1/* 2 * Copyright (c) 2012-2013 Cl��ment B��sch <u pkh me> 3 * 4 * This file is part of FFmpeg. 5 * 6 * FFmpeg is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * FFmpeg is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with FFmpeg; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21#include "avformat.h" 22#include "subtitles.h" 23#include "libavutil/avassert.h" 24#include "libavutil/avstring.h" 25 26AVPacket *ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q, 27 const uint8_t *event, int len, int merge) 28{ 29 AVPacket *subs, *sub; 30 31 if (merge && q->nb_subs > 0) { 32 /* merge with previous event */ 33 34 int old_len; 35 sub = &q->subs[q->nb_subs - 1]; 36 old_len = sub->size; 37 if (av_grow_packet(sub, len) < 0) 38 return NULL; 39 memcpy(sub->data + old_len, event, len); 40 } else { 41 /* new event */ 42 43 if (q->nb_subs >= INT_MAX/sizeof(*q->subs) - 1) 44 return NULL; 45 subs = av_fast_realloc(q->subs, &q->allocated_size, 46 (q->nb_subs + 1) * sizeof(*q->subs)); 47 if (!subs) 48 return NULL; 49 q->subs = subs; 50 sub = &subs[q->nb_subs++]; 51 if (av_new_packet(sub, len) < 0) 52 return NULL; 53 sub->flags |= AV_PKT_FLAG_KEY; 54 sub->pts = sub->dts = 0; 55 memcpy(sub->data, event, len); 56 } 57 return sub; 58} 59 60static int cmp_pkt_sub_ts_pos(const void *a, const void *b) 61{ 62 const AVPacket *s1 = a; 63 const AVPacket *s2 = b; 64 if (s1->pts == s2->pts) { 65 if (s1->pos == s2->pos) 66 return 0; 67 return s1->pos > s2->pos ? 1 : -1; 68 } 69 return s1->pts > s2->pts ? 1 : -1; 70} 71 72static int cmp_pkt_sub_pos_ts(const void *a, const void *b) 73{ 74 const AVPacket *s1 = a; 75 const AVPacket *s2 = b; 76 if (s1->pos == s2->pos) { 77 if (s1->pts == s2->pts) 78 return 0; 79 return s1->pts > s2->pts ? 1 : -1; 80 } 81 return s1->pos > s2->pos ? 1 : -1; 82} 83 84void ff_subtitles_queue_finalize(FFDemuxSubtitlesQueue *q) 85{ 86 int i; 87 88 qsort(q->subs, q->nb_subs, sizeof(*q->subs), 89 q->sort == SUB_SORT_TS_POS ? cmp_pkt_sub_ts_pos 90 : cmp_pkt_sub_pos_ts); 91 for (i = 0; i < q->nb_subs; i++) 92 if (q->subs[i].duration == -1 && i < q->nb_subs - 1) 93 q->subs[i].duration = q->subs[i + 1].pts - q->subs[i].pts; 94} 95 96int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt) 97{ 98 AVPacket *sub = q->subs + q->current_sub_idx; 99 100 if (q->current_sub_idx == q->nb_subs) 101 return AVERROR_EOF; 102 if (av_copy_packet(pkt, sub) < 0) { 103 return AVERROR(ENOMEM); 104 } 105 106 pkt->dts = pkt->pts; 107 q->current_sub_idx++; 108 return 0; 109} 110 111static int search_sub_ts(const FFDemuxSubtitlesQueue *q, int64_t ts) 112{ 113 int s1 = 0, s2 = q->nb_subs - 1; 114 115 if (s2 < s1) 116 return AVERROR(ERANGE); 117 118 for (;;) { 119 int mid; 120 121 if (s1 == s2) 122 return s1; 123 if (s1 == s2 - 1) 124 return q->subs[s1].pts <= q->subs[s2].pts ? s1 : s2; 125 mid = (s1 + s2) / 2; 126 if (q->subs[mid].pts <= ts) 127 s1 = mid; 128 else 129 s2 = mid; 130 } 131} 132 133int ff_subtitles_queue_seek(FFDemuxSubtitlesQueue *q, AVFormatContext *s, int stream_index, 134 int64_t min_ts, int64_t ts, int64_t max_ts, int flags) 135{ 136 if (flags & AVSEEK_FLAG_BYTE) { 137 return AVERROR(ENOSYS); 138 } else if (flags & AVSEEK_FLAG_FRAME) { 139 if (ts < 0 || ts >= q->nb_subs) 140 return AVERROR(ERANGE); 141 q->current_sub_idx = ts; 142 } else { 143 int i, idx = search_sub_ts(q, ts); 144 int64_t ts_selected; 145 146 if (idx < 0) 147 