From 663df1cc68729adc0468d632fb19f6106ddcdca8 Mon Sep 17 00:00:00 2001 From: Alexandre Ratchov Date: Wed, 7 Sep 2022 15:23:42 +0200 Subject: audio: Add sndio backend MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit sndio is the native API used by OpenBSD, although it has been ported to other *BSD's and Linux (packages for Ubuntu, Debian, Void, Arch, etc.). Signed-off-by: Brad Smith Signed-off-by: Alexandre Ratchov Reviewed-by: Volker Rümelin Tested-by: Volker Rümelin Message-Id: Signed-off-by: Gerd Hoffmann --- audio/sndioaudio.c | 565 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 565 insertions(+) create mode 100644 audio/sndioaudio.c (limited to 'audio/sndioaudio.c') diff --git a/audio/sndioaudio.c b/audio/sndioaudio.c new file mode 100644 index 0000000..7c45276 --- /dev/null +++ b/audio/sndioaudio.c @@ -0,0 +1,565 @@ +/* + * SPDX-License-Identifier: ISC + * + * Copyright (c) 2019 Alexandre Ratchov + */ + +/* + * TODO : + * + * Use a single device and open it in full-duplex rather than + * opening it twice (once for playback once for recording). + * + * This is the only way to ensure that playback doesn't drift with respect + * to recording, which is what guest systems expect. + */ + +#include +#include +#include "qemu/osdep.h" +#include "qemu/main-loop.h" +#include "audio.h" +#include "trace.h" + +#define AUDIO_CAP "sndio" +#include "audio_int.h" + +/* default latency in microseconds if no option is set */ +#define SNDIO_LATENCY_US 50000 + +typedef struct SndioVoice { + union { + HWVoiceOut out; + HWVoiceIn in; + } hw; + struct sio_par par; + struct sio_hdl *hdl; + struct pollfd *pfds; + struct pollindex { + struct SndioVoice *self; + int index; + } *pindexes; + unsigned char *buf; + size_t buf_size; + size_t sndio_pos; + size_t qemu_pos; + unsigned int mode; + unsigned int nfds; + bool enabled; +} SndioVoice; + +typedef struct SndioConf { + const char *devname; + unsigned int latency; +} SndioConf; + +/* needed for forward reference */ +static void sndio_poll_in(void *arg); +static void sndio_poll_out(void *arg); + +/* + * stop polling descriptors + */ +static void sndio_poll_clear(SndioVoice *self) +{ + struct pollfd *pfd; + int i; + + for (i = 0; i < self->nfds; i++) { + pfd = &self->pfds[i]; + qemu_set_fd_handler(pfd->fd, NULL, NULL, NULL); + } + + self->nfds = 0; +} + +/* + * write data to the device until it blocks or + * all of our buffered data is written + */ +static void sndio_write(SndioVoice *self) +{ + size_t todo, n; + + todo = self->qemu_pos - self->sndio_pos; + + /* + * transfer data to device, until it blocks + */ + while (todo > 0) { + n = sio_write(self->hdl, self->buf + self->sndio_pos, todo); + if (n == 0) { + break; + } + self->sndio_pos += n; + todo -= n; + } + + if (self->sndio_pos == self->buf_size) { + /* + * we complete the block + */ + self->sndio_pos = 0; + self->qemu_pos = 0; + } +} + +/* + * read data from the device until it blocks or + * there no room any longer + */ +static void sndio_read(SndioVoice *self) +{ + size_t todo, n; + + todo = self->buf_size - self->sndio_pos; + + /* + * transfer data from the device, until it blocks + */ + while (todo > 0) { + n = sio_read(self->hdl, self->buf + self->sndio_pos, todo); + if (n == 0) { + break; + } + self->sndio_pos += n; + todo -= n; + } +} + +/* + * Set handlers for all descriptors libsndio needs to + * poll + */ +static void sndio_poll_wait(SndioVoice *self) +{ + struct pollfd *pfd; + int events, i; + + events = 0; + if (self->mode == SIO_PLAY) { + if (self->sndio_pos < self->qemu_pos) { + events |= POLLOUT; + } + } else { + if (self->sndio_pos < self->buf_size) { + events |= POLLIN; + } + } + + /* + * fill the given array of descriptors with the events sndio + * wants, they are different from our 'event' variable because + * sndio may use descriptors internally. + */ + self->nfds = sio_pollfd(self->hdl, self->pfds, events); + + for (i = 0; i < self->nfds; i++) { + pfd = &self->pfds[i]; + if (pfd->fd < 0) { + continue; + } + qemu_set_fd_handler(pfd->fd, + (pfd->events & POLLIN) ? sndio_poll_in : NULL, + (pfd->events & POLLOUT) ? sndio_poll_out : NULL, + &self->pindexes[i]); + pfd->revents = 0; + } +} + +/* + * call-back called when one of the descriptors + * became readable or writable + */ +static void sndio_poll_event(SndioVoice *self, int index, int event) +{ + int revents; + + /* + * ensure we're not called twice this cycle + */ + sndio_poll_clear(self); + + /* + * make self->pfds[] look as we're returning from poll syscal, + * this is how sio_revents expects events to be. + */ + self->pfds[index].revents = event; + + /* + * tell sndio to handle events and return whether we can read or + * write without blocking. + */ + revents = sio_revents(self->hdl, self->pfds); + if (self->mode == SIO_PLAY) { + if (revents & POLLOUT) { + sndio_write(self); + } + + if (self->qemu_pos < self->buf_size) { + audio_run(self->hw.out.s, "sndio_out"); + } + } else { + if (revents & POLLIN) { + sndio_read(self); + } + + if (self->qemu_pos < self->sndio_pos) { + audio_run(self->hw.in.s, "sndio_in"); + } + } + + /* + * audio_run() may have changed state + */ + if (self->enabled) { + sndio_poll_wait(self); + } +} + +/* + * return the upper limit of the amount of free play buffer space + */ +static size_t sndio_buffer_get_free(HWVoiceOut *hw) +{ + SndioVoice *self = (SndioVoice *) hw; + + return self->buf_size - self->qemu_pos; +} + +/* + * return a buffer where data to play can be stored, + * its size is stored in the location pointed by the size argument. + */ +static void *sndio_get_buffer_out(HWVoiceOut *hw, size_t *size) +{ + SndioVoice *self = (SndioVoice *) hw; + + *size = self->buf_size - self->qemu_pos; + return self->buf + self->qemu_pos; +} + +/* + * put back to sndio back-end a buffer returned by sndio_get_buffer_out() + */ +static size_t sndio_put_buffer_out(HWVoiceOut *hw, void *buf, size_t size) +{ + SndioVoice *self = (SndioVoice *) hw; + + self->qemu_pos += size; + sndio_poll_wait(self); + return size; +} + +/* + * return a buffer from where recorded data is available, + * its size is stored in the location pointed by the size argument. + * it may not exceed the initial value of "*size". + */ +static void *sndio_get_buffer_in(HWVoiceIn *hw, size_t *size) +{ + SndioVoice *self = (SndioVoice *) hw; + size_t todo, max_todo; + + /* + * unlike the get_buffer_out() method, get_buffer_in() + * must return a buffer of at most the given size, see audio.c + */ + max_todo = *size; + + todo = self->sndio_pos - self->qemu_pos; + if (todo > max_todo) { + todo = max_todo; + } + + *size = todo; + return self->buf + self->qemu_pos; +} + +/* + * discard the given amount of recorded data + */ +static void sndio_put_buffer_in(HWVoiceIn *hw, void *buf, size_t size) +{ + SndioVoice *self = (SndioVoice *) hw; + + self->qemu_pos += size; + if (self->qemu_pos == self->buf_size) { + self->qemu_pos = 0; + self->sndio_pos = 0; + } + sndio_poll_wait(self); +} + +/* + * call-back called when one of our descriptors becomes writable + */ +static void sndio_poll_out(void *arg) +{ + struct pollindex *pindex = (struct pollindex *) arg; + + sndio_poll_event(pindex->self, pindex->index, POLLOUT); +} + +/* + * call-back called when one of our descriptors becomes readable + */ +static void sndio_poll_in(void *arg) +{ + struct pollindex *pindex = (struct pollindex *) arg; + + sndio_poll_event(pindex->self, pindex->index, POLLIN); +} + +static void sndio_fini(SndioVoice *self) +{ + if (self->hdl) { + sio_close(self->hdl); + self->hdl = NULL; + } + + g_free(self->pfds); + g_free(self->pindexes); + g_free(self->buf); +} + +static int sndio_init(SndioVoice *self, + struct audsettings *as, int mode, Audiodev *dev) +{ + AudiodevSndioOptions *opts = &dev->u.sndio; + unsigned long long latency; + const char *dev_name; + struct sio_par req; + unsigned int nch; + int i, nfds; + + dev_name = opts->has_dev ? opts->dev : SIO_DEVANY; + latency = opts->has_latency ? opts->latency : SNDIO_LATENCY_US; + + /* open the device in non-blocking mode */ + self->hdl = sio_open(dev_name, mode, 1); + if (self->hdl == NULL) { + dolog("failed to open device\n"); + return -1; + } + + self->mode = mode; + + sio_initpar(&req); + + switch (as->fmt) { + case AUDIO_FORMAT_S8: + req.bits = 8; + req.sig = 1; + break; + case AUDIO_FORMAT_U8: + req.bits = 8; + req.sig = 0; + break; + case AUDIO_FORMAT_S16: + req.bits = 16; + req.sig = 1; + break; + case AUDIO_FORMAT_U16: + req.bits = 16; + req.sig = 0; + break; + case AUDIO_FORMAT_S32: + req.bits = 32; + req.sig = 1; + break; + case AUDIO_FORMAT_U32: + req.bits = 32; + req.sig = 0; + break; + default: + dolog("unknown audio sample format\n"); + return -1; + } + + if (req.bits > 8) { + req.le = as->endianness ? 