1/* 2 * SSA/ASS demuxer 3 * Copyright (c) 2008 Michael Niedermayer 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 "avformat.h" 23 24#define MAX_LINESIZE 2000 25 26typedef struct ASSContext{ 27 uint8_t *event_buffer; 28 uint8_t **event; 29 unsigned int event_count; 30 unsigned int event_index; 31}ASSContext; 32 33static void get_line(ByteIOContext *s, char *buf, int maxlen) 34{ 35 int i = 0; 36 char c; 37 38 do{ 39 c = get_byte(s); 40 if (i < maxlen-1) 41 buf[i++] = c; 42 }while(c != '\n' && c); 43 44 buf[i] = 0; 45} 46 47static int probe(AVProbeData *p) 48{ 49 const char *header= "[Script Info]"; 50 51 if( !memcmp(p->buf , header, strlen(header)) 52 || !memcmp(p->buf+3, header, strlen(header))) 53 return AVPROBE_SCORE_MAX; 54 55 return 0; 56} 57 58static int read_close(AVFormatContext *s) 59{ 60 ASSContext *ass = s->priv_data; 61 62 av_freep(&ass->event_buffer); 63 av_freep(&ass->event); 64 65 return 0; 66} 67 68static int64_t get_pts(const uint8_t *p) 69{ 70 int hour, min, sec, hsec; 71 72 if(sscanf(p, "%*[^,],%d:%d:%d%*c%d", &hour, &min, &sec, &hsec) != 4) 73 return AV_NOPTS_VALUE; 74 75// av_log(NULL, AV_LOG_ERROR, "%d %d %d %d %d [%s]\n", i, hour, min, sec, hsec, p); 76 77 min+= 60*hour; 78 sec+= 60*min; 79 80 return sec*100+hsec; 81} 82 83static int event_cmp(uint8_t **a, uint8_t **b) 84{ 85 return get_pts(*a) - get_pts(*b); 86} 87 88static int read_header(AVFormatContext *s, AVFormatParameters *ap) 89{ 90 int i, header_remaining; 91 ASSContext *ass = s->priv_data; 92 ByteIOContext *pb = s->pb; 93 AVStream *st; 94 int allocated[2]={0}; 95 uint8_t *p, **dst[2]={0}; 96 int pos[2]={0}; 97 98 st = av_new_stream(s, 0); 99 if (!st) 100 return -1; 101 av_set_pts_info(st, 64, 1, 100); 102 st->codec->codec_type = CODEC_TYPE_SUBTITLE; 103 st->codec->codec_id= CODEC_ID_SSA; 104 105 header_remaining= INT_MAX; 106 dst[0] = &st->codec->extradata; 107 dst[1] = &ass->event_buffer; 108 while(!url_feof(pb)){ 109 uint8_t line[MAX_LINESIZE]; 110 111 get_line(pb, line, sizeof(line)); 112 113 if(!memcmp(line, "[Events]", 8)) 114 header_remaining= 2; 115 else if(line[0]=='[') 116 header_remaining= INT_MAX; 117 118 i= header_remaining==0; 119 120 if(i && get_pts(line) == AV_NOPTS_VALUE) 121 continue; 122 123 p = av_fast_realloc(*(dst[i]), &allocated[i], pos[i]+MAX_LINESIZE); 124 if(!p) 125 goto fail; 126 *(dst[i])= p; 127 memcpy(p + pos[i], line, strlen(line)+1); 128 pos[i] += strlen(line); 129 if(i) ass->event_count++; 130 else header_remaining--; 131 } 132 st->codec->extradata_size= pos[0]; 133 134 if(ass->event_count >= UINT_MAX / sizeof(*ass->event)) 135 goto fail; 136 137 ass->event= av_malloc(ass->event_count * sizeof(*ass->event)); 138 p= ass->event_buffer; 139 for(i=0; i<ass->event_count; i++){ 140 ass->event[i]= p; 141 while(*p && *p != '\n') 142 p++; 143 p++; 144 } 145 146 qsort(ass->event, ass->event_count, sizeof(*ass->event), (void*)event_cmp); 147 148 return 0; 149 150fail: 151 read_close(s); 152 153 return -1; 154} 155 156static int read_packet(AVFormatContext *s, AVPacket *pkt) 157{ 158 ASSContext *ass = s->priv_data; 159 uint8_t *p, *end; 160 161 if(ass->event_index >= ass->event_count) 162 return AVERROR(EIO); 163 164 p= ass->event[ ass->event_index ]; 165 166 end= strchr(p, '\n'); 167 av_new_packet(pkt, end ? end-p+1 : strlen(p)); 168 pkt->flags |= PKT_FLAG_KEY; 169 pkt->pos= p - ass->event_buffer + s->streams[0]->codec->extradata_size; 170 pkt->pts= pkt->dts= get_pts(p); 171 memcpy(pkt->data, p, pkt->size); 172 173 ass->event_index++; 174 175 return 0; 176} 177 178AVInputFormat ass_demuxer = { 179 "ass", 180 NULL_IF_CONFIG_SMALL("SSA/ASS format"), 181 sizeof(ASSContext), 182 probe, 183 read_header, 184 read_packet, 185 read_close, 186// read_seek, 187}; 188