2 * 3GPP TS 26.245 Timed Text encoder
3 * Copyright (c) 2012 Philip Langdale <philipl@overt.org>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 #include "libavutil/avassert.h"
25 #include "libavutil/avstring.h"
26 #include "libavutil/intreadwrite.h"
27 #include "ass_split.h"
31 ASSSplitContext *ass_ctx;
38 static av_cold int mov_text_encode_init(AVCodecContext *avctx)
41 * For now, we'll use a fixed default style. When we add styling
42 * support, this will be generated from the ASS style.
44 static uint8_t text_sample_entry[] = {
45 0x00, 0x00, 0x00, 0x00, // uint32_t displayFlags
46 0x01, // int8_t horizontal-justification
47 0xFF, // int8_t vertical-justification
48 0x00, 0x00, 0x00, 0x00, // uint8_t background-color-rgba[4]
50 0x00, 0x00, // int16_t top
51 0x00, 0x00, // int16_t left
52 0x00, 0x00, // int16_t bottom
53 0x00, 0x00, // int16_t right
56 0x00, 0x00, // uint16_t startChar
57 0x00, 0x00, // uint16_t endChar
58 0x00, 0x01, // uint16_t font-ID
59 0x00, // uint8_t face-style-flags
60 0x12, // uint8_t font-size
61 0xFF, 0xFF, 0xFF, 0xFF, // uint8_t text-color-rgba[4]
64 0x00, 0x00, 0x00, 0x12, // uint32_t size
65 'f', 't', 'a', 'b', // uint8_t name[4]
66 0x00, 0x01, // uint16_t entry-count
68 0x00, 0x01, // uint16_t font-ID
69 0x05, // uint8_t font-name-length
70 'S', 'e', 'r', 'i', 'f',// uint8_t font[font-name-length]
75 MovTextContext *s = avctx->priv_data;
77 avctx->extradata_size = sizeof text_sample_entry;
78 avctx->extradata = av_mallocz(avctx->extradata_size);
79 if (!avctx->extradata)
80 return AVERROR(ENOMEM);
82 memcpy(avctx->extradata, text_sample_entry, avctx->extradata_size);
84 s->ass_ctx = ff_ass_split(avctx->subtitle_header);
85 return s->ass_ctx ? 0 : AVERROR_INVALIDDATA;
88 static void mov_text_text_cb(void *priv, const char *text, int len)
90 MovTextContext *s = priv;
91 av_assert0(s->end >= s->ptr);
92 av_strlcpy(s->ptr, text, FFMIN(s->end - s->ptr, len + 1));
93 s->ptr += FFMIN(s->end - s->ptr, len);
96 static void mov_text_new_line_cb(void *priv, int forced)
98 MovTextContext *s = priv;
99 av_assert0(s->end >= s->ptr);
100 av_strlcpy(s->ptr, "\n", FFMIN(s->end - s->ptr, 2));
105 static const ASSCodesCallbacks mov_text_callbacks = {
106 .text = mov_text_text_cb,
107 .new_line = mov_text_new_line_cb,
110 static int mov_text_encode_frame(AVCodecContext *avctx, unsigned char *buf,
111 int bufsize, const AVSubtitle *sub)
113 MovTextContext *s = avctx->priv_data;
118 s->end = s->ptr + sizeof(s->buffer);
120 for (i = 0; i < sub->num_rects; i++) {
122 if (sub->rects[i]->type != SUBTITLE_ASS) {
123 av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n");
124 return AVERROR(ENOSYS);
127 dialog = ff_ass_split_dialog(s->ass_ctx, sub->rects[i]->ass, 0, &num);
128 for (; dialog && num--; dialog++) {
129 ff_ass_split_override_codes(&mov_text_callbacks, s, dialog->text);
133 if (s->ptr == s->buffer)
136 AV_WB16(buf, strlen(s->buffer));
139 len = av_strlcpy(buf, s->buffer, bufsize - 2);
141 if (len > bufsize-3) {
142 av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n");
143 return AVERROR(EINVAL);
149 static int mov_text_encode_close(AVCodecContext *avctx)
151 MovTextContext *s = avctx->priv_data;
152 ff_ass_split_free(s->ass_ctx);
156 AVCodec ff_movtext_encoder = {
158 .long_name = NULL_IF_CONFIG_SMALL("3GPP Timed Text subtitle"),
159 .type = AVMEDIA_TYPE_SUBTITLE,
160 .id = AV_CODEC_ID_MOV_TEXT,
161 .priv_data_size = sizeof(MovTextContext),
162 .init = mov_text_encode_init,
163 .encode_sub = mov_text_encode_frame,
164 .close = mov_text_encode_close,