pcaputil: Support parsing decoder options from FMTP input

[orgads]

pcaputil: Support parsing decoder options from FMTP input

Some codecs need specific flags that are given in the SDP media description. For example, AMR has octet-align=1.

Instead of adding distinct flags for each codec, allow pcaputil to accept the fmtp content and parse the attributes from there.

Example:

pcaputil \
  --dst-port=52422 \
  --codec=AMR/8000 \
  --codec-fmtp='mode-set=0,1,2,3,4,5,6,7;octet-align=1' \
  amr.pcap amr.wav

[sauwming]

It's rather strange to pass the entire SDP as a parameter.
Why not just pass the codec specific parameters only?
e.g. --codec-fmtp='octet-align=1' --codec-fmtp='mode-set=0,1,2,3,4,5,6,7'

[orgads]

How do I parse it and set the params in dec_fmtp?

[sauwming]

https://github.com/pjsip/pjproject/blob/master/pjmedia/src/pjmedia/stream_common.c#L110

You can make it simpler by requiring the parameter to have no whitespace, so:

• find '='
• if '=' exists {anything before '=' is fmtp name, anything after '=' is fmtp val } else {everything is fmtp val}

[orgads]

https://github.com/pjsip/pjproject/blob/master/pjmedia/src/pjmedia/stream_common.c#L110

You can make it simpler by requiring the parameter to have no whitespace, so:

• find '='
• if '=' exists {anything before '=' is fmtp name, anything after '=' is fmtp val } else {everything is fmtp val}

So do you want me to factor this out? What about passing this to the codec? Should I also factor out parts of pjmedia_stream_info_parse_fmtp?

[sauwming]

What I mean is to add new parameter --codec-fmtp and provide very simple parsing in pcaputil to put it in dec_fmtp.

[orgads]

What I mean is to add new parameter --codec-fmtp and provide very simple parsing in pcaputil to put it in dec_fmtp.

Done, with a small refactoring.

[orgads]

The failed test looks unrelated to my changes. @sauwming please review.