1 files changed, 719 insertions, 0 deletions

diff --git a/demux/demux_timeline.c b/demux/demux_timeline.c
new file mode 100644
index 0000000..5572fb5
--- /dev/null
+++ b/demux/demux_timeline.c
@@ -0,0 +1,719 @@
+/*
+ * 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"
+#include "stream/stream.h"
+
+struct segment {
+    int index; // index into virtual_source.segments[] (and timeline.parts[])
+    double start, end;
+    double d_start;
+    char *url;
+    bool lazy;
+    struct demuxer *d;
+    // stream_map[sh_stream.index] = virtual_stream, where sh_stream is a stream
+    // from the source d, and virtual_stream is a streamexported by the
+    // timeline demuxer (virtual_stream.sh). It's used to map the streams of the
+    // source onto the set of streams of the virtual timeline.
+    // Uses NULL for streams that do not appear in the virtual timeline.
+    struct virtual_stream **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)
+    int eos_packets;            // deal with b-frame delay
+    struct virtual_source *src; // group this stream is part of
+};
+
+// This represents a single timeline source. (See timeline.pars[]. For each
+// timeline_par struct there is a virtual_source.)
+struct virtual_source {
+    struct timeline_par *tl;
+
+    bool dash, no_clip, delay_open;
+
+    struct segment **segments;
+    int num_segments;
+    struct segment *current;
+
+    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;
+
+    bool eof_reached;
+    double dts;                 // highest read DTS (or PTS if no DTS available)
+    bool any_selected;          // at least one stream is actually selected
+
+    struct demux_packet *next;
+};
+
+struct priv {
+    struct timeline *tl;
+    bool owns_tl;
+
+    double duration;
+
+    // As the demuxer user sees it.
+    struct virtual_stream **streams;
+    int num_streams;
+
+    struct virtual_source **sources;
+    int num_sources;
+};
+
+static void update_slave_stats(struct demuxer *demuxer, struct demuxer *slave)
+{
+    demux_report_unbuffered_read_bytes(demuxer, demux_get_bytes_read_hack(slave));
+}
+
+static bool target_stream_used(struct segment *seg, struct virtual_stream *vs)
+{
+    for (int n = 0; n < seg->num_stream_map; n++) {
+        if (seg->stream_map[n] == vs)
+            return true;
+    }
+    return false;
+}
+
+// Create mapping from segment streams to virtual timeline streams.
+static void associate_streams(struct demuxer *demuxer,
+                              struct virtual_source *src,
+                              struct segment *seg)
+{
+    if (!seg->d || seg->stream_map)
+        return;
+
+    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);
+        struct virtual_stream *other = NULL;
+
+        for (int i = 0; i < src->num_streams; i++) {
+            struct virtual_stream *vs = src->streams[i];
+
+            // The stream must always have the same media type. Also, a stream
+            // can't be assigned multiple times.
+            if (sh->type != vs->sh->type || target_stream_used(seg, vs))
+                continue;
+
+            // By default pick the first matching stream.
+            if (!other)
+                other = vs;
+
+            // Matching by demuxer ID is supposedly useful and preferable for
+            // ordered chapters.
+            if (sh->demuxer_id >= 0 && sh->demuxer_id == vs->sh->demuxer_id)
+                other = vs;
+        }
+
+        if (!other) {
+            MP_WARN(demuxer, "Source stream %d (%s) unused and hidden.\n",
+                    n, stream_type_name(sh->type));
+        }
+
+        MP_TARRAY_APPEND(seg, seg->stream_map, seg->num_stream_map, other);
+    }
+}
+
+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 x = 0; x < p->num_sources; x++) {
+        struct virtual_source *src = p->sources[x];
+
+        for (int n = 0; n < src->num_segments; n++) {
+            struct segment *seg = src->segments[n];
+
+            if (!seg->d)
+                continue;
+
+            for (int i = 0; i < seg->num_stream_map; i++) {
+                bool selected =
+                    seg->stream_map[i] && seg->stream_map[i]->selected;
+
+                // This stops demuxer readahead for inactive segments.
