gecko-dev/dom/media/MediaMIMETypes.h

212 строки
7.4 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef MediaMIMETypes_h_
#define MediaMIMETypes_h_
#include "VideoUtils.h"
#include "mozilla/Maybe.h"
#include "nsString.h"
namespace mozilla {
// Class containing pointing at a media MIME "type/subtype" string literal.
// See IsMediaMIMEType for restrictions.
// Mainly used to help construct a MediaMIMEType through the statically-checked
// MEDIAMIMETYPE macro, or to compare a MediaMIMEType to a literal.
class DependentMediaMIMEType
{
public:
// Construction from a literal. Checked in debug builds.
// Use MEDIAMIMETYPE macro instead, for static checking.
template <size_t N>
explicit DependentMediaMIMEType(const char (&aType)[N])
: mMIMEType(aType, N - 1)
{
MOZ_ASSERT(IsMediaMIMEType(aType, N - 1), "Invalid media MIME type");
}
// MIME "type/subtype".
const nsDependentCString& AsDependentString() const { return mMIMEType; }
private:
nsDependentCString mMIMEType;
};
// Instantiate a DependentMediaMIMEType from a literal. Statically checked.
#define MEDIAMIMETYPE(LIT) \
static_cast<const DependentMediaMIMEType&>( \
[]() { \
static_assert(IsMediaMIMEType(LIT), "Invalid media MIME type"); \
return DependentMediaMIMEType(LIT); \
}())
// Class containing only pre-parsed lowercase media MIME type/subtype.
class MediaMIMEType
{
public:
// Construction from a DependentMediaMIMEType, with its inherent checks.
// Implicit so MEDIAMIMETYPE can be used wherever a MediaMIMEType is expected.
MOZ_IMPLICIT MediaMIMEType(const DependentMediaMIMEType& aType)
: mMIMEType(aType.AsDependentString())
{
}
// MIME "type/subtype", always lowercase.
const nsACString& AsString() const { return mMIMEType; }
// Comparison with DependentMediaMIMEType.
// Useful to compare to MEDIAMIMETYPE literals.
bool operator==(const DependentMediaMIMEType& aOther) const
{
return mMIMEType.Equals(aOther.AsDependentString());
}
bool operator!=(const DependentMediaMIMEType& aOther) const
{
return !mMIMEType.Equals(aOther.AsDependentString());
}
bool operator==(const MediaMIMEType& aOther) const
{
return mMIMEType.Equals(aOther.mMIMEType);
}
bool operator!=(const MediaMIMEType& aOther) const
{
return !mMIMEType.Equals(aOther.mMIMEType);
}
// True if type starts with "application/".
bool HasApplicationMajorType() const;
// True if type starts with "audio/".
// Note that some audio content could be stored in a "video/..." container!
bool HasAudioMajorType() const;
// True if type starts with "video/".
// Note that this does not guarantee 100% that the content is actually video!
// (e.g., "video/webm" could contain a vorbis audio track.)
bool HasVideoMajorType() const;
size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
private:
friend Maybe<MediaMIMEType> MakeMediaMIMEType(const nsAString& aType);
friend class MediaExtendedMIMEType;
explicit MediaMIMEType(const nsACString& aType);
nsCString mMIMEType; // UTF8 MIME "type/subtype".
};
Maybe<MediaMIMEType> MakeMediaMIMEType(const nsAString& aType);
Maybe<MediaMIMEType> MakeMediaMIMEType(const nsACString& aType);
Maybe<MediaMIMEType> MakeMediaMIMEType(const char* aType);
// A list of codecs attached to a MediaExtendedMIMEType.
class MediaCodecs
{
public:
MediaCodecs() { }
// Construction from a comma-separated list of codecs. Unchecked.
explicit MediaCodecs(const nsAString& aCodecs) : mCodecs(aCodecs) { }
// Construction from a literal comma-separated list of codecs. Unchecked.
template <size_t N>
explicit MediaCodecs(const char (&aCodecs)[N])
: mCodecs(NS_ConvertUTF8toUTF16(aCodecs, N - 1))
{
}
bool IsEmpty() const { return mCodecs.IsEmpty(); }
const nsAString& AsString() const { return mCodecs; }
using RangeType =
const StringListRange<nsString, StringListRangeEmptyItems::ProcessEmptyItems>;
// Produces a range object with begin()&end(), can be used in range-for loops.
