| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * XSUB subtitle decoder | ||
| 3 | * Copyright (c) 2007 Reimar Döffinger | ||
| 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 "libavutil/mathematics.h" | ||
| 23 | #include "libavutil/imgutils.h" | ||
| 24 | #include "libavutil/mem.h" | ||
| 25 | #include "avcodec.h" | ||
| 26 | #include "get_bits.h" | ||
| 27 | #include "bytestream.h" | ||
| 28 | #include "codec_internal.h" | ||
| 29 | |||
| 30 | ✗ | static av_cold int decode_init(AVCodecContext *avctx) { | |
| 31 | ✗ | avctx->pix_fmt = AV_PIX_FMT_PAL8; | |
| 32 | ✗ | return 0; | |
| 33 | } | ||
| 34 | |||
| 35 | static const uint8_t tc_offsets[9] = { 0, 1, 3, 4, 6, 7, 9, 10, 11 }; | ||
| 36 | static const uint8_t tc_muls[9] = { 10, 6, 10, 6, 10, 10, 10, 10, 1 }; | ||
| 37 | |||
| 38 | ✗ | static int64_t parse_timecode(const uint8_t *buf, int64_t packet_time) { | |
| 39 | int i; | ||
| 40 | ✗ | int64_t ms = 0; | |
| 41 | ✗ | if (buf[2] != ':' || buf[5] != ':' || buf[8] != '.') | |
| 42 | ✗ | return AV_NOPTS_VALUE; | |
| 43 | ✗ | for (i = 0; i < sizeof(tc_offsets); i++) { | |
| 44 | ✗ | uint8_t c = buf[tc_offsets[i]] - '0'; | |
| 45 | ✗ | if (c > 9) return AV_NOPTS_VALUE; | |
| 46 | ✗ | ms = (ms + c) * tc_muls[i]; | |
| 47 | } | ||
| 48 | ✗ | return ms - packet_time; | |
| 49 | } | ||
| 50 | |||
| 51 | ✗ | static int decode_frame(AVCodecContext *avctx, AVSubtitle *sub, | |
| 52 | int *got_sub_ptr, const AVPacket *avpkt) | ||
| 53 | { | ||
| 54 | ✗ | const uint8_t *buf = avpkt->data; | |
| 55 | ✗ | int buf_size = avpkt->size; | |
| 56 | AVSubtitleRect *rect; | ||
| 57 | ✗ | const uint8_t *buf_end = buf + buf_size; | |
| 58 | uint8_t *bitmap; | ||
| 59 | int w, h, x, y, i, ret; | ||
| 60 | ✗ | int64_t packet_time = 0; | |
| 61 | GetBitContext gb; | ||
| 62 | ✗ | int has_alpha = avctx->codec_tag == MKTAG('D','X','S','A'); | |
| 63 | int64_t start_display_time, end_display_time; | ||
| 64 | |||
| 65 | // check that at least header fits | ||
| 66 | ✗ | if (buf_size < 27 + 7 * 2 + 4 * (3 + has_alpha)) { | |
| 67 | ✗ | av_log(avctx, AV_LOG_ERROR, "coded frame size %d too small\n", buf_size); | |
| 68 | ✗ | return -1; | |
| 69 | } | ||
| 70 | |||
| 71 | // read start and end time | ||
| 72 | ✗ | if (buf[0] != '[' || buf[13] != '-' || buf[26] != ']') { | |
| 73 | ✗ | av_log(avctx, AV_LOG_ERROR, "invalid time code\n"); | |
| 74 | ✗ | return -1; | |
| 75 | } | ||
| 76 | ✗ | if (avpkt->pts != AV_NOPTS_VALUE) | |
| 77 | ✗ | packet_time = av_rescale_q(avpkt->pts, AV_TIME_BASE_Q, (AVRational){1, 1000}); | |
| 78 | |||
| 79 | ✗ | sub->start_display_time = start_display_time = parse_timecode(buf + 1, packet_time); | |
| 80 | ✗ | sub->end_display_time = end_display_time = parse_timecode(buf + 14, packet_time); | |
| 81 | ✗ | if (sub->start_display_time != start_display_time || | |
| 82 | ✗ | sub-> end_display_time != end_display_time) { | |
| 83 | ✗ | av_log(avctx, AV_LOG_ERROR, "time code not representable in 32bit\n"); | |
| 84 | ✗ | return -1; | |
| 85 | } | ||
| 86 | ✗ | buf += 27; | |
| 87 | |||
| 88 | // read header | ||
| 89 | ✗ | w = bytestream_get_le16(&buf); | |
| 90 | ✗ | h = bytestream_get_le16(&buf); | |
| 91 | ✗ | if (av_image_check_size(w, h, 0, avctx) < 0) | |
| 92 | ✗ | return -1; | |
| 93 | ✗ | x = bytestream_get_le16(&buf); | |
