| 1 | /* |
| 2 | * SSA/ASS decoder |
| 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.h" |
| 26 | #include "ass_split.h" |
| 27 | #include "libavutil/internal.h" |
| 28 | #include "libavutil/mem.h" |
| 29 | |
| 30 | static av_cold int ass_decode_init(AVCodecContext *avctx) |
| 31 | { |
| 32 | avctx->subtitle_header = av_malloc(avctx->extradata_size + 1); |
| 33 | if (!avctx->subtitle_header) |
| 34 | return AVERROR(ENOMEM); |
| 35 | memcpy(avctx->subtitle_header, avctx->extradata, avctx->extradata_size); |
| 36 | avctx->subtitle_header[avctx->extradata_size] = 0; |
| 37 | avctx->subtitle_header_size = avctx->extradata_size; |
| 38 | avctx->priv_data = ff_ass_split(avctx->extradata); |
| 39 | if(!avctx->priv_data) |
| 40 | return -1; |
| 41 | return 0; |
| 42 | } |
| 43 | |
| 44 | static int ass_decode_close(AVCodecContext *avctx) |
| 45 | { |
| 46 | ff_ass_split_free(avctx->priv_data); |
| 47 | avctx->priv_data = NULL; |
| 48 | return 0; |
| 49 | } |
| 50 | |
| 51 | #if CONFIG_SSA_DECODER |
| 52 | static int ssa_decode_frame(AVCodecContext *avctx, void *data, int *got_sub_ptr, |
| 53 | AVPacket *avpkt) |
| 54 | { |
| 55 | const char *ptr = avpkt->data; |
| 56 | int len, size = avpkt->size; |
| 57 | |
| 58 | while (size > 0) { |
| 59 | int duration; |
| 60 | ASSDialog *dialog = ff_ass_split_dialog(avctx->priv_data, ptr, 0, NULL); |
| 61 | if (!dialog) |
| 62 | return AVERROR_INVALIDDATA; |
| 63 | duration = dialog->end - dialog->start; |
| 64 | len = ff_ass_add_rect(data, ptr, 0, duration, 1); |
| 65 | if (len < 0) |
| 66 | return len; |
| 67 | ptr += len; |
| 68 | size -= len; |
| 69 | } |
| 70 | |
| 71 | *got_sub_ptr = avpkt->size > 0; |
| 72 | return avpkt->size; |
| 73 | } |
| 74 | |
| 75 | AVCodec ff_ssa_decoder = { |
| 76 | .name = "ssa", |
| 77 | .long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"), |
| 78 | .type = AVMEDIA_TYPE_SUBTITLE, |
| 79 | .id = AV_CODEC_ID_SSA, |
| 80 | .init = ass_decode_init, |
| 81 | .decode = ssa_decode_frame, |
| 82 | .close = ass_decode_close, |
| 83 | }; |
| 84 | #endif |
| 85 | |
| 86 | #if CONFIG_ASS_DECODER |
| 87 | static int ass_decode_frame(AVCodecContext *avctx, void *data, int *got_sub_ptr, |
| 88 | AVPacket *avpkt) |
| 89 | { |
| 90 | int ret; |
| 91 | AVSubtitle *sub = data; |
| 92 | const char *ptr = avpkt->data; |
| 93 | static const AVRational ass_tb = {1, 100}; |
| 94 | const int ts_start = av_rescale_q(avpkt->pts, avctx->time_base, ass_tb); |
| 95 | const int ts_duration = av_rescale_q(avpkt->duration, avctx->time_base, ass_tb); |
| 96 | |
| 97 | if (avpkt->size <= 0) |
| 98 | return avpkt->size; |
| 99 | |
| 100 | ret = ff_ass_add_rect(sub, ptr, ts_start, ts_duration, 2); |
| 101 | if (ret < 0) { |
| 102 | if (ret == AVERROR_INVALIDDATA) |
| 103 | av_log(avctx, AV_LOG_ERROR, "Invalid ASS packet\n"); |
| 104 | return ret; |
| 105 | } |
| 106 | |
| 107 | *got_sub_ptr = avpkt->size > 0; |
| 108 | return avpkt->size; |
| 109 | } |
| 110 | |
| 111 | AVCodec ff_ass_decoder = { |
| 112 | .name = "ass", |
| 113 | .long_name = NULL_IF_CONFIG_SMALL("ASS (Advanced SubStation Alpha) subtitle"), |
| 114 | .type = AVMEDIA_TYPE_SUBTITLE, |
| 115 | .id = AV_CODEC_ID_ASS, |
| 116 | .init = ass_decode_init, |
| 117 | .decode = ass_decode_frame, |
| 118 | .close = ass_decode_close, |
| 119 | }; |
| 120 | #endif |