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net/mediastreamer: Improve OSS backend code.
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- Reduced jitter and latency.
- Tested with Linphone.

Approved by:	pi (implicit)
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@hselasky
hselasky committed Mar 8, 2022
1 parent 8aaf275 commit 98a1992
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Showing 2 changed files with 222 additions and 24 deletions.
2 changes: 1 addition & 1 deletion net/mediastreamer/Makefile
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Expand Up @@ -2,7 +2,7 @@

PORTNAME= mediastreamer
PORTVERSION= 2.16.1
PORTREVISION= 6
PORTREVISION= 7
CATEGORIES= net
MASTER_SITES= https://www.linphone.org/releases/sources/mediastreamer/

Expand Down
244 changes: 221 additions & 23 deletions net/mediastreamer/files/patch-src__audiofilters__oss.c
View file
@@ -1,23 +1,76 @@
--- src/audiofilters/oss.c.orig 2015-01-30 09:36:13 UTC
--- src/audiofilters/oss.c.orig 2017-04-06 09:27:56 UTC
+++ src/audiofilters/oss.c
@@ -41,7 +41,7 @@ static int configure_fd(int fd, int bits
@@ -37,95 +37,65 @@ MSFilter *ms_oss_read_new(MSSndCard *card);
MSFilter *ms_oss_write_new(MSSndCard *card);


-static int configure_fd(int fd, int bits,int stereo, int rate, int *minsz)
+static int configure_fd(int fd, int bits,int stereo, int rate, int *minsz, int *mindly)
{
int p=0,cond=0;
int i=0;
- int p=0,cond=0;
- int i=0;
- int min_size=0,blocksize=512;
+ int p=0;
+ int min_size=0, blocksize=0;
+ int smp_size = bits / 8;
int err;

//g_message("opening sound device");
@@ -78,54 +78,17 @@ static int configure_fd(int fd, int bits
- //g_message("opening sound device");
- /* unset nonblocking mode */
- /* We wanted non blocking open but now put it back to normal ; thanks Xine !*/
- fcntl(fd, F_SETFL, fcntl(fd, F_GETFL)&~O_NONBLOCK);
+ err = 1;
+ ioctl(fd, FIONBIO, &err);

- /* reset is maybe not needed but takes time*/
- /*ioctl(fd, SNDCTL_DSP_RESET, 0); */
+ switch (bits) {
+ case 16:
+ p=AFMT_S16_NE;
+ break;
+ default:
+ close(fd);
+ return (-1);
+ }

- p=AFMT_S16_NE;
-
err=ioctl(fd,SNDCTL_DSP_SETFMT,&p);
if (err<0){
ms_warning("oss_open: can't set sample format:%s.",strerror(errno));
+ close(fd);
+ return (-1);
}

-
- p = bits; /* 16 bits */
- err=ioctl(fd, SNDCTL_DSP_SAMPLESIZE, &p);
- if (err<0){
- ms_warning("oss_open: can't set sample size to %i:%s.",bits,strerror(errno));
- }
-
p = rate; /* rate in khz*/
err=ioctl(fd, SNDCTL_DSP_SPEED, &p);
- if (err<0){
+ if (err<0 || p != rate){
ms_warning("oss_open: can't set sample rate to %i:%s.",rate,strerror(errno));
+ close(fd);
+ return (-1);
}

p = stereo; /* stereo or not */
err=ioctl(fd, SNDCTL_DSP_STEREO, &p);
if (err<0){
ms_warning("oss_open: can't set mono/stereo mode:%s.",strerror(errno));
+ close(fd);
+ return (-1);
}

- if (rate==16000) blocksize=4096; /* oss emulation is not very good at 16khz */
- else blocksize=blocksize*(rate/8000);
-
ioctl(fd, SNDCTL_DSP_GETBLKSIZE, &min_size);
- ioctl(fd, SNDCTL_DSP_GETBLKSIZE, &min_size);
-
- /**
- * first try SNDCTL_DSP_SETFRAGMENT
- */
Expand Down Expand Up @@ -49,20 +102,25 @@
- min_size=1 << (frag&0x0FFFF);
- ms_message("Max fragment=%x, size selector=%x block size=%i",frag>>16,frag&0x0FFFF,min_size);
- }
- }
-
+ err=ioctl(fd, SNDCTL_DSP_GETBLKSIZE, &min_size);
+ if (err<0){
+ close(fd);
+ return (-1);
}

