[Ekiga-list] RTP payload and G729 codec

[Jure Petrovic]

Hello, 

I am more or less in a blind street here. My codec advertises
recommended frames per packet(2) and max frames per packet(4), but it
just doesn't use 2 frames per packet for encoding unless I explicitly
force them. However, if I do that, voice is totally scrambled. 

On the other hand, decoder is written following the same principle and
it works perfectly (asterisk sends 2 frames per packet).

I listened to Craig's recommendations and I even used part of his code
from gsm codec. Maybe someone will help me, if I attach a piece of code.

This is encoding part:

static int codec_decoder(const struct PluginCodec_Definition * codec, 
                                           void * context,
                                     const void * from, 
                                       unsigned * fromLen,
                                           void * to,         
                                       unsigned * toLen,
                                   unsigned int * flag)
{
	//if (!decoderInUse)
	//  return 0;


	// Do we have at least one complete frame to decode?
	if (*fromLen < L_FRAME_COMPRESSED || *toLen < SAMPLES_PER_FRAME*2) {
		printf("DEBUG::g729codec.c::decoding failed...\n");
		return 0;
	}
	
	int frames;
	frames = MIN(*fromLen/BYTES_PER_FRAME, (*toLen/(SAMPLES_PER_FRAME*2)));
	printf("DEBUG::codec_decoder()::frames: %d\n", frames);

	*fromLen = frames * BYTES_PER_FRAME;
	*toLen   = frames * SAMPLES_PER_FRAME * 2;


	while (frames-- > 0) {
		g729_decode((struct G729STRUCT_DECODE*)context, (char*)from, to);
		from = from + BYTES_PER_FRAME;
		to = to + SAMPLES_PER_FRAME*2;
	}

	return 1;
}


Following this code, this is ekiga's output on the console:

[jure at lap myg729]$ ekiga
It appears that you do not have ekiga.server installed in a valid
location. Factory mode disabled.
       patch.cxx(301)   Patch   Added sink
  from PCM-16
         Clock Rate = 8000
         Frame Time = 8
         Max Bit Rate = 8000
         Max Frame Size = 16
         Needs Jitter = 1
         Rx Frames Per Packet = 2
         Tx Frames Per Packet = 2
    to G.729
         Clock Rate = 8000
         Frame Time = 80
         Max Bit Rate = 8000
         Max Frame Size = 10
         Needs Jitter = 1
         Rx Frames Per Packet = 2
         Tx Frames Per Packet = 2

DEBUG::g729_encoder_init()::starting init...
DEBUG::g729_encoder_init()::Allocated output buffer: 10
g729codec.c::create_encoder() called!
       patch.cxx(301)   Patch   Added sink
  from G.729
         Clock Rate = 8000
         Frame Time = 80
         Max Bit Rate = 8000
         Max Frame Size = 10
         Needs Jitter = 1
         Rx Frames Per Packet = 2
         Tx Frames Per Packet = 2
    to PCM-16
         Clock Rate = 8000
         Frame Time = 8
         Max Bit Rate = 128000
         Max Frame Size = 16
         Needs Jitter = 1
         Rx Frames Per Packet = 240
         Tx Frames Per Packet = 30

g729codec.c::create_decoder() called!
DEBUG::g729_decoder_init()::starting init...
DEBUG::g729_decoder_init()::Allocated output buffer: 160
FIXME
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_decoder()::frames: 2
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_encoder()::frames: 1
DEBUG::codec_decoder()::frames: 2
DEBUG::codec_encoder()::frames: 1


As you can see, decoder accepts 2 frames and decodes them properly.
Encoder gets automatically set to 1 frame. Now, if I force frames=2 in 
encoder part, ekiga sends 2 frames in packet but voice is scrambled.


Any ideas?


Regards, 
Jure Petrovic