yading@10: /*
yading@10:  * SubRip subtitle 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 <stdarg.h>
yading@10: #include "avcodec.h"
yading@10: #include "libavutil/avstring.h"
yading@10: #include "ass_split.h"
yading@10: #include "ass.h"
yading@10: 
yading@10: 
yading@10: #define SRT_STACK_SIZE 64
yading@10: 
yading@10: typedef struct {
yading@10:     AVCodecContext *avctx;
yading@10:     ASSSplitContext *ass_ctx;
yading@10:     char buffer[2048];
yading@10:     char *ptr;
yading@10:     char *end;
yading@10:     char *dialog_start;
yading@10:     int count;
yading@10:     char stack[SRT_STACK_SIZE];
yading@10:     int stack_ptr;
yading@10:     int alignment_applied;
yading@10: } SRTContext;
yading@10: 
yading@10: 
yading@10: #ifdef __GNUC__
yading@10: __attribute__ ((__format__ (__printf__, 2, 3)))
yading@10: #endif
yading@10: static void srt_print(SRTContext *s, const char *str, ...)
yading@10: {
yading@10:     va_list vargs;
yading@10:     va_start(vargs, str);
yading@10:     s->ptr += vsnprintf(s->ptr, s->end - s->ptr, str, vargs);
yading@10:     va_end(vargs);
yading@10: }
yading@10: 
yading@10: static int srt_stack_push(SRTContext *s, const char c)
yading@10: {
yading@10:     if (s->stack_ptr >= SRT_STACK_SIZE)
yading@10:         return -1;
yading@10:     s->stack[s->stack_ptr++] = c;
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static char srt_stack_pop(SRTContext *s)
yading@10: {
yading@10:     if (s->stack_ptr <= 0)
yading@10:         return 0;
yading@10:     return s->stack[--s->stack_ptr];
yading@10: }
yading@10: 
yading@10: static int srt_stack_find(SRTContext *s, const char c)
yading@10: {
yading@10:     int i;
yading@10:     for (i = s->stack_ptr-1; i >= 0; i--)
yading@10:         if (s->stack[i] == c)
yading@10:             break;
yading@10:     return i;
yading@10: }
yading@10: 
yading@10: static void srt_close_tag(SRTContext *s, char tag)
yading@10: {
yading@10:     srt_print(s, "</%c%s>", tag, tag == 'f' ? "ont" : "");
yading@10: }
yading@10: 
yading@10: static void srt_stack_push_pop(SRTContext *s, const char c, int close)
yading@10: {
yading@10:     if (close) {
yading@10:         int i = c ? srt_stack_find(s, c) : 0;
yading@10:         if (i < 0)
yading@10:             return;
yading@10:         while (s->stack_ptr != i)
yading@10:             srt_close_tag(s, srt_stack_pop(s));
yading@10:     } else if (srt_stack_push(s, c) < 0)
yading@10:         av_log(s->avctx, AV_LOG_ERROR, "tag stack overflow\n");
yading@10: }
yading@10: 
yading@10: static void srt_style_apply(SRTContext *s, const char *style)
yading@10: {
yading@10:     ASSStyle *st = ff_ass_style_get(s->ass_ctx, style);
yading@10:     if (st) {
yading@10:         int c = st->primary_color & 0xFFFFFF;
yading@10:         if (st->font_name && strcmp(st->font_name, ASS_DEFAULT_FONT) ||
yading@10:             st->font_size != ASS_DEFAULT_FONT_SIZE ||
yading@10:             c != ASS_DEFAULT_COLOR) {
yading@10:             srt_print(s, "<font");
yading@10:             if (st->font_name && strcmp(st->font_name, ASS_DEFAULT_FONT))
yading@10:                 srt_print(s, " face=\"%s\"", st->font_name);
yading@10:             if (st->font_size != ASS_DEFAULT_FONT_SIZE)
yading@10:                 srt_print(s, " size=\"%d\"", st->font_size);
yading@10:             if (c != ASS_DEFAULT_COLOR)
yading@10:                 srt_print(s, " color=\"#%06x\"",
yading@10:                           (c & 0xFF0000) >> 16 | c & 0xFF00 | (c & 0xFF) << 16);
yading@10:             srt_print(s, ">");
yading@10:             srt_stack_push(s, 'f');
yading@10:         }
yading@10:         if (st->bold != ASS_DEFAULT_BOLD) {
yading@10:             srt_print(s, "<b>");
yading@10:             srt_stack_push(s, 'b');
yading@10:         }
yading@10:         if (st->italic != ASS_DEFAULT_ITALIC) {
