/* * Seeking and index-related functions * Copyright (c) 2000, 2001, 2002 Fabrice Bellard * * 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 <stdint.h> #include "libavutil/avassert.h" #include "libavutil/mathematics.h" #include "libavutil/timestamp.h" #include "avformat.h" #include "avio_internal.h" #include "internal.h" void avpriv_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp) { for (unsigned i = 0; i < s->nb_streams; i++) { AVStream *const st = s->streams[i]; FFStream *const sti = ffstream(st); sti->cur_dts = av_rescale(timestamp, st->time_base.den * (int64_t) ref_st->time_base.num, st->time_base.num * (int64_t) ref_st->time_base.den); } } void ff_reduce_index(AVFormatContext *s, int stream_index) { AVStream *const st = s->streams[stream_index]; FFStream *const sti = ffstream(st); unsigned int max_entries = s->max_index_size / sizeof(AVIndexEntry); if ((unsigned) sti->nb_index_entries >= max_entries) { int i; for (i = 0; 2 * i < sti->nb_index_entries; i++) sti->index_entries[i] = sti->index_entries[2 * i]; sti->nb_index_entries = i; } } int ff_add_index_entry(AVIndexEntry **index_entries, int *nb_index_entries, unsigned int *index_entries_allocated_size, int64_t pos, int64_t timestamp, int size, int distance, int flags) { AVIndexEntry *entries, *ie; int index; if ((unsigned) *nb_index_entries + 1 >= UINT_MAX / sizeof(AVIndexEntry)) return -1; if (timestamp == AV_NOPTS_VALUE) return AVERROR(EINVAL); if (size < 0 || size > 0x3FFFFFFF) return AVERROR(EINVAL); if (is_relative(timestamp)) //FIXME this maintains previous behavior but we should shift by the correct offset once known timestamp -= RELATIVE_TS_BASE; entries = av_fast_realloc(*index_entries, index_entries_allocated_size, (*nb_index_entries + 1) * sizeof(AVIndexEntry)); if (!entries) return -1; *index_entries = entries; index = ff_index_search_timestamp(*index_entries, *nb_index_entries, timestamp, AVSEEK_FLAG_ANY); if (index < 0) { index = (*nb_index_entries)++; ie = &entries[index]; av_assert0(index == 0 || ie[-1].timestamp < timestamp); } else { ie = &entries[index]; if (ie->timestamp != timestamp) { if (ie->timestamp <= timestamp) return -1; memmove(entries + index + 1, entries + index, sizeof(AVIndexEntry) * (*nb_index_entries - index)); (*nb_index_entries)++; } else if (ie->pos == pos && distance < ie->min_distance) // do not reduce the distance distance = ie->min_distance; } ie->pos = pos; ie->timestamp = timestamp; ie->min_distance = distance; ie->size = size; ie->flags = flags; return index; } int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags) { FFStream *const sti = ffstream(st); timestamp = ff_wrap_timestamp(st, timestamp); return ff_add_index_entry(&sti->index_entries, &sti->nb_index_entries, &sti->index_entries_allocated_size, pos, timestamp, size, distance, flags); } int ff_index_search_timestamp(const AVIndexEntry *entries, int nb_entries, int64_t wanted_timestamp, int flags) { int a, b, m; int64_t timestamp; a = -1; b = nb_entries; // Optimize appending index entries at the end. if (b && entries[b - 1].timestamp < wanted_timestamp) a = b - 1; while (b - a > 1) { m = (a + b) >> 1; // Search for the next non-discarded packet. while ((entries[m].flags & AVINDEX_DISCARD_FRAME) && m < b && m < nb_entries - 1) { m++; if (m == b && entries[m].timestamp >= wanted_timestamp) { m = b - 1; break; } } timestamp = entries[m].timestamp; if (timestamp >= wanted_timestamp) b = m; if (timestamp <= wanted_timestamp) a = m; } m = (flags & AVSEEK_FLAG_BACKWARD) ? a : b; if (!(flags & AVSEEK_FLAG_ANY)) while (m >= 0 && m < nb_entries && !