0 : 1; + } + + req.rate = as->freq; + if (mode == SIO_PLAY) { + req.pchan = as->nchannels; + } else { + req.rchan = as->nchannels; + } + + /* set on-device buffer size */ + req.appbufsz = req.rate * latency / 1000000; + + if (!sio_setpar(self->hdl, &req)) { + dolog("failed set audio params\n"); + goto fail; + } + + if (!sio_getpar(self->hdl, &self->par)) { + dolog("failed get audio params\n"); + goto fail; + } + + nch = (mode == SIO_PLAY) ? self->par.pchan : self->par.rchan; + + /* + * With the default setup, sndio supports any combination of parameters + * so these checks are mostly to catch configuration errors. + */ + if (self->par.bits != req.bits || self->par.bps != req.bits / 8 || + self->par.sig != req.sig || (req.bits > 8 && self->par.le != req.le) || + self->par.rate != as->freq || nch != as->nchannels) { + dolog("unsupported audio params\n"); + goto fail; + } + + /* + * we use one block as buffer size; this is how + * transfers get well aligned + */ + self->buf_size = self->par.round * self->par.bps * nch; + + self->buf = g_malloc(self->buf_size); + if (self->buf == NULL) { + dolog("failed to allocate audio buffer\n"); + goto fail; + } + + nfds = sio_nfds(self->hdl); + + self->pfds = g_malloc_n(nfds, sizeof(struct pollfd)); + if (self->pfds == NULL) { + dolog("failed to allocate pollfd structures\n"); + goto fail; + } + + self->pindexes = g_malloc_n(nfds, sizeof(struct pollindex)); + if (self->pindexes == NULL) { + dolog("failed to allocate pollindex structures\n"); + goto fail; + } + + for (i = 0; i < nfds; i++) { + self->pindexes[i].self = self; + self->pindexes[i].index = i; + } + + return 0; +fail: + sndio_fini(self); + return -1; +} + +static void sndio_enable(SndioVoice *self, bool enable) +{ + if (enable) { + sio_start(self->hdl); + self->enabled = true; + sndio_poll_wait(self); + } else { + self->enabled = false; + sndio_poll_clear(self); + sio_stop(self->hdl); + } +} + +static void sndio_enable_out(HWVoiceOut *hw, bool enable) +{ + SndioVoice *self = (SndioVoice *) hw; + + sndio_enable(self, enable); +} + +static void sndio_enable_in(HWVoiceIn *hw, bool enable) +{ + SndioVoice *self = (SndioVoice *) hw; + + sndio_enable(self, enable); +} + +static int sndio_init_out(HWVoiceOut *hw, struct audsettings *as, void *opaque) +{ + SndioVoice *self = (SndioVoice *) hw; + + if (sndio_init(self, as, SIO_PLAY, opaque) == -1) { + return -1; + } + + audio_pcm_init_info(&hw->info, as); + hw->samples = self->par.round; + return 0; +} + +static int sndio_init_in(HWVoiceIn *hw, struct audsettings *as, void *opaque) +{ + SndioVoice *self = (SndioVoice *) hw; + + if (sndio_init(self, as, SIO_REC, opaque) == -1) { + return -1; + } + + audio_pcm_init_info(&hw->info, as); + hw->samples = self->par.round; + return 0; +} + +static void sndio_fini_out(HWVoiceOut *hw) +{ + SndioVoice *self = (SndioVoice *) hw; + + sndio_fini(self); +} + +static void sndio_fini_in(HWVoiceIn *hw) +{ + SndioVoice *self = (SndioVoice *) hw; + + sndio_fini(self); +} + +static void *sndio_audio_init(Audiodev *dev) +{ + assert(dev->driver == AUDIODEV_DRIVER_SNDIO); + return dev; +} + +static void sndio_audio_fini(void *opaque) +{ +} + +static struct audio_pcm_ops sndio_pcm_ops = { + .init_out = sndio_init_out, + .fini_out = sndio_fini_out, + .enable_out = sndio_enable_out, + .write = audio_generic_write, + .buffer_get_free = sndio_buffer_get_free, + .get_buffer_out = sndio_get_buffer_out, + .put_buffer_out = sndio_put_buffer_out, + .init_in = sndio_init_in, + .fini_in = sndio_fini_in, + .read = audio_generic_read, + .enable_in = sndio_enable_in, + .get_buffer_in = sndio_get_buffer_in, + .put_buffer_in = sndio_put_buffer_in, +}; + +static struct audio_driver sndio_audio_driver = { + .name = "sndio", + .descr = "sndio https://sndio.org", + .init = sndio_audio_init, + .fini = sndio_audio_fini, + .pcm_ops = &sndio_pcm_ops, + .can_be_default = 1, + .max_voices_out = INT_MAX, + .max_voices_in = INT_MAX, + .voice_size_out = sizeof(SndioVoice), + .voice_size_in = sizeof(SndioVoice) +}; + +static void register_audio_sndio(void) +{ + audio_driver_register(&sndio_audio_driver); +} + +type_init(register_audio_sndio); -- cgit v1.1