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  2. Qt 6.5.1
  3. Qt Multimedia
  4. C++ 类
  5. QtMultimedia
  6. QMediaFormat

QMediaFormat Class

Describes an encoding format for a multimedia file or stream. 更多...

头： #include <QMediaFormat>
CMake: find_package(Qt6 REQUIRED COMPONENTS Multimedia)
target_link_libraries(mytarget PRIVATE Qt6::Multimedia)
qmake: QT += multimedia

公共类型

枚举类 AudioCodec { WMA, AC3, AAC, ALAC, DolbyTrueHD, …, Unspecified }
enum ConversionMode { Encode, Decode }
enum FileFormat { WMA, AAC, Matroska, WMV, MP3, …, UnspecifiedFormat }
enum ResolveFlags { NoFlags, RequiresVideo }
枚举类 VideoCodec { VP8, MPEG2, MPEG1, WMV, H265, …, Unspecified }

特性

公共函数

QMediaFormat (QMediaFormat::FileFormat format = UnspecifiedFormat)
QMediaFormat (const QMediaFormat & other )
QMediaFormat (QMediaFormat && other )
~QMediaFormat ()
QMediaFormat::AudioCodec audioCodec () const
QMediaFormat::FileFormat fileFormat () const
bool isSupported (QMediaFormat::ConversionMode mode ) const
QMimeType mimeType () const
void resolveForEncoding (QMediaFormat::ResolveFlags flags )
void setAudioCodec (QMediaFormat::AudioCodec codec )
void setFileFormat (QMediaFormat::FileFormat f )
void setVideoCodec (QMediaFormat::VideoCodec codec )
QList<QMediaFormat::AudioCodec> supportedAudioCodecs (QMediaFormat::ConversionMode m )
QList<QMediaFormat::FileFormat> supportedFileFormats (QMediaFormat::ConversionMode m )
QList<QMediaFormat::VideoCodec> supportedVideoCodecs (QMediaFormat::ConversionMode m )
void swap (QMediaFormat & other )
QMediaFormat::VideoCodec videoCodec () const
bool operator!= (const QMediaFormat & other ) const
QMediaFormat & operator= (const QMediaFormat & other )
QMediaFormat & operator= (QMediaFormat && other )
bool operator== (const QMediaFormat & other ) const

静态公共成员

QString audioCodecDescription (QMediaFormat::AudioCodec codec )
QString audioCodecName (QMediaFormat::AudioCodec codec )
QString fileFormatDescription (QMediaFormat::FileFormat fileFormat )
QString fileFormatName (QMediaFormat::FileFormat fileFormat )
QString videoCodecDescription (QMediaFormat::VideoCodec codec )
QString videoCodecName (QMediaFormat::VideoCodec codec )

详细描述

QMediaFormat describes an encoding format for a multimedia file or stream.

You can check whether a certain media format can be used for encoding or decoding using QMediaFormat.

成员类型文档编制

enum class QMediaFormat:: AudioCodec

Describes the audio codec used in multimedia file or stream.

常量 值 描述
QMediaFormat::AudioCodec::WMA 9 Windows Media Audio
QMediaFormat::AudioCodec::AC3 2 Dolby Digital
QMediaFormat::AudioCodec::AAC 1 Advanced Audio Coding
QMediaFormat::AudioCodec::ALAC 10 Apple Lossless Audio Codec
QMediaFormat::AudioCodec::DolbyTrueHD 5 Dolby TrueHD
QMediaFormat::AudioCodec::EAC3 3 Dolby Digital Plus (EAC3)
QMediaFormat::AudioCodec::MP3 0 MPEG-1 Audio Layer III or MPEG-2 Audio Layer III
QMediaFormat::AudioCodec::Wave 8 Waveform Audio File Format
QMediaFormat::AudioCodec::Vorbis 7 Ogg Vorbis
QMediaFormat::AudioCodec::FLAC 4 Free Lossless Audio Codec
QMediaFormat::AudioCodec::Opus 6 Opus Audio Format
QMediaFormat::AudioCodec::Unspecified -1 Unspecified codec

enum QMediaFormat:: ConversionMode

In many cases, systems have asymmetric capabilities and can often decode more formats or codecs than can be encoded. This enum describes the requested conversion mode to be used when checking whether a certain file format or codec is supported.

常量 值 描述
QMediaFormat::Encode 0 Used to check whether a certain file format or codec can be encoded.
QMediaFormat::Decode 1 Used to check whether a certain file format or codec can be decoded.

