diff options
Diffstat (limited to 'sys/i386/isa/sound/mmap_test.c')
| -rw-r--r-- | sys/i386/isa/sound/mmap_test.c | 265 |
1 files changed, 0 insertions, 265 deletions
diff --git a/sys/i386/isa/sound/mmap_test.c b/sys/i386/isa/sound/mmap_test.c deleted file mode 100644 index db5cbc0..0000000 --- a/sys/i386/isa/sound/mmap_test.c +++ /dev/null @@ -1,265 +0,0 @@ -/* - * 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). - */ - -#ifndef lint -static const char rcsid[] = - "$FreeBSD$"; -#endif /* not lint */ - -#include <err.h> -#include <fcntl.h> -#include <stdio.h> -#include <string.h> -#include <unistd.h> -#include <sys/types.h> -#include <sys/mman.h> -#include <sys/soundcard.h> -#include <sys/time.h> - -int -main() -{ - int fd, sz, fsz, tmp, nfrag; - int caps; - - int sd, sl=0, sp; - - unsigned char data[500000], *dp = data; - - caddr_t buf; - struct timeval tim; - - unsigned char *op; - - struct audio_buf_info info; - - int frag = 0xffff000c; /* Max # fragments of 2^13=8k bytes */ - - fd_set writeset; - - close(0); - if ((fd=open("/dev/dsp", O_RDWR, 0))==-1) - err(1, "/dev/dsp"); -/* - * Then setup sampling parameters. Just sampling rate in this case. - */ - - tmp = 8000; - ioctl(fd, SNDCTL_DSP_SPEED, &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 warn("smpl"); - - if (ioctl(fd, SNDCTL_DSP_GETCAPS, &caps)==-1) - { - warn("sorry but your sound driver is too old"); - err(1, "/dev/dsp"); - } - -/* - * 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)) - errx(1, "sorry but your soundcard can't do this"); - -/* - * Select the fragment size. This is propably important only when - * the program uses select(). Fragment 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) - err(1, "GETOSPACE"); - - sz = info.fragstotal * info.fragsize; - fsz = info.fragsize; -/* - * 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 ((buf=mmap(NULL, sz, PROT_WRITE | PROT_READ, MAP_FILE|MAP_SHARED, fd, 0))==(caddr_t)-1) - err(1, "mmap (write)"); - printf("mmap (out) returned %08x\n", buf); - 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); - -/* - * It might be usefull to write some data to the buffer before starting. - */ - - tmp = PCM_ENABLE_OUTPUT; - ioctl(fd, SNDCTL_DSP_SETTRIGGER, &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; - while (1) - { - struct count_info count; - int extra; - - FD_ZERO(&writeset); - FD_SET(fd, &writeset); - - tim.tv_sec = 10; - tim.tv_usec= 0; - - select(fd+1, &writeset, &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 fragment 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) - err(1, "GETOPTR"); - if (count.ptr < 0 ) count.ptr = 0; - nfrag += count.blocks; - - -#ifdef VERBOSE - - printf("\rTotal: %09d, Fragment: %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 fragment 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 'fragment_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 fragment boundary before using it. - * - * It would be very good idea to write few extra samples to next fragment - * too. Otherwise several (uninitialized) samples from next fragment - * 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 fragment - * size is decreased too much. - */ - -/* - * Just a minor clarification to the above. The following line alings - * the pointer to fragment boundaries. Note! Don't trust that fragment - * size is always a power of 2. It may not be so in future. - */ - count.ptr = ((count.ptr+16)/fsz )*fsz; -#ifdef VERBOSE - printf(" memcpy(%6d, %4d)", (dp-data), fsz); - fflush(stdout); -#endif - -/* - * Set few bytes in the beginning of next fragment too. - */ - - if ((count.ptr+fsz+16) < sz) /* Last fragment? */ - extra = 16; - else - extra = 0; - memcpy(op+count.ptr, dp, (fsz+extra)); - dp += fsz; - if (dp > (data+sl-fsz)) - dp = data; - - } - - exit(0); -} |
