| 1 | /* |
| 2 | * 3GPP TS 26.245 Timed Text encoder |
| 3 | * Copyright (c) 2012 Philip Langdale <philipl@overt.org> |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 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. |
| 11 | * |
| 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. |
| 16 | * |
| 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 |
| 20 | */ |
| 21 | |
| 22 | #include <stdarg.h> |
| 23 | #include "avcodec.h" |
| 24 | #include "libavutil/avassert.h" |
| 25 | #include "libavutil/avstring.h" |
| 26 | #include "libavutil/intreadwrite.h" |
| 27 | #include "ass_split.h" |
| 28 | #include "ass.h" |
| 29 | |
| 30 | typedef struct { |
| 31 | ASSSplitContext *ass_ctx; |
| 32 | char buffer[2048]; |
| 33 | char *ptr; |
| 34 | char *end; |
| 35 | } MovTextContext; |
| 36 | |
| 37 | |
| 38 | static av_cold int mov_text_encode_init(AVCodecContext *avctx) |
| 39 | { |
| 40 | /* |
| 41 | * For now, we'll use a fixed default style. When we add styling |
| 42 | * support, this will be generated from the ASS style. |
| 43 | */ |
| 44 | static const 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] |
| 49 | // BoxRecord { |
| 50 | 0x00, 0x00, // int16_t top |
| 51 | 0x00, 0x00, // int16_t left |
| 52 | 0x00, 0x00, // int16_t bottom |
| 53 | 0x00, 0x00, // int16_t right |
| 54 | // }; |
| 55 | // StyleRecord { |
| 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] |
| 62 | // }; |
| 63 | // FontTableBox { |
| 64 | 0x00, 0x00, 0x00, 0x12, // uint32_t size |
| 65 | 'f', 't', 'a', 'b', // uint8_t name[4] |
| 66 | 0x00, 0x01, // uint16_t entry-count |
| 67 | // FontRecord { |
| 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] |
| 71 | // }; |
| 72 | // }; |
| 73 | }; |
| 74 | |
| 75 | MovTextContext *s = avctx->priv_data; |
| 76 | |
| 77 | avctx->extradata_size = sizeof text_sample_entry; |
| 78 | avctx->extradata = av_mallocz(avctx->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE); |
| 79 | if (!avctx->extradata) |
| 80 | return AVERROR(ENOMEM); |
| 81 | |
| 82 | memcpy(avctx->extradata, text_sample_entry, avctx->extradata_size); |
| 83 | |
| 84 | s->ass_ctx = ff_ass_split(avctx->subtitle_header); |
| 85 | return s->ass_ctx ? 0 : AVERROR_INVALIDDATA; |
| 86 | } |
| 87 | |
| 88 | static void mov_text_text_cb(void *priv, const char *text, int len) |
| 89 | { |
| 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); |
| 94 | } |
| 95 | |
| 96 | static void mov_text_new_line_cb(void *priv, int forced) |
| 97 | { |
| 98 | MovTextContext *s = priv; |
| 99 | av_assert0(s->end >= s->ptr); |
| 100 | av_strlcpy(s->ptr, "\n", FFMIN(s->end - s->ptr, 2)); |
| 101 | if (s->end > s->ptr) |
| 102 | s->ptr++; |
| 103 | } |
| 104 | |
| 105 | static const ASSCodesCallbacks mov_text_callbacks = { |
| 106 | .text = mov_text_text_cb, |
| 107 | .new_line = mov_text_new_line_cb, |
| 108 | }; |
| 109 | |
| 110 | static int mov_text_encode_frame(AVCodecContext *avctx, unsigned char *buf, |
| 111 | int bufsize, const AVSubtitle *sub) |
| 112 | { |
| 113 | MovTextContext *s = avctx->priv_data; |
| 114 | ASSDialog *dialog; |
| 115 | int i, len, num; |
| 116 | |
| 117 | s->ptr = s->buffer; |
| 118 | s->end = s->ptr + sizeof(s->buffer); |
| 119 | |
| 120 | for (i = 0; i < sub->num_rects; i++) { |
| 121 | |
| 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); |
| 125 | } |
| 126 | |
| 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); |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | if (s->ptr == s->buffer) |
| 134 | return 0; |
| 135 | |
| 136 | AV_WB16(buf, strlen(s->buffer)); |
| 137 | buf += 2; |
| 138 | |
| 139 | len = av_strlcpy(buf, s->buffer, bufsize - 2); |
| 140 | |
| 141 | if (len > bufsize-3) { |
| 142 | av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n"); |
| 143 | return AVERROR(EINVAL); |
| 144 | } |
| 145 | |
| 146 | return len + 2; |
| 147 | } |
| 148 | |
| 149 | static int mov_text_encode_close(AVCodecContext *avctx) |
| 150 | { |
| 151 | MovTextContext *s = avctx->priv_data; |
| 152 | ff_ass_split_free(s->ass_ctx); |
| 153 | return 0; |
| 154 | } |
| 155 | |
| 156 | AVCodec ff_movtext_encoder = { |
| 157 | .name = "mov_text", |
| 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, |
| 165 | }; |