+                if (!src->current || seg->d != src->current->d)
+                    selected = false;
+                struct sh_stream *sh = demux_get_stream(seg->d, i);
+                demuxer_select_track(seg->d, sh, MP_NOPTS_VALUE, selected);
+
+                update_slave_stats(demuxer, seg->d);
+            }
+        }
+
+        bool was_selected = src->any_selected;
+        src->any_selected = false;
+
+        for (int n = 0; n < src->num_streams; n++)
+            src->any_selected |= src->streams[n]->selected;
+
+        if (!was_selected && src->any_selected) {
+            src->eof_reached = false;
+            src->dts = MP_NOPTS_VALUE;
+            TA_FREEP(&src->next);
+        }
+    }
+}
+
+static void close_lazy_segments(struct demuxer *demuxer,
+                                struct virtual_source *src)
+{
+    // unload previous segment
+    for (int n = 0; n < src->num_segments; n++) {
+        struct segment *seg = src->segments[n];
+        if (seg != src->current && seg->d && seg->lazy) {
+            TA_FREEP(&src->next); // might depend on one of the sub-demuxers
+            demux_free(seg->d);
+            seg->d = NULL;
+        }
+    }
+}
+
+static void reopen_lazy_segments(struct demuxer *demuxer,
+                                 struct virtual_source *src)
+{
+    if (src->current->d)
+        return;
+
+    // Note: in delay_open mode, we must _not_ close segments during demuxing,
+    // because demuxed packets have demux_packet.codec set to objects owned
+    // by the segments. Closing them would create dangling pointers.
+    if (!src->delay_open)
+        close_lazy_segments(demuxer, src);
+
+    struct demuxer_params params = {
+        .init_fragment = src->tl->init_fragment,
+        .skip_lavf_probing = src->tl->dash,
+        .stream_flags = demuxer->stream_origin,
+    };
+    src->current->d = demux_open_url(src->current->url, &params,
+                                     demuxer->cancel, demuxer->global);
+    if (!src->current->d && !demux_cancel_test(demuxer))
+        MP_ERR(demuxer, "failed to load segment\n");
+    if (src->current->d)
+        update_slave_stats(demuxer, src->current->d);
+    associate_streams(demuxer, src, src->current);
+}
+
+static void switch_segment(struct demuxer *demuxer, struct virtual_source *src,
+                           struct segment *new, double start_pts, int flags,
+                           bool init)
+{
+    if (!(flags & SEEK_FORWARD))
+        flags |= SEEK_HR;
+
+    MP_VERBOSE(demuxer, "switch to segment %d\n", new->index);
+
+    if (src->current && src->current->d)
+        update_slave_stats(demuxer, src->current->d);
+
+    src->current = new;
+    reopen_lazy_segments(demuxer, src);
+    if (!new->d)
+        return;
+    reselect_streams(demuxer);
+    if (!src->no_clip)
+        demux_set_ts_offset(new->d, new->start - new->d_start);
+    if (!src->no_clip || !init)
+        demux_seek(new->d, start_pts, flags);
+
+    for (int n = 0; n < src->num_streams; n++) {
+        struct virtual_stream *vs = src->streams[n];
+        vs->eos_packets = 0;
+    }
+
+    src->eof_reached = false;
+    src->eos_packets = 0;
+}
+
+static void do_read_next_packet(struct demuxer *demuxer,
+                                struct virtual_source *src)
+{
+    if (src->next)
+        return;
+
+    struct segment *seg = src->current;
+    if (!seg || !seg->d) {
+        src->eof_reached = true;
+        return;
+    }
+
+    struct demux_packet *pkt = demux_read_any_packet(seg->d);
+    if (!pkt || (!src->no_clip && pkt->pts >= seg->end))
+        src->eos_packets += 1;
+
+    update_slave_stats(demuxer, seg->d);
+
+    // 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 = src->eos_packets > 0;
+    if (eos_reached && src->eos_packets < 100) {
+        for (int n = 0; n < src->num_streams; n++) {
+            struct virtual_stream *vs = src->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;
+            }
+        }
+    }
+
+    src->eof_reached = false;
+
+    if (eos_reached || !pkt) {
+        talloc_free(pkt);
+
+        struct segment *next = NULL;
+        for (int n = 0; n < src->num_segments - 1; n++) {
+            if (src->segments[n] == seg) {
+                next = src->segments[n + 1];
+                break;
