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187 lines
4.4 KiB
187 lines
4.4 KiB
/* |
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* SSA/ASS demuxer |
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* Copyright (c) 2008 Michael Niedermayer |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#include "avformat.h" |
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#define MAX_LINESIZE 2000 |
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typedef struct ASSContext{ |
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uint8_t *event_buffer; |
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uint8_t **event; |
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unsigned int event_count; |
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unsigned int event_index; |
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}ASSContext; |
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static void get_line(ByteIOContext *s, char *buf, int maxlen) |
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{ |
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int i = 0; |
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char c; |
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do{ |
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c = get_byte(s); |
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if (i < maxlen-1 && c != '\r') |
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buf[i++] = c; |
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}while(c != '\n' && c); |
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buf[i] = 0; |
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} |
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static int probe(AVProbeData *p) |
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{ |
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const char *header= "[Script Info]"; |
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if( !memcmp(p->buf , header, strlen(header)) |
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|| !memcmp(p->buf+3, header, strlen(header))) |
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return AVPROBE_SCORE_MAX; |
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return 0; |
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} |
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static int read_close(AVFormatContext *s) |
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{ |
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ASSContext *ass = s->priv_data; |
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av_freep(&ass->event_buffer); |
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av_freep(&ass->event); |
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return 0; |
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} |
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static int64_t get_pts(const uint8_t *p) |
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{ |
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int hour, min, sec, hsec; |
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if(sscanf(p, "%*[^,],%d:%d:%d%*c%d", &hour, &min, &sec, &hsec) != 4) |
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return AV_NOPTS_VALUE; |
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// av_log(NULL, AV_LOG_ERROR, "%d %d %d %d %d [%s]\n", i, hour, min, sec, hsec, p); |
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min+= 60*hour; |
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sec+= 60*min; |
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return sec*100+hsec; |
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} |
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static int event_cmp(uint8_t **a, uint8_t **b) |
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{ |
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return get_pts(*a) - get_pts(*b); |
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} |
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static int read_header(AVFormatContext *s, AVFormatParameters *ap) |
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{ |
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int i, header_remaining; |
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ASSContext *ass = s->priv_data; |
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ByteIOContext *pb = s->pb; |
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AVStream *st; |
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int allocated[2]={0}; |
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uint8_t *p, **dst[2]={0}; |
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int pos[2]={0}; |
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st = av_new_stream(s, 0); |
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if (!st) |
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return -1; |
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av_set_pts_info(st, 64, 1, 100); |
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st->codec->codec_type = CODEC_TYPE_SUBTITLE; |
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st->codec->codec_id= CODEC_ID_SSA; |
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header_remaining= INT_MAX; |
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dst[0] = &st->codec->extradata; |
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dst[1] = &ass->event_buffer; |
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while(!url_feof(pb)){ |
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uint8_t line[MAX_LINESIZE]; |
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get_line(pb, line, sizeof(line)); |
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if(!memcmp(line, "[Events]", 8)) |
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header_remaining= 2; |
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else if(line[0]=='[') |
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header_remaining= INT_MAX; |
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i= header_remaining==0; |
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if(i && get_pts(line) == AV_NOPTS_VALUE) |
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continue; |
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p = av_fast_realloc(*(dst[i]), &allocated[i], pos[i]+MAX_LINESIZE); |
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if(!p) |
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goto fail; |
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*(dst[i])= p; |
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memcpy(p + pos[i], line, strlen(line)+1); |
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pos[i] += strlen(line); |
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if(i) ass->event_count++; |
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else header_remaining--; |
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} |
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st->codec->extradata_size= pos[0]; |
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if(ass->event_count >= UINT_MAX / sizeof(*ass->event)) |
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goto fail; |
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ass->event= av_malloc(ass->event_count * sizeof(*ass->event)); |
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p= ass->event_buffer; |
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for(i=0; i<ass->event_count; i++){ |
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ass->event[i]= p; |
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while(*p && *p != '\n') |
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p++; |
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p++; |
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} |
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qsort(ass->event, ass->event_count, sizeof(*ass->event), event_cmp); |
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return 0; |
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fail: |
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read_close(s); |
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return -1; |
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} |
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static int read_packet(AVFormatContext *s, AVPacket *pkt) |
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{ |
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ASSContext *ass = s->priv_data; |
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uint8_t *p, *end; |
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if(ass->event_index >= ass->event_count) |
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return AVERROR(EIO); |
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p= ass->event[ ass->event_index ]; |
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end= strchr(p, '\n'); |
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av_new_packet(pkt, end ? end-p+1 : strlen(p)); |
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pkt->flags |= PKT_FLAG_KEY; |
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pkt->pos= p - ass->event_buffer + s->streams[0]->codec->extradata_size; |
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pkt->pts= pkt->dts= get_pts(p); |
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memcpy(pkt->data, p, pkt->size); |
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ass->event_index++; |
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return 0; |
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} |
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AVInputFormat ass_demuxer = { |
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"ass", |
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NULL_IF_CONFIG_SMALL("SSA/ASS format"), |
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sizeof(ASSContext), |
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probe, |
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read_header, |
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read_packet, |
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read_close, |
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// read_seek, |
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};
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