87 lines
2.4 KiB
C
87 lines
2.4 KiB
C
|
#include "avcodec.h"
|
||
|
|
#include "bitstream.h"
|
||
|
|
#include "bytestream.h"
|
||
|
|
|
||
|
|
static int decode_init(AVCodecContext *avctx) {
|
||
|
|
avctx->pix_fmt = PIX_FMT_PAL8;
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static const uint8_t runbits[8] = { 2, 2, 6, 6, 10, 10, 14, 14 };
|
||
|
|
|
||
|
|
static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
|
||
|
|
uint8_t *buf, int buf_size) {
|
||
|
|
AVSubtitle *sub = data;
|
||
|
|
uint8_t *buf_end = buf + buf_size;
|
||
|
|
uint8_t *bitmap;
|
||
|
|
int w, h, x, y, rlelen, i;
|
||
|
|
GetBitContext gb;
|
||
|
|
|
||
|
|
// check that at least header fits
|
||
|
|
if (buf_size < 27 + 7 * 2 + 4 * 3) {
|
||
|
|
av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
|
||
|
|
// read header
|
||
|
|
w = bytestream_get_le16(&buf);
|
||
|
|
h = bytestream_get_le16(&buf);
|
||
|
|
if (avcodec_check_dimensions(avctx, w, h) < 0)
|
||
|
|
return -1;
|
||
|
|
x = bytestream_get_le16(&buf);
|
||
|
|
y = bytestream_get_le16(&buf);
|
||
|
|
// skip bottom right position, it gives no new information
|
||
|
|
bytestream_get_le16(&buf);
|
||
|
|
bytestream_get_le16(&buf);
|
||
|
|
rlelen = bytestream_get_le16(&buf);
|
||
|
|
|
||
|
|
// allocate sub and set values
|
||
|
|
if (!sub->rects) {
|
||
|
|
sub->rects = av_mallocz(sizeof(AVSubtitleRect));
|
||
|
|
sub->num_rects = 1;
|
||
|
|
}
|
||
|
|
av_freep(sub->rects[0].bitmap);
|
||
|
|
sub->rects[0].x = x; sub->rects[0].y = y;
|
||
|
|
sub->rects[0].w = w; sub->rects[0].h = h;
|
||
|
|
sub->rects[0].linesize = w;
|
||
|
|
sub->rects[0].bitmap = av_malloc(w * h);
|
||
|
|
sub->rects[0].nb_colors = 4;
|
||
|
|
sub->rects[0].rgba_palette = av_malloc(sub->rects[0].nb_colors * 4);
|
||
|
|
|
||
|
|
// read palette
|
||
|
|
for (i = 0; i < sub->rects[0].nb_colors; i++)
|
||
|
|
sub->rects[0].rgba_palette[i] = bytestream_get_be24(&buf);
|
||
|
|
|
||
|
|
// process RLE-compressed data
|
||
|
|
rlelen = FFMIN(rlelen, buf_end - buf);
|
||
|
|
init_get_bits(&gb, buf, rlelen * 8);
|
||
|
|
bitmap = sub->rects[0].bitmap;
|
||
|
|
for (y = 0; y < h; y++) {
|
||
|
|
for (x = 0; x < w; ) {
|
||
|
|
int log2 = ff_log2_tab[show_bits(&gb, 8)];
|
||
|
|
int run = get_bits(&gb, runbits[log2]);
|
||
|
|
int colour = get_bits(&gb, 2);
|
||
|
|
run = FFMIN(run, w - x);
|
||
|
|
// run length 0 means till end of row
|
||
|
|
if (!run) run = w - x;
|
||
|
|
memset(bitmap, colour, run);
|
||
|
|
bitmap += run;
|
||
|
|
x += run;
|
||
|
|
}
|
||
|
|
align_get_bits(&gb);
|
||
|
|
}
|
||
|
|
*data_size = 1;
|
||
|
|
return buf_size;
|
||
|
|
}
|
||
|
|
|
||
|
|
AVCodec xsub_decoder = {
|
||
|
|
"xsub",
|
||
|
|
CODEC_TYPE_SUBTITLE,
|
||
|
|
CODEC_ID_XSUB,
|
||
|
|
0,
|
||
|
|
decode_init,
|
||
|
|
NULL,
|
||
|
|
NULL,
|
||
|
|
decode_frame,
|
||
|
|
};
|