return idx; 148 for (i = idx; i < q->nb_subs && q->subs[i].pts < min_ts; i++) 149 if (stream_index == -1 || q->subs[i].stream_index == stream_index) 150 idx = i; 151 for (i = idx; i > 0 && q->subs[i].pts > max_ts; i--) 152 if (stream_index == -1 || q->subs[i].stream_index == stream_index) 153 idx = i; 154 155 ts_selected = q->subs[idx].pts; 156 if (ts_selected < min_ts || ts_selected > max_ts) 157 return AVERROR(ERANGE); 158 159 /* look back in the latest subtitles for overlapping subtitles */ 160 for (i = idx - 1; i >= 0; i--) { 161 int64_t pts = q->subs[i].pts; 162 if (q->subs[i].duration <= 0 || 163 (stream_index != -1 && q->subs[i].stream_index != stream_index)) 164 continue; 165 if (pts >= min_ts && pts > ts_selected - q->subs[i].duration) 166 idx = i; 167 else 168 break; 169 } 170 171 /* If the queue is used to store multiple subtitles streams (like with 172 * VobSub) and the stream index is not specified, we need to make sure 173 * to focus on the smallest file position offset for a same timestamp; 174 * queue is ordered by pts and then filepos, so we can take the first 175 * entry for a given timestamp. */ 176 if (stream_index == -1) 177 while (idx > 0 && q->subs[idx - 1].pts == q->subs[idx].pts) 178 idx--; 179 180 q->current_sub_idx = idx; 181 } 182 return 0; 183} 184 185void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q) 186{ 187 int i; 188 189 for (i = 0; i < q->nb_subs; i++) 190 av_free_packet(&q->subs[i]); 191 av_freep(&q->subs); 192 q->nb_subs = q->allocated_size = q->current_sub_idx = 0; 193} 194 195int ff_smil_extract_next_chunk(AVIOContext *pb, AVBPrint *buf, char *c) 196{ 197 int i = 0; 198 char end_chr; 199 200 if (!*c) // cached char? 201 *c = avio_r8(pb); 202 if (!*c) 203 return 0; 204 205 end_chr = *c == '<' ? '>' : '<'; 206 do { 207 av_bprint_chars(buf, *c, 1); 208 *c = avio_r8(pb); 209 i++; 210 } while (*c != end_chr && *c); 211 if (end_chr == '>') { 212 av_bprint_chars(buf, '>', 1); 213 *c = 0; 214 } 215 return i; 216} 217 218const char *ff_smil_get_attr_ptr(const char *s, const char *attr) 219{ 220 int in_quotes = 0; 221 const int len = strlen(attr); 222 223 while (*s) { 224 while (*s) { 225 if (!in_quotes && av_isspace(*s)) 226 break; 227 in_quotes ^= *s == '"'; // XXX: support escaping? 228 s++; 229 } 230 while (av_isspace(*s)) 231 s++; 232 if (!av_strncasecmp(s, attr, len) && s[len] == '=') 233 return s + len + 1 + (s[len + 1] == '"'); 234 } 235 return NULL; 236} 237 238static inline int is_eol(char c) 239{ 240 return c == '\r' || c == '\n'; 241} 242 243void ff_subtitles_read_chunk(AVIOContext *pb, AVBPrint *buf) 244{ 245 char eol_buf[5], last_was_cr = 0; 246 int n = 0, i = 0, nb_eol = 0; 247 248 av_bprint_clear(buf); 249 250 for (;;) { 251 char c = avio_r8(pb); 252 253 if (!c) 254 break; 255 256 /* ignore all initial line breaks */ 257 if (n == 0 && is_eol(c)) 258 continue; 259 260 /* line break buffering: we don't want to add the trailing \r\n */ 261 if (is_eol(c)) { 262 nb_eol += c == '\n' || last_was_cr; 263 if (nb_eol == 2) 264 break; 265 eol_buf[i++] = c; 266 if (i == sizeof(eol_buf) - 1) 267 break; 268 last_was_cr = c == '\r'; 269 continue; 270 } 271 272 /* only one line break followed by data: we flush the line breaks 273 * buffer */ 274 if (i) { 275 eol_buf[i] = 0; 276 av_bprintf(buf, "%s", eol_buf); 277 i = nb_eol = 0; 278 } 279 280 av_bprint_chars(buf, c, 1); 281 n++; 282 } 283} 284