FFmpeg/libavcodec/targa.c
2013-03-08 07:38:30 +01:00

244 lines
7.7 KiB
C

/*
* Targa (.tga) image decoder
* Copyright (c) 2006 Konstantin Shishkov
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; 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 "internal.h"
#include "targa.h"
typedef struct TargaContext {
GetByteContext gb;
int color_type;
int compression_type;
} TargaContext;
static int targa_decode_rle(AVCodecContext *avctx, TargaContext *s,
uint8_t *dst, int w, int h, int stride, int bpp)
{
int x, y;
int depth = (bpp + 1) >> 3;
int type, count;
int diff;
diff = stride - w * depth;
x = y = 0;
while (y < h) {
if (bytestream2_get_bytes_left(&s->gb) <= 0) {
av_log(avctx, AV_LOG_ERROR,
"Ran ouf of data before end-of-image\n");
return AVERROR_INVALIDDATA;
}
type = bytestream2_get_byteu(&s->gb);
count = (type & 0x7F) + 1;
type &= 0x80;
if (x + count > w && x + count + 1 > (h - y) * w) {
av_log(avctx, AV_LOG_ERROR,
"Packet went out of bounds: position (%i,%i) size %i\n",
x, y, count);
return AVERROR_INVALIDDATA;
}
if (!type) {
do {
int n = FFMIN(count, w - x);
bytestream2_get_buffer(&s->gb, dst, n * depth);
count -= n;
dst += n * depth;
x += n;
if (x == w) {
x = 0;
y++;
dst += diff;
}
} while (count > 0);
} else {
uint8_t tmp[4];
bytestream2_get_buffer(&s->gb, tmp, depth);
do {
int n = FFMIN(count, w - x);
count -= n;
x += n;
do {
memcpy(dst, tmp, depth);
dst += depth;
} while (--n);
if (x == w) {
x = 0;
y++;
dst += diff;
}
} while (count > 0);
}
}
return 0;
}
static int decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
TargaContext * const s = avctx->priv_data;
AVFrame * const p = data;
uint8_t *dst;
int stride;
int idlen, compr, y, w, h, bpp, flags, ret;
int first_clr, colors, csize;
bytestream2_init(&s->gb, avpkt->data, avpkt->size);
/* parse image header */
idlen = bytestream2_get_byte(&s->gb);
bytestream2_skip(&s->gb, 1); /* pal */
compr = bytestream2_get_byte(&s->gb);
first_clr = bytestream2_get_le16(&s->gb);
colors = bytestream2_get_le16(&s->gb);
csize = bytestream2_get_byte(&s->gb);
bytestream2_skip(&s->gb, 4); /* 2: x, 2: y */
w = bytestream2_get_le16(&s->gb);
h = bytestream2_get_le16(&s->gb);
bpp = bytestream2_get_byte(&s->gb);
flags = bytestream2_get_byte(&s->gb);
// skip identifier if any
bytestream2_skip(&s->gb, idlen);
switch(bpp){
case 8:
avctx->pix_fmt = ((compr & (~TGA_RLE)) == TGA_BW) ? AV_PIX_FMT_GRAY8 : AV_PIX_FMT_PAL8;
break;
case 15:
avctx->pix_fmt = AV_PIX_FMT_RGB555LE;
break;
case 16:
avctx->pix_fmt = AV_PIX_FMT_RGB555LE;
break;
case 24:
avctx->pix_fmt = AV_PIX_FMT_BGR24;
break;
case 32:
avctx->pix_fmt = AV_PIX_FMT_BGRA;
break;
default:
av_log(avctx, AV_LOG_ERROR, "Bit depth %i is not supported\n", bpp);
return AVERROR_INVALIDDATA;
}
if ((ret = av_image_check_size(w, h, 0, avctx)) < 0)
return ret;
if(w != avctx->width || h != avctx->height)
avcodec_set_dimensions(avctx, w, h);
if ((ret = ff_get_buffer(avctx, p, 0)) < 0){
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return ret;
}
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 AVERROR_INVALIDDATA;
}
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 AVERROR_INVALIDDATA;
}
pal_size = colors * pal_sample_size;
if(avctx->pix_fmt != AV_PIX_FMT_PAL8)//should not occur but skip palette anyway
bytestream2_skip(&s->gb, pal_size);
else{
int t;
uint32_t *pal = ((uint32_t *)p->data[1]) + first_clr;
if (bytestream2_get_bytes_left(&s->gb) < pal_size) {
av_log(avctx, AV_LOG_ERROR,
"Not enough data to read palette\n");
return AVERROR_INVALIDDATA;
}
switch (pal_sample_size) {
case 3:
/* RGB24 */
for (t = 0; t < colors; t++)
*pal++ = bytestream2_get_le24u(&s->gb);
break;
case 2:
/* RGB555 */
for (t = 0; t < colors; t++) {
uint32_t v = bytestream2_get_le16u(&s->gb);
v = ((v & 0x7C00) << 9) |
((v & 0x03E0) << 6) |
((v & 0x001F) << 3);
/* left bit replication */
v |= (v & 0xE0E0E0U) >> 5;
*pal++ = v;
}
break;
}
p->palette_has_changed = 1;
}
}
if ((compr & (~TGA_RLE)) == TGA_NODATA) {
memset(p->data[0], 0, p->linesize[0] * h);
} else {
if(compr & TGA_RLE){
int res = targa_decode_rle(avctx, s, dst, w, h, stride, bpp);
if (res < 0)
return res;
} else {
size_t img_size = w * ((bpp + 1) >> 3);
if (bytestream2_get_bytes_left(&s->gb) < img_size * h) {
av_log(avctx, AV_LOG_ERROR,
"Not enough data available for image\n");
return AVERROR_INVALIDDATA;
}
for (y = 0; y < h; y++) {
bytestream2_get_bufferu(&s->gb, dst, img_size);
dst += stride;
}
}
}
*got_frame = 1;
return avpkt->size;
}
AVCodec ff_targa_decoder = {
.name = "targa",
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_TARGA,
.priv_data_size = sizeof(TargaContext),
.decode = decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
};