| /* |
| * SSA/ASS demuxer |
| * Copyright (c) 2008 Michael Niedermayer |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "avformat.h" |
| #include "internal.h" |
| |
| #define MAX_LINESIZE 2000 |
| |
| typedef struct ASSContext{ |
| uint8_t *event_buffer; |
| uint8_t **event; |
| unsigned int event_count; |
| unsigned int event_index; |
| }ASSContext; |
| |
| static int probe(AVProbeData *p) |
| { |
| const char *header= "[Script Info]"; |
| |
| if( !memcmp(p->buf , header, strlen(header)) |
| || !memcmp(p->buf+3, header, strlen(header))) |
| return AVPROBE_SCORE_MAX; |
| |
| return 0; |
| } |
| |
| static int read_close(AVFormatContext *s) |
| { |
| ASSContext *ass = s->priv_data; |
| |
| av_freep(&ass->event_buffer); |
| av_freep(&ass->event); |
| |
| return 0; |
| } |
| |
| static int64_t get_pts(const uint8_t *p) |
| { |
| int hour, min, sec, hsec; |
| |
| if(sscanf(p, "%*[^,],%d:%d:%d%*c%d", &hour, &min, &sec, &hsec) != 4) |
| return AV_NOPTS_VALUE; |
| |
| // av_log(NULL, AV_LOG_ERROR, "%d %d %d %d %d [%s]\n", i, hour, min, sec, hsec, p); |
| |
| min+= 60*hour; |
| sec+= 60*min; |
| |
| return sec*100+hsec; |
| } |
| |
| static int event_cmp(uint8_t **a, uint8_t **b) |
| { |
| return get_pts(*a) - get_pts(*b); |
| } |
| |
| static int read_header(AVFormatContext *s, AVFormatParameters *ap) |
| { |
| int i, len, header_remaining; |
| ASSContext *ass = s->priv_data; |
| AVIOContext *pb = s->pb; |
| AVStream *st; |
| int allocated[2]={0}; |
| uint8_t *p, **dst[2]={0}; |
| int pos[2]={0}; |
| |
| st = av_new_stream(s, 0); |
| if (!st) |
| return -1; |
| av_set_pts_info(st, 64, 1, 100); |
| st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE; |
| st->codec->codec_id= CODEC_ID_SSA; |
| |
| header_remaining= INT_MAX; |
| dst[0] = &st->codec->extradata; |
| dst[1] = &ass->event_buffer; |
| while(!url_feof(pb)){ |
| uint8_t line[MAX_LINESIZE]; |
| |
| len = ff_get_line(pb, line, sizeof(line)); |
| |
| if(!memcmp(line, "[Events]", 8)) |
| header_remaining= 2; |
| else if(line[0]=='[') |
| header_remaining= INT_MAX; |
| |
| i= header_remaining==0; |
| |
| if(i && get_pts(line) == AV_NOPTS_VALUE) |
| continue; |
| |
| p = av_fast_realloc(*(dst[i]), &allocated[i], pos[i]+MAX_LINESIZE); |
| if(!p) |
| goto fail; |
| *(dst[i])= p; |
| memcpy(p + pos[i], line, len+1); |
| pos[i] += len; |
| if(i) ass->event_count++; |
| else header_remaining--; |
| } |
| st->codec->extradata_size= pos[0]; |
| |
| if(ass->event_count >= UINT_MAX / sizeof(*ass->event)) |
| goto fail; |
| |
| ass->event= av_malloc(ass->event_count * sizeof(*ass->event)); |
| p= ass->event_buffer; |
| for(i=0; i<ass->event_count; i++){ |
| ass->event[i]= p; |
| while(*p && *p != '\n') |
| p++; |
| p++; |
| } |
| |
| qsort(ass->event, ass->event_count, sizeof(*ass->event), (void*)event_cmp); |
| |
| return 0; |
| |
| fail: |
| read_close(s); |
| |
| return -1; |
| } |
| |
| static int read_packet(AVFormatContext *s, AVPacket *pkt) |
| { |
| ASSContext *ass = s->priv_data; |
| uint8_t *p, *end; |
| |
| if(ass->event_index >= ass->event_count) |
| return AVERROR(EIO); |
| |
| p= ass->event[ ass->event_index ]; |
| |
| end= strchr(p, '\n'); |
| av_new_packet(pkt, end ? end-p+1 : strlen(p)); |
| pkt->flags |= AV_PKT_FLAG_KEY; |
| pkt->pos= p - ass->event_buffer + s->streams[0]->codec->extradata_size; |
| pkt->pts= pkt->dts= get_pts(p); |
| memcpy(pkt->data, p, pkt->size); |
| |
| ass->event_index++; |
| |
| return 0; |
| } |
| |
| static int read_seek2(AVFormatContext *s, int stream_index, |
| int64_t min_ts, int64_t ts, int64_t max_ts, int flags) |
| { |
| ASSContext *ass = s->priv_data; |
| |
| if (flags & AVSEEK_FLAG_BYTE) { |
| return AVERROR(ENOSYS); |
| } else if (flags & AVSEEK_FLAG_FRAME) { |
| if (ts < 0 || ts >= ass->event_count) |
| return AVERROR(ERANGE); |
| ass->event_index = ts; |
| } else { |
| int i, idx = -1; |
| int64_t min_ts_diff = INT64_MAX; |
| if (stream_index == -1) { |
| AVRational time_base = s->streams[0]->time_base; |
| ts = av_rescale_q(ts, AV_TIME_BASE_Q, time_base); |
| min_ts = av_rescale_rnd(min_ts, time_base.den, |
| time_base.num * (int64_t)AV_TIME_BASE, |
| AV_ROUND_UP); |
| max_ts = av_rescale_rnd(max_ts, time_base.den, |
| time_base.num * (int64_t)AV_TIME_BASE, |
| AV_ROUND_DOWN); |
| } |
| /* TODO: ass->event[] is sorted by pts so we could do a binary search */ |
| for (i=0; i<ass->event_count; i++) { |
| int64_t pts = get_pts(ass->event[i]); |
| int64_t ts_diff = FFABS(pts - ts); |
| if (pts >= min_ts && pts <= max_ts && ts_diff < min_ts_diff) { |
| min_ts_diff = ts_diff; |
| idx = i; |
| } |
| } |
| if (idx < 0) |
| return AVERROR(ERANGE); |
| ass->event_index = idx; |
| } |
| return 0; |
| } |
| |
| AVInputFormat ff_ass_demuxer = { |
| .name = "ass", |
| .long_name = NULL_IF_CONFIG_SMALL("Advanced SubStation Alpha subtitle format"), |
| .priv_data_size = sizeof(ASSContext), |
| .read_probe = probe, |
| .read_header = read_header, |
| .read_packet = read_packet, |
| .read_close = read_close, |
| .read_seek2 = read_seek2, |
| }; |