mpv/demux/ebml.h

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/*
* This file is part of MPlayer.
*
* MPlayer is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* MPlayer 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with MPlayer; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPLAYER_EBML_H
#define MPLAYER_EBML_H
#include <inttypes.h>
#include <stddef.h>
#include <stdbool.h>
#include "stream/stream.h"
#include "core/bstr.h"
/* EBML version supported */
#define EBML_VERSION 1
enum ebml_elemtype {
EBML_TYPE_SUBELEMENTS,
EBML_TYPE_UINT,
EBML_TYPE_SINT,
EBML_TYPE_FLOAT,
EBML_TYPE_STR,
EBML_TYPE_BINARY,
EBML_TYPE_EBML_ID,
};
struct ebml_field_desc {
uint32_t id;
bool multiple;
int offset;
int count_offset;
const struct ebml_elem_desc *desc;
};
struct ebml_elem_desc {
char *name;
enum ebml_elemtype type;
int size;
int field_count;
const struct ebml_field_desc *fields;
};
struct ebml_parse_ctx {
void *talloc_ctx;
int bytes_read;
bool has_errors;
bool no_error_messages;
};
#include "ebml_types.h"
#define EBML_ID_INVALID 0xffffffff
/* matroska track types */
#define MATROSKA_TRACK_VIDEO 0x01 /* rectangle-shaped pictures aka video */
#define MATROSKA_TRACK_AUDIO 0x02 /* anything you can hear */
#define MATROSKA_TRACK_COMPLEX 0x03 /* audio+video in same track used by DV */
#define MATROSKA_TRACK_LOGO 0x10 /* overlay-pictures displayed over video*/
#define MATROSKA_TRACK_SUBTITLE 0x11 /* text-subtitles */
#define MATROSKA_TRACK_CONTROL 0x20 /* control-codes for menu or other stuff*/
#ifndef UINT64_MAX
#define UINT64_MAX 18446744073709551615ULL
#endif
#ifndef INT64_MAX
#define INT64_MAX 9223372036854775807LL
#endif
#define EBML_UINT_INVALID UINT64_MAX
#define EBML_INT_INVALID INT64_MAX
#define EBML_FLOAT_INVALID -1000000000.0
uint32_t ebml_read_id (stream_t *s, int *length);
uint64_t ebml_read_vlen_uint (bstr *buffer);
int64_t ebml_read_vlen_int (bstr *buffer);
uint64_t ebml_read_length (stream_t *s, int *length);
uint64_t ebml_read_uint (stream_t *s, uint64_t *length);
int64_t ebml_read_int (stream_t *s, uint64_t *length);
double ebml_read_float (stream_t *s, uint64_t *length);
char *ebml_read_ascii (stream_t *s, uint64_t *length);
char *ebml_read_utf8 (stream_t *s, uint64_t *length);
int ebml_read_skip (stream_t *s, uint64_t *length);
demux_mkv: improve robustness against broken files Fixes test7.mkv from the Matroska test file collection, as well as some real broken files I've found in the wild. (Unfortunately, true recovery requires resetting the decoders and playback state with a manual seek, but it's still better than just exiting.) If there are broken EBML elements, try harder to skip them correctly. Do this by searching for the next cluster element. The cluster element intentionally has a long ID, so it's a suitable element for resynchronizing (mkvmerge does something similar). We know that data is corrupt if the ID or length fields of an element are malformed. Additionally, if skipping an unknown element goes past the end of the file, we assume it's corrupt and undo the seek. Do this because it often happens that corrupt data is interpreted as correct EBML elements. Since these elements will have a ridiculous values in their length fields due to the large value range that is possible (0-2^56-2), they will go past the end of the file. So instead of skipping them (which would result in playback termination), try to find the next cluster instead. (We still skip unknown elements that are within the file, as this is needed for correct operation. Also, we first execute the seek, because we don't really know where the file ends. Doing it this way is better for unseekable streams too, because it will still work in the non-error case.) This is done as special case in the packet reading function only. On the other hand, that's the only part of the file that's read after initialization is done.
2013-03-27 23:01:17 +00:00
int ebml_read_skip_or_resync_cluster(stream_t *s, uint64_t *length);
int ebml_resync_cluster(stream_t *s);
uint32_t ebml_read_master (stream_t *s, uint64_t *length);
int ebml_read_element(struct stream *s, struct ebml_parse_ctx *ctx,
void *target, const struct ebml_elem_desc *desc);
#endif /* MPLAYER_EBML_H */