| /* |
| Simple DirectMedia Layer |
| Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org> |
| |
| This software is provided 'as-is', without any express or implied |
| warranty. In no event will the authors be held liable for any damages |
| arising from the use of this software. |
| |
| Permission is granted to anyone to use this software for any purpose, |
| including commercial applications, and to alter it and redistribute it |
| freely, subject to the following restrictions: |
| |
| 1. The origin of this software must not be misrepresented; you must not |
| claim that you wrote the original software. If you use this software |
| in a product, an acknowledgment in the product documentation would be |
| appreciated but is not required. |
| 2. Altered source versions must be plainly marked as such, and must not be |
| misrepresented as being the original software. |
| 3. This notice may not be removed or altered from any source distribution. |
| */ |
| #include "../../SDL_internal.h" |
| |
| #if SDL_AUDIO_DRIVER_OSS |
| |
| /* Allow access to a raw mixing buffer */ |
| |
| #include <stdio.h> /* For perror() */ |
| #include <string.h> /* For strerror() */ |
| #include <errno.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <signal.h> |
| #include <sys/time.h> |
| #include <sys/ioctl.h> |
| #include <sys/stat.h> |
| |
| #if SDL_AUDIO_DRIVER_OSS_SOUNDCARD_H |
| /* This is installed on some systems */ |
| #include <soundcard.h> |
| #else |
| /* This is recommended by OSS */ |
| #include <sys/soundcard.h> |
| #endif |
| |
| #include "SDL_timer.h" |
| #include "SDL_audio.h" |
| #include "../SDL_audio_c.h" |
| #include "../SDL_audiodev_c.h" |
| #include "SDL_dspaudio.h" |
| |
| |
| static void |
| DSP_DetectDevices(void) |
| { |
| SDL_EnumUnixAudioDevices(0, NULL); |
| } |
| |
| |
| static void |
| DSP_CloseDevice(_THIS) |
| { |
| if (this->hidden->audio_fd >= 0) { |
| close(this->hidden->audio_fd); |
| } |
| SDL_free(this->hidden->mixbuf); |
| SDL_free(this->hidden); |
| } |
| |
| |
| static int |
| DSP_OpenDevice(_THIS, void *handle, const char *devname, int iscapture) |
| { |
| const int flags = ((iscapture) ? OPEN_FLAGS_INPUT : OPEN_FLAGS_OUTPUT); |
| int format; |
| int value; |
| int frag_spec; |
| SDL_AudioFormat test_format; |
| |
| /* We don't care what the devname is...we'll try to open anything. */ |
| /* ...but default to first name in the list... */ |
| if (devname == NULL) { |
| devname = SDL_GetAudioDeviceName(0, iscapture); |
| if (devname == NULL) { |
| return SDL_SetError("No such audio device"); |
| } |
| } |
| |
| /* Make sure fragment size stays a power of 2, or OSS fails. */ |
| /* I don't know which of these are actually legal values, though... */ |
| if (this->spec.channels > 8) |
| this->spec.channels = 8; |
| else if (this->spec.channels > 4) |
| this->spec.channels = 4; |
| else if (this->spec.channels > 2) |
| this->spec.channels = 2; |
| |
| /* Initialize all variables that we clean on shutdown */ |
| this->hidden = (struct SDL_PrivateAudioData *) |
| SDL_malloc((sizeof *this->hidden)); |
