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: #include "avformat.h"
yading@11: #include "subtitles.h"
yading@11: #include "libavutil/avassert.h"
yading@11: #include "libavutil/avstring.h"
yading@11: 
yading@11: AVPacket *ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q,
yading@11:                                     const uint8_t *event, int len, int merge)
yading@11: {
yading@11:     AVPacket *subs, *sub;
yading@11: 
yading@11:     if (merge && q->nb_subs > 0) {
yading@11:         /* merge with previous event */
yading@11: 
yading@11:         int old_len;
yading@11:         sub = &q->subs[q->nb_subs - 1];
yading@11:         old_len = sub->size;
yading@11:         if (av_grow_packet(sub, len) < 0)
yading@11:             return NULL;
yading@11:         memcpy(sub->data + old_len, event, len);
yading@11:     } else {
yading@11:         /* new event */
yading@11: 
yading@11:         if (q->nb_subs >= INT_MAX/sizeof(*q->subs) - 1)
yading@11:             return NULL;
yading@11:         subs = av_fast_realloc(q->subs, &q->allocated_size,
yading@11:                                (q->nb_subs + 1) * sizeof(*q->subs));
yading@11:         if (!subs)
yading@11:             return NULL;
yading@11:         q->subs = subs;
yading@11:         sub = &subs[q->nb_subs++];
yading@11:         if (av_new_packet(sub, len) < 0)
yading@11:             return NULL;
yading@11:         sub->flags |= AV_PKT_FLAG_KEY;
yading@11:         sub->pts = sub->dts = 0;
yading@11:         memcpy(sub->data, event, len);
yading@11:     }
yading@11:     return sub;
yading@11: }
yading@11: 
yading@11: static int cmp_pkt_sub(const void *a, const void *b)
yading@11: {
yading@11:     const AVPacket *s1 = a;
yading@11:     const AVPacket *s2 = b;
yading@11:     if (s1->pts == s2->pts) {
yading@11:         if (s1->pos == s2->pos)
yading@11:             return 0;
yading@11:         return s1->pos > s2->pos ? 1 : -1;
yading@11:     }
yading@11:     return s1->pts > s2->pts ? 1 : -1;
yading@11: }
yading@11: 
yading@11: void ff_subtitles_queue_finalize(FFDemuxSubtitlesQueue *q)
yading@11: {
yading@11:     int i;
yading@11: 
yading@11:     qsort(q->subs, q->nb_subs, sizeof(*q->subs), cmp_pkt_sub);
yading@11:     for (i = 0; i < q->nb_subs; i++)
yading@11:         if (q->subs[i].duration == -1 && i < q->nb_subs - 1)
yading@11:             q->subs[i].duration = q->subs[i + 1].pts - q->subs[i].pts;
yading@11: }
yading@11: 
yading@11: int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt)
yading@11: {
yading@11:     AVPacket *sub = q->subs + q->current_sub_idx;
yading@11: 
yading@11:     if (q->current_sub_idx == q->nb_subs)
yading@11:         return AVERROR_EOF;
yading@11:     av_copy_packet(pkt, sub);
yading@11: 
yading@11:     pkt->dts = pkt->pts;
yading@11:     q->current_sub_idx++;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: int ff_subtitles_queue_seek(FFDemuxSubtitlesQueue *q, AVFormatContext *s, int stream_index,
yading@11:                             int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
yading@11: {
yading@11:     if (flags & AVSEEK_FLAG_BYTE) {
yading@11:         return AVERROR(ENOSYS);
yading@11:     } else if (flags & AVSEEK_FLAG_FRAME) {
yading@11:         if (ts < 0 || ts >= q->nb_subs)
yading@11:             return AVERROR(ERANGE);
yading@11:         q->current_sub_idx = ts;
yading@11:     } else {
yading@11:         int i, idx = -1;
yading@11:         int64_t min_ts_diff = INT64_MAX;
yading@11:         int64_t ts_selected;
yading@11:         /* TODO: q->subs[] is sorted by pts so we could do a binary search */
yading@11:         for (i = 0; i < q->nb_subs; i++) {
yading@11:             int64_t pts = q->subs[i].pts;
yading@11:             uint64_t ts_diff = FFABS(pts - ts);
yading@11:             if (pts >= min_ts && pts <= max_ts && ts_diff < min_ts_diff) {
yading@11:                 min_ts_diff = ts_diff;
yading@11:                 idx = i;
yading@11:             }
yading@11:         }
yading@11:         if (idx < 0)
yading@11:             return AVERROR(ERANGE);
yading@11:         /* look back in the latest subtitles for overlapping subtitles */
yading@11:         ts_selected = q->subs[idx].pts;
yading@11:         for (i = idx - 1; i >= 0; i--) {
yading@11:             if (q->subs[i].duration <= 0)
yading@11:                 continue;
yading@11:             if (q->subs[i].pts > ts_selected - q->subs[i].duration)
yading@11:                 idx = i;
yading@11:             else
yading@11:                 break;
yading@11:         }
yading@11:         q->current_sub_idx = idx;
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
yading@11: {
yading@11:     int i;
yading@11: 
yading@11:     for (i = 0; i < q->nb_subs; i++)
yading@11:         av_free_packet(&q->subs[i]);
yading@11:     av_freep(&q->subs);
yading@11:     q->nb_subs = q->allocated_size = q->current_sub_idx = 0;
yading@11: }
yading@11: 
yading@11: int ff_smil_extract_next_chunk(AVIOContext *pb, AVBPrint *buf, char *c)
yading@11: {
yading@11:     int i = 0;
yading@11:     char end_chr;
yading@11: 
yading@11:     if (!*c) // cached char?
