FFmpeg/libavcodec/srtdec.c
Reinhard Tartler 737eb5976f Merge libavcore into libavutil
It is pretty hopeless that other considerable projects will adopt
libavutil alone in other projects. Projects that need small footprint
are better off with more specialized libraries such as gnulib or rather
just copy the necessary parts that they need. With this in mind, nobody
is helped by having libavutil and libavcore split. In order to ease
maintenance inside and around FFmpeg and to reduce confusion where to
put common code, avcore's functionality is merged (back) to avutil.

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
2011-02-15 16:18:21 +01:00

242 lines
9.2 KiB
C

/*
* 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, "%128[^>]>%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,
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,
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;
ff_ass_init(sub);
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,
};