| if (this->hidden == NULL) { |
| return SDL_OutOfMemory(); |
| } |
| SDL_zerop(this->hidden); |
| |
| /* Open the audio device */ |
| this->hidden->audio_fd = open(devname, flags, 0); |
| if (this->hidden->audio_fd < 0) { |
| return SDL_SetError("Couldn't open %s: %s", devname, strerror(errno)); |
| } |
| |
| /* Make the file descriptor use blocking i/o with fcntl() */ |
| { |
| long ctlflags; |
| ctlflags = fcntl(this->hidden->audio_fd, F_GETFL); |
| ctlflags &= ~O_NONBLOCK; |
| if (fcntl(this->hidden->audio_fd, F_SETFL, ctlflags) < 0) { |
| return SDL_SetError("Couldn't set audio blocking mode"); |
| } |
| } |
| |
| /* Get a list of supported hardware formats */ |
| if (ioctl(this->hidden->audio_fd, SNDCTL_DSP_GETFMTS, &value) < 0) { |
| perror("SNDCTL_DSP_GETFMTS"); |
| return SDL_SetError("Couldn't get audio format list"); |
| } |
| |
| /* Try for a closest match on audio format */ |
| format = 0; |
| for (test_format = SDL_FirstAudioFormat(this->spec.format); |
| !format && test_format;) { |
| #ifdef DEBUG_AUDIO |
| fprintf(stderr, "Trying format 0x%4.4x\n", test_format); |
| #endif |
| switch (test_format) { |
| case AUDIO_U8: |
| if (value & AFMT_U8) { |
| format = AFMT_U8; |
| } |
| break; |
| case AUDIO_S16LSB: |
| if (value & AFMT_S16_LE) { |
| format = AFMT_S16_LE; |
| } |
| break; |
| case AUDIO_S16MSB: |
| if (value & AFMT_S16_BE) { |
| format = AFMT_S16_BE; |
| } |
| break; |
| #if 0 |
| /* |
| * These formats are not used by any real life systems so they are not |
| * needed here. |
| */ |
| case AUDIO_S8: |
| if (value & AFMT_S8) { |
| format = AFMT_S8; |
| } |
| break; |
| case AUDIO_U16LSB: |
| if (value & AFMT_U16_LE) { |
| format = AFMT_U16_LE; |
| } |
| break; |
| case AUDIO_U16MSB: |
| if (value & AFMT_U16_BE) { |
| format = AFMT_U16_BE; |
| } |
| break; |
| #endif |
| default: |
| format = 0; |
| break; |
| } |
| if (!format) { |
| test_format = SDL_NextAudioFormat(); |
| } |
| } |
| if (format == 0) { |
| return SDL_SetError("Couldn't find any hardware audio formats"); |
| } |
| this->spec.format = test_format; |
| |
| /* Set the audio format */ |
| value = format; |
| if ((ioctl(this->hidden->audio_fd, SNDCTL_DSP_SETFMT, &value) < 0) || |
| (value != format)) { |
| perror("SNDCTL_DSP_SETFMT"); |
| return SDL_SetError("Couldn't set audio format"); |
| } |
| |
| /* Set the number of channels of output */ |
| value = this->spec.channels; |
| if (ioctl(this->hidden->audio_fd, SNDCTL_DSP_CHANNELS, &value) < 0) { |
| perror("SNDCTL_DSP_CHANNELS"); |
| return SDL_SetError("Cannot set the number of channels"); |
| } |
| this->spec.channels = value; |
| |
| /* Set the DSP frequency */ |
| value = this->spec.freq; |
| if (ioctl(this->hidden->audio_fd, SNDCTL_DSP_SPEED, &value) < 0) { |
| perror("SNDCTL_DSP_SPEED"); |
| return SDL_SetError("Couldn't set audio frequency"); |
| } |
| this->spec.freq = value; |
| |
| /* Calculate the final parameters for this audio specification */ |
| SDL_CalculateAudioSpec(&this->spec); |
| |
| /* Determine the power of two of the fragment size */ |
