Bug 114 - Incorrect sound stream encoding for slow frame rates.

[netsweng]

Benjamin Wolsey 2011-07-01 07:22:20 EDT

Setting an mp3 sound stream for a SWF with a very slow frame rate (e.g. 1 or
0.5 frames per second) results in the stream sound blocks containing much more
data than they claim to.

With a sample rate of 44kHz, a frame rate of 0.5 frames per second means each
sound block contains 88000 stereo samples, but both the sound stream head and
each sound stream block advertise a maximum of about 22000. I guess there is an
integer overflow somewhere.

Because the pp uses the value in the sound stream head to determine the frame
rate while a streaming sound is playing, this means that the SWF plays at 2
frames per second.

Also, because the sample count in each block is used to determine how much
sound is played, the sound is truncated.

All samples count value is a uint16_t, so if this is to work properly, I guess
that several smaller blocks would have to be added between each showframe until
all samples are written.