yading@10: /*
yading@10:  * SubRip subtitle decoder
yading@10:  * Copyright (c) 2010  Aurelien Jacobs <aurel@gnuage.org>
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: #include "libavutil/avstring.h"
yading@10: #include "libavutil/common.h"
yading@10: #include "libavutil/intreadwrite.h"
yading@10: #include "libavutil/parseutils.h"
yading@10: #include "avcodec.h"
yading@10: #include "ass.h"
yading@10: 
yading@10: static int html_color_parse(AVCodecContext *avctx, const char *str)
yading@10: {
yading@10:     uint8_t rgba[4];
yading@10:     if (av_parse_color(rgba, str, strcspn(str, "\" >"), avctx) < 0)
yading@10:         return -1;
yading@10:     return rgba[0] | rgba[1] << 8 | rgba[2] << 16;
yading@10: }
yading@10: 
yading@10: enum {
yading@10:     PARAM_UNKNOWN = -1,
yading@10:     PARAM_SIZE,
yading@10:     PARAM_COLOR,
yading@10:     PARAM_FACE,
yading@10:     PARAM_NUMBER
yading@10: };
yading@10: 
yading@10: typedef struct {
yading@10:     char tag[128];
yading@10:     char param[PARAM_NUMBER][128];
yading@10: } SrtStack;
yading@10: 
yading@10: static const char *srt_to_ass(AVCodecContext *avctx, char *out, char *out_end,
yading@10:                               const char *in, int x1, int y1, int x2, int y2)
yading@10: {
yading@10:     char *param, buffer[128], tmp[128];
yading@10:     int len, tag_close, sptr = 1, line_start = 1, an = 0, end = 0;
yading@10:     SrtStack stack[16];
yading@10: 
yading@10:     stack[0].tag[0] = 0;
yading@10:     strcpy(stack[0].param[PARAM_SIZE],  "{\\fs}");
yading@10:     strcpy(stack[0].param[PARAM_COLOR], "{\\c}");
yading@10:     strcpy(stack[0].param[PARAM_FACE],  "{\\fn}");
yading@10: 
yading@10:     if (x1 >= 0 && y1 >= 0) {
yading@10:         if (x2 >= 0 && y2 >= 0 && (x2 != x1 || y2 != y1))
yading@10:             snprintf(out, out_end-out,
yading@10:                             "{\\an1}{\\move(%d,%d,%d,%d)}", x1, y1, x2, y2);
yading@10:         else
yading@10:             snprintf(out, out_end-out, "{\\an1}{\\pos(%d,%d)}", x1, y1);
yading@10:         out += strlen(out);
yading@10:     }
yading@10: 
yading@10:     for (; out < out_end && !end && *in; in++) {
yading@10:         switch (*in) {
yading@10:         case '\r':
yading@10:             break;
yading@10:         case '\n':
yading@10:             if (line_start) {
yading@10:                 end = 1;
yading@10:                 break;
yading@10:             }
yading@10:             while (out[-1] == ' ')
yading@10:                 out--;
yading@10:             snprintf(out, out_end-out, "\\N");
yading@10:             if(out<out_end) out += strlen(out);
yading@10:             line_start = 1;
yading@10:             break;
yading@10:         case ' ':
yading@10:             if (!line_start)
yading@10:                 *out++ = *in;
yading@10:             break;
yading@10:         case '{':    /* skip all {\xxx} substrings except for {\an%d}
yading@10:                         and all microdvd like styles such as {Y:xxx} */
yading@10:             len = 0;
yading@10:             an += sscanf(in, "{\\an%*1u}%n", &len) >= 0 && len > 0;
yading@10:             if ((an != 1 && (len = 0, sscanf(in, "{\\%*[^}]}%n", &len) >= 0 && len > 0)) ||
yading@10:                 (len = 0, sscanf(in, "{%*1[CcFfoPSsYy]:%*[^}]}%n", &len) >= 0 && len > 0)) {
yading@10:                 in += len - 1;
yading@10:             } else
yading@10:                 *out++ = *in;
yading@10:             break;
yading@10:         case '<':
yading@10:             tag_close = in[1] == '/';
yading@10:             len = 0;
yading@10:             if (sscanf(in+tag_close+1, "%127[^>]>%n", buffer, &len) >= 1 && len > 0) {
yading@10:                 if ((param = strchr(buffer, ' ')))
yading@10:                     *param++ = 0;
yading@10:                 if ((!tag_close && sptr < FF_ARRAY_ELEMS(stack)) ||
yading@10:                     ( tag_close && sptr > 0 && !strcmp(stack[sptr-1].tag, buffer))) {
yading@10:                     int i, j, unknown = 0;
yading@10:                     in += len + tag_close;
yading@10:                     if (!tag_close)
yading@10:                         memset(stack+sptr, 0, sizeof(*stack));
yading@10:                     if (!strcmp(buffer, "font")) {
yading@10:                         if (tag_close) {
yading@10:                             for (i=PARAM_NUMBER-1; i>=0; i--)
yading@10:                                 if (stack[sptr-1].param[i][0])
