Also, don't code DRED that's redundant with the main packet

Should make synthesis easier in the future

So it can be used outside of the SILK PLC

output() renamed to decode(), dred objects using alloc() and free(),
OpusDRED now passed as cost for decoding.

Makes it possible to do a "dry run" generation for in-place padding

Michael Klingbeil authored 1 year ago and Jean-Marc Valin committed 1 year ago

Add unit tests for opus_packet_extensions_count, opus_packet_extensions_parse,
and opus_packet_extensions_generate. Add various assertions for NULL buffers or
negative length arguments. Add explicit check for invalid length in
opus_packet_extensions_count. Check for extension id >127 in
opus_packet_extensions_generate. Check for invalid length input in
opus_packet_extensions_generate.

Signed-off-by: Jean-Marc Valin <jmvalin@amazon.com>

Makes shallow copy of decoder possible again

Avoids conflict with LPCNet, so that LPCNet headers can be included in
Opus

progressive decode, avoid storing DRED decoder state