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mpv/demux/demux_edl.c
wm4 5901c3ae0d demux_edl: fix assertion failure on exit in obscure ytdl cases
If a DASH-hack EDL has an init fragment is set, it opens the init
fragment as such to get the track layout (including codec etc.) and
avoids opening actual fragments until actual playback. It does not get
added to the source array, so it leaks on exit, which triggers an
obscure (but very justified) assertion in thread_tools.c:106. Fix the
leak by adding the additional demuxer instance to the sources arrays,
which gets it freed.

This is a regression from when I rewrote some of the timeline handling.
I decided that in order to make memory management slightly simpler,
freeing a timeline should only free elements in the sources array. That
is OK; I just didn't re-test with pseudo-DASH that has init fragments,
and just hit a video that uses that by accidents. These videos are
rather scarce (apparently) so it happened only now.

The real solution would probably be adding demuxer reference counting.
This EDL memory management is just too messy, and throwing refcounting
at such problems is an effective and popular fix. Then you'd get
debugging nightmares with incorrect refcounts too, though.
2019-09-19 20:37:04 +02:00

460 lines
15 KiB
C

/*
* Original author: Uoti Urpala
*
* 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 <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <inttypes.h>
#include <math.h>
#include "mpv_talloc.h"
#include "demux.h"
#include "timeline.h"
#include "common/msg.h"
#include "options/path.h"
#include "misc/bstr.h"
#include "common/common.h"
#include "stream/stream.h"
#define HEADER "# mpv EDL v0\n"
struct tl_part {
char *filename; // what is stream_open()ed
double offset; // offset into the source file
bool offset_set;
bool chapter_ts;
double length; // length of the part (-1 if rest of the file)
char *title;
};
struct tl_parts {
bool disable_chapters;
bool dash, no_clip;
char *init_fragment_url;
struct tl_part *parts;
int num_parts;
struct tl_parts *next;
};
struct tl_root {
struct tl_parts **pars;
int num_pars;
};
struct priv {
bstr data;
bool allow_any;
};
// Parse a time (absolute file time or duration). Currently equivalent to a
// number. Return false on failure.
static bool parse_time(bstr str, double *out_time)
{
bstr rest;
double time = bstrtod(str, &rest);
if (!str.len || rest.len || !isfinite(time))
return false;
*out_time = time;
return true;
}
static struct tl_parts *add_part(struct tl_root *root)
{
struct tl_parts *tl = talloc_zero(root, struct tl_parts);
MP_TARRAY_APPEND(root, root->pars, root->num_pars, tl);
return tl;
}
/* Returns a list of parts, or NULL on parse error.
* Syntax (without file header or URI prefix):
* url ::= <entry> ( (';' | '\n') <entry> )*
* entry ::= <param> ( <param> ',' )*
* param ::= [<string> '='] (<string> | '%' <number> '%' <bytes>)
*/
static struct tl_root *parse_edl(bstr str)
{
struct tl_root *root = talloc_zero(NULL, struct tl_root);
struct tl_parts *tl = add_part(root);
while (str.len) {
if (bstr_eatstart0(&str, "#")) {
bstr_split_tok(str, "\n", &(bstr){0}, &str);
continue;
}
if (bstr_eatstart0(&str, "\n") || bstr_eatstart0(&str, ";"))
continue;
bool is_header = bstr_eatstart0(&str, "!");
bstr f_type = {0};
bstr f_init = {0};
struct tl_part p = { .length = -1 };
int nparam = 0;
while (1) {
bstr name, val;
// Check if it's of the form "name=..."
int next = bstrcspn(str, "=%,;\n");
if (next > 0 && next < str.len && str.start[next] == '=') {
name = bstr_splice(str, 0, next);
str = bstr_cut(str, next + 1);
} else if (is_header) {
const char *names[] = {"type"}; // implied name
name = bstr0(nparam < 1 ? names[nparam] : "-");
} else {
const char *names[] = {"file", "start", "length"}; // implied name
name = bstr0(nparam < 3 ? names[nparam] : "-");
}
if (bstr_eatstart0(&str, "%")) {
int len = bstrtoll(str, &str, 0);
if (!bstr_startswith0(str, "%") || (len > str.len - 1))
goto error;
val = bstr_splice(str, 1, len + 1);
str = bstr_cut(str, len + 1);
} else {
next = bstrcspn(str, ",;\n");
val = bstr_splice(str, 0, next);
str = bstr_cut(str, next);
}
// Interpret parameters. Explicitly ignore unknown ones.
