Audio streams download speed issue

[JoshukLite]

All audio streams of the video has slow download speed. On the average it starts after 25% already downloaded, then every 8th cycle of the read operation (in BaseStream.download method) takes up to 2.5 seconds (waiting for data, sleep?)

pafy/pafy/backend_shared.py

Lines 625 to 635 in e6348cf

	while self._active:
	chunk = response.read(chunksize)
	outfh.write(chunk)
	elapsed = time.time() - t0
	bytesdone += len(chunk)
	if elapsed:
	rate = ((float(bytesdone) - float(offset)) / 1024.0) / elapsed
	eta = (total - bytesdone) / (rate * 1024)
	else: # Avoid ZeroDivisionError
	rate = 0
	eta = 0

Same result on all audio streams. No problems with video streams.
Here is a snippet of the method working time in milliseconds:

[vn-ki]

This will be fixed by #203. I will make the requested changes this weekend and get it merged.

[JoshukLite]

great! thanks

[ritiek]

Closed by #203.