yading@11: /*
yading@11:  * Copyright (c) 2012 Clément Bœsch
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: /**
yading@11:  * @file
yading@11:  * SAMI subtitle demuxer
yading@11:  * @see http://msdn.microsoft.com/en-us/library/ms971327.aspx
yading@11:  */
yading@11: 
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: #include "subtitles.h"
yading@11: #include "libavcodec/internal.h"
yading@11: #include "libavutil/avstring.h"
yading@11: #include "libavutil/bprint.h"
yading@11: #include "libavutil/intreadwrite.h"
yading@11: 
yading@11: typedef struct {
yading@11:     FFDemuxSubtitlesQueue q;
yading@11: } SAMIContext;
yading@11: 
yading@11: static int sami_probe(AVProbeData *p)
yading@11: {
yading@11:     const unsigned char *ptr = p->buf;
yading@11: 
yading@11:     if (AV_RB24(ptr) == 0xEFBBBF)
yading@11:         ptr += 3;  /* skip UTF-8 BOM */
yading@11:     return !strncmp(ptr, "<SAMI>", 6) ? AVPROBE_SCORE_MAX : 0;
yading@11: }
yading@11: 
yading@11: static int sami_read_header(AVFormatContext *s)
yading@11: {
yading@11:     SAMIContext *sami = s->priv_data;
yading@11:     AVStream *st = avformat_new_stream(s, NULL);
yading@11:     AVBPrint buf, hdr_buf;
yading@11:     char c = 0;
yading@11:     int res = 0, got_first_sync_point = 0;
yading@11: 
yading@11:     if (!st)
yading@11:         return AVERROR(ENOMEM);
yading@11:     avpriv_set_pts_info(st, 64, 1, 1000);
yading@11:     st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
yading@11:     st->codec->codec_id   = AV_CODEC_ID_SAMI;
yading@11: 
yading@11:     av_bprint_init(&buf,     0, AV_BPRINT_SIZE_UNLIMITED);
yading@11:     av_bprint_init(&hdr_buf, 0, AV_BPRINT_SIZE_UNLIMITED);
yading@11: 
yading@11:     while (!url_feof(s->pb)) {
yading@11:         AVPacket *sub;
yading@11:         const int64_t pos = avio_tell(s->pb) - (c != 0);
yading@11:         int is_sync, n = ff_smil_extract_next_chunk(s->pb, &buf, &c);
yading@11: 
yading@11:         if (n == 0)
yading@11:             break;
yading@11: 
yading@11:         is_sync = !av_strncasecmp(buf.str, "<SYNC", 5);
yading@11:         if (is_sync)
yading@11:             got_first_sync_point = 1;
yading@11: 
yading@11:         if (!got_first_sync_point) {
yading@11:             av_bprintf(&hdr_buf, "%s", buf.str);
yading@11:         } else {
yading@11:             sub = ff_subtitles_queue_insert(&sami->q, buf.str, buf.len, !is_sync);
yading@11:             if (!sub) {
yading@11:                 res = AVERROR(ENOMEM);
yading@11:                 goto end;
yading@11:             }
yading@11:             if (is_sync) {
yading@11:                 const char *p = ff_smil_get_attr_ptr(buf.str, "Start");
yading@11:                 sub->pos      = pos;
yading@11:                 sub->pts      = p ? strtol(p, NULL, 10) : 0;
yading@11:                 sub->duration = -1;
yading@11:             }
yading@11:         }
yading@11:         av_bprint_clear(&buf);
yading@11:     }
yading@11: 
yading@11:     res = avpriv_bprint_to_extradata(st->codec, &hdr_buf);
yading@11:     if (res < 0)
yading@11:         goto end;
yading@11: 
yading@11:     ff_subtitles_queue_finalize(&sami->q);
yading@11: 
yading@11: end:
yading@11:     av_bprint_finalize(&buf, NULL);
yading@11:     return res;
yading@11: }
yading@11: 
yading@11: static int sami_read_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     SAMIContext *sami = s->priv_data;
yading@11:     return ff_subtitles_queue_read_packet(&sami->q, pkt);
yading@11: }
yading@11: 
yading@11: static int sami_read_seek(AVFormatContext *s, int stream_index,
yading@11:                           int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
yading@11: {
yading@11:     SAMIContext *sami = s->priv_data;
yading@11:     return ff_subtitles_queue_seek(&sami->q, s, stream_index,
yading@11:                                    min_ts, ts, max_ts, flags);
yading@11: }
yading@11: 
yading@11: static int sami_read_close(AVFormatContext *s)
yading@11: {
yading@11:     SAMIContext *sami = s->priv_data;
yading@11:     ff_subtitles_queue_clean(&sami->q);
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_sami_demuxer = {
yading@11:     .name           = "sami",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("SAMI subtitle format"),
yading@11:     .priv_data_size = sizeof(SAMIContext),
yading@11:     .read_probe     = sami_probe,
yading@11:     .read_header    = sami_read_header,
yading@11:     .read_packet    = sami_read_packet,
yading@11:     .read_seek2     = sami_read_seek,
yading@11:     .read_close     = sami_read_close,
yading@11:     .extensions     = "smi,sami",
yading@11: };