def computeVariableBitrate(self, mp3):
if self.quality <= QUALITY_FAST:
return
count = 0
if QUALITY_BEST <= self.quality:
self.warning(
"Process all MPEG audio frames to compute exact duration")
max_count = None
else:
max_count = 500 * self.quality
total_bit_rate = 0.0
for index, frame in enumerate(mp3.array("frames/frame")):
if index < 3:
continue
bit_rate = frame.getBitRate()
if bit_rate:
total_bit_rate += float(bit_rate)
count += 1
if max_count and max_count <= count:
break
if not count:
return
bit_rate = total_bit_rate / count
self.bit_rate = (bit_rate,
_("%s (Variable bit rate)") % humanBitRate(bit_rate))
duration = timedelta(seconds=float(mp3["frames"].size) / bit_rate)
self.duration = duration
def computeBitrate(self, frame):
bit_rate = frame.getBitRate() # may returns None on error
if not bit_rate:
return
self.bit_rate = (bit_rate, _("%s (constant)") % humanBitRate(bit_rate))
self.duration = timedelta(seconds=float(frame["/frames"].size) /
bit_rate)