+            }
+        }
+        if (!next) {
+            src->eof_reached = true;
+            return;
+        }
+        switch_segment(demuxer, src, next, next->start, 0, true);
+        return; // reader will retry
+    }
+
+    if (pkt->stream < 0 || pkt->stream >= seg->num_stream_map)
+        goto drop;
+
+    if (!src->no_clip || src->delay_open) {
+        pkt->segmented = true;
+        if (!pkt->codec)
+            pkt->codec = demux_get_stream(seg->d, pkt->stream)->codec;
+    }
+    if (!src->no_clip) {
+        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;
+    }
+
+    struct virtual_stream *vs = seg->stream_map[pkt->stream];
+    if (!vs)
+        goto drop;
+
+    // for refresh seeks, demux.c prefers monotonically increasing packet pos
+    // since the packet pos is meaningless anyway for timeline, use it
+    if (pkt->pos >= 0)
+        pkt->pos |= (seg->index & 0x7FFFULL) << 48;
+
+    if (pkt->pts != MP_NOPTS_VALUE && !src->no_clip && 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;
+        }
+    }
+
+    double dts = pkt->dts != MP_NOPTS_VALUE ? pkt->dts : pkt->pts;
+    if (src->dts == MP_NOPTS_VALUE || (dts != MP_NOPTS_VALUE && dts > src->dts))
+        src->dts = dts;
+
+    pkt->stream = vs->sh->index;
+    src->next = pkt;
+    return;
+
+drop:
+    talloc_free(pkt);
+}
+
+static bool d_read_packet(struct demuxer *demuxer, struct demux_packet **out_pkt)
+{
+    struct priv *p = demuxer->priv;
+    struct virtual_source *src = NULL;
+
+    for (int x = 0; x < p->num_sources; x++) {
+        struct virtual_source *cur = p->sources[x];
+
+        if (!cur->any_selected || cur->eof_reached)
+            continue;
+
+        if (!cur->current)
+            switch_segment(demuxer, cur, cur->segments[0], 0, 0, true);
+
+        if (!cur->any_selected || !cur->current || !cur->current->d)
+            continue;
+
+        if (!src || cur->dts == MP_NOPTS_VALUE ||
+            (src->dts != MP_NOPTS_VALUE && cur->dts < src->dts))
+            src = cur;
+    }
+
+    if (!src)
+        return false;
+
+    do_read_next_packet(demuxer, src);
+    *out_pkt = src->next;
+    src->next = NULL;
+    return true;
+}
+
+static void seek_source(struct demuxer *demuxer, struct virtual_source *src,
+                        double pts, int flags)
+{
+    struct segment *new = src->segments[src->num_segments - 1];
+    for (int n = 0; n < src->num_segments; n++) {
+        if (pts < src->segments[n]->end) {
+            new = src->segments[n];
+            break;
+        }
+    }
+
+    switch_segment(demuxer, src, new, pts, flags, false);
+
+    src->dts = MP_NOPTS_VALUE;
+    TA_FREEP(&src->next);
+}
+
+static void d_seek(struct demuxer *demuxer, double seek_pts, int flags)
+{
+    struct priv *p = demuxer->priv;
+
+    seek_pts = seek_pts * ((flags & SEEK_FACTOR) ? p->duration : 1);
+    flags &= SEEK_FORWARD | SEEK_HR;
+
+    // The intention is to seek audio streams to the same target as video
+    // streams if they are separate streams. Video streams usually have more
+    // coarse keyframe snapping, which could leave video without audio.
+    struct virtual_source *master = NULL;
+    bool has_slaves = false;
+    for (int x = 0; x < p->num_sources; x++) {
+        struct virtual_source *src = p->sources[x];
+
+        bool any_audio = false, any_video = false;
+        for (int i = 0; i < src->num_streams; i++) {
+            struct virtual_stream *str = src->streams[i];
+            if (str->selected) {
+                if (str->sh->type == STREAM_VIDEO)
+                    any_video = true;
+                if (str->sh->type == STREAM_AUDIO)
+                    any_audio = true;
+            }
+        }
+
+        if (any_video)
+            master = src;
+        // A true slave stream is audio-only; this also prevents that the master
+        // stream is considered a slave stream.
+        if (any_audio && !any_video)
+            has_slaves = true;
+    }
+
+    if (!has_slaves)
+        master = NULL;
+
+    if (master) {
+        seek_source(demuxer, master, seek_pts, flags);
+        do_read_next_packet(demuxer, master);
+        if (master->next && master->next->pts != MP_NOPTS_VALUE) {
+            // Assume we got a seek target. Actually apply the heuristic.
