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:  * Raw subtitles decoder
yading@10:  */
yading@10: 
yading@10: #include "avcodec.h"
yading@10: #include "ass.h"
yading@10: #include "libavutil/bprint.h"
yading@10: #include "libavutil/opt.h"
yading@10: 
yading@10: typedef struct {
yading@10:     AVClass *class;
yading@10:     const char *linebreaks;
yading@10:     int keep_ass_markup;
yading@10: } TextContext;
yading@10: 
yading@10: #define OFFSET(x) offsetof(TextContext, x)
yading@10: #define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
yading@10: static const AVOption options[] = {
yading@10:     { "keep_ass_markup", "Set if ASS tags must be escaped", OFFSET(keep_ass_markup), AV_OPT_TYPE_INT,    {.i64=0}, 0, 1, .flags=SD },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: static int text_event_to_ass(const AVCodecContext *avctx, AVBPrint *buf,
yading@10:                              const char *p, const char *p_end)
yading@10: {
yading@10:     const TextContext *text = avctx->priv_data;
yading@10: 
yading@10:     for (; p < p_end && *p; p++) {
yading@10: 
yading@10:         /* forced custom line breaks, not accounted as "normal" EOL */
yading@10:         if (text->linebreaks && strchr(text->linebreaks, *p)) {
yading@10:             av_bprintf(buf, "\\N");
yading@10: 
yading@10:         /* standard ASS escaping so random characters don't get mis-interpreted
yading@10:          * as ASS */
yading@10:         } else if (!text->keep_ass_markup && strchr("{}\\", *p)) {
yading@10:             av_bprintf(buf, "\\%c", *p);
yading@10: 
yading@10:         /* some packets might end abruptly (no \0 at the end, like for example
yading@10:          * in some cases of demuxing from a classic video container), some
yading@10:          * might be terminated with \n or \r\n which we have to remove (for
yading@10:          * consistency with those who haven't), and we also have to deal with
yading@10:          * evil cases such as \r at the end of the buffer (and no \0 terminated
yading@10:          * character) */
yading@10:         } else if (p[0] == '\n') {
yading@10:             /* some stuff left so we can insert a line break */
yading@10:             if (p < p_end - 1)
yading@10:                 av_bprintf(buf, "\\N");
yading@10:         } else if (p[0] == '\r' && p < p_end - 1 && p[1] == '\n') {
yading@10:             /* \r followed by a \n, we can skip it. We don't insert the \N yet
yading@10:              * because we don't know if it is followed by more text */
yading@10:             continue;
yading@10: 
yading@10:         /* finally, a sane character */
yading@10:         } else {
yading@10:             av_bprint_chars(buf, *p, 1);
yading@10:         }
yading@10:     }
yading@10:     av_bprintf(buf, "\r\n");
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int text_decode_frame(AVCodecContext *avctx, void *data,
yading@10:                              int *got_sub_ptr, AVPacket *avpkt)
yading@10: {
yading@10:     AVBPrint buf;
yading@10:     AVSubtitle *sub = data;
yading@10:     const char *ptr = avpkt->data;
yading@10:     const int ts_start     = av_rescale_q(avpkt->pts,      avctx->time_base, (AVRational){1,100});
yading@10:     const int ts_duration  = avpkt->duration != -1 ?
