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/avstring.h"
25 #include "libavutil/intreadwrite.h"
26 #include "ass_split.h"
30 ASSSplitContext *ass_ctx;
37 static av_cold int mov_text_encode_init(AVCodecContext *avctx)
40 * For now, we'll use a fixed default style. When we add styling
41 * support, this will be generated from the ASS style.
43 static uint8_t text_sample_entry[] = {
44 0x00, 0x00, 0x00, 0x00, // uint32_t displayFlags
45 0x01, // int8_t horizontal-justification
46 0xFF, // int8_t vertical-justification
47 0x00, 0x00, 0x00, 0x00, // uint8_t background-color-rgba[4]
49 0x00, 0x00, // int16_t top
50 0x00, 0x00, // int16_t left
51 0x00, 0x00, // int16_t bottom
52 0x00, 0x00, // int16_t right
55 0x00, 0x00, // uint16_t startChar
56 0x00, 0x00, // uint16_t endChar
57 0x00, 0x01, // uint16_t font-ID
58 0x00, // uint8_t face-style-flags
59 0x12, // uint8_t font-size
60 0xFF, 0xFF, 0xFF, 0xFF, // uint8_t text-color-rgba[4]
63 0x00, 0x00, 0x00, 0x12, // uint32_t size
64 'f', 't', 'a', 'b', // uint8_t name[4]
65 0x00, 0x01, // uint16_t entry-count
67 0x00, 0x01, // uint16_t font-ID
68 0x05, // uint8_t font-name-length
69 'S', 'e', 'r', 'i', 'f',// uint8_t font[font-name-length]
74 MovTextContext *s = avctx->priv_data;
76 avctx->extradata_size = sizeof text_sample_entry;
77 avctx->extradata = av_mallocz(avctx->extradata_size);
78 if (!avctx->extradata)
79 return AVERROR(ENOMEM);
81 memcpy(avctx->extradata, text_sample_entry, avctx->extradata_size);
83 s->ass_ctx = ff_ass_split(avctx->subtitle_header);
84 return s->ass_ctx ? 0 : AVERROR_INVALIDDATA;
87 static void mov_text_text_cb(void *priv, const char *text, int len)
89 MovTextContext *s = priv;
90 av_strlcpy(s->ptr, text, FFMIN(s->end - s->ptr, len + 1));
94 static void mov_text_new_line_cb(void *priv, int forced)
96 MovTextContext *s = priv;
97 av_strlcpy(s->ptr, "\n", FFMIN(s->end - s->ptr, 2));
101 static const ASSCodesCallbacks mov_text_callbacks = {
102 .text = mov_text_text_cb,
103 .new_line = mov_text_new_line_cb,
106 static int mov_text_encode_frame(AVCodecContext *avctx, unsigned char *buf,
107 int bufsize, const AVSubtitle *sub)
109 MovTextContext *s = avctx->priv_data;
114 s->end = s->ptr + sizeof(s->buffer);
116 for (i = 0; i < sub->num_rects; i++) {
118 if (sub->rects[i]->type != SUBTITLE_ASS) {
119 av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n");
120 return AVERROR(ENOSYS);
123 dialog = ff_ass_split_dialog(s->ass_ctx, sub->rects[i]->ass, 0, &num);
124 for (; dialog && num--; dialog++) {
125 ff_ass_split_override_codes(&mov_text_callbacks, s, dialog->text);
129 if (s->ptr == s->buffer)
132 AV_WB16(buf, strlen(s->buffer));
135 len = av_strlcpy(buf, s->buffer, bufsize - 2);
137 if (len > bufsize-3) {
138 av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n");
139 return AVERROR(EINVAL);
145 static int mov_text_encode_close(AVCodecContext *avctx)
147 MovTextContext *s = avctx->priv_data;
148 ff_ass_split_free(s->ass_ctx);
152 AVCodec ff_movtext_encoder = {
154 .long_name = NULL_IF_CONFIG_SMALL("3GPP Timed Text subtitle"),
155 .type = AVMEDIA_TYPE_SUBTITLE,
156 .id = AV_CODEC_ID_MOV_TEXT,
157 .priv_data_size = sizeof(MovTextContext),
158 .init = mov_text_encode_init,
159 .encode_sub = mov_text_encode_frame,
160 .close = mov_text_encode_close,