The QAudioFormat class stores audio stream parameter information. 更多...
| 头： | #include <QAudioFormat> |
| qmake: | QT += multimedia |
| enum | Endian { BigEndian, LittleEndian } |
| enum | SampleType { Unknown, SignedInt, UnSignedInt, Float } |
| QAudioFormat (const QAudioFormat & other ) | |
| QAudioFormat () | |
| QAudioFormat & | operator= (const QAudioFormat & other ) |
| ~QAudioFormat () | |
| QAudioFormat::Endian | byteOrder () const |
| qint32 | bytesForDuration (qint64 duration ) const |
| qint32 | bytesForFrames (qint32 frameCount ) const |
| int | bytesPerFrame () const |
| int | channelCount () const |
| QString | codec () const |
| qint64 | durationForBytes (qint32 bytes ) const |
| qint64 | durationForFrames (qint32 frameCount ) const |
| qint32 | framesForBytes (qint32 byteCount ) const |
| qint32 | framesForDuration (qint64 duration ) const |
| bool | isValid () const |
| int | sampleRate () const |
| int | sampleSize () const |
| QAudioFormat::SampleType | sampleType () const |
| void | setByteOrder (QAudioFormat::Endian byteOrder ) |
| void | setChannelCount (int channels ) |
| void | setCodec (const QString & codec ) |
| void | setSampleRate (int samplerate ) |
| void | setSampleSize (int sampleSize ) |
| void | setSampleType (QAudioFormat::SampleType sampleType ) |
| bool | operator!= (const QAudioFormat & other ) const |
| bool | operator== (const QAudioFormat & other ) const |
An audio format specifies how data in an audio stream is arranged, i.e, how the stream is to be interpreted. The encoding itself is specified by the codec () used for the stream.
In addition to the encoding, QAudioFormat contains other parameters that further specify how the audio sample data is arranged. These are the frequency, the number of channels, the sample size, the sample type, and the byte order. The following table describes these in more detail.
| 参数 | 描述 |
|---|---|
| 采样率 | Samples per second of audio data in Hertz. |
| 通道数 | The number of audio channels (typically one for mono or two for stereo) |
| 采样大小 | How much data is stored in each sample (typically 8 or 16 bits) |
| 采样类型 | Numerical representation of sample (typically signed integer, unsigned integer or float) |
| 字节序 | Byte ordering of sample (typically little endian, big endian) |
This class is typically used in conjunction with QAudioInput or QAudioOutput to allow you to specify the parameters of the audio stream being read or written, or with QAudioBuffer when dealing with samples in memory.
You can obtain audio formats compatible with the audio device used through functions in QAudioDeviceInfo . This class also lets you query available parameter values for a device, so that you can set the parameters yourself. See the QAudioDeviceInfo class description for details. You need to know the format of the audio streams you wish to play or record.
In the common case of interleaved linear PCM data, the codec will be "audio/pcm", and the samples for all channels will be interleaved. One sample for each channel for the same instant in time is referred to as a frame in Qt Multimedia (and other places).
| 常量 | 值 | 描述 |
|---|---|---|
QAudioFormat::BigEndian
|
QSysInfo::BigEndian
|
Samples are big endian byte order |
QAudioFormat::LittleEndian
|
QSysInfo::LittleEndian
|
Samples are little endian byte order |
| 常量 | 值 | 描述 |
|---|---|---|
QAudioFormat::Unknown
|
0
|
不设置 |
QAudioFormat::SignedInt
|
1
|
采样是有符号整数 |
QAudioFormat::UnSignedInt
|
2
|
采样是无符号整数 |
QAudioFormat::Float
|
3
|
采样是浮点数 |
构造新的音频格式使用 other .
构建新的音频格式。
值的初始化如下：
codec()
= ""
赋值 other 到此 QAudioFormat 实现。
销毁此音频格式。
Returns the current byteOrder value.
另请参阅 setByteOrder ().
Returns the number of bytes required for this audio format for duration 微秒。
返回 0 若此格式无效。
Note that some rounding may occur if duration is not an exact fraction of the sampleRate ().
另请参阅 durationForBytes ().
Returns the number of bytes required for frameCount frames of this format.
返回 0 若此格式无效。
另请参阅 bytesForDuration ().
Returns the number of bytes required to represent one frame (a sample in each channel) in this format.
Returns 0 if this format is invalid.
返回当前通道计数值。
另请参阅 setChannelCount ().
返回当前编解码器标识符。
另请参阅 setCodec () 和 QAudioDeviceInfo::supportedCodecs ().
Returns the number of microseconds represented by bytes in this format.
返回 0 若此格式无效。
Note that some rounding may occur if bytes is not an exact multiple of the number of bytes per frame.
另请参阅 bytesForDuration ().
Return the number of microseconds represented by frameCount frames in this format.
Returns the number of frames represented by byteCount in this format.
Note that some rounding may occur if byteCount is not an exact multiple of the number of bytes per frame.
Each frame has one sample per channel.
另请参阅 framesForDuration ().
Returns the number of frames required to represent duration microseconds in this format.
Note that some rounding may occur if duration is not an exact fraction of the sampleRate ().
Returns true if all of the parameters are valid.
返回当前采样率 (以赫兹为单位)。
另请参阅 setSampleRate ().
返回当前采样大小值 (以位为单位)。
另请参阅 setSampleSize () 和 bytesPerFrame ().
返回当前 SampleType 值。
另请参阅 setSampleType ().
设置 byteOrder to byteOrder .
另请参阅 byteOrder ().
将通道计数设为 channels .
另请参阅 channelCount ().
将编解码器设为 codec .
The parameter to this function should be one of the types reported by the QAudioDeviceInfo::supportedCodecs () function for the audio device you are working with.
另请参阅 codec () 和 QAudioDeviceInfo::supportedCodecs ().
Sets the sample rate to samplerate Hertz.
另请参阅 sampleRate ().
Sets the sample size to the sampleSize specified, in bits.
This is typically 8 or 16, but some systems may support higher sample sizes.
另请参阅 sampleSize ().
设置 sampleType to sampleType .
另请参阅 sampleType ().
返回 true，若此 QAudioFormat is not equal to the other QAudioFormat ；否则返回 false。
All elements of QAudioFormat are used for the comparison.
返回 true，若此 QAudioFormat is equal to the other QAudioFormat ；否则返回 false。
All elements of QAudioFormat are used for the comparison.