/* PipeWire * * Copyright © 2021 Wim Taymans * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. */ #include #include #include #include #include #include #include #include "config.h" #include #include #include #include #include #include #include #include /** \page page_module_loopback PipeWire Module: Loopback * * The loopback module passes the output of a capture stream unmodified to a playback stream. * It can be used to construct a link between a source and sink but also to * create new virtual sinks or sources or to remap channel between streams. * * Because both ends of the loopback are built with streams, the session manager can * manage the configuration and connection with the sinks and sources. * * ## Module Options * * - `node.description`: a human readable name for the loopback streams * - `target.delay.sec`: delay in seconds as float (Since 0.3.60) * - `capture.props = {}`: properties to be passed to the input stream * - `playback.props = {}`: properties to be passed to the output stream * * ## General options * * Options with well-known behavior. Most options can be added to the global * configuration or the individual streams: * * - \ref PW_KEY_REMOTE_NAME * - \ref PW_KEY_AUDIO_RATE * - \ref PW_KEY_AUDIO_CHANNELS * - \ref SPA_KEY_AUDIO_POSITION * - \ref PW_KEY_MEDIA_NAME * - \ref PW_KEY_NODE_LATENCY * - \ref PW_KEY_NODE_DESCRIPTION * - \ref PW_KEY_NODE_GROUP * - \ref PW_KEY_NODE_LINK_GROUP * - \ref PW_KEY_NODE_VIRTUAL * - \ref PW_KEY_NODE_NAME: See notes below. If not specified, defaults to * 'loopback--'. * * Stream only properties: * * - \ref PW_KEY_MEDIA_CLASS * - \ref PW_KEY_NODE_NAME: if not given per stream, the global node.name will be * prefixed with 'input.' and 'output.' to generate a capture and playback * stream node.name respectively. * * ## Example configuration of a virtual sink * * This Virtual sink routes stereo input to the rear channels of a 7.1 sink. * *\code{.unparsed} * context.modules = [ * { name = libpipewire-module-loopback * args = { * node.description = "CM106 Stereo Pair 2" * #target.delay.sec = 1.5 * capture.props = { * node.name = "CM106_stereo_pair_2" * media.class = "Audio/Sink" * audio.position = [ FL FR ] * } * playback.props = { * node.name = "playback.CM106_stereo_pair_2" * audio.position = [ RL RR ] * target.object = "alsa_output.usb-0d8c_USB_Sound_Device-00.analog-surround-71" * node.dont-reconnect = true * stream.dont-remix = true * node.passive = true * } * } * } * ] *\endcode * * ## See also * * `pw-loopback` : a tool that loads the loopback module with given parameters. */ #define NAME "loopback" PW_LOG_TOPIC_STATIC(mod_topic, "mod." NAME); #define PW_LOG_TOPIC_DEFAULT mod_topic static const struct spa_dict_item module_props[] = { { PW_KEY_MODULE_AUTHOR, "Wim Taymans " }, { PW_KEY_MODULE_DESCRIPTION, "Create loopback streams" }, { PW_KEY_MODULE_USAGE, " [ remote.name= ] " "[ node.latency= ] " "[ node.description= ] " "[ audio.rate= ] " "[ audio.channels= ] " "[ audio.position= ] " "[ target.delay.sec= ] " "[ capture.props= ] " "[ playback.props= ] " }, { PW_KEY_MODULE_VERSION, PACKAGE_VERSION }, }; #include #include #include #include #include #include #include #include #include struct impl { struct pw_context *context; struct pw_impl_module *module; struct spa_hook module_listener; struct pw_core *core; struct spa_hook core_proxy_listener; struct spa_hook core_listener; struct pw_properties *capture_props; struct pw_stream *capture; struct spa_hook capture_listener; struct spa_audio_info_raw capture_info; struct spa_latency_info capture_latency; struct pw_properties *playback_props; struct pw_stream *playback; struct spa_hook playback_listener; struct spa_audio_info_raw playback_info; struct spa_latency_info playback_latency; unsigned int do_disconnect:1; unsigned int recalc_delay:1; float