(entries[m].flags & AVINDEX_KEYFRAME)) m += (flags & AVSEEK_FLAG_BACKWARD) ? -1 : 1; if (m == nb_entries) return -1; return m; } void ff_configure_buffers_for_index(AVFormatContext *s, int64_t time_tolerance) { int64_t pos_delta = 0; int64_t skip = 0; //We could use URLProtocol flags here but as many user applications do not use URLProtocols this would be unreliable const char *proto = avio_find_protocol_name(s->url); FFIOContext *ctx; av_assert0(time_tolerance >= 0); if (!proto) { av_log(s, AV_LOG_INFO, "Protocol name not provided, cannot determine if input is local or " "a network protocol, buffers and access patterns cannot be configured " "optimally without knowing the protocol\n"); } if (proto && !(strcmp(proto, "file") && strcmp(proto, "pipe") && strcmp(proto, "cache"))) return; for (unsigned ist1 = 0; ist1 < s->nb_streams; ist1++) { AVStream *const st1 = s->streams[ist1]; FFStream *const sti1 = ffstream(st1); for (unsigned ist2 = 0; ist2 < s->nb_streams; ist2++) { AVStream *const st2 = s->streams[ist2]; FFStream *const sti2 = ffstream(st2); if (ist1 == ist2) continue; for (int i1 = 0, i2 = 0; i1 < sti1->nb_index_entries; i1++) { const AVIndexEntry *const e1 = &sti1->index_entries[i1]; int64_t e1_pts = av_rescale_q(e1->timestamp, st1->time_base, AV_TIME_BASE_Q); skip = FFMAX(skip, e1->size); for (; i2 < sti2->nb_index_entries; i2++) { const AVIndexEntry *const e2 = &sti2->index_entries[i2]; int64_t e2_pts = av_rescale_q(e2->timestamp, st2->time_base, AV_TIME_BASE_Q); if (e2_pts < e1_pts || e2_pts - (uint64_t)e1_pts < time_tolerance) continue; pos_delta = FFMAX(pos_delta, e1->pos - e2->pos); break; } } } } pos_delta *= 2; ctx = ffiocontext(s->pb); /* XXX This could be adjusted depending on protocol*/ if (s->pb->buffer_size < pos_delta && pos_delta < (1<<24)) { av_log(s, AV_LOG_VERBOSE, "Reconfiguring buffers to size %"PRId64"\n", pos_delta); /* realloc the buffer and the original data will be retained */ if (ffio_realloc_buf(s->pb, pos_delta)) { av_log(s, AV_LOG_ERROR, "Realloc buffer fail.\n"); return; } ctx->short_seek_threshold = FFMAX(ctx->short_seek_threshold, pos_delta/2); } if (skip < (1<<23)) { ctx->short_seek_threshold = FFMAX(ctx->short_seek_threshold, skip); } } int av_index_search_timestamp(AVStream *st, int64_t wanted_timestamp, int flags) { const FFStream *const sti = ffstream(st); return ff_index_search_timestamp(sti->index_entries, sti->nb_index_entries, wanted_timestamp, flags); } int avformat_index_get_entries_count(const AVStream *st) { return cffstream(st)->nb_index_entries; } const AVIndexEntry *avformat_index_get_entry(AVStream *st, int idx) { const FFStream *const sti = ffstream(st); if (idx < 0 || idx >= sti->nb_index_entries) return NULL; return &sti->index_entries[idx]; } const AVIndexEntry *avformat_index_get_entry_from_timestamp(AVStream *st, int64_t wanted_timestamp, int flags) { const FFStream *const sti = ffstream(st); int idx = ff_index_search_timestamp(sti->index_entries, sti->nb_index_entries, wanted_timestamp, flags); if (idx < 0) return NULL; return &sti->index_entries[idx]; } static int64_t read_timestamp(AVFormatContext *s, int stream_index, int64_t *ppos, int64_t pos_limit, int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t )) { int64_t ts = read_timestamp(s, stream_index, ppos, pos_limit); if (stream_index >= 0) ts = ff_wrap_timestamp(s->streams[stream_index], ts); return ts; } int ff_seek_frame_binary(AVFormatContext *s, int stream_index, int64_t target_ts, int flags) { const AVInputFormat *const avif = s->iformat; int64_t pos_min = 0, pos_max = 0, pos, pos_limit; int64_t ts_min, ts_max, ts; int index; int64_t ret; AVStream *st; FFStream *sti; if (stream_index < 0) return -1; av_log(s, AV_LOG_TRACE, "read_seek: %d %s\n", stream_index, av_ts2str(target_ts)); ts_max = ts_min = AV_NOPTS_VALUE; pos_limit = -1; // GCC falsely says it may be uninitialized. st = s->streams[stream_index]; sti = ffstream(st); if (sti->index_entries) { const AVIndexEntry *e; /* FIXME: Whole function must be checked for non-keyframe entries in * index case, especially read_timestamp(). */ index = av_index_search_timestamp(st, target_ts, flags | AVSEEK_FLAG_BACKWARD); index = FFMAX(index, 0); e = &sti->index_entries[index]; if (e->timestamp <= target_ts || e->pos == e->min_distance) { pos_min = e->pos; ts_min = e->timestamp; av_log(s, AV_LOG_TRACE, "using cached pos_min=0x%"PRIx64" dts_min=%s\n", pos_min, av_ts2str(ts_min)); } else { av_assert1(index == 0); } index = av_index_search_timestamp(st, target_ts, flags & ~AVSEEK_FLAG_BACKWARD); av_assert0(index < sti->nb_index_entries); if (index >= 0) { e = &sti->index_entries[index]; av_assert1(e->timestamp >= target_ts); pos_max = e->pos; ts_max = e->timestamp; pos_limit = pos_max - e->min_distance; av_log(s, AV_LOG_TRACE, "using cached pos_max=0x%"PRIx64" pos_limit=0x%"PRIx64 " dts_max=%s\n", pos_max, pos_limit, av_ts2str(ts_max)); } } pos = ff_gen_search(s, stream_index, target_ts, pos_min, pos_max, pos_limit, ts_min, ts_max, flags, &ts, avif->read_timestamp); if (pos < 0) return -1; /* do the seek */ if ((ret = avio_seek(s->pb, pos, SEEK_SET)) < 0) return ret; ff_read_frame_flush(s); avpriv_update_cur_dts(s, st, ts); return 0; } int ff_find_last_ts(AVFormatContext *s, int stream_index, int64_t *ts, int64_t *pos, int64_t (*read_timestamp_func)(struct AVFormatContext *, int , int64_t *, int64_t )) { int64_t step = 1024; int64_t limit, ts_max; int64_t filesize = avio_size(s->pb); int64_t pos_max = filesize - 1; do { limit = pos_max; pos_max = FFMAX(0, (pos_max) - step); ts_max = read_timestamp(s, stream_index, &pos_max, limit, read_timestamp_func); step += step; } while (ts_max == AV_NOPTS_VALUE && 2*limit > step); if (ts_max == AV_NOPTS_VALUE) return -1; for (;;) { int64_t tmp_pos = pos_max + 1; int64_t tmp_ts = read_timestamp(s, stream_index, &tmp_pos, INT64_MAX, read_timestamp_func); if (tmp_ts == AV_NOPTS_VALUE) break; av_assert0(tmp_pos > pos_max); ts_max = tmp_ts; pos_max = tmp_pos; if (tmp_pos >= filesize) break; } if (ts) *ts = ts_max; if (pos) *pos = pos_max; return 0; } int64_t ff_gen_search(AVFormatContext *s, int stream_index, int64_t target_ts, int64_t pos_min, int64_t pos_max, int64_t pos_limit, int64_t ts_min, int64_t ts_max, int flags, int64_t *ts_ret, int64_t (*read_timestamp_func)(struct AVFormatContext *, int, int64_t *, int64_t)) { FFFormatContext *const si = ffformatcontext(s); int64_t pos, ts; int64_t start_pos; int no_change; int ret; av_log(s, AV_LOG_TRACE, "gen_seek: %d %s\n", stream_index, av_ts2str(target_ts)); if (ts_min == AV_NOPTS_VALUE) { pos_min = si->data_offset; ts_min = read_timestamp(s, stream_index, &pos_min, INT64_MAX, read_timestamp_func); if (ts_min == AV_NOPTS_VALUE) return -1; } if (ts_min >= target_ts) { *ts_ret = ts_min; return pos_min; } if (ts_max == AV_NOPTS_VALUE) { if ((ret = ff_find_last_ts(s, stream_index, &ts_max, &pos_max, read_timestamp_func)) < 0) return ret; pos_limit = pos_max; } if (ts_max <= target_ts) { *ts_ret = ts_max; return pos_max; } av_assert0(ts_min < ts_max); no_change = 0; while (pos_min < pos_limit) { av_log(s, AV_LOG_TRACE, "pos_min=0x%"PRIx64" pos_max=0x%"PRIx64" dts_min=%s dts_max=%s\n", pos_min, pos_max, av_ts2str(ts_min), av_ts2str(ts_max)); av_assert0(pos_limit <= pos_max); if (no_change == 0) { int64_t approximate_keyframe_distance = pos_max - pos_limit; // interpolate position (better than dichotomy) pos = av_rescale(target_ts - ts_min, pos_max - pos_min, ts_max - ts_min) + pos_min - approximate_keyframe_distance; } else if (no_change == 1) { // bisection if interpolation did not change min / max pos last time pos = (pos_min + pos_limit) >> 1; } else { /* linear search if bisection failed, can only