mpv/demux/demux_edl.c

327 lines
10 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)
};
struct tl_parts {
struct tl_part *parts;
int num_parts;
};
struct priv {
bstr data;
};
// 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;
}
/* 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_parts *parse_edl(bstr str)
{
struct tl_parts *tl = talloc_zero(NULL, struct tl_parts);
while (str.len) {
if (bstr_eatstart0(&str, "#"))
bstr_split_tok(str, "\n", &(bstr){0}, &str);
if (bstr_eatstart0(&str, "\n") || bstr_eatstart0(&str, ";"))
continue;
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 {
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 (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;
}
nparam++;
if (!bstr_eatstart0(&str, ","))
break;
}
if (!p.filename)
goto error;
MP_TARRAY_APPEND(tl, tl->parts, tl->num_parts, p);
}
if (!tl->num_parts)
goto error;
return tl;
error:
talloc_free(tl);
return NULL;
}
static struct demuxer *open_source(struct timeline *tl, char *filename)
{
for (int n = 0; n < tl->num_sources; n++) {
struct demuxer *d = tl->sources[n];
if (strcmp(d->stream->url, filename) == 0)
return d;
}
struct demuxer *d = demux_open_url(filename, NULL, tl->cancel, tl->global);
if (d) {
MP_TARRAY_APPEND(tl, tl->sources, tl->num_sources, d);
} else {
MP_ERR(tl, "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);
}
}
}
// return length of the source in seconds, or -1 if unknown
static double source_get_length(struct demuxer *demuxer)
{
double time;
// <= 0 means DEMUXER_CTRL_NOTIMPL or DEMUXER_CTRL_DONTKNOW
if (demux_control(demuxer, DEMUXER_CTRL_GET_TIME_LENGTH, &time) <= 0)
time = -1;
return time;
}
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 void build_timeline(struct timeline *tl, struct tl_parts *parts)
{
tl->parts = talloc_array_ptrtype(tl, tl->parts, parts->num_parts + 1);
double starttime = 0;
for (int n = 0; n < parts->num_parts; n++) {
struct tl_part *part = &parts->parts[n];
struct demuxer *source = open_source(tl, part->filename);
if (!source)
goto error;
resolve_timestamps(part, source);
double end_time = source_get_length(source);
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(tl, "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(tl, "EDL: entry %d uses %f "
"seconds, but file has only %f seconds.\n",
n, end_part, end_time);
}
}
// 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->filename);
MP_TARRAY_APPEND(tl, tl->chapters, tl->num_chapters, ch);
// Also copy the source file's chapters for the relevant parts
copy_chapters(&tl->chapters, &tl->num_chapters, source, part->offset,
part->length, starttime);
tl->parts[n] = (struct timeline_part) {
.start = starttime,
.source_start = part->offset,
.source = source,
};
starttime += part->length;
}
tl->parts[parts->num_parts] = (struct timeline_part) {.start = starttime};
tl->num_parts = parts->num_parts;
tl->track_layout = tl->parts[0].source;
return;
error:
tl->num_parts = 0;
tl->num_chapters = 0;
}
// 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_parts *parts = parse_edl(p->data);
if (!parts) {
MP_ERR(tl, "Error in EDL.\n");
return;
}
MP_TARRAY_APPEND(tl, tl->sources, tl->num_sources, tl->demuxer);
// Source is .edl and not edl:// => don't allow arbitrary paths
if (tl->demuxer->stream->uncached_type != STREAMTYPE_EDL)
fix_filenames(parts, tl->demuxer->filename);
build_timeline(tl, parts);
talloc_free(parts);
}
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->uncached_type == STREAMTYPE_EDL) {
p->data = bstr0(s->path);
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);
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,
};