The SoundStreamBlock tag defines the data of a sound effect previously defined with a SoundStreamHead or a SoundStreamHead2 tag.
WARNING: This tag requires you to save the swf_tag structure in long format whatever the size of the data (i.e. f_tag_and_size & 0x3F == 0x3F always true even if the size is 62 or less.)
The data depends on the SoundStreamHead definition and is variable in size. Please, see the DefineSound tag for more information about sound data.