yading@10:             srt_print(s, "<i>");
yading@10:             srt_stack_push(s, 'i');
yading@10:         }
yading@10:         if (st->underline != ASS_DEFAULT_UNDERLINE) {
yading@10:             srt_print(s, "<u>");
yading@10:             srt_stack_push(s, 'u');
yading@10:         }
yading@10:         if (st->alignment != ASS_DEFAULT_ALIGNMENT) {
yading@10:             srt_print(s, "{\\an%d}", st->alignment);
yading@10:             s->alignment_applied = 1;
yading@10:         }
yading@10:     }
yading@10: }
yading@10: 
yading@10: 
yading@10: static av_cold int srt_encode_init(AVCodecContext *avctx)
yading@10: {
yading@10:     SRTContext *s = avctx->priv_data;
yading@10:     s->avctx = avctx;
yading@10:     s->ass_ctx = ff_ass_split(avctx->subtitle_header);
yading@10:     return s->ass_ctx ? 0 : AVERROR_INVALIDDATA;
yading@10: }
yading@10: 
yading@10: static void srt_text_cb(void *priv, const char *text, int len)
yading@10: {
yading@10:     SRTContext *s = priv;
yading@10:     av_strlcpy(s->ptr, text, FFMIN(s->end-s->ptr, len+1));
yading@10:     s->ptr += len;
yading@10: }
yading@10: 
yading@10: static void srt_new_line_cb(void *priv, int forced)
yading@10: {
yading@10:     srt_print(priv, "\r\n");
yading@10: }
yading@10: 
yading@10: static void srt_style_cb(void *priv, char style, int close)
yading@10: {
yading@10:     srt_stack_push_pop(priv, style, close);
yading@10:     if (!close)
yading@10:         srt_print(priv, "<%c>", style);
yading@10: }
yading@10: 
yading@10: static void srt_color_cb(void *priv, unsigned int color, unsigned int color_id)
yading@10: {
yading@10:     if (color_id > 1)
yading@10:         return;
yading@10:     srt_stack_push_pop(priv, 'f', color == 0xFFFFFFFF);
yading@10:     if (color != 0xFFFFFFFF)
yading@10:         srt_print(priv, "<font color=\"#%06x\">",
yading@10:               (color & 0xFF0000) >> 16 | color & 0xFF00 | (color & 0xFF) << 16);
yading@10: }
yading@10: 
yading@10: static void srt_font_name_cb(void *priv, const char *name)
yading@10: {
yading@10:     srt_stack_push_pop(priv, 'f', !name);
yading@10:     if (name)
yading@10:         srt_print(priv, "<font face=\"%s\">", name);
yading@10: }
yading@10: 
yading@10: static void srt_font_size_cb(void *priv, int size)
yading@10: {
yading@10:     srt_stack_push_pop(priv, 'f', size < 0);
yading@10:     if (size >= 0)
yading@10:         srt_print(priv, "<font size=\"%d\">", size);
yading@10: }
yading@10: 
yading@10: static void srt_alignment_cb(void *priv, int alignment)
yading@10: {
yading@10:     SRTContext *s = priv;
yading@10:     if (!s->alignment_applied && alignment >= 0) {
yading@10:         srt_print(s, "{\\an%d}", alignment);
yading@10:         s->alignment_applied = 1;
yading@10:     }
yading@10: }
yading@10: 
yading@10: static void srt_cancel_overrides_cb(void *priv, const char *style)
yading@10: {
yading@10:     srt_stack_push_pop(priv, 0, 1);
yading@10:     srt_style_apply(priv, style);
yading@10: }
yading@10: 
yading@10: static void srt_move_cb(void *priv, int x1, int y1, int x2, int y2,
yading@10:                         int t1, int t2)
yading@10: {
yading@10:     SRTContext *s = priv;
yading@10: 
yading@10:     if (s->avctx->codec->id == AV_CODEC_ID_SRT) {
yading@10:     char buffer[32];
yading@10:     int len = snprintf(buffer, sizeof(buffer),
yading@10:                        "  X1:%03u X2:%03u Y1:%03u Y2:%03u", x1, x2, y1, y2);
yading@10:     if (s->end - s->ptr > len) {
yading@10:         memmove(s->dialog_start+len, s->dialog_start, s->ptr-s->dialog_start+1);
yading@10:         memcpy(s->dialog_start, buffer, len);
yading@10:         s->ptr += len;
yading@10:     }
yading@10:     }
yading@10: }
yading@10: 
yading@10: static void srt_end_cb(void *priv)
yading@10: {
yading@10:     SRTContext *s = priv;
