/* * 3GPP TS 26.245 Timed Text encoder * Copyright (c) 2012 Philip Langdale <philipl@overt.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/avassert.h" #include "libavutil/avstring.h" #include "libavutil/intreadwrite.h" #include "ass_split.h" #include "ass.h" typedef struct { ASSSplitContext *ass_ctx; char buffer[2048]; char *ptr; char *end; } MovTextContext; static av_cold int mov_text_encode_init(AVCodecContext *avctx) { /* * For now, we'll use a fixed default style. When we add styling * support, this will be generated from the ASS style. */ static uint8_t text_sample_entry[] = { 0x00, 0x00, 0x00, 0x00, // uint32_t displayFlags 0x01, // int8_t horizontal-justification 0xFF, // int8_t vertical-justification 0x00, 0x00, 0x00, 0x00, // uint8_t background-color-rgba[4] // BoxRecord { 0x00, 0x00, // int16_t top 0x00, 0x00, // int16_t left 0x00, 0x00, // int16_t bottom 0x00, 0x00, // int16_t right // }; // StyleRecord { 0x00, 0x00, // uint16_t startChar 0x00, 0x00, // uint16_t endChar 0x00, 0x01, // uint16_t font-ID 0x00, // uint8_t face-style-flags 0x12, // uint8_t font-size 0xFF, 0xFF, 0xFF, 0xFF, // uint8_t text-color-rgba[4] // }; // FontTableBox { 0x00, 0x00, 0x00, 0x12, // uint32_t size 'f', 't', 'a', 'b', // uint8_t name[4] 0x00, 0x01, // uint16_t entry-count // FontRecord { 0x00, 0x01, // uint16_t font-ID 0x05, // uint8_t font-name-length 'S', 'e', 'r', 'i', 'f',// uint8_t font[font-name-length] // }; // }; }; MovTextContext *s = avctx->priv_data; avctx->extradata_size = sizeof text_sample_entry; avctx->extradata = av_mallocz(avctx->extradata_size); if (!avctx->extradata) return AVERROR(ENOMEM); memcpy(avctx->extradata, text_sample_entry, avctx->extradata_size); s->ass_ctx = ff_ass_split(avctx->subtitle_header); return s->ass_ctx ? 0 : AVERROR_INVALIDDATA; } static void mov_text_text_cb(void *priv, const char *text, int len) { MovTextContext *s = priv; av_assert0(s->end >= s->ptr); av_strlcpy(s->ptr, text, FFMIN(s->end - s->ptr, len + 1)); s->ptr += FFMIN(s->end - s->ptr, len); } static void mov_text_new_line_cb(void *priv, int forced) { MovTextContext *s = priv; av_assert0(s->end >= s->ptr); av_strlcpy(s->ptr, "\n", FFMIN(s->end - s->ptr, 2)); if (s->end > s->ptr) s->ptr++; } static const ASSCodesCallbacks mov_text_callbacks = { .text = mov_text_text_cb, .new_line = mov_text_new_line_cb, }; static int mov_text_encode_frame(AVCodecContext *avctx, unsigned char *buf, int bufsize, const AVSubtitle *sub) { MovTextContext *s = avctx->priv_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++) { ff_ass_split_override_codes(&mov_text_callbacks, s, dialog->text); } } if (s->ptr == s->buffer) return 0; AV_WB16(buf, strlen(s->buffer)); buf += 2; len = av_strlcpy(buf, s->buffer, bufsize - 2); if (len > bufsize-3) { av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n"); return AVERROR(EINVAL); } return len + 2; } static int mov_text_encode_close(AVCodecContext *avctx) { MovTextContext *s = avctx->priv_data; ff_ass_split_free(s->ass_ctx); return 0; } AVCodec ff_movtext_encoder = { .name = "mov_text", .long_name = NULL_IF_CONFIG_SMALL("3GPP Timed Text subtitle"), .type = AVMEDIA_TYPE_SUBTITLE, .id = AV_CODEC_ID_MOV_TEXT, .priv_data_size = sizeof(MovTextContext), .init = mov_text_encode_init, .encode_sub = mov_text_encode_frame, .close = mov_text_encode_close, };