FFmpeg/libavcodec/targa.c

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/*
* 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 "avcodec.h"
enum TargaCompr{
TGA_NODATA = 0, // no image data
TGA_PAL = 1, // palettized
TGA_RGB = 2, // true-color
TGA_BW = 3, // black & white or grayscale
TGA_RLE = 8, // flag pointing that data is RLE-coded
};
typedef struct TargaContext {
AVFrame picture;
int width, height;
int bpp;
int color_type;
int compression_type;
} TargaContext;
static void targa_decode_rle(AVCodecContext *avctx, TargaContext *s, uint8_t *src, 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;
diff = stride - w * depth;
x = y = 0;
while(y < h){
type = *src++;
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;
}
for(i = 0; i < count; i++){
switch(depth){
case 1:
*dst = *src;
break;
case 2:
*((uint16_t*)dst) = AV_RL16(src);
break;
case 3:
dst[0] = src[0];
dst[1] = src[1];
dst[2] = src[2];
break;
case 4:
*((uint32_t*)dst) = AV_RL32(src);
break;
}
dst += depth;
if(!type)
src += depth;
x++;
if(x == w){
x = 0;
y++;
dst += diff;
}
}
if(type)
src += depth;
}
}
static int decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
uint8_t *buf, int buf_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, x, y, w, h, bpp, flags;
int first_clr, colors, csize;
/* parse image header */
idlen = *buf++;
pal = *buf++;
compr = *buf++;
first_clr = AV_RL16(buf); buf += 2;
colors = AV_RL16(buf); buf += 2;
csize = *buf++;
x = AV_RL16(buf); buf += 2;
y = AV_RL16(buf); buf += 2;
w = AV_RL16(buf); buf += 2;
h = AV_RL16(buf); buf += 2;
bpp = *buf++;
flags = *buf++;
//skip identifier if any
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:
avctx->pix_fmt = PIX_FMT_RGB555;
break;
case 16:
avctx->pix_fmt = PIX_FMT_RGB555;
break;
case 24:
avctx->pix_fmt = PIX_FMT_BGR24;
break;
case 32:
avctx->pix_fmt = PIX_FMT_RGB32;
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(avcodec_check_dimensions(avctx, w, h))
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(avctx->pix_fmt == PIX_FMT_PAL8 && avctx->palctrl){
memcpy(p->data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
if(avctx->palctrl->palette_changed){
p->palette_has_changed = 1;
avctx->palctrl->palette_changed = 0;
}
}
if(colors){
if((colors + first_clr) > 256){
av_log(avctx, AV_LOG_ERROR, "Incorrect palette: %i colors with offset %i\n", colors, first_clr);
return -1;
}
if(csize != 24){
av_log(avctx, AV_LOG_ERROR, "Palette entry size %i bits is not supported\n", csize);
return -1;
}
if(avctx->pix_fmt != PIX_FMT_PAL8)//should not occur but skip palette anyway
buf += colors * ((csize + 1) >> 3);
else{
int r, g, b, t;
int32_t *pal = ((int32_t*)p->data[1]) + first_clr;
for(t = 0; t < colors; t++){
r = *buf++;
g = *buf++;
b = *buf++;
*pal++ = (b << 16) | (g << 8) | r;
}
p->palette_has_changed = 1;
avctx->palctrl->palette_changed = 0;
}
}
if((compr & (~TGA_RLE)) == TGA_NODATA)
memset(p->data[0], 0, p->linesize[0] * s->height);
else{
if(compr & TGA_RLE)
targa_decode_rle(avctx, s, buf, dst, avctx->width, avctx->height, stride, bpp);
else{
for(y = 0; y < s->height; y++){
#ifdef WORDS_BIGENDIAN
if((s->bpp + 1) >> 3 == 2){
uint16_t *dst16 = (uint16_t*)dst;
for(x = 0; x < s->width; x++)
dst16[x] = AV_RL16(buf + x * 2);
}else if((s->bpp + 1) >> 3 == 4){
uint32_t *dst32 = (uint32_t*)dst;
for(x = 0; x < s->width; x++)
dst32[x] = AV_RL32(buf + x * 4);
}else
#endif
memcpy(dst, buf, s->width * ((s->bpp + 1) >> 3));
dst += stride;
buf += s->width * ((s->bpp + 1) >> 3);
}
}
}
*picture= *(AVFrame*)&s->picture;
*data_size = sizeof(AVPicture);
return buf_size;
}
static int targa_init(AVCodecContext *avctx){
TargaContext *s = avctx->priv_data;
avcodec_get_frame_defaults((AVFrame*)&s->picture);
avctx->coded_frame= (AVFrame*)&s->picture;
s->picture.data[0] = NULL;
return 0;
}
static int targa_end(AVCodecContext *avctx){
TargaContext *s = avctx->priv_data;
if(s->picture.data[0])
avctx->release_buffer(avctx, &s->picture);
return 0;
}
AVCodec targa_decoder = {
"targa",
CODEC_TYPE_VIDEO,
CODEC_ID_TARGA,
sizeof(TargaContext),
targa_init,
NULL,
targa_end,
decode_frame,
0,
NULL
};