yading@10: 
yading@10:     srt_stack_push_pop(priv, 0, 1);
yading@10:     if (s->avctx->codec->id == AV_CODEC_ID_SRT)
yading@10:         srt_print(priv, "\r\n\r\n");
yading@10: }
yading@10: 
yading@10: static const ASSCodesCallbacks srt_callbacks = {
yading@10:     .text             = srt_text_cb,
yading@10:     .new_line         = srt_new_line_cb,
yading@10:     .style            = srt_style_cb,
yading@10:     .color            = srt_color_cb,
yading@10:     .font_name        = srt_font_name_cb,
yading@10:     .font_size        = srt_font_size_cb,
yading@10:     .alignment        = srt_alignment_cb,
yading@10:     .cancel_overrides = srt_cancel_overrides_cb,
yading@10:     .move             = srt_move_cb,
yading@10:     .end              = srt_end_cb,
yading@10: };
yading@10: 
yading@10: static int srt_encode_frame(AVCodecContext *avctx,
yading@10:                             unsigned char *buf, int bufsize, const AVSubtitle *sub)
yading@10: {
yading@10:     SRTContext *s = avctx->priv_data;
yading@10:     ASSDialog *dialog;
yading@10:     int i, len, num;
yading@10: 
yading@10:     s->ptr = s->buffer;
yading@10:     s->end = s->ptr + sizeof(s->buffer);
yading@10: 
yading@10:     for (i=0; i<sub->num_rects; i++) {
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 AVERROR(ENOSYS);
yading@10:         }
yading@10: 
yading@10:         dialog = ff_ass_split_dialog(s->ass_ctx, sub->rects[i]->ass, 0, &num);
yading@10:         for (; dialog && num--; dialog++) {
yading@10:             if (avctx->codec->id == AV_CODEC_ID_SRT) {
yading@10:                 int sh, sm, ss, sc = 10 * dialog->start;
yading@10:                 int eh, em, es, ec = 10 * dialog->end;
yading@10:                 sh = sc/3600000;  sc -= 3600000*sh;
yading@10:                 sm = sc/  60000;  sc -=   60000*sm;
yading@10:                 ss = sc/   1000;  sc -=    1000*ss;
yading@10:                 eh = ec/3600000;  ec -= 3600000*eh;
yading@10:                 em = ec/  60000;  ec -=   60000*em;
yading@10:                 es = ec/   1000;  ec -=    1000*es;
yading@10:                 srt_print(s,"%d\r\n%02d:%02d:%02d,%03d --> %02d:%02d:%02d,%03d\r\n",
yading@10:                           ++s->count, sh, sm, ss, sc, eh, em, es, ec);
yading@10:                 s->dialog_start = s->ptr - 2;
yading@10:             }
yading@10:             s->alignment_applied = 0;
yading@10:             srt_style_apply(s, dialog->style);
yading@10:             ff_ass_split_override_codes(&srt_callbacks, s, dialog->text);
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     if (s->ptr == s->buffer)
yading@10:         return 0;
yading@10: 
yading@10:     len = av_strlcpy(buf, s->buffer, bufsize);
yading@10: 
yading@10:     if (len > bufsize-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:     return len;
yading@10: }
yading@10: 
yading@10: static int srt_encode_close(AVCodecContext *avctx)
yading@10: {
yading@10:     SRTContext *s = avctx->priv_data;
yading@10:     ff_ass_split_free(s->ass_ctx);
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: #if CONFIG_SRT_ENCODER
yading@10: /* deprecated encoder */
yading@10: AVCodec ff_srt_encoder = {
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:     .priv_data_size = sizeof(SRTContext),
yading@10:     .init           = srt_encode_init,
yading@10:     .encode_sub     = srt_encode_frame,
yading@10:     .close          = srt_encode_close,
yading@10: };
yading@10: #endif
yading@10: 
yading@10: #if CONFIG_SUBRIP_ENCODER
yading@10: AVCodec ff_subrip_encoder = {
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:     .priv_data_size = sizeof(SRTContext),
yading@10:     .init           = srt_encode_init,
yading@10:     .encode_sub     = srt_encode_frame,
yading@10:     .close          = srt_encode_close,
yading@10: };
yading@10: #endif