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-rw-r--r--libavformat/seek.c753
1 files changed, 753 insertions, 0 deletions
diff --git a/libavformat/seek.c b/libavformat/seek.c
new file mode 100644
index 0000000000..40169736df
--- /dev/null
+++ b/libavformat/seek.c
@@ -0,0 +1,753 @@
+/*
+ * 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 av_uninit(pos_min), av_uninit(pos_max), 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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-27 19:25:20 +0000