yading@10: /*
yading@10:  * SSA/ASS encoder
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 <string.h>
yading@10: 
yading@10: #include "avcodec.h"
yading@10: #include "ass_split.h"
yading@10: #include "ass.h"
yading@10: #include "libavutil/avstring.h"
yading@10: #include "libavutil/internal.h"
yading@10: #include "libavutil/mem.h"
yading@10: 
yading@10: typedef struct {
yading@10:     int id; ///< current event id, ReadOrder field
yading@10: } ASSEncodeContext;
yading@10: 
yading@10: static av_cold int ass_encode_init(AVCodecContext *avctx)
yading@10: {
yading@10:     avctx->extradata = av_malloc(avctx->subtitle_header_size + 1);
yading@10:     if (!avctx->extradata)
yading@10:         return AVERROR(ENOMEM);
yading@10:     memcpy(avctx->extradata, avctx->subtitle_header, avctx->subtitle_header_size);
yading@10:     avctx->extradata_size = avctx->subtitle_header_size;
yading@10:     avctx->extradata[avctx->extradata_size] = 0;
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int ass_encode_frame(AVCodecContext *avctx,
yading@10:                             unsigned char *buf, int bufsize,
yading@10:                             const AVSubtitle *sub)
yading@10: {
yading@10:     ASSEncodeContext *s = avctx->priv_data;
yading@10:     int i, len, total_len = 0;
yading@10: 
yading@10:     for (i=0; i<sub->num_rects; i++) {
yading@10:         char ass_line[2048];
yading@10:         const char *ass = sub->rects[i]->ass;
yading@10: 
yading@10:         if (sub->rects[i]->type != SUBTITLE_ASS) {
yading@10:             av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n");
yading@10:             return -1;
yading@10:         }
yading@10: 
yading@10:         if (strncmp(ass, "Dialogue: ", 10)) {
yading@10:             av_log(avctx, AV_LOG_ERROR, "AVSubtitle rectangle ass \"%s\""
yading@10:                    " does not look like a SSA markup\n", ass);
yading@10:             return AVERROR_INVALIDDATA;
yading@10:         }
yading@10: 
yading@10:         if (avctx->codec->id == AV_CODEC_ID_ASS) {
yading@10:             long int layer;
yading@10:             char *p;
yading@10: 
yading@10:             if (i > 0) {
yading@10:                 av_log(avctx, AV_LOG_ERROR, "ASS encoder supports only one "
yading@10:                        "ASS rectangle field.\n");
yading@10:                 return AVERROR_INVALIDDATA;
yading@10:             }
yading@10: 
yading@10:             ass += 10; // skip "Dialogue: "
yading@10:             /* parse Layer field. If it's a Marked field, the content
yading@10:              * will be "Marked=N" instead of the layer num, so we will
yading@10:              * have layer=0, which is fine. */
yading@10:             layer = strtol(ass, &p, 10);
yading@10:             if (*p) p += strcspn(p, ",") + 1; // skip layer or marked
yading@10:             if (*p) p += strcspn(p, ",") + 1; // skip start timestamp
yading@10:             if (*p) p += strcspn(p, ",") + 1; // skip end timestamp
yading@10:             snprintf(ass_line, sizeof(ass_line), "%d,%ld,%s", ++s->id, layer, p);
yading@10:             ass_line[strcspn(ass_line, "\r\n")] = 0;
yading@10:             ass = ass_line;
yading@10:         }
yading@10:         len = av_strlcpy(buf+total_len, ass, bufsize-total_len);
yading@10: 
yading@10:         if (len > bufsize-total_len-1) {
yading@10:             av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n");
yading@10:             return -1;
yading@10:         }
yading@10: 
yading@10:         total_len += len;
yading@10:     }
yading@10: 
yading@10:     return total_len;
yading@10: }
yading@10: 
yading@10: #if CONFIG_SSA_ENCODER
yading@10: AVCodec ff_ssa_encoder = {
yading@10:     .name         = "ssa",
yading@10:     .long_name    = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"),
yading@10:     .type         = AVMEDIA_TYPE_SUBTITLE,
yading@10:     .id           = AV_CODEC_ID_SSA,
yading@10:     .init         = ass_encode_init,
yading@10:     .encode_sub   = ass_encode_frame,
yading@10:     .priv_data_size = sizeof(ASSEncodeContext),
yading@10: };
yading@10: #endif
yading@10: 
yading@10: #if CONFIG_ASS_ENCODER
yading@10: AVCodec ff_ass_encoder = {
yading@10:     .name         = "ass",
yading@10:     .long_name    = NULL_IF_CONFIG_SMALL("ASS (Advanced SubStation Alpha) subtitle"),
yading@10:     .type         = AVMEDIA_TYPE_SUBTITLE,
yading@10:     .id           = AV_CODEC_ID_ASS,
yading@10:     .init         = ass_encode_init,
yading@10:     .encode_sub   = ass_encode_frame,
yading@10:     .priv_data_size = sizeof(ASSEncodeContext),
yading@10: };
yading@10: #endif