- if (min_size>blocksize)
- {
- ms_warning("dsp block size set to %i.",min_size);
- }else{
- /* no need to access the card with less latency than needed*/
- min_size=blocksize;
- }
+ /* compute 20ms buffer */
+ blocksize = (rate / 50) * 2;
+ if (stereo)
+ /* compute a 20ms buffer by default */
+ blocksize = (rate / 50) * smp_size;
+ if (stereo) {
+ blocksize *= 2;
+ if (min_size > blocksize)
+ smp_size *= 2;
}
+ if (blocksize > min_size)
+ blocksize = min_size;

ms_message("/dev/dsp opened: rate=%i,bits=%i,stereo=%i blocksize=%i.",
Expand All @@ -71,25 +129,165 @@

/* start recording !!! Alex */
{
@@ -135,7 +98,7 @@ static int configure_fd(int fd, int bits
@@ -135,7 +105,8 @@ static int configure_fd(int fd, int bits,int stereo, i
res=ioctl(fd, SNDCTL_DSP_SETTRIGGER, &fl);
if (res<0) ms_warning("OSS_TRIGGER: %s",strerror(errno));
}
- *minsz=min_size;
+ *minsz=blocksize;
+ *mindly = ((uint64_t)1000000 * (uint64_t)blocksize) / (uint64_t)(2 * rate * smp_size);
return fd;
}

@@ -365,7 +328,11 @@ static void * oss_thread(void *p){
@@ -156,23 +127,23 @@ typedef struct OssData{
bool_t stereo;
} OssData;

-static void oss_open(OssData* d, int *minsz){
+static void oss_open(OssData* d, int *minsz, int *mindly){
int fd=open(d->pcmdev,O_RDWR|O_NONBLOCK);
if (fd>0) {
- d->pcmfd_read=d->pcmfd_write=configure_fd(fd, d->bits, d->stereo, d->rate, minsz);
+ d->pcmfd_read=d->pcmfd_write=configure_fd(fd, d->bits, d->stereo, d->rate, minsz, mindly);
return ;
}
ms_warning ("Cannot open a single fd in rw mode for [%s] trying to open two",d->pcmdev);

d->pcmfd_read=open(d->pcmdev,O_RDONLY|O_NONBLOCK);
if (d->pcmfd_read > 0) {
- d->pcmfd_read=configure_fd(d->pcmfd_read, d->bits, d->stereo, d->rate, minsz);
+ d->pcmfd_read=configure_fd(d->pcmfd_read, d->bits, d->stereo, d->rate, minsz, mindly);
} else {
ms_error("Cannot open fd in ro mode for [%s]",d->pcmdev);
}
d->pcmfd_write=open(d->pcmdev,O_WRONLY|O_NONBLOCK);
if (d->pcmfd_write > 0) {
- d->pcmfd_write=configure_fd(d->pcmfd_write, d->bits, d->stereo, d->rate, minsz);
+ d->pcmfd_write=configure_fd(d->pcmfd_write, d->bits, d->stereo, d->rate, minsz, mindly);
} else {
ms_error("Cannot open fd in wr mode for [%s]",d->pcmdev);
}
@@ -327,61 +298,78 @@ static void * oss_thread(void *p){
MSSndCard *card=(MSSndCard*)p;
OssData *d=(OssData*)card->data;
int bsize=0;
- uint8_t *rtmpbuff=NULL;
- uint8_t *wtmpbuff=NULL;
+ int mindly=1000;
+ uint8_t *tmpbuff;
int err;
- mblk_t *rm=NULL;
- bool_t did_read=FALSE;

