/* * SSA/ASS encoder * 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 <string.h> #include "avcodec.h" #include "ass.h" #include "libavutil/avstring.h" #include "libavutil/internal.h" #include "libavutil/mem.h" typedef struct { int id; ///< current event id, ReadOrder field } ASSEncodeContext; static av_cold int ass_encode_init(AVCodecContext *avctx) { avctx->extradata = av_malloc(avctx->subtitle_header_size + 1); if (!avctx->extradata) return AVERROR(ENOMEM); memcpy(avctx->extradata, avctx->subtitle_header, avctx->subtitle_header_size); avctx->extradata_size = avctx->subtitle_header_size; avctx->extradata[avctx->extradata_size] = 0; return 0; } static int ass_encode_frame(AVCodecContext *avctx, unsigned char *buf, int bufsize, const AVSubtitle *sub) { ASSEncodeContext *s = avctx->priv_data; int i, len, total_len = 0; for (i=0; i<sub->num_rects; i++) { char ass_line[2048]; const char *ass = sub->rects[i]->ass; long int layer; char *p; if (sub->rects[i]->type != SUBTITLE_ASS) { av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n"); return AVERROR(EINVAL); } #if FF_API_ASS_TIMING if (!strncmp(ass, "Dialogue: ", 10)) { if (i > 0) { av_log(avctx, AV_LOG_ERROR, "ASS encoder supports only one " "ASS rectangle field.\n"); return AVERROR_INVALIDDATA; } ass += 10; // skip "Dialogue: " /* parse Layer field. If it's a Marked field, the content * will be "Marked=N" instead of the layer num, so we will * have layer=0, which is fine. */ layer = strtol(ass, &p, 10); #define SKIP_ENTRY(ptr) do { \ char *sep = strchr(ptr, ','); \ if (sep) \ ptr = sep + 1; \ } while (0) SKIP_ENTRY(p); // skip layer or marked SKIP_ENTRY(p); // skip start timestamp SKIP_ENTRY(p); // skip end timestamp snprintf(ass_line, sizeof(ass_line), "%d,%ld,%s", ++s->id, layer, p); ass_line[strcspn(ass_line, "\r\n")] = 0; ass = ass_line; } #endif len = av_strlcpy(buf+total_len, ass, bufsize-total_len); if (len > bufsize-total_len-1) { av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n"); return AVERROR(EINVAL); } total_len += len; } return total_len; } #if CONFIG_SSA_ENCODER AVCodec ff_ssa_encoder = { .name = "ssa", .long_name = NULL_IF_CONFIG_SMALL("ASS (Advanced SubStation Alpha) subtitle"), .type = AVMEDIA_TYPE_SUBTITLE, .id = AV_CODEC_ID_ASS, .init = ass_encode_init, .encode_sub = ass_encode_frame, .priv_data_size = sizeof(ASSEncodeContext), }; #endif #if CONFIG_ASS_ENCODER AVCodec ff_ass_encoder = { .name = "ass", .long_name = NULL_IF_CONFIG_SMALL("ASS (Advanced SubStation Alpha) subtitle"), .type = AVMEDIA_TYPE_SUBTITLE, .id = AV_CODEC_ID_ASS, .init = ass_encode_init, .encode_sub = ass_encode_frame, .priv_data_size = sizeof(ASSEncodeContext), }; #endif