另请参阅 supportedFileFormats , supportedAudioCodecs ，和 supportedVideoCodecs .

enum QMediaFormat:: FileFormat

Describes the container format used in a multimedia file or stream.

常量 值 描述
QMediaFormat::WMA 9 Windows Media Audio
QMediaFormat::AAC 8 Advanced Audio Coding
QMediaFormat::Matroska 2 Matroska (MKV)
QMediaFormat::WMV 0 Windows Media Video
QMediaFormat::MP3 10 MPEG-1 Audio Layer III or MPEG-2 Audio Layer III
QMediaFormat::Wave 12 Waveform Audio File Format
QMediaFormat::Ogg 4 Ogg
QMediaFormat::MPEG4 3 MPEG-4
QMediaFormat::AVI 1 Audio Video Interleave
QMediaFormat::QuickTime 5 QuickTime
QMediaFormat::WebM 6 WebM
QMediaFormat::Mpeg4Audio 7 MPEG-4 Part 3 or MPEG-4 Audio (formally ISO/IEC 14496-3)
QMediaFormat::FLAC 11 Free Lossless Audio Codec
QMediaFormat::UnspecifiedFormat -1 The format is unspecified.

enum QMediaFormat:: ResolveFlags

Describes the requirements for resolving a suitable format for QMediaRecorder .

常量 值 描述
QMediaFormat::NoFlags 0 No requirements
QMediaFormat::RequiresVideo 1 A video codec is required

另请参阅 resolveForEncoding ().

enum class QMediaFormat:: VideoCodec

Describes the video coded used in multimedia file or stream.

常量 值 描述
QMediaFormat::VideoCodec::VP8 5 VP8
QMediaFormat::VideoCodec::MPEG2 1 MPEG-2
QMediaFormat::VideoCodec::MPEG1 0 MPEG-1
QMediaFormat::VideoCodec::WMV 9 Windows Media Video
QMediaFormat::VideoCodec::H265 4 High Efficiency Video Coding (HEVC)
QMediaFormat::VideoCodec::H264 3 Advanced Video Coding
QMediaFormat::VideoCodec::MPEG4 2 MPEG-4
QMediaFormat::VideoCodec::AV1 7 AOMedia Video 1
QMediaFormat::VideoCodec::MotionJPEG 10 MotionJPEG
QMediaFormat::VideoCodec::VP9 6 VP9
QMediaFormat::VideoCodec::Theora 8 Theora
QMediaFormat::VideoCodec::Unspecified -1 Video codec not specified

特性文档编制

audioCodec : AudioCodec

This property holds the audio codec of the media.

访问函数：

QMediaFormat::AudioCodec audioCodec () const
void setAudioCodec (QMediaFormat::AudioCodec codec )

另请参阅 QMediaFormat::AudioCodec .

fileFormat : FileFormat

This property holds the file (container) format of the media.

访问函数：

QMediaFormat::FileFormat fileFormat () const
void setFileFormat (QMediaFormat::FileFormat f )

另请参阅 QMediaFormat::FileFormat .

videoCodec : VideoCodec

This property holds the video codec of the media.

访问函数：

QMediaFormat::VideoCodec videoCodec () const
void setVideoCodec (QMediaFormat::VideoCodec codec )

另请参阅 QMediaFormat::VideoCodec .

成员函数文档编制

QMediaFormat:: QMediaFormat ( QMediaFormat::FileFormat format = UnspecifiedFormat)

Constructs a QMediaFormat object for format .

QMediaFormat:: QMediaFormat (const QMediaFormat & other )

Constructs a QMediaFormat object by copying from other .

QMediaFormat:: QMediaFormat ( QMediaFormat && other )

Constructs a QMediaFormat objects by moving from other .

QMediaFormat:: ~QMediaFormat ()

销毁 QMediaFormat 对象。

QMediaFormat::AudioCodec QMediaFormat:: audioCodec () const

Returns the audio codec used in this format.

注意： Getter function for property audioCodec.

另请参阅 setAudioCodec () 和 QMediaFormat::AudioCodec .

[static invokable] QString QMediaFormat:: audioCodecDescription ( QMediaFormat::AudioCodec codec )

Returns a description for codec .

注意： 此函数可以被援引，通过元对象系统和从 QML。见 Q_INVOKABLE .

[static invokable] QString QMediaFormat:: audioCodecName ( QMediaFormat::AudioCodec codec )

Returns a string based name for codec .

注意： 此函数可以被援引，通过元对象系统和从 QML。见 Q_INVOKABLE .

