diff options
Diffstat (limited to 'source/3rd-party/SDL2/src/audio/dsp/SDL_dspaudio.c')
| -rw-r--r-- | source/3rd-party/SDL2/src/audio/dsp/SDL_dspaudio.c | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/source/3rd-party/SDL2/src/audio/dsp/SDL_dspaudio.c b/source/3rd-party/SDL2/src/audio/dsp/SDL_dspaudio.c new file mode 100644 index 0000000..77653be --- /dev/null +++ b/source/3rd-party/SDL2/src/audio/dsp/SDL_dspaudio.c @@ -0,0 +1,320 @@ +/* + Simple DirectMedia Layer + Copyright (C) 1997-2018 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: */ |