if (is_header) {
if (bstr_equals0(name, "type")) {
f_type = val;
} else if (bstr_equals0(name, "init")) {
f_init = val;
}
} else {
if (bstr_equals0(name, "file")) {
p.filename = bstrto0(tl, val);
} else if (bstr_equals0(name, "start")) {
if (!parse_time(val, &p.offset))
goto error;
p.offset_set = true;
} else if (bstr_equals0(name, "length")) {
if (!parse_time(val, &p.length))
goto error;
} else if (bstr_equals0(name, "timestamps")) {
if (bstr_equals0(val, "chapters"))
p.chapter_ts = true;
} else if (bstr_equals0(name, "title")) {
p.title = bstrto0(tl, val);
}
}
nparam++;
if (!bstr_eatstart0(&str, ","))
break;
}
if (is_header) {
if (bstr_equals0(f_type, "mp4_dash")) {
tl->dash = true;
if (f_init.len)
tl->init_fragment_url = bstrto0(tl, f_init);
} else if (bstr_equals0(f_type, "no_clip")) {
tl->no_clip = true;
} else if (bstr_equals0(f_type, "new_stream")) {
tl = add_part(root);
} else if (bstr_equals0(f_type, "no_chapters")) {
tl->disable_chapters = true;
} else {
goto error;
}
} else {
if (!p.filename)
goto error;
MP_TARRAY_APPEND(tl, tl->parts, tl->num_parts, p);
}
}
if (!root->num_pars)
goto error;
for (int n = 0; n < root->num_pars; n++) {
if (root->pars[n]->num_parts < 1)
goto error;
}
return root;
error:
talloc_free(root);
return NULL;
}
static struct demuxer *open_source(struct timeline *root,
struct timeline_par *tl, char *filename)
{
for (int n = 0; n < tl->num_parts; n++) {
struct demuxer *d = tl->parts[n].source;
if (d && strcmp(d->stream->url, filename) == 0)
return d;
}
struct demuxer_params params = {
.init_fragment = tl->init_fragment,
};
struct demuxer *d = demux_open_url(filename, &params, root->cancel,
root->global);
if (d) {
MP_TARRAY_APPEND(root, root->sources, root->num_sources, d);
} else {
MP_ERR(root, "EDL: Could not open source file '%s'.\n", filename);
}
return d;
}
static double demuxer_chapter_time(struct demuxer *demuxer, int n)
{
if (n < 0 || n >= demuxer->num_chapters)
return -1;
return demuxer->chapters[n].pts;
}
// Append all chapters from src to the chapters array.
// Ignore chapters outside of the given time range.
static void copy_chapters(struct demux_chapter **chapters, int *num_chapters,
struct demuxer *src, double start, double len,
double dest_offset)
{
for (int n = 0; n < src->num_chapters; n++) {
double time = demuxer_chapter_time(src, n);
if (time >= start && time <= start + len) {
struct demux_chapter ch = {
.pts = dest_offset + time - start,
.metadata = mp_tags_dup(*chapters, src->chapters[n].metadata),
};
MP_TARRAY_APPEND(NULL, *chapters, *num_chapters, ch);
}
}
}
static void resolve_timestamps(struct tl_part *part, struct demuxer *demuxer)
{
if (part->chapter_ts) {
double start = demuxer_chapter_time(demuxer, part->offset);
double length = part->length;
double end = length;
if (end >= 0)
end = demuxer_chapter_time(demuxer, part->offset + part->length);
if (end >= 0 && start >= 0)
length = end - start;
part->offset = start;
part->length = length;
}
if (!part->offset_set)
part->offset = demuxer->start_time;
}
static struct timeline_par *build_timeline(struct timeline *root,
struct tl_parts *parts)
{
struct timeline_par *tl = talloc_zero(root, struct timeline_par);
MP_TARRAY_APPEND(root, root->pars, root->num_pars, tl);
tl->track_layout = NULL;
tl->dash = parts->dash;
tl->no_clip = parts->no_clip;
if (parts->init_fragment_url && parts->init_fragment_url[0]) {
MP_VERBOSE(root, "Opening init fragment...\n");
stream_t *s = stream_create(parts->init_fragment_url, STREAM_READ,
root->cancel, root->global);
if (s)
tl->init_fragment = stream_read_complete(s, tl, 1000000);
free_stream(s);
if (!tl->init_fragment.len) {
MP_ERR(root, "Could not read init fragment.\n");
goto error;
}
struct demuxer_params params = {
.init_fragment = tl->init_fragment,
};
tl->track_layout = demux_open_url("memory://", &params, root->cancel,
root->global);
if (!tl->track_layout) {
MP_ERR(root, "Could not demux init fragment.\n");
goto error;
}
MP_TARRAY_APPEND(root, root->sources, root->num_sources, tl->track_layout);
}
tl->parts = talloc_array_ptrtype(tl, tl->parts, parts->num_parts);
double starttime = 0;
for (int n = 0; n < parts->num_parts; n++) {
struct tl_part *part = &parts->parts[n];
struct demuxer *source = NULL;
if (tl->dash) {
part->offset = starttime;
if (part->length <= 0)
MP_WARN(root, "Segment %d has unknown duration.\n", n);
if (part->offset_set)
MP_WARN(root, "Offsets are ignored.\n");
if (!tl->track_layout)
tl->track_layout = open_source(root, tl, part->filename);
} else {
MP_VERBOSE(root, "Opening segment %d...\n", n);
source = open_source(root, tl, part->filename);
if (!source)
goto error;
resolve_timestamps(part, source);
double end_time = source->duration;
if (end_time >= 0)
end_time += source->start_time;
// Unknown length => use rest of the file. If duration is unknown, make
// something up.
