Update of /cvsroot/alsa/alsa-oss/test
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv4048
Added Files:
.cvsignore Makefile.am mmap_test.c
Log Message:
Copied mmap_test from alsa-driver/test directory
--- NEW FILE: .cvsignore ---
Makefile
Makefile.in
.deps
.libs
*.lo
*.la
--- NEW FILE: Makefile.am ---
check_PROGRAMS=mmap_test mmap_test_redir
mmap_test_redir_LDADD=../oss-redir/libossredir.la
INCLUDES=-I$(top_srcdir)/oss-redir
CFLAGS=-static -Wall -pipe -g
EXTRA_DIST=
test_mmap_test: mmap_test_redir
OSS_REDIRECTOR=libalsatoss.so mmap_test_redir
--- NEW FILE: mmap_test.c ---
/*
* This is a simple program which demonstrates use of mmapped DMA buffer
* of the sound driver directly from application program.
*
* This sample program works (currently) only with Linux, FreeBSD and BSD/OS
* (FreeBSD and BSD/OS require OSS version 3.8-beta16 or later.
*
* Note! Don't use mmapped DMA buffers (direct audio) unless you have
* very good reasons to do it. Programs using this feature will not
* work with all soundcards. GUS (GF1) is one of them (GUS MAX works).
*
* This program requires version 3.5-beta7 or later of OSS
* (3.8-beta16 or later in FreeBSD and BSD/OS).
*/
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/soundcard.h>
#include <sys/time.h>
main()
{
int fd, sz, fsz, i, tmp, n, l, have_data=0, nfrag;
int caps, idx;
int sd, sl=0, sp;
unsigned char data[500000], *dp = data;
struct buffmem_desc imemd, omemd;
caddr_t buf;
struct timeval tim;
unsigned char *op;
struct audio_buf_info info;
int frag = 0xffff000c; /* Max # periods of 2^13=8k bytes */
fd_set writeset;
close(0);
if ((fd=open("/dev/dsp", O_RDWR, 0))==-1)
{
perror("/dev/dsp");
exit(-1);
}
/*
* Then setup sampling parameters. Just sampling rate in this case.
*/
tmp = 48000;
ioctl(fd, SNDCTL_DSP_SPEED, &tmp);
printf("Speed set to %d\n", tmp);
/*
* Load some test data.
*/
sl = sp = 0;
if ((sd=open("smpl", O_RDONLY, 0))!=-1)
{
sl = read(sd, data, sizeof(data));
printf("%d bytes read from file.\n", sl);
close(sd);
}
else perror("smpl");
if (ioctl(fd, SNDCTL_DSP_GETCAPS, &caps)==-1)
{
perror("/dev/dsp");
fprintf(stderr, "Sorry but your sound driver is too old\n");
exit(-1);
}
/*
* Check that the device has capability to do this. Currently just
* CS4231 based cards will work.
*
* The application should also check for DSP_CAP_MMAP bit but this
* version of driver doesn't have it yet.
*/
/* ioctl(fd, SNDCTL_DSP_SETSYNCRO, 0); */
/*
* You need version 3.5-beta7 or later of the sound driver before next
* two lines compile. There is no point to modify this program to
* compile with older driver versions since they don't have working
* mmap() support.
*/
if (!(caps & DSP_CAP_TRIGGER) ||
!(caps & DSP_CAP_MMAP))
{
fprintf(stderr, "Sorry but your soundcard can't do this\n");
exit(-1);
}
/*
* Select the period size. This is propably important only when
* the program uses select(). Period size defines how often
* select call returns.
*/
ioctl(fd, SNDCTL_DSP_SETFRAGMENT, &frag);
/*
* Compute total size of the buffer. It's important to use this value
* in mmap() call.
*/
if (ioctl(fd, SNDCTL_DSP_GETOSPACE, &info)==-1)
{
perror("GETOSPACE");
exit(-1);
}
sz = info.fragstotal * info.fragsize;
fsz = info.fragsize;
printf( "info.fragstotal = %i\n", info.fragstotal );
printf( "info.fragsize = %i\n", info.fragsize );
printf( "info.periods = %i\n", info.fragments );
printf( "info.bytes = %i\n", info.bytes );
/*
* Call mmap().
*
* IMPORTANT NOTE!!!!!!!!!!!
*
* Full duplex audio devices have separate input and output buffers.
* It is not possible to map both of them at the same mmap() call. The buffer
* is selected based on the prot argument in the following way:
*
* - PROT_READ (alone) selects the input buffer.
* - PROT_WRITE (alone) selects the output buffer.
