chromium/media/formats/webm/webm_parser.h

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_FORMATS_WEBM_WEBM_PARSER_H_
#define MEDIA_FORMATS_WEBM_WEBM_PARSER_H_

#include <stdint.h>

#include <string>
#include <vector>

#include "base/memory/raw_ptr.h"
#include "media/base/media_export.h"

namespace media {

// Interface for receiving WebM parser events.
//
// Each method is called when an element of the specified type is parsed.
// The ID of the element that was parsed is given along with the value
// stored in the element. List elements generate calls at the start and
// end of the list. Any pointers passed to these methods are only guaranteed
// to be valid for the life of that call. Each method (except for OnListStart)
// returns a bool that indicates whether the parsed data is valid. OnListStart
// returns a pointer to a WebMParserClient object, which should be used to
// handle elements parsed out of the list being started. If false (or NULL by
// OnListStart) is returned then the parse is immediately terminated and an
// error is reported by the parser.
class MEDIA_EXPORT WebMParserClient { … };

struct ListElementInfo;

// Parses a WebM list element and all of its children. This
// class supports incremental parsing of the list so Parse()
// can be called multiple times with pieces of the list.
// IsParsingComplete() will return true once the entire list has
// been parsed.
class MEDIA_EXPORT WebMListParser { … };

// Parses an element header & returns the ID and element size.
//
// Returns < 0 if the parse fails.
// Returns 0 if more data is needed.
// Returning > 0 indicates success & the number of bytes parsed.
// |*id| contains the element ID on success and is undefined otherwise.
// |*element_size| contains the element size on success and is undefined
//                 otherwise.
int MEDIA_EXPORT WebMParseElementHeader(const uint8_t* buf,
                                        int size,
                                        int* id,
                                        int64_t* element_size);

}  // namespace media

#endif  // MEDIA_FORMATS_WEBM_WEBM_PARSER_H_