/* * SubRip subtitle decoder * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org> * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; 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/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 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:%d X2:%d Y1:%d Y2:%d", &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 = AV_CODEC_ID_SRT, .init = ff_ass_subtitle_header_default, .decode = srt_decode_frame, };