| for (frag_spec = 0; (0x01U << frag_spec) < this->spec.size; ++frag_spec); |
| if ((0x01U << frag_spec) != this->spec.size) { |
| return SDL_SetError("Fragment size must be a power of two"); |
| } |
| frag_spec |= 0x00020000; /* two fragments, for low latency */ |
| |
| /* Set the audio buffering parameters */ |
| #ifdef DEBUG_AUDIO |
| fprintf(stderr, "Requesting %d fragments of size %d\n", |
| (frag_spec >> 16), 1 << (frag_spec & 0xFFFF)); |
| #endif |
| if (ioctl(this->hidden->audio_fd, SNDCTL_DSP_SETFRAGMENT, &frag_spec) < 0) { |
| perror("SNDCTL_DSP_SETFRAGMENT"); |
| } |
| #ifdef DEBUG_AUDIO |
| { |
| audio_buf_info info; |
| ioctl(this->hidden->audio_fd, SNDCTL_DSP_GETOSPACE, &info); |
| fprintf(stderr, "fragments = %d\n", info.fragments); |
| fprintf(stderr, "fragstotal = %d\n", info.fragstotal); |
| fprintf(stderr, "fragsize = %d\n", info.fragsize); |
| fprintf(stderr, "bytes = %d\n", info.bytes); |
| } |
| #endif |
| |
| /* Allocate mixing buffer */ |
| if (!iscapture) { |
| this->hidden->mixlen = this->spec.size; |
| this->hidden->mixbuf = (Uint8 *) SDL_malloc(this->hidden->mixlen); |
| if (this->hidden->mixbuf == NULL) { |
| return SDL_OutOfMemory(); |
| } |
| SDL_memset(this->hidden->mixbuf, this->spec.silence, this->spec.size); |
| } |
| |
| /* We're ready to rock and roll. :-) */ |
| return 0; |
| } |
| |
| |
| static void |
| DSP_PlayDevice(_THIS) |
| { |
| struct SDL_PrivateAudioData *h = this->hidden; |
| if (write(h->audio_fd, h->mixbuf, h->mixlen) == -1) { |
| perror("Audio write"); |
| SDL_OpenedAudioDeviceDisconnected(this); |
| } |
| #ifdef DEBUG_AUDIO |
| fprintf(stderr, "Wrote %d bytes of audio data\n", h->mixlen); |
| #endif |
| } |
| |
| static Uint8 * |
| DSP_GetDeviceBuf(_THIS) |
| { |
| return (this->hidden->mixbuf); |
| } |
| |
| static int |
| DSP_CaptureFromDevice(_THIS, void *buffer, int buflen) |
| { |
| return (int) read(this->hidden->audio_fd, buffer, buflen); |
| } |
| |
| static void |
| DSP_FlushCapture(_THIS) |
| { |
| struct SDL_PrivateAudioData *h = this->hidden; |
| audio_buf_info info; |
| if (ioctl(h->audio_fd, SNDCTL_DSP_GETISPACE, &info) == 0) { |
| while (info.bytes > 0) { |
| char buf[512]; |
| const size_t len = SDL_min(sizeof (buf), info.bytes); |
| const ssize_t br = read(h->audio_fd, buf, len); |
| if (br <= 0) { |
| break; |
| } |
| info.bytes -= br; |
| } |
| } |
| } |
| |
| static int |
| DSP_Init(SDL_AudioDriverImpl * impl) |
| { |
| /* Set the function pointers */ |
| impl->DetectDevices = DSP_DetectDevices; |
| impl->OpenDevice = DSP_OpenDevice; |
| impl->PlayDevice = DSP_PlayDevice; |
| impl->GetDeviceBuf = DSP_GetDeviceBuf; |
| impl->CloseDevice = DSP_CloseDevice; |
| impl->CaptureFromDevice = DSP_CaptureFromDevice; |
| impl->FlushCapture = DSP_FlushCapture; |
| |
| impl->AllowsArbitraryDeviceNames = 1; |
| impl->HasCaptureSupport = SDL_TRUE; |
| |
| return 1; /* this audio target is available. */ |
| } |
| |
| |
| AudioBootStrap DSP_bootstrap = { |
| "dsp", "OSS /dev/dsp standard audio", DSP_Init, 0 |
| }; |
| |
| #endif /* SDL_AUDIO_DRIVER_OSS */ |
| |
| /* vi: set ts=4 sw=4 expandtab: */ |