happen if there * are very few or no keyframes between min/max */ pos = pos_min; } if (pos <= pos_min) pos = pos_min + 1; else if (pos > pos_limit) pos = pos_limit; start_pos = pos; // May pass pos_limit instead of -1. ts = read_timestamp(s, stream_index, &pos, INT64_MAX, read_timestamp_func); if (pos == pos_max) no_change++; else no_change = 0; av_log(s, AV_LOG_TRACE, "%"PRId64" %"PRId64" %"PRId64" / %s %s %s" " target:%s limit:%"PRId64" start:%"PRId64" noc:%d\n", pos_min, pos, pos_max, av_ts2str(ts_min), av_ts2str(ts), av_ts2str(ts_max), av_ts2str(target_ts), pos_limit, start_pos, no_change); if (ts == AV_NOPTS_VALUE) { av_log(s, AV_LOG_ERROR, "read_timestamp() failed in the middle\n"); return -1; } if (target_ts <= ts) { pos_limit = start_pos - 1; pos_max = pos; ts_max = ts; } if (target_ts >= ts) { pos_min = pos; ts_min = ts; } } pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max; ts = (flags & AVSEEK_FLAG_BACKWARD) ? ts_min : ts_max; #if 0 pos_min = pos; ts_min = read_timestamp(s, stream_index, &pos_min, INT64_MAX, read_timestamp_func); pos_min++; ts_max = read_timestamp(s, stream_index, &pos_min, INT64_MAX, read_timestamp_func); av_log(s, AV_LOG_TRACE, "pos=0x%"PRIx64" %s<=%s<=%s\n", pos, av_ts2str(ts_min), av_ts2str(target_ts), av_ts2str(ts_max)); #endif *ts_ret = ts; return pos; } static int seek_frame_byte(AVFormatContext *s, int stream_index, int64_t pos, int flags) { FFFormatContext *const si = ffformatcontext(s); int64_t pos_min, pos_max; pos_min = si->data_offset; pos_max = avio_size(s->pb) - 1; if (pos < pos_min) pos = pos_min; else if (pos > pos_max) pos = pos_max; avio_seek(s->pb, pos, SEEK_SET); s->io_repositioned = 1; return 0; } static int seek_frame_generic(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) { FFFormatContext *const si = ffformatcontext(s); AVStream *const st = s->streams[stream_index]; FFStream *const sti = ffstream(st); const AVIndexEntry *ie; int index; int64_t ret; index = av_index_search_timestamp(st, timestamp, flags); if (index < 0 && sti->nb_index_entries && timestamp < sti->index_entries[0].timestamp) return -1; if (index < 0 || index == sti->nb_index_entries - 1) { AVPacket *const pkt = si->pkt; int nonkey = 0; if (sti->nb_index_entries) { av_assert0(sti->index_entries); ie = &sti->index_entries[sti->nb_index_entries - 1]; if ((ret = avio_seek(s->pb, ie->pos, SEEK_SET)) < 0) return ret; s->io_repositioned = 1; avpriv_update_cur_dts(s, st, ie->timestamp); } else { if ((ret = avio_seek(s->pb, si->data_offset, SEEK_SET)) < 0) return ret; s->io_repositioned = 1; } av_packet_unref(pkt); for (;;) { int read_status; do { read_status = av_read_frame(s, pkt); } while (read_status == AVERROR(EAGAIN)); if (read_status < 0) break; if (stream_index == pkt->stream_index && pkt->dts > timestamp) { if (pkt->flags & AV_PKT_FLAG_KEY) { av_packet_unref(pkt); break; } if (nonkey++ > 1000 && st->codecpar->codec_id != AV_CODEC_ID_CDGRAPHICS) { av_log(s, AV_LOG_ERROR,"seek_frame_generic failed as this stream seems to contain no keyframes after the target timestamp, %d non keyframes found\n", nonkey); av_packet_unref(pkt); break; } } av_packet_unref(pkt); } index = av_index_search_timestamp(st, timestamp, flags); } if (index < 0) return -1; ff_read_frame_flush(s); if (s->iformat->read_seek) if (s->iformat->read_seek(s, stream_index, timestamp, flags) >= 0) return 0; ie = &sti->index_entries[index]; if ((ret = avio_seek(s->pb, ie->pos, SEEK_SET)) < 0) return ret; s->io_repositioned = 1; avpriv_update_cur_dts(s, st, ie->timestamp); return 0; } static int seek_frame_internal(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) { AVStream *st; int ret; if (flags & AVSEEK_FLAG_BYTE) { if (s->iformat->flags & AVFMT_NO_BYTE_SEEK) return -1; ff_read_frame_flush(s); return