+            MP_VERBOSE(demuxer, "adjust seek target from %f to %f\n", seek_pts,
+                       master->next->pts);
+            seek_pts = master->next->pts;
+            flags &= ~(unsigned)SEEK_FORWARD;
+        }
+    }
+
+    for (int x = 0; x < p->num_sources; x++) {
+        struct virtual_source *src = p->sources[x];
+        if (src != master && src->any_selected)
+            seek_source(demuxer, src, seek_pts, flags);
+    }
+}
+
+static void print_timeline(struct demuxer *demuxer)
+{
+    struct priv *p = demuxer->priv;
+
+    MP_VERBOSE(demuxer, "Timeline segments:\n");
+    for (int x = 0; x < p->num_sources; x++) {
+        struct virtual_source *src = p->sources[x];
+
+        if (x >= 1)
+            MP_VERBOSE(demuxer, " --- new parallel stream ---\n");
+
+        for (int n = 0; n < src->num_segments; n++) {
+            struct segment *seg = src->segments[n];
+            int src_num = n;
+            for (int i = 0; i < n; i++) {
+                if (seg->d && src->segments[i]->d == seg->d) {
+                    src_num = i;
+                    break;
+                }
+            }
+            MP_VERBOSE(demuxer, " %2d: %12f - %12f [%12f] (",
+                       n, seg->start, seg->end, seg->d_start);
+            for (int i = 0; i < seg->num_stream_map; i++) {
+                struct virtual_stream *vs = seg->stream_map[i];
+                MP_VERBOSE(demuxer, "%s%d", i ? " " : "",
+                           vs ? vs->sh->index : -1);
+            }
+            MP_VERBOSE(demuxer, ")\n  source %d:'%s'\n", src_num, seg->url);
+        }
+
+        if (src->dash)
+            MP_VERBOSE(demuxer, " (Using pseudo-DASH mode.)\n");
+    }
+    MP_VERBOSE(demuxer, "Total duration: %f\n", p->duration);
+}
+
+// Copy various (not all) metadata fields from src to dst, but try not to
+// overwrite fields in dst that are unset in src.
+// May keep data from src by reference.
+// Imperfect and arbitrary, only suited for EDL stuff.
+static void apply_meta(struct sh_stream *dst, struct sh_stream *src)
+{
+    if (src->demuxer_id >= 0)
+        dst->demuxer_id = src->demuxer_id;
+    if (src->title)
+        dst->title = src->title;
+    if (src->lang)
+        dst->lang = src->lang;
+    dst->default_track = src->default_track;
+    dst->forced_track = src->forced_track;
+    if (src->hls_bitrate)
+        dst->hls_bitrate = src->hls_bitrate;
+    dst->missing_timestamps = src->missing_timestamps;
+    if (src->attached_picture)
+        dst->attached_picture = src->attached_picture;
+    dst->image = src->image;
+}
+
+// This is mostly for EDL user-defined metadata.
+static struct sh_stream *find_matching_meta(struct timeline_par *tl, int index)
+{
+    for (int n = 0; n < tl->num_sh_meta; n++) {
+        struct sh_stream *sh = tl->sh_meta[n];
+        if (sh->index == index || sh->index < 0)
+            return sh;
+    }
+    return NULL;
+}
+
+static bool add_tl(struct demuxer *demuxer, struct timeline_par *tl)
+{
+    struct priv *p = demuxer->priv;
+
+    struct virtual_source *src = talloc_ptrtype(p, src);
+    *src = (struct virtual_source){
+        .tl = tl,
+        .dash = tl->dash,
+        .delay_open = tl->delay_open,
+        .no_clip = tl->no_clip || tl->dash,
+        .dts = MP_NOPTS_VALUE,
+    };
+
+    if (!tl->num_parts)
+        return false;
+
+    MP_TARRAY_APPEND(p, p->sources, p->num_sources, src);
+
+    p->duration = MPMAX(p->duration, tl->parts[tl->num_parts - 1].end);
+
+    struct demuxer *meta = tl->track_layout;
+
+    // delay_open streams normally have meta==NULL, and 1 virtual stream
+    int num_streams = 0;
+    if (tl->delay_open) {
+        num_streams = tl->num_sh_meta;
+    } else if (meta) {
+        num_streams = demux_get_num_stream(meta);
+    }
+    for (int n = 0; n < num_streams; n++) {
+        struct sh_stream *new = NULL;
+
+        if (tl->delay_open) {
+            struct sh_stream *tsh = tl->sh_meta[n];
+            new = demux_alloc_sh_stream(tsh->type);
+            new->codec = tsh->codec;
+            apply_meta(new, tsh);
+            demuxer->is_network = true;
+            demuxer->is_streaming = true;
+        } else {
+            struct sh_stream *sh = demux_get_stream(meta, n);
+            new = demux_alloc_sh_stream(sh->type);
+            apply_meta(new, sh);
+            new->codec = sh->codec;
+            struct sh_stream *tsh = find_matching_meta(tl, n);
+            if (tsh)
+                apply_meta(new, tsh);
+        }
+
+        demux_add_sh_stream(demuxer, new);
+        struct virtual_stream *vs = talloc_ptrtype(p, vs);
+        *vs = (struct virtual_stream){
+            .src = src,
+            .sh = new,
+        };
+        MP_TARRAY_APPEND(p, p->streams, p->num_streams, vs);
+        assert(demux_get_stream(demuxer, p->num_streams - 1) == new);
+        MP_TARRAY_APPEND(src, src->streams, src->num_streams, vs);
+    }
+
+    for (int n = 0; n < tl->num_parts; n++) {
+        struct timeline_part *part = &tl->parts[n];
+
+        // demux_timeline already does caching, doing it for the sub-demuxers
+        // would be pointless and wasteful.