target_delay; struct spa_ringbuffer buffer; uint8_t *buffer_data; uint32_t buffer_size; }; static void capture_destroy(void *d) { struct impl *impl = d; spa_hook_remove(&impl->capture_listener); impl->capture = NULL; } static void recalculate_delay(struct impl *impl) { uint32_t target = impl->capture_info.rate * impl->target_delay, cdelay, pdelay; uint32_t delay, w; struct pw_time pwt; pw_stream_get_time_n(impl->playback, &pwt, sizeof(pwt)); pdelay = pwt.delay; pw_stream_get_time_n(impl->capture, &pwt, sizeof(pwt)); cdelay = pwt.delay; delay = target - SPA_MIN(target, pdelay + cdelay); delay = SPA_MIN(delay, impl->buffer_size / 4); spa_ringbuffer_get_write_index(&impl->buffer, &w); spa_ringbuffer_read_update(&impl->buffer, w - (delay * 4)); pw_log_info("target:%d c:%d + p:%d + delay:%d = (%d)", target, cdelay, pdelay, delay, cdelay + pdelay + delay); } static void capture_process(void *d) { struct impl *impl = d; pw_stream_trigger_process(impl->playback); } static void playback_process(void *d) { struct impl *impl = d; struct pw_buffer *in, *out; uint32_t i; if (impl->recalc_delay) { recalculate_delay(impl); impl->recalc_delay = false; } if ((in = pw_stream_dequeue_buffer(impl->capture)) == NULL) pw_log_debug("out of capture buffers: %m"); if ((out = pw_stream_dequeue_buffer(impl->playback)) == NULL) pw_log_debug("out of playback buffers: %m"); if (in != NULL && out != NULL) { uint32_t outsize = UINT32_MAX; int32_t stride = 0; struct spa_data *d; const void *src[in->buffer->n_datas]; uint32_t r, w, buffer_size; for (i = 0; i < in->buffer->n_datas; i++) { uint32_t offs, size; d = &in->buffer->datas[i]; offs = SPA_MIN(d->chunk->offset, d->maxsize); size = SPA_MIN(d->chunk->size, d->maxsize - offs); src[i] = SPA_PTROFF(d->data, offs, void); outsize = SPA_MIN(outsize, size); stride = SPA_MAX(stride, d->chunk->stride); } if (impl->buffer_size > 0) { buffer_size = impl->buffer_size; spa_ringbuffer_get_write_index(&impl->buffer, &w); for (i = 0; i < in->buffer->n_datas; i++) { void *buffer_data = &impl->buffer_data[i * buffer_size]; spa_ringbuffer_write_data(&impl->buffer, buffer_data, buffer_size, w % buffer_size, src[i], outsize); src[i] = buffer_data; } w += outsize; spa_ringbuffer_write_update(&impl->buffer, w); spa_ringbuffer_get_read_index(&impl->buffer, &r); } else { r = 0; buffer_size = outsize; } for (i = 0; i < out->buffer->n_datas; i++) { d = &out->buffer->datas[i]; outsize = SPA_MIN(outsize, d->maxsize); if (i < in->buffer->n_datas) spa_ringbuffer_read_data(&impl->buffer, src[i], buffer_size, r % buffer_size, d->data, outsize); else memset(d->data, 0, outsize); d->chunk->offset = 0; d->chunk->size = outsize; d->chunk->stride = stride; } if (impl->buffer_size > 0) { r += outsize; spa_ringbuffer_read_update(&impl->buffer, r); } } if (in != NULL) pw_stream_queue_buffer(impl->capture, in); if (out != NULL) pw_stream_queue_buffer(impl->playback, out); } static void param_latency_changed(struct impl *impl, const struct spa_pod *param, struct spa_latency_info *info, struct pw_stream *other) { struct spa_latency_info latency; uint8_t buffer[1024]; struct spa_pod_builder b; const struct spa_pod *params[1]; if (spa_latency_parse(param, &latency) < 0) return; *info = latency; spa_pod_builder_init(&b, buffer, sizeof(buffer)); params[0] = spa_latency_build(&b, SPA_PARAM_Latency, &latency); pw_stream_update_params(other, params, 1); impl->recalc_delay = true; } static void stream_state_changed(void *data, enum pw_stream_state old, enum pw_stream_state state, const char *error) { struct impl *impl = data; switch (state) { case PW_STREAM_STATE_PAUSED: pw_stream_flush(impl->playback, false); pw_stream_flush(impl->capture, false); impl->recalc_delay = true; break; case PW_STREAM_STATE_UNCONNECTED: pw_log_info("module %p: unconnected", impl); pw_impl_module_schedule_destroy(impl->module); break; case