yading@11:         *c = avio_r8(pb);
yading@11:     if (!*c)
yading@11:         return 0;
yading@11: 
yading@11:     end_chr = *c == '<' ? '>' : '<';
yading@11:     do {
yading@11:         av_bprint_chars(buf, *c, 1);
yading@11:         *c = avio_r8(pb);
yading@11:         i++;
yading@11:     } while (*c != end_chr && *c);
yading@11:     if (end_chr == '>') {
yading@11:         av_bprint_chars(buf, '>', 1);
yading@11:         *c = 0;
yading@11:     }
yading@11:     return i;
yading@11: }
yading@11: 
yading@11: const char *ff_smil_get_attr_ptr(const char *s, const char *attr)
yading@11: {
yading@11:     int in_quotes = 0;
yading@11:     const int len = strlen(attr);
yading@11: 
yading@11:     while (*s) {
yading@11:         while (*s) {
yading@11:             if (!in_quotes && av_isspace(*s))
yading@11:                 break;
yading@11:             in_quotes ^= *s == '"'; // XXX: support escaping?
yading@11:             s++;
yading@11:         }
yading@11:         while (av_isspace(*s))
yading@11:             s++;
yading@11:         if (!av_strncasecmp(s, attr, len) && s[len] == '=')
yading@11:             return s + len + 1 + (s[len + 1] == '"');
yading@11:     }
yading@11:     return NULL;
yading@11: }
yading@11: 
yading@11: static inline int is_eol(char c)
yading@11: {
yading@11:     return c == '\r' || c == '\n';
yading@11: }
yading@11: 
yading@11: void ff_subtitles_read_chunk(AVIOContext *pb, AVBPrint *buf)
yading@11: {
yading@11:     char eol_buf[5];
yading@11:     int n = 0, i = 0, nb_eol = 0;
yading@11: 
yading@11:     av_bprint_clear(buf);
yading@11: 
yading@11:     for (;;) {
yading@11:         char c = avio_r8(pb);
yading@11: 
yading@11:         if (!c)
yading@11:             break;
yading@11: 
yading@11:         /* ignore all initial line breaks */
yading@11:         if (n == 0 && is_eol(c))
yading@11:             continue;
yading@11: 
yading@11:         /* line break buffering: we don't want to add the trailing \r\n */
yading@11:         if (is_eol(c)) {
yading@11:             nb_eol += c == '\n';
yading@11:             if (nb_eol == 2)
yading@11:                 break;
yading@11:             eol_buf[i++] = c;
yading@11:             if (i == sizeof(eol_buf) - 1)
yading@11:                 break;
yading@11:             continue;
yading@11:         }
yading@11: 
yading@11:         /* only one line break followed by data: we flush the line breaks
yading@11:          * buffer */
yading@11:         if (i) {
yading@11:             eol_buf[i] = 0;
yading@11:             av_bprintf(buf, "%s", eol_buf);
yading@11:             i = nb_eol = 0;
yading@11:         }
yading@11: 
yading@11:         av_bprint_chars(buf, c, 1);
yading@11:         n++;
yading@11:     }
yading@11: }