[gst-devel] faac does not seem to respect bitrate

[Francis Rammeloo]

It seems that faac does not always the requested respect bitrates. I
have tested this on my Windows machine (using the WinBuilds) by
converting a 128kbps mp3 to several mp4 files with different bitrates:

gst-launch-0.10 filesrc location=kylie.mp3 ! decodebin2 ! faac
bitrate=16000 ! mp4mux ! filesink location=16.mp4

gst-launch-0.10 filesrc location=kylie.mp3 ! decodebin2 ! faac
bitrate=32000 ! mp4mux ! filesink location=32.mp4

gst-launch-0.10 filesrc location=kylie.mp3 ! decodebin2 ! faac
bitrate=64000 ! mp4mux ! filesink location=64.mp4

gst-launch-0.10 filesrc location=kylie.mp3 ! decodebin2 ! faac
bitrate=128000 ! mp4mux ! filesink location=128.mp4

gst-launch-0.10 filesrc location=kylie.mp3 ! decodebin2 ! faac
bitrate=256000 ! mp4mux ! filesink location=256.mp4

gst-launch-0.10 filesrc location=kylie.mp3 ! decodebin2 ! faac
bitrate=320000 ! mp4mux ! filesink location=320.mp4


The resulting filesizes show the issue:

29/01/2010  12:57    <DIR>          .
29/01/2010  12:57    <DIR>          ..
29/01/2010  12:55         4.402.912 32.mp4
29/01/2010  11:57         5.071.153 kylie.mp3
29/01/2010  12:58         4.403.427 64.mp4
29/01/2010  12:59         5.164.493 128.mp4
29/01/2010  12:59         8.918.765 256.mp4
29/01/2010  13:00         8.918.881 320.mp4
29/01/2010  13:01         4.402.803 16.mp4


Is there a way to make it respect the requested bitrates?

Grts,
Francis