| 1 | /* |
| 2 | * SSA/ASS encoder |
| 3 | * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.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 <string.h> |
| 23 | |
| 24 | #include "avcodec.h" |
| 25 | #include "ass_split.h" |
| 26 | #include "ass.h" |
| 27 | #include "libavutil/avstring.h" |
| 28 | #include "libavutil/internal.h" |
| 29 | #include "libavutil/mem.h" |
| 30 | |
| 31 | typedef struct { |
| 32 | int id; ///< current event id, ReadOrder field |
| 33 | } ASSEncodeContext; |
| 34 | |
| 35 | static av_cold int ass_encode_init(AVCodecContext *avctx) |
| 36 | { |
| 37 | avctx->extradata = av_malloc(avctx->subtitle_header_size + 1); |
| 38 | if (!avctx->extradata) |
| 39 | return AVERROR(ENOMEM); |
| 40 | memcpy(avctx->extradata, avctx->subtitle_header, avctx->subtitle_header_size); |
| 41 | avctx->extradata_size = avctx->subtitle_header_size; |
| 42 | avctx->extradata[avctx->extradata_size] = 0; |
| 43 | return 0; |
| 44 | } |
| 45 | |
| 46 | static int ass_encode_frame(AVCodecContext *avctx, |
| 47 | unsigned char *buf, int bufsize, |
| 48 | const AVSubtitle *sub) |
| 49 | { |
| 50 | ASSEncodeContext *s = avctx->priv_data; |
| 51 | int i, len, total_len = 0; |
| 52 | |
| 53 | for (i=0; i<sub->num_rects; i++) { |
| 54 | char ass_line[2048]; |
| 55 | const char *ass = sub->rects[i]->ass; |
| 56 | |
| 57 | if (sub->rects[i]->type != SUBTITLE_ASS) { |
| 58 | av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n"); |
| 59 | return -1; |
| 60 | } |
| 61 | |
| 62 | if (strncmp(ass, "Dialogue: ", 10)) { |
| 63 | av_log(avctx, AV_LOG_ERROR, "AVSubtitle rectangle ass \"%s\"" |
| 64 | " does not look like a SSA markup\n", ass); |
| 65 | return AVERROR_INVALIDDATA; |
| 66 | } |
| 67 | |
| 68 | if (avctx->codec->id == AV_CODEC_ID_ASS) { |
| 69 | long int layer; |
| 70 | char *p; |
| 71 | |
| 72 | if (i > 0) { |
| 73 | av_log(avctx, AV_LOG_ERROR, "ASS encoder supports only one " |
| 74 | "ASS rectangle field.\n"); |
| 75 | return AVERROR_INVALIDDATA; |
| 76 | } |
| 77 | |
| 78 | ass += 10; // skip "Dialogue: " |
| 79 | /* parse Layer field. If it's a Marked field, the content |
| 80 | * will be "Marked=N" instead of the layer num, so we will |
| 81 | * have layer=0, which is fine. */ |
| 82 | layer = strtol(ass, &p, 10); |
| 83 | |
| 84 | #define SKIP_ENTRY(ptr) do { \ |
| 85 | char *sep = strchr(ptr, ','); \ |
| 86 | if (sep) \ |
| 87 | ptr = sep + 1; \ |
| 88 | } while (0) |
| 89 | |
| 90 | SKIP_ENTRY(p); // skip layer or marked |
| 91 | SKIP_ENTRY(p); // skip start timestamp |
| 92 | SKIP_ENTRY(p); // skip end timestamp |
| 93 | snprintf(ass_line, sizeof(ass_line), "%d,%ld,%s", ++s->id, layer, p); |
| 94 | ass_line[strcspn(ass_line, "\r\n")] = 0; |
| 95 | ass = ass_line; |
| 96 | } |
| 97 | len = av_strlcpy(buf+total_len, ass, bufsize-total_len); |
| 98 | |
| 99 | if (len > bufsize-total_len-1) { |
| 100 | av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n"); |
| 101 | return -1; |
| 102 | } |
| 103 | |
| 104 | total_len += len; |
| 105 | } |
| 106 | |
| 107 | return total_len; |
| 108 | } |
| 109 | |
| 110 | #if CONFIG_SSA_ENCODER |
| 111 | AVCodec ff_ssa_encoder = { |
| 112 | .name = "ssa", |
| 113 | .long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"), |
| 114 | .type = AVMEDIA_TYPE_SUBTITLE, |
| 115 | .id = AV_CODEC_ID_SSA, |
| 116 | .init = ass_encode_init, |
| 117 | .encode_sub = ass_encode_frame, |
| 118 | .priv_data_size = sizeof(ASSEncodeContext), |
| 119 | }; |
| 120 | #endif |
| 121 | |
| 122 | #if CONFIG_ASS_ENCODER |
| 123 | AVCodec ff_ass_encoder = { |
| 124 | .name = "ass", |
| 125 | .long_name = NULL_IF_CONFIG_SMALL("ASS (Advanced SubStation Alpha) subtitle"), |
| 126 | .type = AVMEDIA_TYPE_SUBTITLE, |
| 127 | .id = AV_CODEC_ID_ASS, |
| 128 | .init = ass_encode_init, |
| 129 | .encode_sub = ass_encode_frame, |
| 130 | .priv_data_size = sizeof(ASSEncodeContext), |
| 131 | }; |
| 132 | #endif |