/* * SubRip subtitle 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 "config_components.h" #include <stdarg.h> #include "avcodec.h" #include "libavutil/avstring.h" #include "libavutil/bprint.h" #include "ass_split.h" #include "ass.h" #include "codec_internal.h" #define SRT_STACK_SIZE 64 typedef struct { AVCodecContext *avctx; ASSSplitContext *ass_ctx; AVBPrint buffer; char stack[SRT_STACK_SIZE]; int stack_ptr; int alignment_applied; } SRTContext; #ifdef __GNUC__ __attribute__ ((__format__ (__printf__, 2, 3))) #endif static void srt_print(SRTContext *s, const char *str, ...) { va_list vargs; va_start(vargs, str); av_vbprintf(&s->buffer, str, vargs); va_end(vargs); } static int srt_stack_push(SRTContext *s, const char c) { if (s->stack_ptr >= SRT_STACK_SIZE) return -1; s->stack[s->stack_ptr++] = c; return 0; } static char srt_stack_pop(SRTContext *s) { if (s->stack_ptr <= 0) return 0; return s->stack[--s->stack_ptr]; } static int srt_stack_find(SRTContext *s, const char c) { int i; for (i = s->stack_ptr-1; i >= 0; i--) if (s->stack[i] == c) break; return i; } static void srt_close_tag(SRTContext *s, char tag) { srt_print(s, "</%c%s>", tag, tag == 'f' ? "ont" : ""); } static void srt_stack_push_pop(SRTContext *s, const char c, int close) { if (close) { int i = c ? srt_stack_find(s, c) : 0; if (i < 0) return; while (s->stack_ptr != i) srt_close_tag(s, srt_stack_pop(s)); } else if (srt_stack_push(s, c) < 0) av_log(s->avctx, AV_LOG_ERROR, "tag stack overflow\n"); } static void srt_style_apply(SRTContext *s, const char *style) { ASSStyle *st = ff_ass_style_get(s->ass_ctx, style); if (st) { int c = st->primary_color & 0xFFFFFF; if (st->font_name && strcmp(st->font_name, ASS_DEFAULT_FONT) || st->font_size != ASS_DEFAULT_FONT_SIZE || c != ASS_DEFAULT_COLOR) { srt_print(s, "<font"); if (st->font_name && strcmp(st->font_name, ASS_DEFAULT_FONT)) srt_print(s, " face=\"%s\"", st->font_name); if (st->font_size != ASS_DEFAULT_FONT_SIZE) srt_print(s, " size=\"%d\"", st->font_size); if (c != ASS_DEFAULT_COLOR) srt_print(s, " color=\"#%06x\"", (c & 0xFF0000) >> 16 | c & 0xFF00 | (c & 0xFF) << 16); srt_print(s, ">"); srt_stack_push(s, 'f'); } if (st->bold != ASS_DEFAULT_BOLD) { srt_print(s, "<b>"); srt_stack_push(s, 'b'); } if (st->italic != ASS_DEFAULT_ITALIC) { srt_print(s, "<i>"); srt_stack_push(s, 'i'); } if (st->underline != ASS_DEFAULT_UNDERLINE) { srt_print(s, "<u>"); srt_stack_push(s, 'u'); } if (st->alignment != ASS_DEFAULT_ALIGNMENT) { srt_print(s, "{\\an%d}", st->alignment); s->alignment_applied = 1; } } } static av_cold int srt_encode_init(AVCodecContext *avctx) { SRTContext *s = avctx->priv_data; s->avctx = avctx; s->ass_ctx = ff_ass_split(avctx->subtitle_header); av_bprint_init(&s->buffer, 0, AV_BPRINT_SIZE_UNLIMITED); return s->ass_ctx ? 0 : AVERROR_INVALIDDATA; } static void srt_text_cb(void *priv, const char *text, int len) { SRTContext *s = priv; av_bprint_append_data(&s->buffer, text, len); } static void srt_new_line_cb(void *priv, int forced) { srt_print(priv, "\r\n"); } static void srt_style_cb(void *priv, char style, int close) { srt_stack_push_pop(priv, style, close); if (!close) srt_print(priv, "<%c>", style); } static void srt_color_cb(void *priv, unsigned int color, unsigned int color_id) { if (color_id > 1) return; srt_stack_push_pop(priv, 'f', color == 0xFFFFFFFF); if (color != 0xFFFFFFFF) srt_print(priv, "<font color=\"#%06x\">", (color & 0xFF0000) >> 16 | color & 0xFF00 | (color & 0xFF) << 16); } static void srt_font_name_cb(void *priv, const char *name) { srt_stack_push_pop(priv, 'f', !name); if (name) srt_print(priv, "<font face=\"%s\">", name); } static void