yading@10:                                     for (j=sptr-2; j>=0; j--)
yading@10:                                         if (stack[j].param[i][0]) {
yading@10:                                             snprintf(out, out_end-out,
yading@10:                                                             "%s", stack[j].param[i]);
yading@10:                                             if(out<out_end) out += strlen(out);
yading@10:                                             break;
yading@10:                                         }
yading@10:                         } else {
yading@10:                             while (param) {
yading@10:                                 if (!strncmp(param, "size=", 5)) {
yading@10:                                     unsigned font_size;
yading@10:                                     param += 5 + (param[5] == '"');
yading@10:                                     if (sscanf(param, "%u", &font_size) == 1) {
yading@10:                                         snprintf(stack[sptr].param[PARAM_SIZE],
yading@10:                                              sizeof(stack[0].param[PARAM_SIZE]),
yading@10:                                              "{\\fs%u}", font_size);
yading@10:                                     }
yading@10:                                 } else if (!strncmp(param, "color=", 6)) {
yading@10:                                     param += 6 + (param[6] == '"');
yading@10:                                     snprintf(stack[sptr].param[PARAM_COLOR],
yading@10:                                          sizeof(stack[0].param[PARAM_COLOR]),
yading@10:                                          "{\\c&H%X&}",
yading@10:                                          html_color_parse(avctx, param));
yading@10:                                 } else if (!strncmp(param, "face=", 5)) {
yading@10:                                     param += 5 + (param[5] == '"');
yading@10:                                     len = strcspn(param,
yading@10:                                                   param[-1] == '"' ? "\"" :" ");
yading@10:                                     av_strlcpy(tmp, param,
yading@10:                                                FFMIN(sizeof(tmp), len+1));
yading@10:                                     param += len;
yading@10:                                     snprintf(stack[sptr].param[PARAM_FACE],
yading@10:                                              sizeof(stack[0].param[PARAM_FACE]),
yading@10:                                              "{\\fn%s}", tmp);
yading@10:                                 }
yading@10:                                 if ((param = strchr(param, ' ')))
yading@10:                                     param++;
yading@10:                             }
yading@10:                             for (i=0; i<PARAM_NUMBER; i++)
yading@10:                                 if (stack[sptr].param[i][0]) {
yading@10:                                     snprintf(out, out_end-out,
yading@10:                                                     "%s", stack[sptr].param[i]);
yading@10:                                     if(out<out_end) out += strlen(out);
yading@10:                                 }
yading@10:                         }
yading@10:                     } else if (!buffer[1] && strspn(buffer, "bisu") == 1) {
yading@10:                         snprintf(out, out_end-out,
yading@10:                                         "{\\%c%d}", buffer[0], !tag_close);
yading@10:                         if(out<out_end) out += strlen(out);
yading@10:                     } else {
yading@10:                         unknown = 1;
yading@10:                         snprintf(tmp, sizeof(tmp), "</%s>", buffer);
yading@10:                     }
yading@10:                     if (tag_close) {
yading@10:                         sptr--;
yading@10:                     } else if (unknown && !strstr(in, tmp)) {
yading@10:                         in -= len + tag_close;
yading@10:                         *out++ = *in;
yading@10:                     } else
yading@10:                         av_strlcpy(stack[sptr++].tag, buffer,
yading@10:                                    sizeof(stack[0].tag));
yading@10:                     break;
yading@10:                 }
yading@10:             }
yading@10:         default:
yading@10:             *out++ = *in;
yading@10:             break;