if (part->length < 0) {
if (end_time < 0) {
MP_WARN(root, "EDL: source file '%s' has unknown duration.\n",
part->filename);
end_time = 1;
}
part->length = end_time - part->offset;
} else if (end_time >= 0) {
double end_part = part->offset + part->length;
if (end_part > end_time) {
MP_WARN(root, "EDL: entry %d uses %f "
"seconds, but file has only %f seconds.\n",
n, end_part, end_time);
}
}
if (!parts->disable_chapters) {
// Add a chapter between each file.
struct demux_chapter ch = {
.pts = starttime,
.metadata = talloc_zero(tl, struct mp_tags),
};
mp_tags_set_str(ch.metadata, "title",
part->title ? part->title : part->filename);
MP_TARRAY_APPEND(root, root->chapters, root->num_chapters, ch);
// Also copy the source file's chapters for the relevant parts
copy_chapters(&root->chapters, &root->num_chapters, source,
part->offset, part->length, starttime);
}
}
tl->parts[n] = (struct timeline_part) {
.start = starttime,
.end = starttime + part->length,
.source_start = part->offset,
.source = source,
.url = talloc_strdup(tl, part->filename),
};
starttime = tl->parts[n].end;
if (source && !tl->track_layout)
tl->track_layout = source;
}
if (!tl->track_layout)
goto error;
if (!root->meta)
root->meta = tl->track_layout;
tl->num_parts = parts->num_parts;
return tl;
error:
root->num_pars = 0;
return NULL;
}
// For security, don't allow relative or absolute paths, only plain filenames.
// Also, make these filenames relative to the edl source file.
static void fix_filenames(struct tl_parts *parts, char *source_path)
{
struct bstr dirname = mp_dirname(source_path);
for (int n = 0; n < parts->num_parts; n++) {
struct tl_part *part = &parts->parts[n];
char *filename = mp_basename(part->filename); // plain filename only
part->filename = mp_path_join_bstr(parts, dirname, bstr0(filename));
}
}
static void build_mpv_edl_timeline(struct timeline *tl)
{
struct priv *p = tl->demuxer->priv;
struct tl_root *root = parse_edl(p->data);
if (!root) {
MP_ERR(tl, "Error in EDL.\n");
return;
}
bool all_dash = true;
bool all_no_clip = true;
bool all_single = true;
for (int n = 0; n < root->num_pars; n++) {
struct tl_parts *parts = root->pars[n];
if (!p->allow_any)
fix_filenames(parts, tl->demuxer->filename);
struct timeline_par *par = build_timeline(tl, parts);
if (!par)
break;
all_dash &= par->dash;
all_no_clip &= par->no_clip;
all_single &= par->num_parts == 1;
}
if (all_dash) {
tl->format = "dash";
} else if (all_no_clip && all_single) {
tl->format = "multi";
} else {
tl->format = "edl";
}
talloc_free(root);
}
static int try_open_file(struct demuxer *demuxer, enum demux_check check)
{
if (!demuxer->access_references)
return -1;
struct priv *p = talloc_zero(demuxer, struct priv);
demuxer->priv = p;
demuxer->fully_read = true;
struct stream *s = demuxer->stream;
if (s->info && strcmp(s->info->name, "edl") == 0) {
p->data = bstr0(s->path);
// Source is edl:// and not .edl => allow arbitrary paths
p->allow_any = true;
return 0;
}
if (check >= DEMUX_CHECK_UNSAFE) {
if (!bstr_equals0(stream_peek(s, strlen(HEADER)), HEADER))
return -1;
}
p->data = stream_read_complete(s, demuxer, 1000000);
if (p->data.start == NULL)
return -1;
bstr_eatstart0(&p->data, HEADER);
demux_close_stream(demuxer);
return 0;
}
const struct demuxer_desc demuxer_desc_edl = {
.name = "edl",
.desc = "Edit decision list",
.open = try_open_file,
.load_timeline = build_mpv_edl_timeline,
};