srt_font_size_cb(void *priv, int size) { srt_stack_push_pop(priv, 'f', size < 0); if (size >= 0) srt_print(priv, "<font size=\"%d\">", size); } static void srt_alignment_cb(void *priv, int alignment) { SRTContext *s = priv; if (!s->alignment_applied && alignment >= 0) { srt_print(s, "{\\an%d}", alignment); s->alignment_applied = 1; } } static void srt_cancel_overrides_cb(void *priv, const char *style) { srt_stack_push_pop(priv, 0, 1); srt_style_apply(priv, style); } static void srt_move_cb(void *priv, int x1, int y1, int x2, int y2, int t1, int t2) { // TODO: add a AV_PKT_DATA_SUBTITLE_POSITION side data when a new subtitles // encoding API passing the AVPacket is available. } static void srt_end_cb(void *priv) { srt_stack_push_pop(priv, 0, 1); } static const ASSCodesCallbacks srt_callbacks = { .text = srt_text_cb, .new_line = srt_new_line_cb, .style = srt_style_cb, .color = srt_color_cb, .font_name = srt_font_name_cb, .font_size = srt_font_size_cb, .alignment = srt_alignment_cb, .cancel_overrides = srt_cancel_overrides_cb, .move = srt_move_cb, .end = srt_end_cb, }; static const ASSCodesCallbacks text_callbacks = { .text = srt_text_cb, .new_line = srt_new_line_cb, }; static int encode_frame(AVCodecContext *avctx, unsigned char *buf, int bufsize, const AVSubtitle *sub, const ASSCodesCallbacks *cb) { SRTContext *s = avctx->priv_data; ASSDialog *dialog; int i; av_bprint_clear(&s->buffer); for (i=0; i<sub->num_rects; i++) { const char *ass = sub->rects[i]->ass; if (sub->rects[i]->type != SUBTITLE_ASS) { av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n"); return AVERROR(EINVAL); } dialog = ff_ass_split_dialog(s->ass_ctx, ass); if (!dialog) return AVERROR(ENOMEM); s->alignment_applied = 0; if (avctx->codec_id == AV_CODEC_ID_SUBRIP) srt_style_apply(s, dialog->style); ff_ass_split_override_codes(cb, s, dialog->text); ff_ass_free_dialog(&dialog); } if (!av_bprint_is_complete(&s->buffer)) return AVERROR(ENOMEM); if (!s->buffer.len) return 0; if (s->buffer.len > bufsize) { av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n"); return AVERROR_BUFFER_TOO_SMALL; } memcpy(buf, s->buffer.str, s->buffer.len); return s->buffer.len; } static int srt_encode_frame(AVCodecContext *avctx, unsigned char *buf, int bufsize, const AVSubtitle *sub) { return encode_frame(avctx, buf, bufsize, sub, &srt_callbacks); } static int text_encode_frame(AVCodecContext *avctx, unsigned char *buf, int bufsize, const AVSubtitle *sub) { return encode_frame(avctx, buf, bufsize, sub, &text_callbacks); } static int srt_encode_close(AVCodecContext *avctx) { SRTContext *s = avctx->priv_data; ff_ass_split_free(s->ass_ctx); av_bprint_finalize(&s->buffer, NULL); return 0; } #if CONFIG_SRT_ENCODER /* deprecated encoder */ const FFCodec ff_srt_encoder = { .p.name = "srt", CODEC_LONG_NAME("SubRip subtitle"), .p.type = AVMEDIA_TYPE_SUBTITLE, .p.id = AV_CODEC_ID_SUBRIP, .priv_data_size = sizeof(SRTContext), .init = srt_encode_init, FF_CODEC_ENCODE_SUB_CB(srt_encode_frame), .close = srt_encode_close, }; #endif #if CONFIG_SUBRIP_ENCODER const FFCodec ff_subrip_encoder = { .p.name = "subrip", CODEC_LONG_NAME("SubRip subtitle"), .p.type = AVMEDIA_TYPE_SUBTITLE, .p.id = AV_CODEC_ID_SUBRIP, .priv_data_size = sizeof(SRTContext), .init = srt_encode_init, FF_CODEC_ENCODE_SUB_CB(srt_encode_frame), .close = srt_encode_close, }; #endif #if CONFIG_TEXT_ENCODER const FFCodec ff_text_encoder = { .p.name = "text", CODEC_LONG_NAME("Raw text subtitle"), .p.type = AVMEDIA_TYPE_SUBTITLE, .p.id = AV_CODEC_ID_TEXT, .priv_data_size = sizeof(SRTContext), .init = srt_encode_init, FF_CODEC_ENCODE_SUB_CB(text_encode_frame), .close = srt_encode_close, }; #endif