yading@10:         }
yading@10:         if (*in != ' ' && *in != '\r' && *in != '\n')
yading@10:             line_start = 0;
yading@10:     }
yading@10: 
yading@10:     out = FFMIN(out, out_end-3);
yading@10:     while (!strncmp(out-2, "\\N", 2))
yading@10:         out -= 2;
yading@10:     while (out[-1] == ' ')
yading@10:         out--;
yading@10:     snprintf(out, out_end-out, "\r\n");
yading@10:     return in;
yading@10: }
yading@10: 
yading@10: static const char *read_ts(const char *buf, int *ts_start, int *ts_end,
yading@10:                            int *x1, int *y1, int *x2, int *y2)
yading@10: {
yading@10:     int i, hs, ms, ss, he, me, se;
yading@10: 
yading@10:     for (i=0; i<2; i++) {
yading@10:         /* try to read timestamps in either the first or second line */
yading@10:         int c = sscanf(buf, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d"
yading@10:                        "%*[ ]X1:%u X2:%u Y1:%u Y2:%u",
yading@10:                        &hs, &ms, &ss, ts_start, &he, &me, &se, ts_end,
yading@10:                        x1, x2, y1, y2);
yading@10:         buf += strcspn(buf, "\n") + 1;
yading@10:         if (c >= 8) {
yading@10:             *ts_start = 100*(ss + 60*(ms + 60*hs)) + *ts_start/10;
yading@10:             *ts_end   = 100*(se + 60*(me + 60*he)) + *ts_end  /10;
yading@10:             return buf;
yading@10:         }
yading@10:     }
yading@10:     return NULL;
yading@10: }
yading@10: 
yading@10: static int srt_decode_frame(AVCodecContext *avctx,
yading@10:                             void *data, int *got_sub_ptr, AVPacket *avpkt)
yading@10: {
yading@10:     AVSubtitle *sub = data;
yading@10:     int ts_start, ts_end, x1 = -1, y1 = -1, x2 = -1, y2 = -1;
yading@10:     char buffer[2048];
yading@10:     const char *ptr = avpkt->data;
yading@10:     const char *end = avpkt->data + avpkt->size;
yading@10:     int size;
yading@10:     const uint8_t *p = av_packet_get_side_data(avpkt, AV_PKT_DATA_SUBTITLE_POSITION, &size);
yading@10: 
yading@10:     if (p && size == 16) {
yading@10:         x1 = AV_RL32(p     );
yading@10:         y1 = AV_RL32(p +  4);
yading@10:         x2 = AV_RL32(p +  8);
yading@10:         y2 = AV_RL32(p + 12);
yading@10:     }
yading@10: 
yading@10:     if (avpkt->size <= 0)
yading@10:         return avpkt->size;
yading@10: 
yading@10:     while (ptr < end && *ptr) {
yading@10:         if (avctx->codec->id == AV_CODEC_ID_SRT) {
yading@10:             ptr = read_ts(ptr, &ts_start, &ts_end, &x1, &y1, &x2, &y2);
yading@10:             if (!ptr)
yading@10:                 break;
yading@10:         } else {
yading@10:             // Do final divide-by-10 outside rescale to force rounding down.
yading@10:             ts_start = av_rescale_q(avpkt->pts,
yading@10:                                     avctx->time_base,
yading@10:                                     (AVRational){1,100});
yading@10:             ts_end   = av_rescale_q(avpkt->pts + avpkt->duration,
yading@10:                                     avctx->time_base,
yading@10:                                     (AVRational){1,100});
yading@10:         }
yading@10:         ptr = srt_to_ass(avctx, buffer, buffer+sizeof(buffer), ptr,
yading@10:                          x1, y1, x2, y2);
yading@10:         ff_ass_add_rect(sub, buffer, ts_start, ts_end-ts_start, 0);
yading@10:     }
yading@10: 
yading@10:     *got_sub_ptr = sub->num_rects > 0;
yading@10:     return avpkt->size;
yading@10: }
yading@10: 
yading@10: #if CONFIG_SRT_DECODER
yading@10: /* deprecated decoder */
yading@10: AVCodec ff_srt_decoder = {
yading@10:     .name         = "srt",
yading@10:     .long_name    = NULL_IF_CONFIG_SMALL("SubRip subtitle with embedded timing"),
yading@10:     .type         = AVMEDIA_TYPE_SUBTITLE,
yading@10:     .id           = AV_CODEC_ID_SRT,
yading@10:     .init         = ff_ass_subtitle_header_default,
yading@10:     .decode       = srt_decode_frame,
yading@10: };
yading@10: #endif
yading@10: 
yading@10: #if CONFIG_SUBRIP_DECODER
yading@10: AVCodec ff_subrip_decoder = {
yading@10:     .name         = "subrip",
yading@10:     .long_name    = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
yading@10:     .type         = AVMEDIA_TYPE_SUBTITLE,
yading@10:     .id           = AV_CODEC_ID_SUBRIP,
yading@10:     .init         = ff_ass_subtitle_header_default,
yading@10:     .decode       = srt_decode_frame,
yading@10: };
yading@10: #endif