1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-07 11:13:41 +02:00
FFmpeg/libavcodec/targa.c
Andreas Rheinhardt 4243da4ff4 avcodec/codec_internal: Use union for FFCodec decode/encode callbacks
This is possible, because every given FFCodec has to implement
exactly one of these. Doing so decreases sizeof(FFCodec) and
therefore decreases the size of the binary.
Notice that in case of position-independent code the decrease
is in .data.rel.ro, so that this translates to decreased
memory consumption.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-04-05 20:02:37 +02:00

317 lines
10 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 "codec_internal.h"
#include "internal.h"
#include "targa.h"
typedef struct TargaContext {
GetByteContext gb;
} TargaContext;
static uint8_t *advance_line(uint8_t *start, uint8_t *line,
int stride, int *y, int h, int interleave)
{
*y += interleave;
if (*y < h) {
return line + interleave * stride;
} else {
*y = (*y + 1) & (interleave - 1);
if (*y && *y < h) {
return start + *y * stride;
} else {
return NULL;
}
}
}
static int targa_decode_rle(AVCodecContext *avctx, TargaContext *s,
uint8_t *start, int w, int h, int stride,
int bpp, int interleave)
{
int x, y;
int depth = (bpp + 1) >> 3;
int type, count;
uint8_t *line = start;
uint8_t *dst = line;
x = y = count = 0;
while (dst) {
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 (!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;
dst = line = advance_line(start, line, stride, &y, h, interleave);
}
} while (dst && 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;
dst = line = advance_line(start, line, stride, &y, h, interleave);
}
} while (dst && count > 0);
}
}
if (count) {
av_log(avctx, AV_LOG_ERROR, "Packet went out of bounds\n");
return AVERROR_INVALIDDATA;
}
return 0;
}
static int decode_frame(AVCodecContext *avctx, AVFrame *p,
int *got_frame, AVPacket *avpkt)
{
TargaContext * const s = avctx->priv_data;
uint8_t *dst;
int stride;
int idlen, pal, compr, y, w, h, bpp, flags, ret;
int first_clr, colors, csize;
int interleave;
size_t img_size;
bytestream2_init(&s->gb, avpkt->data, avpkt->size);
/* parse image header */
idlen = bytestream2_get_byte(&s->gb);
pal = bytestream2_get_byte(&s->gb);
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);
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;
}
if (bytestream2_get_bytes_left(&s->gb) < idlen + 2*colors) {
av_log(avctx, AV_LOG_ERROR,
"Not enough data to read header\n");
return AVERROR_INVALIDDATA;
}
// 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:
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 (colors && (colors + first_clr) > 256) {
av_log(avctx, AV_LOG_ERROR, "Incorrect palette: %i colors with offset %i\n", colors, first_clr);
return AVERROR_INVALIDDATA;
}
if ((ret = ff_set_dimensions(avctx, w, h)) < 0)
return ret;
if ((compr & (~TGA_RLE)) == TGA_NODATA) {
return avpkt->size;
}
if (!(compr & TGA_RLE)) {
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;
}
}
if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
return ret;
p->pict_type = AV_PICTURE_TYPE_I;
if (flags & TGA_TOPTOBOTTOM) {
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];
}
interleave = flags & TGA_INTERLEAVE2 ? 2 :
flags & TGA_INTERLEAVE4 ? 4 : 1;
if (colors) {
int pal_size, pal_sample_size;
switch (csize) {
case 32: pal_sample_size = 4; break;
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 4:
for (t = 0; t < colors; t++)
*pal++ = bytestream2_get_le32u(&s->gb);
break;
case 3:
/* RGB24 */
for (t = 0; t < colors; t++)
*pal++ = (0xffU<<24) | 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++ = (0xffU<<24) | v;
}
break;
}
p->palette_has_changed = 1;
}
}
if (compr & TGA_RLE) {
int res = targa_decode_rle(avctx, s, dst, w, h, stride, bpp, interleave);
if (res < 0)
return res;
} else {
uint8_t *line;
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;
}
line = dst;
y = 0;
do {
bytestream2_get_buffer(&s->gb, line, img_size);
line = advance_line(dst, line, stride, &y, h, interleave);
} while (line);
}
if (flags & TGA_RIGHTTOLEFT) { // right-to-left, needs horizontal flip
int x;
for (y = 0; y < h; y++) {
void *line = &p->data[0][y * p->linesize[0]];
for (x = 0; x < w >> 1; x++) {
switch (bpp) {
case 32:
FFSWAP(uint32_t, ((uint32_t *)line)[x], ((uint32_t *)line)[w - x - 1]);
break;
case 24:
FFSWAP(uint8_t, ((uint8_t *)line)[3 * x ], ((uint8_t *)line)[3 * w - 3 * x - 3]);
FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 1], ((uint8_t *)line)[3 * w - 3 * x - 2]);
FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 2], ((uint8_t *)line)[3 * w - 3 * x - 1]);
break;
case 16:
FFSWAP(uint16_t, ((uint16_t *)line)[x], ((uint16_t *)line)[w - x - 1]);
break;
case 8:
FFSWAP(uint8_t, ((uint8_t *)line)[x], ((uint8_t *)line)[w - x - 1]);
}
}
}
}
*got_frame = 1;
return avpkt->size;
}
const FFCodec ff_targa_decoder = {
.p.name = "targa",
.p.long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_TARGA,
.p.capabilities = AV_CODEC_CAP_DR1,
.priv_data_size = sizeof(TargaContext),
FF_CODEC_DECODE_CB(decode_frame),
};