/*
* SubRip subtitle decoder
* Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
*
* 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/avstring.h"
#include "libavutil/parseutils.h"
#include "avcodec.h"
#include "ass.h"
static int html_color_parse(AVCodecContext *avctx, const char *str)
{
uint8_t rgba[4];
if (av_parse_color(rgba, str, strcspn(str, "\" >"), avctx) < 0)
return -1;
return rgba[0] | rgba[1] << 8 | rgba[2] << 16;
}
enum {
PARAM_UNKNOWN = -1,
PARAM_SIZE,
PARAM_COLOR,
PARAM_FACE,
PARAM_NUMBER
};
typedef struct {
char tag[128];
char param[PARAM_NUMBER][128];
} SrtStack;
static const char *srt_to_ass(AVCodecContext *avctx, char *out, char *out_end,
const char *in, int x1, int y1, int x2, int y2)
{
char c, *param, buffer[128], tmp[128];
int len, tag_close, sptr = 1, line_start = 1, an = 0, end = 0;
SrtStack stack[16];
stack[0].tag[0] = 0;
strcpy(stack[0].param[PARAM_SIZE], "{\\fs}");
strcpy(stack[0].param[PARAM_COLOR], "{\\c}");
strcpy(stack[0].param[PARAM_FACE], "{\\fn}");
if (x1 >= 0 && y1 >= 0) {
if (x2 >= 0 && y2 >= 0 && (x2 != x1 || y2 != y1))
out += snprintf(out, out_end-out,
"{\\an1}{\\move(%d,%d,%d,%d)}", x1, y1, x2, y2);
else
out += snprintf(out, out_end-out, "{\\an1}{\\pos(%d,%d)}", x1, y1);
}
for (; out < out_end && !end && *in; in++) {
switch (*in) {
case '\r':
break;
case '\n':
if (line_start) {
end = 1;
break;
}
while (out[-1] == ' ')
out--;
out += snprintf(out, out_end-out, "\\N");
line_start = 1;
break;
case ' ':
if (!line_start)
*out++ = *in;
break;
case '{': /* skip all {\xxx} substrings except for {\an%d}
and all microdvd like styles such as {Y:xxx} */
an += sscanf(in, "{\\an%*1u}%c", &c) == 1;
if ((an != 1 && sscanf(in, "{\\%*[^}]}%n%c", &len, &c) > 0) ||
sscanf(in, "{%*1[CcFfoPSsYy]:%*[^}]}%n%c", &len, &c) > 0) {
in += len - 1;
} else
*out++ = *in;
break;
case '<':
tag_close = in[1] == '/';
if (sscanf(in+tag_close+1, "%127[^>]>%n%c", buffer, &len,&c) >= 2) {
if ((param = strchr(buffer, ' ')))
*param++ = 0;
if ((!tag_close && sptr < FF_ARRAY_ELEMS(stack)) ||
( tag_close && sptr > 0 && !strcmp(stack[sptr-1].tag, buffer))) {
int i, j, unknown = 0;
in += len + tag_close;
if (!tag_close)
memset(stack+sptr, 0, sizeof(*stack));
if (!strcmp(buffer, "font")) {
if (tag_close) {
for (i=PARAM_NUMBER-1; i>=0; i--)
if (stack[sptr-1].param[i][0])
for (j=sptr-2; j>=0; j--)
if (stack[j].param[i][0]) {
out += snprintf(out, out_end-out,
"%s", stack[j].param[i]);
break;
}
} else {
while (param) {
if (!strncmp(param, "size=", 5)) {
unsigned font_size;
param += 5 + (param[5] == '"');
if (sscanf(param, "%u", &font_size) == 1) {
snprintf(stack[sptr].param[PARAM_SIZE],
sizeof(stack[0].param[PARAM_SIZE]),
"{\\fs%u}", font_size);
}
} else if (!strncmp(param, "color=", 6)) {
param += 6 + (param[6] == '"');
snprintf(stack[sptr].param[PARAM_COLOR],
sizeof(stack[0].param[PARAM_COLOR]),
"{\\c&H%X&}",
html_color_parse(avctx, param));
} else if (!strncmp(param, "face=", 5)) {
param += 5 + (param[5] == '"');
len = strcspn(param,
param[-1] == '"' ? "\"" :" ");
av_strlcpy(tmp, param,
FFMIN(sizeof(tmp), len+1));
param += len;
snprintf(stack[sptr].param[PARAM_FACE],
sizeof(stack[0].param[PARAM_FACE]),
"{\\fn%s}", tmp);
}
if ((param = strchr(param, ' ')))
param++;
}
for (i=0; i<PARAM_NUMBER; i++)
if (stack[sptr].param[i][0])
out += snprintf(out, out_end-out,
"%s", stack[sptr].param[i]);
}
} else if (!buffer[1] && strspn(buffer, "bisu") == 1) {
out += snprintf(out, out_end-out,
"{\\%c%d}", buffer[0], !tag_close);
} else {
unknown = 1;
snprintf(tmp, sizeof(tmp), "</%s>", buffer);
}
if (tag_close) {
sptr--;
} else if (unknown && !strstr(in, tmp)) {
in -= len + tag_close;
*out++ = *in;
} else
av_strlcpy(stack[sptr++].tag, buffer,
sizeof(stack[0].tag));
break;
}
}
default:
*out++ = *in;
break;
}
if (*in != ' ' && *in != '\r' && *in != '\n')
line_start = 0;
}
out = FFMIN(out, out_end-3);
while (!strncmp(out-2, "\\N", 2))
out -= 2;
while (out[-1] == ' ')
out--;
out += snprintf(out, out_end-out, "\r\n");
return in;
}
static const char *read_ts(const char *buf, int *ts_start, int *ts_end,
int *x1, int *y1, int *x2, int *y2)
{
int i, hs, ms, ss, he, me, se;
for (i=0; i<2; i++) {
/* try to read timestamps in either the first or second line */
int c = sscanf(buf, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d"
"%*[ ]X1:%u X2:%u Y1:%u Y2:%u",
&hs, &ms, &ss, ts_start, &he, &me, &se, ts_end,
x1, x2, y1, y2);
buf += strcspn(buf, "\n") + 1;
if (c >= 8) {
*ts_start = 100*(ss + 60*(ms + 60*hs)) + *ts_start/10;
*ts_end = 100*(se + 60*(me + 60*he)) + *ts_end /10;
return buf;
}
}
return NULL;
}
static int srt_decode_frame(AVCodecContext *avctx,
void *data, int *got_sub_ptr, AVPacket *avpkt)
{
AVSubtitle *sub = data;
int ts_start, ts_end, x1 = -1, y1 = -1, x2 = -1, y2 = -1;
char buffer[2048];
const char *ptr = avpkt->data;
const char *end = avpkt->data + avpkt->size;
if (avpkt->size <= 0)
return avpkt->size;
while (ptr < end && *ptr) {
ptr = read_ts(ptr, &ts_start, &ts_end, &x1, &y1, &x2, &y2);
if (!ptr)
break;
ptr = srt_to_ass(avctx, buffer, buffer+sizeof(buffer), ptr,
x1, y1, x2, y2);
ff_ass_add_rect(sub, buffer, ts_start, ts_end, 0);
}
*got_sub_ptr = sub->num_rects > 0;
return avpkt->size;
}
AVCodec ff_srt_decoder = {
.name = "srt",
.long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
.type = AVMEDIA_TYPE_SUBTITLE,
.id = CODEC_ID_SRT,
.init = ff_ass_subtitle_header_default,
.decode = srt_decode_frame,
};