/*
* 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/common.h"
#include "libavutil/intreadwrite.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 SrtStack {
char tag[128];
char param[PARAM_NUMBER][128];
} SrtStack;
static void rstrip_spaces_buf(AVBPrint *buf)
{
while (buf->len > 0 && buf->str[buf->len - 1] == ' ')
buf->str[--buf->len] = 0;
}
static void srt_to_ass(AVCodecContext *avctx, AVBPrint *dst,
const char *in, int x1, int y1, int x2, int y2)
{
char *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) {
/* XXX: here we rescale coordinate assuming they are in DVD resolution
* (720x480) since we don't have anything better */
if (x2 >= 0 && y2 >= 0 && (x2 != x1 || y2 != y1) && x2 >= x1 && y2 >= y1) {
/* text rectangle defined, write the text at the center of the rectangle */
const int cx = x1 + (x2 - x1)/2;
const int cy = y1 + (y2 - y1)/2;
const int scaled_x = cx * ASS_DEFAULT_PLAYRESX / 720;
const int scaled_y = cy * ASS_DEFAULT_PLAYRESY / 480;
av_bprintf(dst, "{\\an5}{\\pos(%d,%d)}", scaled_x, scaled_y);
} else {
/* only the top left corner, assume the text starts in that corner */
const int scaled_x = x1 * ASS_DEFAULT_PLAYRESX / 720;
const int scaled_y = y1 * ASS_DEFAULT_PLAYRESY / 480;
av_bprintf(dst, "{\\an1}{\\pos(%d,%d)}", scaled_x, scaled_y);
}
}
for (; !end && *in; in++) {
switch (*in) {
case '\r':
break;
case '\n':
if (line_start) {
end = 1;
break;
}
rstrip_spaces_buf(dst);
av_bprintf(dst, "\\N");
line_start = 1;
break;
case ' ':
if (!line_start)
av_bprint_chars(dst, *in, 1);
break;
case '{': /* skip all {\xxx} substrings except for {\an%d}
and all microdvd like styles such as {Y:xxx} */
len = 0;
an += sscanf(in, "{\\an%*1u}%n", &len) >= 0 && len > 0;
if ((an != 1 && (len = 0, sscanf(in, "{\\%*[^}]}%n", &len) >= 0 && len > 0)) ||
(len = 0, sscanf(in, "{%*1[CcFfoPSsYy]:%*[^}]}%n", &len) >= 0 && len > 0)) {
in += len - 1;
} else
av_bprint_chars(dst, *in, 1);
break;
case '<':
tag_close = in[1] == '/';
len = 0;
if (sscanf(in+tag_close+1, "%127[^>]>%n", buffer, &len) >= 1 && len > 0) {
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]) {
av_bprintf(dst, "%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])
av_bprintf(dst, "%s", stack[sptr].param[i]);
}
} else if (!buffer[1] && strspn(buffer, "bisu") == 1) {
av_bprintf(dst, "{\\%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;
av_bprint_chars(dst, *in, 1);
} else
av_strlcpy(stack[sptr++].tag, buffer,
sizeof(stack[0].tag));
break;
}
}
default:
av_bprint_chars(dst, *in, 1);
break;
}
if (*in != ' ' && *in != '\r' && *in != '\n')
line_start = 0;
}
while (dst->len >= 2 && !strncmp(&dst->str[dst->len - 2], "\\N", 2))
dst->len -= 2;
dst->str[dst->len] = 0;
rstrip_spaces_buf(dst);
}
static int srt_decode_frame(AVCodecContext *avctx,
void *data, int *got_sub_ptr, AVPacket *avpkt)
{
AVSubtitle *sub = data;
AVBPrint buffer;
int ts_start, ts_end, x1 = -1, y1 = -1, x2 = -1, y2 = -1;
int size, ret;
const uint8_t *p = av_packet_get_side_data(avpkt, AV_PKT_DATA_SUBTITLE_POSITION, &size);
if (p && size == 16) {
x1 = AV_RL32(p );
y1 = AV_RL32(p + 4);
x2 = AV_RL32(p + 8);
y2 = AV_RL32(p + 12);
}
if (avpkt->size <= 0)
return avpkt->size;
av_bprint_init(&buffer, 0, AV_BPRINT_SIZE_UNLIMITED);
// TODO: reindent
// Do final divide-by-10 outside rescale to force rounding down.
ts_start = av_rescale_q(avpkt->pts,
avctx->time_base,
(AVRational){1,100});
ts_end = av_rescale_q(avpkt->pts + avpkt->duration,
avctx->time_base,
(AVRational){1,100});
srt_to_ass(avctx, &buffer, avpkt->data, x1, y1, x2, y2);
ret = ff_ass_add_rect_bprint(sub, &buffer, ts_start, ts_end-ts_start);
av_bprint_finalize(&buffer, NULL);
if (ret < 0)
return ret;
*got_sub_ptr = sub->num_rects > 0;
return avpkt->size;
}
#if CONFIG_SRT_DECODER
/* deprecated decoder */
AVCodec ff_srt_decoder = {
.name = "srt",
.long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
.type = AVMEDIA_TYPE_SUBTITLE,
.id = AV_CODEC_ID_SUBRIP,
.init = ff_ass_subtitle_header_default,
.decode = srt_decode_frame,
};
#endif
#if CONFIG_SUBRIP_DECODER
AVCodec ff_subrip_decoder = {
.name = "subrip",
.long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
.type = AVMEDIA_TYPE_SUBTITLE,
.id = AV_CODEC_ID_SUBRIP,
.init = ff_ass_subtitle_header_default,
.decode = srt_decode_frame,
};
#endif