;
CHECK_BUFFER_SIZE(buf, buf_end, pal_size, "color table");
if(avctx->pix_fmt != PIX_FMT_PAL8)//should not occur but skip palette anyway
buf += pal_size;
else{
int t;
uint32_t *pal = ((uint32_t *)p->data[1]) + first_clr;
switch (pal_sample_size) {
case 3:
/* RGB24 */
for (t = 0; t < colors; t++)
*pal++ = (0xffU<<24) | bytestream_get_le24(&buf);
break;
case 2:
/* RGB555 */
for (t = 0; t < colors; t++) {
uint32_t v = bytestream_get_le16(&buf);
v = ((v & 0x7C00) << 9) |
((v & 0x03E0) << 6) |
((v & 0x001F) << 3);
/* left bit replication */
v |= (v & 0xE0E0E0U) >> 5;
*pal++ = (0xffU<<24) | v;
}
break;
}
p->palette_has_changed = 1;
}
}
if((compr & (~TGA_RLE)) == TGA_NODATA)
memset(p->data[0], 0, p->linesize[0] * s->height);
else{
if(compr & TGA_RLE){
int res = targa_decode_rle(avctx, s, buf, buf_end - buf, dst, avctx->width, avctx->height, stride, bpp);
if (res < 0)
return -1;
buf += res;
}else{
size_t img_size = s->width * ((s->bpp + 1) >> 3);
CHECK_BUFFER_SIZE(buf, buf_end, img_size, "image data");
for(y = 0; y < s->height; y++){
memcpy(dst, buf, img_size);
dst += stride;
buf += img_size;
}
}
}
if(flags & 0x10){ // right-to-left, needs horizontal flip
int x;
for(y = 0; y < s->height; y++){
void *line = &p->data[0][y * p->linesize[0]];
for(x = 0; x < s->width >> 1; x++){
switch(s->bpp){
case 32:
FFSWAP(uint32_t, ((uint32_t *)line)[x], ((uint32_t *)line)[s->width - x - 1]);
break;
case 24:
FFSWAP(uint8_t, ((uint8_t *)line)[3 * x ], ((uint8_t *)line)[3 * s->width - 3 * x - 3]);
FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 1], ((uint8_t *)line)[3 * s->width - 3 * x - 2]);
FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 2], ((uint8_t *)line)[3 * s->width - 3 * x - 1]);
break;
case 16:
FFSWAP(uint16_t, ((uint16_t *)line)[x], ((uint16_t *)line)[s->width - x - 1]);
break;
case 8:
FFSWAP(uint8_t, ((uint8_t *)line)[x], ((uint8_t *)line)[s->width - x - 1]);
}
}
}
}
*picture= *(AVFrame*)&s->picture;
*data_size = sizeof(AVPicture);
return avpkt->size;
}
static av_cold int targa_init(AVCodecContext *avctx){
TargaContext *s = avctx->priv_data;
avcodec_get_frame_defaults((AVFrame*)&s->picture);
avctx->coded_frame= (AVFrame*)&s->picture;
return 0;
}
static av_cold int targa_end(AVCodecContext *avctx){
TargaContext *s = avctx->priv_data;
if(s->picture.data[0])
avctx->release_buffer(avctx, &s->picture);
return 0;
}
AVCodec ff_targa_decoder = {
.name = "targa",
.type = AVMEDIA_TYPE_VIDEO,
.id = CODEC_ID_TARGA,
.priv_data_size = sizeof(TargaContext),
.init = targa_init,
.close = targa_end,
.decode = decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
};