seek_frame_byte(s, stream_index, timestamp, flags); } if (stream_index < 0) { stream_index = av_find_default_stream_index(s); if (stream_index < 0) return -1; st = s->streams[stream_index]; /* timestamp for default must be expressed in AV_TIME_BASE units */ timestamp = av_rescale(timestamp, st->time_base.den, AV_TIME_BASE * (int64_t) st->time_base.num); } /* first, we try the format specific seek */ if (s->iformat->read_seek) { ff_read_frame_flush(s); ret = s->iformat->read_seek(s, stream_index, timestamp, flags); } else ret = -1; if (ret >= 0) return 0; if (s->iformat->read_timestamp && !(s->iformat->flags & AVFMT_NOBINSEARCH)) { ff_read_frame_flush(s); return ff_seek_frame_binary(s, stream_index, timestamp, flags); } else if (!(s->iformat->flags & AVFMT_NOGENSEARCH)) { ff_read_frame_flush(s); return seek_frame_generic(s, stream_index, timestamp, flags); } else return -1; } int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) { int ret; if (s->iformat->read_seek2 && !s->iformat->read_seek) { int64_t min_ts = INT64_MIN, max_ts = INT64_MAX; if ((flags & AVSEEK_FLAG_BACKWARD)) max_ts = timestamp; else min_ts = timestamp; return avformat_seek_file(s, stream_index, min_ts, timestamp, max_ts, flags & ~AVSEEK_FLAG_BACKWARD); } ret = seek_frame_internal(s, stream_index, timestamp, flags); if (ret >= 0) ret = avformat_queue_attached_pictures(s); return ret; } int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags) { if (min_ts > ts || max_ts < ts) return -1; if (stream_index < -1 || stream_index >= (int)s->nb_streams) return AVERROR(EINVAL); if (s->seek2any > 0) flags |= AVSEEK_FLAG_ANY; flags &= ~AVSEEK_FLAG_BACKWARD; if (s->iformat->read_seek2) { int ret; ff_read_frame_flush(s); if (stream_index == -1 && s->nb_streams == 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 | AV_ROUND_PASS_MINMAX); max_ts = av_rescale_rnd(max_ts, time_base.den, time_base.num * (int64_t)AV_TIME_BASE, AV_ROUND_DOWN | AV_ROUND_PASS_MINMAX); stream_index = 0; } ret = s->iformat->read_seek2(s, stream_index, min_ts, ts, max_ts, flags); if (ret >= 0) ret = avformat_queue_attached_pictures(s); return ret; } if (s->iformat->read_timestamp) { // try to seek via read_timestamp() } // Fall back on old API if new is not implemented but old is. // Note the old API has somewhat different semantics. if (s->iformat->read_seek || 1) { int dir = (ts - (uint64_t)min_ts > (uint64_t)max_ts - ts ? AVSEEK_FLAG_BACKWARD : 0); int ret = av_seek_frame(s, stream_index, ts, flags | dir); if (ret < 0 && ts != min_ts && max_ts != ts) { ret = av_seek_frame(s, stream_index, dir ? max_ts : min_ts, flags | dir); if (ret >= 0) ret = av_seek_frame(s, stream_index, ts, flags | (dir^AVSEEK_FLAG_BACKWARD)); } return ret; } // try some generic seek like seek_frame_generic() but with new ts semantics return -1; //unreachable } /** Flush the frame reader. */ void ff_read_frame_flush(AVFormatContext *s) { FFFormatContext *const si = ffformatcontext(s); ff_flush_packet_queue(s); /* Reset read state for each stream. */ for (unsigned i = 0; i < s->nb_streams; i++) { AVStream *const st = s->streams[i]; FFStream *const sti = ffstream(st); if (sti->parser) { av_parser_close(sti->parser); sti->parser = NULL; } sti->last_IP_pts = AV_NOPTS_VALUE; sti->last_dts_for_order_check = AV_NOPTS_VALUE; if (sti->first_dts == AV_NOPTS_VALUE) sti->cur_dts = RELATIVE_TS_BASE; else /* We set the current DTS to an unspecified origin. */ sti->cur_dts = AV_NOPTS_VALUE; sti->probe_packets = s->max_probe_packets; for (int j = 0; j < MAX_REORDER_DELAY + 1; j++) sti->pts_buffer[j] = AV_NOPTS_VALUE; if (si->inject_global_side_data) sti->inject_global_side_data = 1; sti->skip_samples = 0; } } int avformat_flush(AVFormatContext *s) { ff_read_frame_flush(s); return 0; }