mpv/demux/demux_timeline.c

387 lines
12 KiB
C

/*
* This file is part of mpv.
*
* mpv 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.
*
* mpv 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 mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include <limits.h>
#include "common/common.h"
#include "common/msg.h"
#include "demux.h"
#include "timeline.h"
#include "stheader.h"
struct segment {
int index;
double start, end;
double d_start;
struct demuxer *d;
// stream_map[sh_stream.index] = index into priv.streams, where sh_stream
// is a stream from the source d. It's used to map the streams of the
// source onto the set of streams of the virtual timeline.
// Uses -1 for streams that do not appear in the virtual timeline.
int *stream_map;
int num_stream_map;
};
// Information for each stream on the virtual timeline. (Mirrors streams
// exposed by demux_timeline.)
struct virtual_stream {
struct sh_stream *sh; // stream exported by demux_timeline
bool selected; // ==demux_stream_is_selected(sh)
bool new_segment; // whether a new segment needs to be signaled
int eos_packets; // deal with b-frame delay
};
struct priv {
struct timeline *tl;
double duration;
struct segment **segments;
int num_segments;
struct segment *current;
// As the demuxer user sees it.
struct virtual_stream *streams;
int num_streams;
// Total number of packets received past end of segment. Used
// to be clever about determining when to switch segments.
int eos_packets;
};
static void reselect_streams(struct demuxer *demuxer)
{
struct priv *p = demuxer->priv;
for (int n = 0; n < p->num_streams; n++) {
struct virtual_stream *vs = &p->streams[n];
vs->selected = demux_stream_is_selected(vs->sh);
}
for (int n = 0; n < p->num_segments; n++) {
struct segment *seg = p->segments[n];
for (int i = 0; i < seg->num_stream_map; i++) {
struct sh_stream *sh = demux_get_stream(seg->d, i);
bool selected = false;
if (seg->stream_map[i] >= 0)
selected = p->streams[seg->stream_map[i]].selected;
// This stops demuxer readahead for inactive segments.
if (!p->current || seg->d != p->current->d)
selected = false;
demuxer_select_track(seg->d, sh, selected);
}
}
}
static void switch_segment(struct demuxer *demuxer, struct segment *new,
double start_pts, int flags)
{
struct priv *p = demuxer->priv;
bool new_segment = p->current != new;
if (!(flags & (SEEK_FORWARD | SEEK_BACKWARD)))
flags |= SEEK_BACKWARD | SEEK_HR;
MP_VERBOSE(demuxer, "switch to segment %d\n", new->index);
p->current = new;
reselect_streams(demuxer);
demux_set_ts_offset(new->d, new->start - new->d_start);
demux_seek(new->d, start_pts, flags);
for (int n = 0; n < p->num_streams; n++) {
struct virtual_stream *vs = &p->streams[n];
if (new_segment)
vs->new_segment = true;
vs->eos_packets = 0;
}
p->eos_packets = 0;
}
static void d_seek(struct demuxer *demuxer, double seek_pts, int flags)
{
struct priv *p = demuxer->priv;
double pts = seek_pts * ((flags & SEEK_FACTOR) ? p->duration : 1);
flags &= SEEK_FORWARD | SEEK_BACKWARD | SEEK_HR;
struct segment *new = p->segments[p->num_segments - 1];
for (int n = 0; n < p->num_segments; n++) {
if (pts < p->segments[n]->end) {
new = p->segments[n];
break;
}
}
switch_segment(demuxer, new, pts, flags);
}
static int d_fill_buffer(struct demuxer *demuxer)
{
struct priv *p = demuxer->priv;
if (!p->current)
switch_segment(demuxer, p->segments[0], 0, 0);
struct segment *seg = p->current;
struct demux_packet *pkt = demux_read_any_packet(seg->d);
if (!pkt || pkt->pts >= seg->end)
p->eos_packets += 1;
// Test for EOF. Do this here to properly run into EOF even if other
// streams are disabled etc. If it somehow doesn't manage to reach the end
// after demuxing a high (bit arbitrary) number of packets, assume one of
// the streams went EOF early.
bool eos_reached = p->eos_packets > 0;
if (eos_reached && p->eos_packets < 100) {
for (int n = 0; n < p->num_streams; n++) {
struct virtual_stream *vs = &p->streams[n];
if (vs->selected) {
int max_packets = 0;
if (vs->sh->type == STREAM_AUDIO)
max_packets = 1;
if (vs->sh->type == STREAM_VIDEO)
max_packets = 16;
eos_reached &= vs->eos_packets >= max_packets;
}
}
}
if (eos_reached || !pkt) {
talloc_free(pkt);
struct segment *next = NULL;
for (int n = 0; n < p->num_segments - 1; n++) {
if (p->segments[n] == seg) {
next = p->segments[n + 1];
break;
}
}
if (!next)
return 0;
switch_segment(demuxer, next, next->start, 0);
return 1; // reader will retry
}
if (pkt->stream < 0 || pkt->stream > seg->num_stream_map)
goto drop;
if (!pkt->codec)
pkt->codec = demux_get_stream(seg->d, pkt->stream)->codec;
if (pkt->start == MP_NOPTS_VALUE || pkt->start < seg->start)
pkt->start = seg->start;
if (pkt->end == MP_NOPTS_VALUE || pkt->end > seg->end)
pkt->end = seg->end;
pkt->stream = seg->stream_map[pkt->stream];
if (pkt->stream < 0)
goto drop;
struct virtual_stream *vs = &p->streams[pkt->stream];
if (pkt->pts != MP_NOPTS_VALUE && pkt->pts >= seg->end) {
// Trust the keyframe flag. Might not always be a good idea, but will
// be sufficient at least with mkv. The problem is that this flag is
// not well-defined in libavformat and is container-dependent.
