diff options
Diffstat (limited to 'libavcodec/srtenc.c')
| -rw-r--r-- | libavcodec/srtenc.c | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/libavcodec/srtenc.c b/libavcodec/srtenc.c new file mode 100644 index 0000000..56d3397 --- /dev/null +++ b/libavcodec/srtenc.c @@ -0,0 +1,301 @@ +/* + * 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 <stdarg.h> +#include "avcodec.h" +#include "libavutil/avstring.h" +#include "ass_split.h" +#include "ass.h" + + +#define SRT_STACK_SIZE 64 + +typedef struct { + AVCodecContext *avctx; + ASSSplitContext *ass_ctx; + char buffer[2048]; + char *ptr; + char *end; + char *dialog_start; + int count; + 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); + s->ptr += vsnprintf(s->ptr, s->end - s->ptr, 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 = 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); + return s->ass_ctx ? 0 : AVERROR_INVALIDDATA; +} + +static void srt_text_cb(void *priv, const char *text, int len) +{ + SRTContext *s = priv; + av_strlcpy(s->ptr, text, FFMIN(s->end-s->ptr, len+1)); + s->ptr += 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) +{ + SRTContext *s = priv; + char buffer[32]; + int len = snprintf(buffer, sizeof(buffer), + " X1:%03u X2:%03u Y1:%03u Y2:%03u", x1, x2, y1, y2); + if (s->end - s->ptr > len) { + memmove(s->dialog_start+len, s->dialog_start, s->ptr-s->dialog_start+1); + memcpy(s->dialog_start, buffer, len); + s->ptr += len; + } +} + +static void srt_end_cb(void *priv) +{ + srt_stack_push_pop(priv, 0, 1); + srt_print(priv, "\r\n\r\n"); +} + +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 int srt_encode_frame(AVCodecContext *avctx, + unsigned char *buf, int bufsize, void *data) +{ + SRTContext *s = avctx->priv_data; + AVSubtitle *sub = data; + ASSDialog *dialog; + int i, len, num; + + s->ptr = s->buffer; + s->end = s->ptr + sizeof(s->buffer); + + for (i=0; i<sub->num_rects; i++) { + + if (sub->rects[i]->type != SUBTITLE_ASS) { + av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n"); + return AVERROR(ENOSYS); + } + + dialog = ff_ass_split_dialog(s->ass_ctx, sub->rects[i]->ass, 0, &num); + for (; dialog && num--; dialog++) { + int sh, sm, ss, sc = 10 * dialog->start; + int eh, em, es, ec = 10 * dialog->end; + sh = sc/3600000; sc -= 3600000*sh; + sm = sc/ 60000; sc -= 60000*sm; + ss = sc/ 1000; sc -= 1000*ss; + eh = ec/3600000; ec -= 3600000*eh; + em = ec/ 60000; ec -= 60000*em; + es = ec/ 1000; ec -= 1000*es; + srt_print(s,"%d\r\n%02d:%02d:%02d,%03d --> %02d:%02d:%02d,%03d\r\n", + ++s->count, sh, sm, ss, sc, eh, em, es, ec); + s->alignment_applied = 0; + s->dialog_start = s->ptr - 2; + srt_style_apply(s, dialog->style); + ff_ass_split_override_codes(&srt_callbacks, s, dialog->text); + } + } + + if (s->ptr == s->buffer) + return 0; + + len = av_strlcpy(buf, s->buffer, bufsize); + + if (len > bufsize-1) { + av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n"); + return -1; + } + + return len; +} + +static int srt_encode_close(AVCodecContext *avctx) +{ + SRTContext *s = avctx->priv_data; + ff_ass_split_free(s->ass_ctx); + return 0; +} + +AVCodec ff_srt_encoder = { + .name = "srt", + .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"), + .type = AVMEDIA_TYPE_SUBTITLE, + .id = CODEC_ID_SRT, + .priv_data_size = sizeof(SRTContext), + .init = srt_encode_init, + .encode = srt_encode_frame, + .close = srt_encode_close, +}; |
