diff options
Diffstat (limited to 'libavformat/subtitles.c')
| -rw-r--r-- | libavformat/subtitles.c | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/libavformat/subtitles.c b/libavformat/subtitles.c new file mode 100644 index 0000000..fce2bf1 --- /dev/null +++ b/libavformat/subtitles.c @@ -0,0 +1,283 @@ +/* + * Copyright (c) 2012-2013 Clément Bœsch <u pkh me> + * + * 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 "subtitles.h" +#include "libavutil/avassert.h" +#include "libavutil/avstring.h" + +AVPacket *ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q, + const uint8_t *event, int len, int merge) +{ + AVPacket *subs, *sub; + + if (merge && q->nb_subs > 0) { + /* merge with previous event */ + + int old_len; + sub = &q->subs[q->nb_subs - 1]; + old_len = sub->size; + if (av_grow_packet(sub, len) < 0) + return NULL; + memcpy(sub->data + old_len, event, len); + } else { + /* new event */ + + if (q->nb_subs >= INT_MAX/sizeof(*q->subs) - 1) + return NULL; + subs = av_fast_realloc(q->subs, &q->allocated_size, + (q->nb_subs + 1) * sizeof(*q->subs)); + if (!subs) + return NULL; + q->subs = subs; + sub = &subs[q->nb_subs++]; + if (av_new_packet(sub, len) < 0) + return NULL; + sub->flags |= AV_PKT_FLAG_KEY; + sub->pts = sub->dts = 0; + memcpy(sub->data, event, len); + } + return sub; +} + +static int cmp_pkt_sub_ts_pos(const void *a, const void *b) +{ + const AVPacket *s1 = a; + const AVPacket *s2 = b; + if (s1->pts == s2->pts) { + if (s1->pos == s2->pos) + return 0; + return s1->pos > s2->pos ? 1 : -1; + } + return s1->pts > s2->pts ? 1 : -1; +} + +static int cmp_pkt_sub_pos_ts(const void *a, const void *b) +{ + const AVPacket *s1 = a; + const AVPacket *s2 = b; + if (s1->pos == s2->pos) { + if (s1->pts == s2->pts) + return 0; + return s1->pts > s2->pts ? 1 : -1; + } + return s1->pos > s2->pos ? 1 : -1; +} + +void ff_subtitles_queue_finalize(FFDemuxSubtitlesQueue *q) +{ + int i; + + qsort(q->subs, q->nb_subs, sizeof(*q->subs), + q->sort == SUB_SORT_TS_POS ? cmp_pkt_sub_ts_pos + : cmp_pkt_sub_pos_ts); + for (i = 0; i < q->nb_subs; i++) + if (q->subs[i].duration == -1 && i < q->nb_subs - 1) + q->subs[i].duration = q->subs[i + 1].pts - q->subs[i].pts; +} + +int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt) +{ + AVPacket *sub = q->subs + q->current_sub_idx; + + if (q->current_sub_idx == q->nb_subs) + return AVERROR_EOF; + if (av_copy_packet(pkt, sub) < 0) { + return AVERROR(ENOMEM); + } + + pkt->dts = pkt->pts; + q->current_sub_idx++; + return 0; +} + +static int search_sub_ts(const FFDemuxSubtitlesQueue *q, int64_t ts) +{ + int s1 = 0, s2 = q->nb_subs - 1; + + if (s2 < s1) + return AVERROR(ERANGE); + + for (;;) { + int mid; + + if (s1 == s2) + return s1; + if (s1 == s2 - 1) + return q->subs[s1].pts <= q->subs[s2].pts ? s1 : s2; + mid = (s1 + s2) / 2; + if (q->subs[mid].pts <= ts) + s1 = mid; + else + s2 = mid; + } +} + +int ff_subtitles_queue_seek(FFDemuxSubtitlesQueue *q, AVFormatContext *s, int stream_index, + int64_t min_ts, int64_t ts, int64_t max_ts, int flags) +{ + if (flags & AVSEEK_FLAG_BYTE) { + return AVERROR(ENOSYS); + } else if (flags & AVSEEK_FLAG_FRAME) { + if (ts < 0 || ts >= q->nb_subs) + return AVERROR(ERANGE); + q->current_sub_idx = ts; + } else { + int i, idx = search_sub_ts(q, ts); + int64_t ts_selected; + + if (idx < 0) + return idx; + for (i = idx; i < q->nb_subs && q->subs[i].pts < min_ts; i++) + if (stream_index == -1 || q->subs[i].stream_index == stream_index) + idx = i; + for (i = idx; i > 0 && q->subs[i].pts > max_ts; i--) + if (stream_index == -1 || q->subs[i].stream_index == stream_index) + idx = i; + + ts_selected = q->subs[idx].pts; + if (ts_selected < min_ts || ts_selected > max_ts) + return AVERROR(ERANGE); + + /* look back in the latest subtitles for overlapping subtitles */ + for (i = idx - 1; i >= 0; i--) { + int64_t pts = q->subs[i].pts; + if (q->subs[i].duration <= 0 || + (stream_index != -1 && q->subs[i].stream_index != stream_index)) + continue; + if (pts >= min_ts && pts > ts_selected - q->subs[i].duration) + idx = i; + else + break; + } + + /* If the queue is used to store multiple subtitles streams (like with + * VobSub) and the stream index is not specified, we need to make sure + * to focus on the smallest file position offset for a same timestamp; + * queue is ordered by pts and then filepos, so we can take the first + * entry for a given timestamp. */ + if (stream_index == -1) + while (idx > 0 && q->subs[idx - 1].pts == q->subs[idx].pts) + idx--; + + q->current_sub_idx = idx; + } + return 0; +} + +void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q) +{ + int i; + + for (i = 0; i < q->nb_subs; i++) + av_free_packet(&q->subs[i]); + av_freep(&q->subs); + q->nb_subs = q->allocated_size = q->current_sub_idx = 0; +} + +int ff_smil_extract_next_chunk(AVIOContext *pb, AVBPrint *buf, char *c) +{ + int i = 0; + char end_chr; + + if (!*c) // cached char? + *c = avio_r8(pb); + if (!*c) + return 0; + + end_chr = *c == '<' ? '>' : '<'; + do { + av_bprint_chars(buf, *c, 1); + *c = avio_r8(pb); + i++; + } while (*c != end_chr && *c); + if (end_chr == '>') { + av_bprint_chars(buf, '>', 1); + *c = 0; + } + return i; +} + +const char *ff_smil_get_attr_ptr(const char *s, const char *attr) +{ + int in_quotes = 0; + const int len = strlen(attr); + + while (*s) { + while (*s) { + if (!in_quotes && av_isspace(*s)) + break; + in_quotes ^= *s == '"'; // XXX: support escaping? + s++; + } + while (av_isspace(*s)) + s++; + if (!av_strncasecmp(s, attr, len) && s[len] == '=') + return s + len + 1 + (s[len + 1] == '"'); + } + return NULL; +} + +static inline int is_eol(char c) +{ + return c == '\r' || c == '\n'; +} + +void ff_subtitles_read_chunk(AVIOContext *pb, AVBPrint *buf) +{ + char eol_buf[5], last_was_cr = 0; + int n = 0, i = 0, nb_eol = 0; + + av_bprint_clear(buf); + + for (;;) { + char c = avio_r8(pb); + + if (!c) + break; + + /* ignore all initial line breaks */ + if (n == 0 && is_eol(c)) + continue; + + /* line break buffering: we don't want to add the trailing \r\n */ + if (is_eol(c)) { + nb_eol += c == '\n' || last_was_cr; + if (nb_eol == 2) + break; + eol_buf[i++] = c; + if (i == sizeof(eol_buf) - 1) + break; + last_was_cr = c == '\r'; + continue; + } + + /* only one line break followed by data: we flush the line breaks + * buffer */ + if (i) { + eol_buf[i] = 0; + av_bprintf(buf, "%s", eol_buf); + i = nb_eol = 0; + } + + av_bprint_chars(buf, c, 1); + n++; + } +} |