if (pkt->keyframe || vs->eos_packets == INT_MAX) {
vs->eos_packets = INT_MAX;
goto drop;
} else {
vs->eos_packets += 1;
}
}
pkt->new_segment |= vs->new_segment;
vs->new_segment = false;
demux_add_packet(vs->sh, pkt);
return 1;
drop:
talloc_free(pkt);
return 1;
}
static void print_timeline(struct demuxer *demuxer)
{
struct priv *p = demuxer->priv;
MP_VERBOSE(demuxer, "Timeline segments:\n");
for (int n = 0; n < p->num_segments; n++) {
struct segment *seg = p->segments[n];
int src_num = -1;
for (int i = 0; i < p->tl->num_sources; i++) {
if (p->tl->sources[i] == seg->d) {
src_num = i;
break;
}
}
MP_VERBOSE(demuxer, " %2d: %12f [%12f] (", n, seg->start, seg->d_start);
for (int i = 0; i < seg->num_stream_map; i++)
MP_VERBOSE(demuxer, "%s%d", i ? " " : "", seg->stream_map[i]);
MP_VERBOSE(demuxer, ") %d:'%s'\n", src_num, seg->d->filename);
}
MP_VERBOSE(demuxer, "Total duration: %f\n", p->duration);
}
static bool target_stream_used(struct segment *seg, int target_index)
{
for (int n = 0; n < seg->num_stream_map; n++) {
if (seg->stream_map[n] == target_index)
return true;
}
return false;
}
// Create mapping from segment streams to virtual timeline streams.
static void associate_streams(struct demuxer *demuxer, struct segment *seg)
{
struct priv *p = demuxer->priv;
int counts[STREAM_TYPE_COUNT] = {0};
int num_streams = demux_get_num_stream(seg->d);
for (int n = 0; n < num_streams; n++) {
struct sh_stream *sh = demux_get_stream(seg->d, n);
// Try associating by demuxer ID (supposedly useful for ordered chapters).
struct sh_stream *other =
demuxer_stream_by_demuxer_id(demuxer, sh->type, sh->demuxer_id);
if (!other || !target_stream_used(seg, other->index)) {
// Try to associate the first unused stream with matching media type.
for (int i = 0; i < p->num_streams; i++) {
struct sh_stream *cur = p->streams[i].sh;
if (cur->type == sh->type && !target_stream_used(seg, cur->index))
{
other = cur;
break;
}
}
}
MP_TARRAY_APPEND(seg, seg->stream_map, seg->num_stream_map,
other ? other->index : -1);
counts[sh->type] += 1;
}
}
static int d_open(struct demuxer *demuxer, enum demux_check check)
{
struct priv *p = demuxer->priv = talloc_zero(demuxer, struct priv);
p->tl = demuxer->params ? demuxer->params->timeline : NULL;
if (!p->tl || p->tl->num_parts < 1)
return -1;
p->duration = p->tl->parts[p->tl->num_parts].start;
demuxer->chapters = p->tl->chapters;
demuxer->num_chapters = p->tl->num_chapters;
struct demuxer *meta = p->tl->track_layout;
demuxer->metadata = meta->metadata;
demuxer->attachments = meta->attachments;
demuxer->num_attachments = meta->num_attachments;
int num_streams = demux_get_num_stream(meta);
for (int n = 0; n < num_streams; n++) {
struct sh_stream *sh = demux_get_stream(meta, n);
struct sh_stream *new = demux_alloc_sh_stream(sh->type);
new->demuxer_id = sh->demuxer_id;
new->codec = sh->codec;
new->title = sh->title;
new->lang = sh->lang;
new->default_track = sh->default_track;
new->forced_track = sh->forced_track;
new->hls_bitrate = sh->hls_bitrate;
new->missing_timestamps = sh->missing_timestamps;
demux_add_sh_stream(demuxer, new);
struct virtual_stream vs = {
.sh = new,
};
MP_TARRAY_APPEND(p, p->streams, p->num_streams, vs);
}
for (int n = 0; n < p->tl->num_parts; n++) {
struct timeline_part *part = &p->tl->parts[n];
struct timeline_part *next = &p->tl->parts[n + 1];
struct segment *seg = talloc_ptrtype(p, seg);
*seg = (struct segment){
.d = part->source,
.d_start = part->source_start,
.start = part->start,
.end = next->start,
};
associate_streams(demuxer, seg);
seg->index = n;
MP_TARRAY_APPEND(p, p->segments, p->num_segments, seg);
}
print_timeline(demuxer);
demuxer->seekable = true;
demuxer->partially_seekable = false;
demuxer->filetype = meta->filetype ? meta->filetype : meta->desc->name;
reselect_streams(demuxer);
return 0;
}
static void d_close(struct demuxer *demuxer)
{
struct priv *p = demuxer->priv;
struct demuxer *master = p->tl->demuxer;
timeline_destroy(p->tl);
free_demuxer(master);
}
static int d_control(struct demuxer *demuxer, int cmd, void *arg)
{
struct priv *p = demuxer->priv;
switch (cmd) {
case DEMUXER_CTRL_GET_TIME_LENGTH: {
*(double *)arg = p->duration;
return DEMUXER_CTRL_OK;
}
case DEMUXER_CTRL_SWITCHED_TRACKS:
reselect_streams(demuxer);
return DEMUXER_CTRL_OK;
}
return DEMUXER_CTRL_NOTIMPL;
}
const demuxer_desc_t demuxer_desc_timeline = {
.name = "timeline",
.desc = "timeline segments",
.fill_buffer = d_fill_buffer,
.open = d_open,
.close = d_close,
.seek = d_seek,
.control = d_control,
};