| 94 | ✗ | y = bytestream_get_le16(&buf); | |
| 95 | // skip bottom right position, it gives no new information | ||
| 96 | ✗ | bytestream_get_le16(&buf); | |
| 97 | ✗ | bytestream_get_le16(&buf); | |
| 98 | // The following value is supposed to indicate the start offset | ||
| 99 | // (relative to the palette) of the data for the second field, | ||
| 100 | // however there are files in which it has a bogus value and thus | ||
| 101 | // we just ignore it | ||
| 102 | ✗ | bytestream_get_le16(&buf); | |
| 103 | |||
| 104 | ✗ | if (buf_end - buf < h + 3*4) | |
| 105 | ✗ | return AVERROR_INVALIDDATA; | |
| 106 | |||
| 107 | // allocate sub and set values | ||
| 108 | ✗ | sub->rects = av_mallocz(sizeof(*sub->rects)); | |
| 109 | ✗ | if (!sub->rects) | |
| 110 | ✗ | return AVERROR(ENOMEM); | |
| 111 | |||
| 112 | ✗ | sub->rects[0] = rect = av_mallocz(sizeof(*sub->rects[0])); | |
| 113 | ✗ | if (!sub->rects[0]) | |
| 114 | ✗ | return AVERROR(ENOMEM); | |
| 115 | ✗ | sub->num_rects = 1; | |
| 116 | ✗ | rect->x = x; rect->y = y; | |
| 117 | ✗ | rect->w = w; rect->h = h; | |
| 118 | ✗ | rect->type = SUBTITLE_BITMAP; | |
| 119 | ✗ | rect->linesize[0] = w; | |
| 120 | ✗ | rect->data[0] = av_malloc(w * h); | |
| 121 | ✗ | rect->nb_colors = 4; | |
| 122 | ✗ | rect->data[1] = av_mallocz(AVPALETTE_SIZE); | |
| 123 | ✗ | if (!rect->data[0] || !rect->data[1]) | |
| 124 | ✗ | return AVERROR(ENOMEM); | |
| 125 | |||
| 126 | // read palette | ||
| 127 | ✗ | for (i = 0; i < rect->nb_colors; i++) | |
| 128 | ✗ | ((uint32_t*)rect->data[1])[i] = bytestream_get_be24(&buf); | |
| 129 | |||
| 130 | ✗ | if (!has_alpha) { | |
| 131 | // make all except background (first entry) non-transparent | ||
| 132 | ✗ | for (i = 1; i < rect->nb_colors; i++) | |
| 133 | ✗ | ((uint32_t *)rect->data[1])[i] |= 0xff000000; | |
| 134 | } else { | ||
| 135 | ✗ | for (i = 0; i < rect->nb_colors; i++) | |
| 136 | ✗ | ((uint32_t *)rect->data[1])[i] |= (unsigned)*buf++ << 24; | |
| 137 | } | ||
| 138 | |||
| 139 | // process RLE-compressed data | ||
| 140 | ✗ | if ((ret = init_get_bits8(&gb, buf, buf_end - buf)) < 0) | |
| 141 | ✗ | return ret; | |
| 142 | ✗ | bitmap = rect->data[0]; | |
| 143 | ✗ | for (y = 0; y < h; y++) { | |
| 144 | // interlaced: do odd lines | ||
| 145 | ✗ | if (y == (h + 1) / 2) bitmap = rect->data[0] + w; | |
| 146 | ✗ | for (x = 0; x < w; ) { | |
| 147 | ✗ | int log2 = ff_log2_tab[show_bits(&gb, 8)]; | |
| 148 | ✗ | int run = get_bits(&gb, 14 - 4 * (log2 >> 1)); | |
| 149 | ✗ | int color = get_bits(&gb, 2); | |
| 150 | ✗ | run = FFMIN(run, w - x); | |
| 151 | // run length 0 means till end of row | ||
| 152 | ✗ | if (!run) run = w - x; | |
| 153 | ✗ | memset(bitmap, color, run); | |
| 154 | ✗ | bitmap += run; | |
| 155 | ✗ | x += run; | |
| 156 | } | ||
| 157 | // interlaced, skip every second line | ||
| 158 | ✗ | bitmap += w; | |
| 159 | ✗ | align_get_bits(&gb); | |
| 160 | } | ||
| 161 | ✗ | *got_sub_ptr = 1; | |
| 162 | ✗ | return buf_size; | |
| 163 | } | ||
| 164 | |||
| 165 | const FFCodec ff_xsub_decoder = { | ||
| 166 | .p.name = "xsub", | ||
| 167 | CODEC_LONG_NAME("XSUB"), | ||
| 168 | .p.type = AVMEDIA_TYPE_SUBTITLE, | ||
| 169 | .p.id = AV_CODEC_ID_XSUB, | ||
| 170 | .init = decode_init, | ||
| 171 | FF_CODEC_DECODE_SUB_CB(decode_frame), | ||
| 172 | }; | ||
| 173 |