[MPlayer-users] speed/bitrates with mp3lame vbr, varying q and aq

[HR]

Posting some results from mencoder -oac mp3lame lame vbr encodings, hope
it has some value for someone. If there is interest, I can repeat the
experiment with other type of material. Running a test of re-encoding
the audio of a TV-grab with more noise, will post later.

HR


Original source: Beauty and the Beast DVD, AC3 5.1 at bitrate 384000
Encoding source: decoded vob on HD from mplayer -dumpstream
Length: 5248.24 seconds, 131206 frames
Target: lame vbr=4 (mtrh) mp3

In summary, I'd recommend q=2:aq=0 for similar material because
* neither q nor aq seems to have any significant influence on speed
* increasing quality to q=2 still kept the bitrate < 128 kbps
* q=9 results in exactly the same file size as q=3, but has supposedly
worst quality
* on the subjective side, if you are short on bits, q=8 produces very
decent quality and lowest bitrate


Details:


BITRATES
--------
frameno-q=0:aq=0.avi => audio bitrate 156320 bps
frameno-q=1:aq=0.avi => audio bitrate 151960 bps
frameno-q=2:aq=0.avi => audio bitrate 117440 bps
frameno-q=3:aq=0.avi => audio bitrate 114240 bps
frameno-q=4:aq=0.avi => audio bitrate 111120 bps
frameno-q=5:aq=0.avi => audio bitrate 108056 bps
frameno-q=6:aq=0.avi => audio bitrate 104168 bps
frameno-q=7:aq=0.avi => audio bitrate 100768 bps
frameno-q=8:aq=0.avi => audio bitrate 97120 bps
frameno-q=9:aq=0.avi => audio bitrate 114240 bps
(bitrates for aq=2 are the same)


SPEED
-----

--------------------
Encoding with q=9:aq=0

real    28m13.702s
user    24m54.030s
sys     1m4.900s


--------------------
Encoding with q=8:aq=0

real    27m45.776s
user    24m21.180s
sys     1m3.370s


--------------------
Encoding with q=7:aq=0

real    27m28.733s
user    24m13.260s
sys     1m0.930s


--------------------
Encoding with q=6:aq=0

real    27m45.598s
user    24m29.330s
sys     1m2.400s


--------------------
Encoding with q=5:aq=0

real    27m58.594s
user    24m41.390s
sys     1m2.940s


--------------------
Encoding with q=4:aq=0

real    29m3.229s
user    24m54.740s
sys     1m5.930s


--------------------
Encoding with q=3:aq=0

real    36m24.155s
user    26m7.930s
sys     1m12.420s


--------------------
Encoding with q=2:aq=0

real    28m30.454s
user    25m1.960s
sys     1m3.210s


--------------------
Encoding with q=1:aq=0

real    27m2.396s
user    23m4.230s
sys     1m7.440s

--------------------
Encoding with q=0:aq=0

real    34m30.493s
user    24m20.800s
sys     1m14.510s


--------------------
Encoding with q=9:aq=2

real    29m14.197s
user    24m52.920s
sys     1m7.730s


--------------------
Encoding with q=8:aq=2

real    33m12.306s
user    24m54.160s
sys     1m7.680s


--------------------
Encoding with q=7:aq=2

real    31m42.215s
user    24m54.280s
sys     1m9.480s


--------------------
Encoding with q=6:aq=2

real    27m26.065s
user    24m13.460s
sys     1m1.710s


--------------------
Encoding with q=5:aq=2

real    27m57.044s
user    24m36.650s
sys     1m5.140s


--------------------
Encoding with q=4:aq=2

real    28m4.817s
user    24m40.660s
sys     1m7.260s


--------------------
Encoding with q=3:aq=2

real    28m11.228s
user    24m50.020s
sys     1m3.050s


--------------------
Encoding with q=2:aq=2

real    29m36.125s
user    25m7.240s
sys     1m9.160s


--------------------
Encoding with q=1:aq=2

real    27m25.160s
user    22m56.510s
sys     1m7.890s


--------------------
Encoding with q=0:aq=2

real    26m26.149s
user    23m4.830s
sys     1m4.450s