JPEXS Free Flash Decompiler Issue Tracker

I don't understand what you want. You can export sound stream head to a file - see attachment, all soundstream blocks will be exported. What you mean by separate? If the stream contains lets say 1252 blocks, you want what to do with them? You can already play them in the sounds section.

for example i want 1 sound from blocks cid334 but it mixed with other sounds the block plays on specific frame ,how can i export the sound from the frame without other sounds

The term "sound block" means a small portion of soundstream which fits into single frame. If the SWF has the framerate of 30 fps, then 1 SWF frame would play 33 milliseconds. That's how single sound block is usually long for 30fps SWF. So you surely don't want a 1 sound block. You may want a sound blocks range - let's say from frame 1 to frame 500, that would be a sound with useful length. The "sound blockS" also does not mean there are multiple sounds in the stream. You cannot separate the sounds (let's say "speaking" and "background sound") if they were mixed into one stream. So... you can't export them separately. They were mixed during SWF compilation.