yading@10:                              av_rescale_q(avpkt->duration, avctx->time_base, (AVRational){1,100}) : -1;
yading@10: 
yading@10:     av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
yading@10:     if (ptr && avpkt->size > 0 && *ptr &&
yading@10:         !text_event_to_ass(avctx, &buf, ptr, ptr + avpkt->size)) {
yading@10:         if (!av_bprint_is_complete(&buf)) {
yading@10:             av_bprint_finalize(&buf, NULL);
yading@10:             return AVERROR(ENOMEM);
yading@10:         }
yading@10:         ff_ass_add_rect(sub, buf.str, ts_start, ts_duration, 0);
yading@10:     }
yading@10:     *got_sub_ptr = sub->num_rects > 0;
yading@10:     av_bprint_finalize(&buf, NULL);
yading@10:     return avpkt->size;
yading@10: }
yading@10: 
yading@10: #define DECLARE_CLASS(decname) static const AVClass decname ## _decoder_class = {   \
yading@10:     .class_name = #decname " decoder",      \
yading@10:     .item_name  = av_default_item_name,     \
yading@10:     .option     = decname ## _options,      \
yading@10:     .version    = LIBAVUTIL_VERSION_INT,    \
yading@10: }
yading@10: 
yading@10: #if CONFIG_TEXT_DECODER
yading@10: #define text_options options
yading@10: DECLARE_CLASS(text);
yading@10: 
yading@10: AVCodec ff_text_decoder = {
yading@10:     .name           = "text",
yading@10:     .priv_data_size = sizeof(TextContext),
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("Raw text subtitle"),
yading@10:     .type           = AVMEDIA_TYPE_SUBTITLE,
yading@10:     .id             = AV_CODEC_ID_TEXT,
yading@10:     .decode         = text_decode_frame,
yading@10:     .init           = ff_ass_subtitle_header_default,
yading@10:     .priv_class     = &text_decoder_class,
yading@10: };
yading@10: #endif
yading@10: 
yading@10: #if CONFIG_VPLAYER_DECODER || CONFIG_PJS_DECODER || CONFIG_SUBVIEWER1_DECODER
yading@10: 
yading@10: static int linebreak_init(AVCodecContext *avctx)
yading@10: {
yading@10:     TextContext *text = avctx->priv_data;
yading@10:     text->linebreaks = "|";
yading@10:     return ff_ass_subtitle_header_default(avctx);
yading@10: }
yading@10: 
yading@10: #if CONFIG_VPLAYER_DECODER
yading@10: #define vplayer_options options
yading@10: DECLARE_CLASS(vplayer);
yading@10: 
yading@10: AVCodec ff_vplayer_decoder = {
yading@10:     .name           = "vplayer",
yading@10:     .priv_data_size = sizeof(TextContext),
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("VPlayer subtitle"),
yading@10:     .type           = AVMEDIA_TYPE_SUBTITLE,
yading@10:     .id             = AV_CODEC_ID_VPLAYER,
yading@10:     .decode         = text_decode_frame,
yading@10:     .init           = linebreak_init,
yading@10:     .priv_class     = &vplayer_decoder_class,
yading@10: };
yading@10: #endif
yading@10: 
yading@10: #if CONFIG_PJS_DECODER
yading@10: #define pjs_options options
yading@10: DECLARE_CLASS(pjs);
yading@10: 
yading@10: AVCodec ff_pjs_decoder = {
yading@10:     .name           = "pjs",
yading@10:     .priv_data_size = sizeof(TextContext),
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("PJS subtitle"),
yading@10:     .type           = AVMEDIA_TYPE_SUBTITLE,
yading@10:     .id             = AV_CODEC_ID_PJS,
yading@10:     .decode         = text_decode_frame,
yading@10:     .init           = linebreak_init,
yading@10:     .priv_class     = &pjs_decoder_class,
yading@10: };
yading@10: #endif
yading@10: 
yading@10: #if CONFIG_SUBVIEWER1_DECODER
yading@10: #define subviewer1_options options
yading@10: DECLARE_CLASS(subviewer1);
yading@10: 
yading@10: AVCodec ff_subviewer1_decoder = {
yading@10:     .name           = "subviewer1",
yading@10:     .priv_data_size = sizeof(TextContext),
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("SubViewer1 subtitle"),
yading@10:     .type           = AVMEDIA_TYPE_SUBTITLE,
yading@10:     .id             = AV_CODEC_ID_SUBVIEWER1,
yading@10:     .decode         = text_decode_frame,
yading@10:     .init           = linebreak_init,
yading@10:     .priv_class     = &subviewer1_decoder_class,
yading@10: };
yading@10: #endif
yading@10: 
yading@10: #endif /* text subtitles with '|' line break */