libsswf: sswf::Envelope Class Reference

The constructor initializes an envelope with a position and the volume on the left and right sides. If the sound is not stereo, the volume of both sides should be set to the same value.

The left and right volumes go from 0 (mute) to 32768 (max. power). The effect of using values outside this range is undefined.

The position is always defined as if the rate of the sound was 44,100k. So you need to multiply all positions by some value to obtain the correct envelope position.

So, if the rate of the sound is defined a R, the factor you need to use is:

44,100 / rate

In other words:

ratefactor

5,512	8
11,025	4
22,050	2
44,100	1

Also, positions need to be defined between the start and stop positions of the corresponding sswf::SoundInfo (see the sswf::SoundInfo::SetRange(unsigned long start, unsigned long end) function.)

Note that the volume is clamped to the range 0 to 32768.

Bug:

The Envelope does not know whether the sound it will affect is stereo or mono. This may not be a problem with newer versions of the Macromedia players.

Parameters:

[in]	p	The position where the new volume applies
[in]	l	The volume on the left side (0 to 32768)
[in]	r	The volume on the left side (0 to 32768)

See also:

sswf::Envelope::Envelope(const Envelope& envelope)

sswf::SoundInfo

sswf::SoundInfo::SetRange(unsigned long start, unsigned long end)

sswf::TagStartSound

sswf::TagSound

References f_left, f_position, and f_right.

This function can be used to copy an envelope in another.

See also:

sswf::Envelope::Envelope(unsigned long p, unsigned short l, unsigned short r)

References f_left, f_position, and f_right.

This function returns the volume for the left side.

Returns:

The left side volume

References f_left.

This function returns the position of the this envelope.

Returns:

The position of the envelope

References f_position.

Referenced by sswf::SoundInfo::AddEnvelope().

This function returns the volume for the right side.

Returns:

The right side volume

References f_right.

This function is used to save an envelope as the SWF player expects. It saves the position, left and then right volumes.

Parameters:

[in]

data

The Data buffer where the envelope is to be saved

References f_left, f_position, f_right, sswf::Data::PutLong(), and sswf::Data::PutShort().

Referenced by Envelope(), Left(), and Save().

Referenced by Envelope(), Position(), and Save().

Referenced by Envelope(), Right(), and Save().