* - PROT_WRITE|PROT_READ together select the output buffer. This combination
* is required in BSD to make the buffer accessible. With just PROT_WRITE
* every attempt to access the returned buffer will result in segmentation/bus
* error. PROT_READ|PROT_WRITE is also permitted in Linux with OSS version
* 3.8-beta16 and later (earlier versions don't accept it).
*
* Non duplex devices have just one buffer. When an application wants to do both
* input and output it's recommended that the device is closed and re-opened when
* switching between modes. PROT_READ|PROT_WRITE can be used to open the buffer
* for both input and output (with OSS 3.8-beta16 and later) but the result may be
* unpredictable.
*/
#if 1
if ((buf=mmap(NULL, sz, PROT_WRITE, MAP_FILE|MAP_SHARED, fd, 0))==(caddr_t)-1)
{
perror("mmap (write)");
exit(-1);
}
printf("mmap (out) returned %08x\n", buf);
#else
buf=data;
#endif
op=buf;
/*
* op contains now a pointer to the DMA buffer
*/
/*
* Then it's time to start the engine. The driver doesn't allow read() and/or
* write() when the buffer is mapped. So the only way to start operation is
* to togle device's enable bits. First set them off. Setting them on enables
* recording and/or playback.
*/
tmp = 0;
ioctl(fd, SNDCTL_DSP_SETTRIGGER, &tmp);
printf("Trigger set to %08x\n", tmp);
/*
* It might be usefull to write some data to the buffer before starting.
*/
tmp = PCM_ENABLE_OUTPUT;
ioctl(fd, SNDCTL_DSP_SETTRIGGER, &tmp);
printf("Trigger set to %08x\n", tmp);
/*
* The machine is up and running now. Use SNDCTL_DSP_GETOPTR to get the
* buffer status.
*
* NOTE! The driver empties each buffer fragmen after they have been
* played. This prevents looping sound if there are some performance problems
* in the application side. For similar reasons it recommended that the
* application uses some amout of play ahead. It can rewrite the unplayed
* data later if necessary.
*/
nfrag = 0;
for (idx=0; idx<40; idx++)
{
struct count_info count;
int p, l, extra;
FD_ZERO(&writeset);
FD_SET(fd, &writeset);
tim.tv_sec = 10;
tim.tv_usec= 0;
select(fd+1, NULL, &writeset, NULL, NULL);
/*
* SNDCTL_DSP_GETOPTR (and GETIPTR as well) return three items. The
* bytes field returns number of bytes played since start. It can be used
* as a real time clock.
*
* The blocks field returns number of period transitions (interrupts) since
* previous GETOPTR call. It can be used as a method to detect underrun
* situations.
*
* The ptr field is the DMA pointer inside the buffer area (in bytes from
* the beginning of total buffer area).
*/
if (ioctl(fd, SNDCTL_DSP_GETOPTR, &count)==-1)
{
perror("GETOPTR");
exit(-1);
}
nfrag += count.blocks;
#ifdef VERBOSE
printf("Total: %09d, Period: %03d, Ptr: %06d",
count.bytes, nfrag, count.ptr);
fflush(stdout);
#endif
/*
* Caution! This version doesn't check for bounds of the DMA
* memory area. It's possible that the returned pointer value is not aligned
* to period boundaries. It may be several samples behind the boundary
* in case there was extra delay between the actual hardware interrupt and
* the time when DSP_GETOPTR was called.
*
* Don't just call memcpy() with length set to 'period_size' without
* first checking that the transfer really fits to the buffer area.
* A mistake of just one byte causes seg fault. It may be easiest just
* to align the returned pointer value to period boundary before using it.
*
* It would be very good idea to write few extra samples to next period
* too. Otherwise several (uninitialized) samples from next period
* will get played before your program gets chance to initialize them.
* Take in count the fact thaat there are other processes batling about
* the same CPU. This effect is likely to be very annoying if period
* size is decreased too much.
*/
/*
* Just a minor clarification to the above. The following line alings
* the pointer to period boundaries. Note! Don't trust that period
* size is always a power of 2. It may not be so in future.
*/
count.ptr = (count.ptr/fsz)*fsz;
#ifdef VERBOSE
printf(" memcpy(%6d, %4d)\n", (dp-data), fsz);
fflush(stdout);
#endif
/*
* Set few bytes in the beginning of next period too.
*/
if ((count.ptr+fsz+16) < sz) /* Last period? */
extra = 16;
else
extra = 0;
memcpy(op+count.ptr, dp, fsz+extra);
dp += fsz;
if (dp > (data+sl-fsz))
dp = data;
}
close(fd);
printf( ">>>> open (2)\n" ); fflush( stdout );
if ((fd=open("/dev/dsp", O_RDWR, 0))==-1)
{
perror("/dev/dsp");
exit(-1);
}
close( fd );
exit(0);
}
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