// This will iterate through all codecs, even empty ones (except if the
// original list was an empty string). Iterators dereference to
// 'const nsDependentString', valid for as long as this MediaCodecs object.
RangeType Range() const
{
return RangeType(mCodecs);
};
bool Contains(const nsAString& aCodec) const;
bool ContainsAll(const MediaCodecs& aCodecs) const;
template <size_t N>
bool operator==(const char (&aType)[N]) const
{
return mCodecs.EqualsASCII(aType, N - 1);
}
size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
private:
// UTF16 comma-separated list of codecs.
// See http://www.rfc-editor.org/rfc/rfc4281.txt for the description
// of the 'codecs' parameter.
nsString mCodecs;
};
// Class containing pre-parsed media MIME type parameters, e.g.:
// MIME type/subtype, optional codecs, etc.
class MediaExtendedMIMEType
{
public:
explicit MediaExtendedMIMEType(const MediaMIMEType& aType);
explicit MediaExtendedMIMEType(MediaMIMEType&& aType);
// MIME "type/subtype".
const MediaMIMEType& Type() const { return mMIMEType; }
// Was there an explicit 'codecs' parameter provided?
bool HaveCodecs() const { return mHaveCodecs; }
// Codecs. May be empty if not provided or explicitly provided as empty.
const MediaCodecs& Codecs() const { return mCodecs; }
// Sizes and rates.
Maybe<int32_t> GetWidth() const { return GetMaybeNumber(mWidth); }
Maybe<int32_t> GetHeight() const { return GetMaybeNumber(mHeight); }
Maybe<int32_t> GetFramerate() const { return GetMaybeNumber(mFramerate); }
Maybe<int32_t> GetBitrate() const { return GetMaybeNumber(mBitrate); }
// Original string. Note that "type/subtype" may not be lowercase,
// use Type().AsString() instead to get the normalized "type/subtype".
const nsACString& OriginalString() const { return mOriginalString; }
size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
private:
friend Maybe<MediaExtendedMIMEType> MakeMediaExtendedMIMEType(const nsAString& aType);
MediaExtendedMIMEType(const nsACString& aOriginalString,
const nsACString& aMIMEType,
bool aHaveCodecs, const nsAString& aCodecs,
int32_t aWidth, int32_t aHeight,
int32_t aFramerate, int32_t aBitrate);
Maybe<int32_t> GetMaybeNumber(int32_t aNumber) const
{
return (aNumber < 0) ? Maybe<int32_t>(Nothing()) : Some(int32_t(aNumber));
}
nsCString mOriginalString; // Original full string.
MediaMIMEType mMIMEType; // MIME type/subtype.
bool mHaveCodecs = false; // If false, mCodecs must be empty.
MediaCodecs mCodecs;
int32_t mWidth = -1; // -1 if not provided.
int32_t mHeight = -1; // -1 if not provided.
int32_t mFramerate = -1; // -1 if not provided.
int32_t mBitrate = -1; // -1 if not provided.
};
Maybe<MediaExtendedMIMEType> MakeMediaExtendedMIMEType(const nsAString& aType);
Maybe<MediaExtendedMIMEType> MakeMediaExtendedMIMEType(const nsACString& aType);
Maybe<MediaExtendedMIMEType> MakeMediaExtendedMIMEType(const char* aType);
} // namespace mozilla
#endif // MediaMIMETypes_h_