[static invokable] QString QMediaFormat:: fileFormatDescription ( QMediaFormat::FileFormat fileFormat )

Returns a description for fileFormat .

注意： 此函数可以被援引，通过元对象系统和从 QML。见 Q_INVOKABLE .

[static invokable] QString QMediaFormat:: fileFormatName ( QMediaFormat::FileFormat fileFormat )

Returns a string based name for fileFormat .

注意： 此函数可以被援引，通过元对象系统和从 QML。见 Q_INVOKABLE .

[invokable] bool QMediaFormat:: isSupported ( QMediaFormat::ConversionMode mode ) const

返回 true if Qt Multimedia can encode or decode this format, depending on mode .

注意： 此函数可以被援引，通过元对象系统和从 QML。见 Q_INVOKABLE .

QMimeType QMediaFormat:: mimeType () const

返回 MIME 类型 for the file format used in this media format.

void QMediaFormat:: resolveForEncoding ( QMediaFormat::ResolveFlags flags )

Resolves the format, based on flags , to a format that is supported by QMediaRecorder .

This method tries to find the best possible match for unspecified settings. Settings that are not supported by the recorder will be modified to the closest match that is supported.

When resolving, priority is given in the following order:

  1. File format
  2. Video codec
  3. Audio codec

void QMediaFormat:: setAudioCodec ( QMediaFormat::AudioCodec codec )

Sets the audio codec to codec .

注意： setter 函数对于特性 audioCodec .

另请参阅 audioCodec () 和 QMediaFormat::AudioCodec .

void QMediaFormat:: setVideoCodec ( QMediaFormat::VideoCodec codec )

Sets the video codec to codec .

注意： setter 函数对于特性 videoCodec .

另请参阅 videoCodec () 和 QMediaFormat::VideoCodec .

[invokable] QList < QMediaFormat::AudioCodec > QMediaFormat:: supportedAudioCodecs ( QMediaFormat::ConversionMode m )

Returns a list of audio codecs for the chosen file format and video codec ( m ).

To get all supported audio codecs, run this query on a default constructed QMediaFormat .

注意： 此函数可以被援引，通过元对象系统和从 QML。见 Q_INVOKABLE .

另请参阅 QMediaFormat::ConversionMode .

[invokable] QList < QMediaFormat::FileFormat > QMediaFormat:: supportedFileFormats ( QMediaFormat::ConversionMode m )

Returns a list of file formats for the audio and video codec indicated by m .

To get all supported file formats, run this query on a default constructed QMediaFormat .

注意： 此函数可以被援引，通过元对象系统和从 QML。见 Q_INVOKABLE .

另请参阅 QMediaFormat::ConversionMode .

[invokable] QList < QMediaFormat::VideoCodec > QMediaFormat:: supportedVideoCodecs ( QMediaFormat::ConversionMode m )

Returns a list of video codecs for the chosen file format and audio codec ( m ).

To get all supported video codecs, run this query on a default constructed MediaFormat.

注意： 此函数可以被援引，通过元对象系统和从 QML。见 Q_INVOKABLE .

另请参阅 QMediaFormat::ConversionMode .

void QMediaFormat:: swap ( QMediaFormat & other )

Swaps the media format with other .

QMediaFormat::VideoCodec QMediaFormat:: videoCodec () const

Returns the video codec used in this format.

注意： Getter function for property videoCodec.

另请参阅 setVideoCodec () 和 QMediaFormat::VideoCodec .

[static invokable] QString QMediaFormat:: videoCodecDescription ( QMediaFormat::VideoCodec codec )

Returns a description for codec .

注意： 此函数可以被援引，通过元对象系统和从 QML。见 Q_INVOKABLE .

[static invokable] QString QMediaFormat:: videoCodecName ( QMediaFormat::VideoCodec codec )

Returns a string based name for codec .

注意： 此函数可以被援引，通过元对象系统和从 QML。见 Q_INVOKABLE .

bool QMediaFormat:: operator!= (const QMediaFormat & other ) const

返回 true if other is not equal to the current media format, otherwise returns false .

QMediaFormat &QMediaFormat:: operator= (const QMediaFormat & other )

拷贝 other 到此 QMediaFormat 对象。

QMediaFormat &QMediaFormat:: operator= ( QMediaFormat && other )

移动 other 到此 QMediaFormat 对象。

bool QMediaFormat:: operator== (const QMediaFormat & other ) const

返回 true if other is equal to the current media format, otherwise returns false .

内容

  1. 公共类型

  2. 特性

  3. 公共函数

  4. 静态公共成员

  5. 详细描述