Things that need to be done...

0. Fix that ugly crash that happens sometimes when Ctrl+C-ing with jack output active:

Program terminated with signal 11, Segmentation fault.
[New process 6293]
[New process 6291]
[New process 6292]
[New process 6284]
#0  0x00002aced607695b in memcpy () from /lib/libc.so.6
(gdb) bt
#0  0x00002aced607695b in memcpy () from /lib/libc.so.6
#1  0x00002aced5b4f092 in jack_ringbuffer_read () from /usr/lib/libjack.so.0
#2  0x00000000004151dd in process_callback ()
#3  0x00002aced5b4bf40 in Jack::JackClient::Execute () from /usr/lib/libjack.so.0
#4  0x00002aced5b5f8da in Jack::JackPosixThread::ThreadHandler () from /usr/lib/libjack.so.0
#5  0x00002aced6354fa7 in start_thread () from /lib/libpthread.so.0
#6  0x00002aced60c802d in clone () from /lib/libc.so.6


1. mpg123 could pick up new sample rates suggested by the output modules (like a jack server fixed to 96kHz) and adapt to that.

Though the practical rates for MPEG audio are up to 48kHz ... but one could easily upsample.
Currently, we detect standard rates and resample when needed... but not new ones.

4. Prevent ID3v2 tags from being parsed multiple times after seek.

I need to carry a list of ID3v2 frame addresses that already have been parsed into the data structures.
Currently, this is a possible memory leak when the seek index is disabled (tag data at file beginning) or id3 data is just somewhere in the stream.
That being said, in the "normal" case, there is no leak.

5. What's about SINGLE_MIX?
Check what is _really_ happening there, make some test file...

6. Ensure proper operation of free format with the feeder.
MPG123_NEED_MORE needs to be propagated from the freeformat framesize guesser.