+        if (part->source) {
+            demuxer->is_network |= part->source->is_network;
+            demuxer->is_streaming |= part->source->is_streaming;
+        }
+
+        if (!part->source)
+            assert(tl->dash || tl->delay_open);
+
+        struct segment *seg = talloc_ptrtype(src, seg);
+        *seg = (struct segment){
+            .d = part->source,
+            .url = part->source ? part->source->filename : part->url,
+            .lazy = !part->source,
+            .d_start = part->source_start,
+            .start = part->start,
+            .end = part->end,
+        };
+
+        associate_streams(demuxer, src, seg);
+
+        seg->index = n;
+        MP_TARRAY_APPEND(src, src->segments, src->num_segments, seg);
+    }
+
+    if (tl->track_layout) {
+        demuxer->is_network |= tl->track_layout->is_network;
+        demuxer->is_streaming |= tl->track_layout->is_streaming;
+    }
+    return true;
+}
+
+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_pars < 1)
+        return -1;
+
+    demuxer->chapters = p->tl->chapters;
+    demuxer->num_chapters = p->tl->num_chapters;
+
+    struct demuxer *meta = p->tl->meta;
+    if (meta) {
+        demuxer->metadata = meta->metadata;
+        demuxer->attachments = meta->attachments;
+        demuxer->num_attachments = meta->num_attachments;
+        demuxer->editions = meta->editions;
+        demuxer->num_editions = meta->num_editions;
+        demuxer->edition = meta->edition;
+    }
+
+    for (int n = 0; n < p->tl->num_pars; n++) {
+        if (!add_tl(demuxer, p->tl->pars[n]))
+            return -1;
+    }
+
+    if (!p->num_sources)
+        return -1;
+
+    demuxer->is_network |= p->tl->is_network;
+    demuxer->is_streaming |= p->tl->is_streaming;
+
+    demuxer->duration = p->duration;
+
+    print_timeline(demuxer);
+
+    demuxer->seekable = true;
+    demuxer->partially_seekable = false;
+
+    const char *format_name = "unknown";
+    if (meta)
+        format_name = meta->filetype ? meta->filetype : meta->desc->name;
+    demuxer->filetype = talloc_asprintf(p, "%s/%s", p->tl->format, format_name);
+
+    reselect_streams(demuxer);
+
+    p->owns_tl = true;
+    return 0;
+}
+
+static void d_close(struct demuxer *demuxer)
+{
+    struct priv *p = demuxer->priv;
+
+    for (int x = 0; x < p->num_sources; x++) {
+        struct virtual_source *src = p->sources[x];
+
+        src->current = NULL;
+        TA_FREEP(&src->next);
+        close_lazy_segments(demuxer, src);
+    }
+
+    if (p->owns_tl) {
+        struct demuxer *master = p->tl->demuxer;
+        timeline_destroy(p->tl);
+        demux_free(master);
+    }
+}
+
+static void d_switched_tracks(struct demuxer *demuxer)
+{
+    reselect_streams(demuxer);
+}
+
+const demuxer_desc_t demuxer_desc_timeline = {
+    .name = "timeline",
+    .desc = "timeline segments",
+    .read_packet = d_read_packet,
+    .open = d_open,
+    .close = d_close,
+    .seek = d_seek,
+    .switched_tracks = d_switched_tracks,
+};