- oss_open(d,&bsize);
- if (d->pcmfd_read>=0){
- rtmpbuff=(uint8_t*)alloca(bsize);
- }
- if (d->pcmfd_write>=0){
- wtmpbuff=(uint8_t*)alloca(bsize);
- }
+ oss_open(d,&bsize,&mindly);
+
+ tmpbuff=(uint8_t*)alloca(bsize);
+
while(d->read_started || d->write_started){
- did_read=FALSE;
- if (d->pcmfd_read>=0){
+ while (d->pcmfd_read>=0){
if (d->read_started){
- if (rm==NULL) rm=allocb(bsize,0);
- err=read(d->pcmfd_read,rm->b_wptr,bsize);
+ err=read(d->pcmfd_read,tmpbuff,bsize);
if (err<0){
- ms_warning("Fail to read %i bytes from soundcard: %s",
- bsize,strerror(errno));
- }else{
- did_read=TRUE;
+ if (errno != EWOULDBLOCK) {
+ ms_warning("Fail to read %i bytes from soundcard: %s",
+ bsize,strerror(errno));
+ }
+ break;
+ }else if (err>0) {
+ mblk_t *rm=allocb(err,0);
+ memcpy(rm->b_wptr,tmpbuff,err);
rm->b_wptr+=err;
ms_mutex_lock(&d->mutex);
putq(&d->rq,rm);
ms_mutex_unlock(&d->mutex);
- rm=NULL;
+ } else {
+ break;
}
}else {
/* case where we have no reader filtern the read is performed for synchronisation */
- int sz = read(d->pcmfd_read,rtmpbuff,bsize);
- if( sz==-1) ms_warning("sound device read error %s ",strerror(errno));
- else did_read=TRUE;
+ int sz = read(d->pcmfd_read,tmpbuff,bsize);
+ if(sz<0){
+ ms_warning("sound device read error %s ",strerror(errno));
+ break;
+ }
}
}
if (d->pcmfd_write>=0){
- if (d->pcmfd_write>=0){
- if (d->write_started){
+ int bufsize = 0;
+ ioctl(d->pcmfd_write, SNDCTL_DSP_GETODELAY, &bufsize);
+ if (bufsize >= bsize){
- err=ms_bufferizer_read(d->bufferizer,wtmpbuff,bsize);
+
+ while (d->pcmfd_write>=0){
+ struct audio_buf_info ai;
+ int bufsize;
+ if (ioctl(d->pcmfd_write, SNDCTL_DSP_GETOSPACE, &ai) < 0)
+ break;
+ bufsize = ai.fragstotal * ai.fragsize - ai.bytes;
+ if (bufsize >= (2 * bsize)){
+ /* wait for buffer to empty */
+ break;
+ }else if (d->write_started){
err=ms_bufferizer_read(d->bufferizer,wtmpbuff,bsize);
+ ms_mutex_lock(&d->mutex);
+ err=ms_bufferizer_read(d->bufferizer,tmpbuff,bsize);
+ ms_mutex_unlock(&d->mutex);
if (err==bsize){
err=write(d->pcmfd_write,wtmpbuff,bsize);
- err=write(d->pcmfd_write,wtmpbuff,bsize);
+ err=write(d->pcmfd_write,tmpbuff,bsize);
if (err<0){
ms_warning("Fail to write %i bytes from soundcard: %s",
- bsize,strerror(errno));
+ bsize,strerror(errno));
+ break;
}
+ } else {
+ break;
}
}else {
int sz;
- memset(wtmpbuff,0,bsize);
- sz = write(d->pcmfd_write,wtmpbuff,bsize);
- if( sz!=bsize) ms_warning("sound device write returned %i !",sz);
+ memset(tmpbuff,0,bsize);
+ sz = write(d->pcmfd_write,tmpbuff,bsize);
+ if(sz!=bsize) {
+ ms_warning("sound device write returned %i !",sz);
+ break;
+ }
}
}
- if (!did_read) usleep(20000); /*avoid 100%cpu loop for nothing*/
+ usleep(mindly);
}
if (d->pcmfd_read==d->pcmfd_write && d->pcmfd_read>=0 ) {
close(d->pcmfd_read);
@@ -509,10 +497,10 @@ static int set_nchannels(MSFilter *f, void *arg){
}

static MSFilterMethod oss_methods[]={
- { MS_FILTER_SET_SAMPLE_RATE , set_rate },
+ { MS_FILTER_SET_SAMPLE_RATE , set_rate },
{ MS_FILTER_GET_SAMPLE_RATE , get_rate },
{ MS_FILTER_SET_NCHANNELS , set_nchannels },
- { 0 , NULL }
+ { 0 , NULL }
};

MSFilterDesc oss_read_desc={

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