PW_STREAM_STATE_ERROR: pw_log_info("module %p: error: %s", impl, error); break; default: break; } } static void recalculate_buffer(struct impl *impl) { if (impl->target_delay > 0.0f) { uint32_t delay = impl->capture_info.rate * impl->target_delay; void *data; impl->buffer_size = (delay + (1u<<15)) * 4; data = realloc(impl->buffer_data, impl->buffer_size * impl->capture_info.channels); if (data == NULL) { pw_log_warn("can't allocate delay buffer, delay disabled: %m"); impl->buffer_size = 0; free(impl->buffer_data); } impl->buffer_data = data; spa_ringbuffer_init(&impl->buffer); } else { impl->buffer_size = 0; free(impl->buffer_data); impl->buffer_data = NULL; } pw_log_info("configured delay:%f buffer:%d", impl->target_delay, impl->buffer_size); impl->recalc_delay = true; } static void capture_param_changed(void *data, uint32_t id, const struct spa_pod *param) { struct impl *impl = data; switch (id) { case SPA_PARAM_Format: { struct spa_audio_info_raw info; if (param == NULL) return; if (spa_format_audio_raw_parse(param, &info) < 0) return; if (info.rate == 0 || info.channels == 0 || info.channels > SPA_AUDIO_MAX_CHANNELS) return; impl->capture_info = info; recalculate_buffer(impl); break; } case SPA_PARAM_Latency: param_latency_changed(impl, param, &impl->capture_latency, impl->playback); break; } } static const struct pw_stream_events in_stream_events = { PW_VERSION_STREAM_EVENTS, .destroy = capture_destroy, .process = capture_process, .state_changed = stream_state_changed, .param_changed = capture_param_changed, }; static void playback_destroy(void *d) { struct impl *impl = d; spa_hook_remove(&impl->playback_listener); impl->playback = NULL; } static void playback_param_changed(void *data, uint32_t id, const struct spa_pod *param) { struct impl *impl = data; switch (id) { case SPA_PARAM_Latency: param_latency_changed(impl, param, &impl->playback_latency, impl->capture); break; } } static const struct pw_stream_events out_stream_events = { PW_VERSION_STREAM_EVENTS, .destroy = playback_destroy, .process = playback_process, .state_changed = stream_state_changed, .param_changed = playback_param_changed, }; static int setup_streams(struct impl *impl) { int res; uint32_t n_params; const struct spa_pod *params[1]; uint8_t buffer[1024]; struct spa_pod_builder b; impl->capture = pw_stream_new(impl->core, "loopback capture", impl->capture_props); impl->capture_props = NULL; if (impl->capture == NULL) return -errno; pw_stream_add_listener(impl->capture, &impl->capture_listener, &in_stream_events, impl); impl->playback = pw_stream_new(impl->core, "loopback playback", impl->playback_props); impl->playback_props = NULL; if (impl->playback == NULL) return -errno; pw_stream_add_listener(impl->playback, &impl->playback_listener, &out_stream_events, impl); /* connect playback first to activate it before capture triggers it */ n_params = 0; spa_pod_builder_init(&b, buffer, sizeof(buffer)); params[n_params++] = spa_format_audio_raw_build(&b, SPA_PARAM_EnumFormat, &impl->playback_info); if ((res = pw_stream_connect(impl->playback, PW_DIRECTION_OUTPUT, PW_ID_ANY, PW_STREAM_FLAG_AUTOCONNECT | PW_STREAM_FLAG_MAP_BUFFERS | PW_STREAM_FLAG_RT_PROCESS | PW_STREAM_FLAG_TRIGGER, params, n_params)) < 0) return res; n_params = 0; spa_pod_builder_init(&b, buffer, sizeof(buffer)); params[n_params++] = spa_format_audio_raw_build(&b, SPA_PARAM_EnumFormat, &impl->capture_info); if ((res = pw_stream_connect(impl->capture, PW_DIRECTION_INPUT, PW_ID_ANY, PW_STREAM_FLAG_AUTOCONNECT | PW_STREAM_FLAG_MAP_BUFFERS | PW_STREAM_FLAG_RT_PROCESS, params, n_params)) < 0) return res; return 0; } static void core_error(void *data, uint32_t id, int seq, int res, const char *message) { struct impl *impl = data; if (res == -ENOENT) { pw_log_info("message id:%u seq:%d res:%d (%s): %s", id, seq, res, spa_strerror(res), message); } else { pw_log_warn("error id:%u seq:%d res:%d (%s): %s", id, seq, res, spa_strerror(res), message); } if (id == PW_ID_CORE && res == -EPIPE) pw_impl_module_schedule_destroy(impl->module); } static const struct pw_core_events core_events = { PW_VERSION_CORE_EVENTS, .error = core_error, }; static void core_destroy(void *d) { struct impl *impl = d; spa_hook_remove(&impl->core_listener); impl->core = NULL; pw_impl_module_schedule_destroy(impl->module); } static const struct pw_proxy_events core_proxy_events = { .destroy = core_destroy, }; static void impl_destroy(struct impl *impl) { /* deactivate both streams before destroying any of them */ if (impl->capture) pw_stream_set_active(impl->capture, false); if (impl->playback) pw_stream_set_active(impl->playback, false); if (impl->capture) pw_stream_destroy(impl->capture); if (impl->playback) pw_stream_destroy(impl->playback); if (impl->core && impl->do_disconnect) pw_core_disconnect(impl->core); pw_properties_free(impl->capture_props); pw_properties_free(impl->playback_props); free(impl); } static void module_destroy(void *data) { struct impl *impl = data; spa_hook_remove(&impl->module_listener); impl_destroy(impl); } static const struct pw_impl_module_events module_events = { PW_VERSION_IMPL_MODULE_EVENTS, .destroy = module_destroy, }; static uint32_t channel_from_name(const char *name) { int i; for (i = 0; spa_type_audio_channel[i].name; i++) { if (spa_streq(name, spa_debug_type_short_name(spa_type_audio_channel[i].name))) return spa_type_audio_channel[i].type; } return SPA_AUDIO_CHANNEL_UNKNOWN; } static void parse_position(struct spa_audio_info_raw *info, const char *val, size_t len) { struct spa_json it[2]; char v[256]; spa_json_init(&it[0], val, len); if (spa_json_enter_array(&it[0], &it[1]) <= 0) spa_json_init(&it[1], val, len); info->channels = 0; while (spa_json_get_string(&it[1], v, sizeof(v)) > 0 && info->channels < SPA_AUDIO_MAX_CHANNELS) { info->position[info->channels++] = channel_from_name(v); } } static void parse_audio_info(struct pw_properties *props, struct spa_audio_info_raw *info) { const char *str; *info = SPA_AUDIO_INFO_RAW_INIT( .format = SPA_AUDIO_FORMAT_F32P); info->rate = pw_properties_get_int32(props, PW_KEY_AUDIO_RATE, 0); info->channels = pw_properties_get_uint32(props, PW_KEY_AUDIO_CHANNELS, 0); info->channels = SPA_MIN(info->channels, SPA_AUDIO_MAX_CHANNELS); if ((str = pw_properties_get(props, SPA_KEY_AUDIO_POSITION)) != NULL) parse_position(info, str, strlen(str)); } static void copy_props(struct impl *impl, struct pw_properties *props, const char *key) { const char *str; if ((str = pw_properties_get(props, key)) != NULL) { if (pw_properties_get(impl->capture_props, key) == NULL) pw_properties_set(impl->capture_props, key, str); if (pw_properties_get(impl->playback_props, key) == NULL) pw_properties_set(impl->playback_props, key, str); } } SPA_EXPORT int pipewire__module_init(struct pw_impl_module *module, const char *args) { struct pw_context *context = pw_impl_module_get_context(module); struct pw_properties *props; struct impl *impl; uint32_t id = pw_global_get_id(pw_impl_module_get_global(module)); uint32_t pid = getpid(); const char *str; int res; PW_LOG_TOPIC_INIT(mod_topic); impl = calloc(1, sizeof(struct impl)); if (impl == NULL) return -errno; pw_log_debug("module %p: new %s", impl, args); if (args) props = pw_properties_new_string(args); else props = pw_properties_new(NULL, NULL); if (props == NULL) { res = -errno; pw_log_error( "can't create properties: %m"); goto error; } impl->capture_props = pw_properties_new(NULL, NULL); impl->playback_props = pw_properties_new(NULL, NULL); if (impl->capture_props == NULL || impl->playback_props == NULL) { res = -errno; pw_log_error( "can't create properties: %m"); goto error; } impl->module = module; impl->context = context; if (pw_properties_get(props, PW_KEY_NODE_GROUP) == NULL) pw_properties_setf(props, PW_KEY_NODE_GROUP, "loopback-%u-%u", pid, id); if (pw_properties_get(props, PW_KEY_NODE_LINK_GROUP) == NULL) pw_properties_setf(props, PW_KEY_NODE_LINK_GROUP, "loopback-%u-%u", pid, id); if (pw_properties_get(props, PW_KEY_NODE_VIRTUAL) == NULL) pw_properties_set(props, PW_KEY_NODE_VIRTUAL, "true"); if (pw_properties_get(props, "resample.prefill") == NULL) pw_properties_set(props, "resample.prefill", "true"); if ((str = pw_properties_get(props, "capture.props")) != NULL) pw_properties_update_string(impl->capture_props, str, strlen(str)); if ((str = pw_properties_get(props, "playback.props")) != NULL) pw_properties_update_string(impl->playback_props, str, strlen(str)); if ((str = pw_properties_get(props, "target.delay.sec")) != NULL) spa_atof(str, &impl->target_delay); if (impl->target_delay > 0.0f && pw_properties_get(props, PW_KEY_NODE_LATENCY) == NULL) /* a source and sink (USB) usually have a 1.5 quantum delay, so we use * a 2 times smaller quantum to compensate */ pw_properties_setf(props, PW_KEY_NODE_LATENCY, "%u/%u", (unsigned)(impl->target_delay * 48000 / 3), 48000); copy_props(impl, props, PW_KEY_AUDIO_RATE); copy_props(impl, props, PW_KEY_AUDIO_CHANNELS); copy_props(impl, props, SPA_KEY_AUDIO_POSITION); copy_props(impl, props, PW_KEY_NODE_DESCRIPTION); copy_props(impl, props, PW_KEY_NODE_GROUP); copy_props(impl, props, PW_KEY_NODE_LINK_GROUP); copy_props(impl, props, PW_KEY_NODE_LATENCY); copy_props(impl, props, PW_KEY_NODE_VIRTUAL); copy_props(impl, props, PW_KEY_MEDIA_NAME); copy_props(impl, props, "resample.prefill"); if ((str = pw_properties_get(props, PW_KEY_NODE_NAME)) == NULL) { pw_properties_setf(props, PW_KEY_NODE_NAME, "loopback-%u-%u", pid, id); str = pw_properties_get(props, PW_KEY_NODE_NAME); } if (pw_properties_get(impl->capture_props, PW_KEY_NODE_NAME) == NULL) pw_properties_setf(impl->capture_props, PW_KEY_NODE_NAME, "input.%s", str); if (pw_properties_get(impl->playback_props, PW_KEY_NODE_NAME) == NULL) pw_properties_setf(impl->playback_props, PW_KEY_NODE_NAME, "output.%s", str); if (pw_properties_get(impl->capture_props, PW_KEY_NODE_DESCRIPTION) == NULL) pw_properties_set(impl->capture_props, PW_KEY_NODE_DESCRIPTION, str); if (pw_properties_get(impl->playback_props, PW_KEY_NODE_DESCRIPTION) == NULL) pw_properties_set(impl->playback_props, PW_KEY_NODE_DESCRIPTION, str); parse_audio_info(impl->capture_props, &impl->capture_info); parse_audio_info(impl->playback_props, &impl->playback_info); if (pw_properties_get(impl->capture_props, PW_KEY_MEDIA_NAME) == NULL) pw_properties_setf(impl->capture_props, PW_KEY_MEDIA_NAME, "%s input", pw_properties_get(impl->capture_props, PW_KEY_NODE_DESCRIPTION)); if (pw_properties_get(impl->playback_props, PW_KEY_MEDIA_NAME) == NULL) pw_properties_setf(impl->playback_props, PW_KEY_MEDIA_NAME, "%s output", pw_properties_get(impl->playback_props, PW_KEY_NODE_DESCRIPTION)); impl->core = pw_context_get_object(impl->context, PW_TYPE_INTERFACE_Core); if (impl->core == NULL) { str = pw_properties_get(props, PW_KEY_REMOTE_NAME); impl->core = pw_context_connect(impl->context, pw_properties_new( PW_KEY_REMOTE_NAME, str, NULL), 0); impl->do_disconnect = true; } if (impl->core == NULL) { res = -errno; pw_log_error("can't connect: %m"); goto error; } pw_properties_free(props); pw_proxy_add_listener((struct pw_proxy*)impl->core, &impl->core_proxy_listener, &core_proxy_events, impl); pw_core_add_listener(impl->core, &impl->core_listener, &core_events, impl); setup_streams(impl); pw_impl_module_add_listener(module, &impl->module_listener, &module_events, impl); pw_impl_module_update_properties(module, &SPA_DICT_INIT_ARRAY(module_props)); return 0; error: pw_properties_free(props); impl_destroy(impl); return res; }