00001 /* 00002 * SSA/ASS demuxer 00003 * Copyright (c) 2008 Michael Niedermayer 00004 * 00005 * This file is part of FFmpeg. 00006 * 00007 * FFmpeg is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * FFmpeg is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with FFmpeg; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00022 #include "avformat.h" 00023 00024 #define MAX_LINESIZE 2000 00025 00026 typedef struct ASSContext{ 00027 uint8_t *event_buffer; 00028 uint8_t **event; 00029 unsigned int event_count; 00030 unsigned int event_index; 00031 }ASSContext; 00032 00033 static void get_line(ByteIOContext *s, char *buf, int maxlen) 00034 { 00035 int i = 0; 00036 char c; 00037 00038 do{ 00039 c = get_byte(s); 00040 if (i < maxlen-1) 00041 buf[i++] = c; 00042 }while(c != '\n' && c); 00043 00044 buf[i] = 0; 00045 } 00046 00047 static int probe(AVProbeData *p) 00048 { 00049 const char *header= "[Script Info]"; 00050 00051 if( !memcmp(p->buf , header, strlen(header)) 00052 || !memcmp(p->buf+3, header, strlen(header))) 00053 return AVPROBE_SCORE_MAX; 00054 00055 return 0; 00056 } 00057 00058 static int read_close(AVFormatContext *s) 00059 { 00060 ASSContext *ass = s->priv_data; 00061 00062 av_freep(&ass->event_buffer); 00063 av_freep(&ass->event); 00064 00065 return 0; 00066 } 00067 00068 static int64_t get_pts(const uint8_t *p) 00069 { 00070 int hour, min, sec, hsec; 00071 00072 if(sscanf(p, "%*[^,],%d:%d:%d%*c%d", &hour, &min, &sec, &hsec) != 4) 00073 return AV_NOPTS_VALUE; 00074 00075 // av_log(NULL, AV_LOG_ERROR, "%d %d %d %d %d [%s]\n", i, hour, min, sec, hsec, p); 00076 00077 min+= 60*hour; 00078 sec+= 60*min; 00079 00080 return sec*100+hsec; 00081 } 00082 00083 static int event_cmp(uint8_t **a, uint8_t **b) 00084 { 00085 return get_pts(*a) - get_pts(*b); 00086 } 00087 00088 static int read_header(AVFormatContext *s, AVFormatParameters *ap) 00089 { 00090 int i, header_remaining; 00091 ASSContext *ass = s->priv_data; 00092 ByteIOContext *pb = s->pb; 00093 AVStream *st; 00094 int allocated[2]={0}; 00095 uint8_t *p, **dst[2]={0}; 00096 int pos[2]={0}; 00097 00098 st = av_new_stream(s, 0); 00099 if (!st) 00100 return -1; 00101 av_set_pts_info(st, 64, 1, 100); 00102 st->codec->codec_type = CODEC_TYPE_SUBTITLE; 00103 st->codec->codec_id= CODEC_ID_SSA; 00104 00105 header_remaining= INT_MAX; 00106 dst[0] = &st->codec->extradata; 00107 dst[1] = &ass->event_buffer; 00108 while(!url_feof(pb)){ 00109 uint8_t line[MAX_LINESIZE]; 00110 00111 get_line(pb, line, sizeof(line)); 00112 00113 if(!memcmp(line, "[Events]", 8)) 00114 header_remaining= 2; 00115 else if(line[0]=='[') 00116 header_remaining= INT_MAX; 00117 00118 i= header_remaining==0; 00119 00120 if(i && get_pts(line) == AV_NOPTS_VALUE) 00121 continue; 00122 00123 p = av_fast_realloc(*(dst[i]), &allocated[i], pos[i]+MAX_LINESIZE); 00124 if(!p) 00125 goto fail; 00126 *(dst[i])= p; 00127 memcpy(p + pos[i], line, strlen(line)+1); 00128 pos[i] += strlen(line); 00129 if(i) ass->event_count++; 00130 else header_remaining--; 00131 } 00132 st->codec->extradata_size= pos[0]; 00133 00134 if(ass->event_count >= UINT_MAX / sizeof(*ass->event)) 00135 goto fail; 00136 00137 ass->event= av_malloc(ass->event_count * sizeof(*ass->event)); 00138 p= ass->event_buffer; 00139 for(i=0; i<ass->event_count; i++){ 00140 ass->event[i]= p; 00141 while(*p && *p != '\n') 00142 p++; 00143 p++; 00144 } 00145 00146 qsort(ass->event, ass->event_count, sizeof(*ass->event), (void*)event_cmp); 00147 00148 return 0; 00149 00150 fail: 00151 read_close(s); 00152 00153 return -1; 00154 } 00155 00156 static int read_packet(AVFormatContext *s, AVPacket *pkt) 00157 { 00158 ASSContext *ass = s->priv_data; 00159 uint8_t *p, *end; 00160 00161 if(ass->event_index >= ass->event_count) 00162 return AVERROR(EIO); 00163 00164 p= ass->event[ ass->event_index ]; 00165 00166 end= strchr(p, '\n'); 00167 av_new_packet(pkt, end ? end-p+1 : strlen(p)); 00168 pkt->flags |= PKT_FLAG_KEY; 00169 pkt->pos= p - ass->event_buffer + s->streams[0]->codec->extradata_size; 00170 pkt->pts= pkt->dts= get_pts(p); 00171 memcpy(pkt->data, p, pkt->size); 00172 00173 ass->event_index++; 00174 00175 return 0; 00176 } 00177 00178 AVInputFormat ass_demuxer = { 00179 "ass", 00180 NULL_IF_CONFIG_SMALL("SSA/ASS format"), 00181 sizeof(ASSContext), 00182 probe, 00183 read_header, 00184 read_packet, 00185 read_close, 00186 // read_seek, 00187 };