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[AVT] RTP SEND-RECV / Problem with linux 8.0 Sound.
Hi Steve,
I've developed an RTP Stack. Now i'm doing the testing for the same.
The stack is being tested on Linux 8.0, afterwords this will be ported
to some RTOS...
I've tested my stack with one SEND-Only session on one machine & RECV-
Only session on other machine. It worked fine !!! I was able to communi-
cate with the other endpoint using my stack(But a small delay was there).
Now i'm testing SendRecv session (ie sending and receiving in single (or
multiple) thread)(I'll be reading/writing to /dev/dsp inside a loop)
The sequence of operations on single thread is given below,
while(1)
{
//read from /dev/dsp.
//Send this to n/w using RTP
//recv data from RTP Stack.
//Write this data to /dev/dsp
}
The problem lies here...
In this progam i'm reciving the data frm remote session correctly...and
i'm writing that data after receiving ... but after each write the my
audio has a delay in palying the next packet... wt i'm trying to say is
the data from the remote machine seems to be non-contineous. Where as
when i tried with send-only & recv-only the real-time playback was
contineous...
I've opened the audio device using one of the files provided by vovida.
I'm attatching that file.
Sampling rate 44100Hz, 16Bits.
Please help me with this issue...
Thanks in Advance,
Regards,
P Lavin
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//static const char* const phoneJack_cxx_Version =
// "$Id: soundcardTest.cxx,v 1.1 2001/03/09 01:40:55 kimle Exp $";
#include <stdio.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/soundcard.h>
//#include "RtpSession.hxx"
//#include "cpLog.h"
#define NETWORK_RTP_RATE 160
static int deviceFD;
//RtpSession* audioStack;
//RtpPacket* outRtpPkt;
//RtpPacket* inRtpPkt;
//RtpPayloadType apiCodec;
static int apiRate;
audio_buf_info info;
void *iPtr,*oPtr;
int openAudioHardware( const char* pname ,int samplingRate)
{
//cerr <<"Opening audio hardware\n";
int audioFD,min_size,blk_size=1024,cond,i,p;
int ioctlParam;
// open audio device
if( ( audioFD = open( pname, O_RDWR, 0 ) ) == -1 )
{
perror("Open failed:");
return -1;
}
#if 0
ioctl(audioFD,SNDCTL_DSP_GETBLKSIZE,&min_size);
if(min_size > blk_size)
{
cond=1;
p=min_size/blk_size;
while(cond)
{
i=ioctl(audioFD,SNDCTL_DSP_SUBDIVIDE,&p);
if((i==0)||(p==1)) cond=0;
else p=p/2;
}
}
ioctl(audioFD,SNDCTL_DSP_GETBLKSIZE,&min_size);
printf("SNDCTL_DSP_GETBLKSIZE(size)=%d\n",min_size);
#endif
// query audio formats
ioctlParam = 16;
if( ioctl( audioFD, SNDCTL_DSP_SAMPLESIZE, &ioctlParam ) == -1 )
{
perror("SNDCTL_DSP_SAMPLESIZE");
return -1;
}
ioctlParam = -1;
if( ioctl( audioFD, SNDCTL_DSP_GETFMTS, &ioctlParam ) == -1 )
{
perror("SNDCTL_DSP_GETFMTS");
return -1;
}
// choose codec
if( ioctlParam & AFMT_MU_LAW )
{
//cpLog(LOG_DEBUG,"Setting sound card to ulaw");
ioctlParam = AFMT_MU_LAW;
//apiCodec = rtpPayloadPCMU;
//apiRate = 160;
}
else if( ioctlParam & AFMT_S16_LE )
{
//cpLog(LOG_DEBUG,"Setting sound card to linear16");
ioctlParam = AFMT_S16_LE;
//apiCodec = rtpPayloadL16_mono;
//apiRate = 320;
}
else
{
//cpLog(LOG_ERR,"Sound card doesn't support any known encodings");
printf("Sound card supports the following (Mask:%d:)\n", ioctlParam);
if( ioctlParam & AFMT_MU_LAW ) printf(" AFMT_MU_LAW\n");
if( ioctlParam & AFMT_A_LAW ) printf(" AFMT_A_LAW\n");
if( ioctlParam & AFMT_IMA_ADPCM ) printf(" AFMT_IMA_ADPCM\n");
if( ioctlParam & AFMT_U8 ) printf(" AFMT_U8\n");
if( ioctlParam & AFMT_S16_LE ) printf(" AFMT_S16_LE\n");
if( ioctlParam & AFMT_S16_BE ) printf(" AFMT_S16_BE\n");
if( ioctlParam & AFMT_S8 ) printf(" AFMT_S8\n");
if( ioctlParam & AFMT_U16_LE ) printf(" AFMT_U16_LE\n");
if( ioctlParam & AFMT_U16_BE ) printf(" AFMT_U16_BE\n");
if( ioctlParam & AFMT_MPEG ) printf(" AFMT_MPEG\n");
return -1;
}
//Setting Duplex
if( ioctl( audioFD, SNDCTL_DSP_SETDUPLEX,0 ) == -1 )
{
perror("SNDCTL_DSP_SETDUPLEX");
return -1;
}
// setting audio device parameters
int ioctlParamSave = ioctlParam;
if( ioctl( audioFD, SNDCTL_DSP_SETFMT, &ioctlParam ) == -1 )
{
perror("SNDCTL_DSP_SETFMT");
return -1;
}
if( ioctlParam != ioctlParamSave )
{
perror("Failed to set DSP Format, sound card returned format");
return -1;
}
ioctlParam = 1;
if( ioctl( audioFD, SNDCTL_DSP_CHANNELS, &ioctlParam ) == -1 )
{
perror("SNDCTL_DSP_CHANNELS");
return -1;
}
if( ioctlParam != 1)
{
perror("Failed to set channels");
return -1;
}
ioctlParam = samplingRate;
if( ioctl( audioFD, SNDCTL_DSP_SPEED, &ioctlParam ) == -1 )
{
perror("SNDCTL_DSP_SPEED");
return -1;
}
if( ioctlParam != samplingRate )
{
perror("Failed to set sample rate");
return -1;
}
#if 0
ioctl(audioFD,SNDCTL_DSP_GETISPACE,&info);
printf("ISpace\nNo of Fragments:%d,\nTotal fragments allocated for buffering:%d,\nFragment size:%d,\nTotal Available Bytes %d \n\n",info.fragments,info.fragstotal,info.fragsize,info.bytes);
ioctl(audioFD,SNDCTL_DSP_GETOSPACE,&info);
printf("OSpace\nNo of Fragments:%d,\nTotal fragments allocated for buffering:%d,\nFragment size:%d,\nTotal Available Bytes %d \n\n",info.fragments,info.fragstotal,info.fragsize,info.bytes);
//ioctl(audioFD,SNDCTL_DSP_GETOPTR,oPtr);
//ioctl(audioFD,SNDCTL_DSP_GETOPTR,iPtr);
#endif
return audioFD;
}
int closeAudioHardware( int audioFD )
{
//cerr <<"Closing audio hardware\n";
if( ioctl( audioFD, SNDCTL_DSP_RESET, 0 ) == -1 )
{
perror("SNDCTL_DSP_RESET");
}
close( audioFD );
return 1;
}
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