yading@10: /*
yading@10:  * Copyright (c) 2012 Clément Bœsch
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: /**
yading@10:  * @file
yading@10:  * SAMI subtitle decoder
yading@10:  * @see http://msdn.microsoft.com/en-us/library/ms971327.aspx
yading@10:  */
yading@10: 
yading@10: #include "ass.h"
yading@10: #include "libavutil/avstring.h"
yading@10: #include "libavutil/bprint.h"
yading@10: 
yading@10: typedef struct {
yading@10:     AVBPrint source;
yading@10:     AVBPrint content;
yading@10:     AVBPrint full;
yading@10: } SAMIContext;
yading@10: 
yading@10: static int sami_paragraph_to_ass(AVCodecContext *avctx, const char *src)
yading@10: {
yading@10:     SAMIContext *sami = avctx->priv_data;
yading@10:     int ret = 0;
yading@10:     char *tag = NULL;
yading@10:     char *dupsrc = av_strdup(src);
yading@10:     char *p = dupsrc;
yading@10: 
yading@10:     av_bprint_clear(&sami->content);
yading@10:     for (;;) {
yading@10:         char *saveptr = NULL;
yading@10:         int prev_chr_is_space = 0;
yading@10:         AVBPrint *dst = &sami->content;
yading@10: 
yading@10:         /* parse & extract paragraph tag */
yading@10:         p = av_stristr(p, "<P");
yading@10:         if (!p)
yading@10:             break;
yading@10:         if (p[2] != '>' && !av_isspace(p[2])) { // avoid confusion with tags such as <PRE>
yading@10:             p++;
yading@10:             continue;
yading@10:         }
yading@10:         if (dst->len) // add a separator with the previous paragraph if there was one
yading@10:             av_bprintf(dst, "\\N");
yading@10:         tag = av_strtok(p, ">", &saveptr);
yading@10:         if (!tag || !saveptr)
yading@10:             break;
yading@10:         p = saveptr;
yading@10: 
yading@10:         /* check if the current paragraph is the "source" (speaker name) */
yading@10:         if (av_stristr(tag, "ID=Source") || av_stristr(tag, "ID=\"Source\"")) {
yading@10:             dst = &sami->source;
yading@10:             av_bprint_clear(dst);
yading@10:         }
yading@10: 
yading@10:         /* if empty event -> skip subtitle */
yading@10:         while (av_isspace(*p))
yading@10:             p++;
yading@10:         if (!strncmp(p, "&nbsp;", 6)) {
yading@10:             ret = -1;
yading@10:             goto end;
yading@10:         }
yading@10: 
yading@10:         /* extract the text, stripping most of the tags */
yading@10:         while (*p) {
yading@10:             if (*p == '<') {
yading@10:                 if (!av_strncasecmp(p, "<P", 2) && (p[2] == '>' || av_isspace(p[2])))
yading@10:                     break;
yading@10:                 if (!av_strncasecmp(p, "<BR", 3))
yading@10:                     av_bprintf(dst, "\\N");
yading@10:                 p++;
yading@10:                 while (*p && *p != '>')
yading@10:                     p++;
yading@10:                 if (!*p)
yading@10:                     break;
yading@10:                 if (*p == '>')
yading@10:                     p++;
yading@10:             }
yading@10:             if (!av_isspace(*p))
yading@10:                 av_bprint_chars(dst, *p, 1);
yading@10:             else if (!prev_chr_is_space)
yading@10:                 av_bprint_chars(dst, ' ', 1);
yading@10:             prev_chr_is_space = av_isspace(*p);
yading@10:             p++;
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     av_bprint_clear(&sami->full);
yading@10:     if (sami->source.len)
yading@10:         av_bprintf(&sami->full, "{\\i1}%s{\\i0}\\N", sami->source.str);
yading@10:     av_bprintf(&sami->full, "%s\r\n", sami->content.str);
yading@10: 
yading@10: end:
yading@10:     av_free(dupsrc);
yading@10:     return ret;
yading@10: }
yading@10: 
yading@10: static int sami_decode_frame(AVCodecContext *avctx,
yading@10:                              void *data, int *got_sub_ptr, AVPacket *avpkt)
yading@10: {
yading@10:     AVSubtitle *sub = data;
yading@10:     const char *ptr = avpkt->data;
yading@10:     SAMIContext *sami = avctx->priv_data;
yading@10: 
yading@10:     if (ptr && avpkt->size > 0 && !sami_paragraph_to_ass(avctx, ptr)) {
yading@10:         int ts_start     = av_rescale_q(avpkt->pts, avctx->time_base, (AVRational){1,100});
yading@10:         int ts_duration  = avpkt->duration != -1 ?
yading@10:                            av_rescale_q(avpkt->duration, avctx->time_base, (AVRational){1,100}) : -1;
yading@10:         ff_ass_add_rect(sub, sami->full.str, ts_start, ts_duration, 0);
yading@10:     }
yading@10:     *got_sub_ptr = sub->num_rects > 0;
yading@10:     return avpkt->size;
yading@10: }
yading@10: 
yading@10: static av_cold int sami_init(AVCodecContext *avctx)
yading@10: {
yading@10:     SAMIContext *sami = avctx->priv_data;
yading@10:     av_bprint_init(&sami->source,  0, 2048);
yading@10:     av_bprint_init(&sami->content, 0, 2048);
yading@10:     av_bprint_init(&sami->full,    0, 2048);
yading@10:     return ff_ass_subtitle_header_default(avctx);
yading@10: }
yading@10: 
yading@10: static av_cold int sami_close(AVCodecContext *avctx)
yading@10: {
yading@10:     SAMIContext *sami = avctx->priv_data;
yading@10:     av_bprint_finalize(&sami->source,  NULL);
yading@10:     av_bprint_finalize(&sami->content, NULL);
yading@10:     av_bprint_finalize(&sami->full,    NULL);
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: AVCodec ff_sami_decoder = {
yading@10:     .name           = "sami",
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("SAMI subtitle"),
yading@10:     .type           = AVMEDIA_TYPE_SUBTITLE,
yading@10:     .id             = AV_CODEC_ID_SAMI,
yading@10:     .priv_data_size = sizeof(SAMIContext),
yading@10:     .init           = sami_init,
yading@10:     .close          = sami_close,
yading@10:     .decode         = sami_decode_frame,
yading@10: };