diff options
author | Clément Bœsch <u@pkh.me> | 2013-09-08 14:36:57 +0400 |
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committer | Clément Bœsch <u@pkh.me> | 2013-09-08 14:54:49 +0400 |
commit | b1319e14e3b068045a9147244f3edd5863abe6fd (patch) | |
tree | aca5067aadae758a07d4b4b086cc826cee035208 /libavformat/subtitles.c | |
parent | 1ca4bf930bab681a79fb591330043675c7cfd798 (diff) |
avformat/subtitles: binary search seeking.
Diffstat (limited to 'libavformat/subtitles.c')
-rw-r--r-- | libavformat/subtitles.c | 50 |
1 files changed, 36 insertions, 14 deletions
diff --git a/libavformat/subtitles.c b/libavformat/subtitles.c index b796f4062c..d4607970ac 100644 --- a/libavformat/subtitles.c +++ b/libavformat/subtitles.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2012 Clément Bœsch + * Copyright (c) 2012-2013 Clément Bœsch <u pkh me> * * This file is part of FFmpeg. * @@ -94,6 +94,28 @@ int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt) 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) { @@ -104,23 +126,23 @@ int ff_subtitles_queue_seek(FFDemuxSubtitlesQueue *q, AVFormatContext *s, int st return AVERROR(ERANGE); q->current_sub_idx = ts; } else { - int i, idx = -1; - int64_t min_ts_diff = INT64_MAX; + int i, idx = search_sub_ts(q, ts); int64_t ts_selected; - /* TODO: q->subs[] is sorted by pts so we could do a binary search */ - for (i = 0; i < q->nb_subs; i++) { - int64_t pts = q->subs[i].pts; - uint64_t ts_diff = FFABS(pts - ts); - if ((stream_index == -1 || q->subs[i].stream_index == stream_index) && - pts >= min_ts && pts <= max_ts && ts_diff < min_ts_diff) { - min_ts_diff = ts_diff; - idx = i; - } - } + 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 */ - ts_selected = q->subs[idx].pts; for (i = idx - 1; i >= 0; i--) { int64_t pts = q->subs[i].pts; if (q->subs[i].duration <= 0 || |