>Also, Fraunhofer use intensity stereo at low bitrates. Maybe you could compare LAME
>with FhG -no-is.
No can do. The Fraunhofer ACM codec only says if the output is in Stereo or Mono.
Winamp displays these "Stereo" files created by FhG ACM as being "Joint Stereo", but
I'm not sure if it really is JS or if Winamp is incorrectly displaying IS as JS.
What is IS? Is it like JS at low frequencies with panned mono highs, or is it every
frequency band in panned mono?
I think it's quite disastrous that the standard Fraunhofer encoder doesn't let you
specify exactly how you want stereo files to be treated. The encoder knows nothing
about the system that the files will be played back on, & can't really be sure if that
mode will be best. Thanks heaps to whoever added the -m option to Lame with all its
parameters. More options = better control (usually).
I just did some tests with v3.83. Mostly the low sample rate stuff. 24/56/JS from
v3.83 is better than both 24/64/JS 22/64/JS from v3.62! Well done, everyone! :-) The
resampling works a charm too! Just a couple of things though.
1- Compressed a 4'30" song to MP3 using the command line lame.exe -v -V8 -B40 -mm -c
-h -p --lowpass 5.3 --resample 12 --noshort in.wav out.mp3
a- The average bitrate was reported as 19 kBit/sec by the frame analyser at the end
of encoding (which was correct), but when I loaded it in Winamp, it thought the file
was 38 kBit/sec. It also reported the song as being 2'15" (half of what it actually
was). Winamp bug or Lame bug? Winamp didn't stop when it got to 2'15" though. And it
DID actually play the whole song, so that's a good sign...
b- Using the same options, except with resampling to 11025 Hz, the file averaged 27
kBit/sec. That puzzles me too. Shouldn't it be slightly smaller in size than the 12
kHz sample?
2- Winamp refused to play back an 11025 Hz - 96 kBit/sec - Stereo MP3. The
--strictly-enforce-ISO option didn't work. A(nother) bug in Winamp, perhaps?
3- When using CDex to convert a 12 kHz - 64 kBit/sec - Stereo MP3 to a Layer-3 WAV,
the Fraunhofer ACM wouldn't load it. The WAV header was correct. Then I checked the
compression options for the Fraunhofer ACM. 12 kHz was ABSENT! Does FhG have something
against MP3 with 12kHz?
Shawn
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