/*** This file is part of PulseAudio. Copyright 2009 Intel Corporation Contributor: Pierre-Louis Bossart PulseAudio is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. PulseAudio is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with PulseAudio; if not, see . ***/ #ifdef HAVE_CONFIG_H #include #endif #include #include #include #include #include #include #include #include #include #include PA_MODULE_AUTHOR("Pierre-Louis Bossart, Georg Chini"); PA_MODULE_DESCRIPTION("Loopback from source to sink"); PA_MODULE_VERSION(PACKAGE_VERSION); PA_MODULE_LOAD_ONCE(false); PA_MODULE_USAGE( "source= " "sink= " "adjust_time= " "latency_msec= " "max_latency_msec= " "log_interval= " "fast_adjust_threshold_msec= " "adjust_threshold_usec= " "format= " "rate= " "channels= " "channel_map= " "sink_input_properties= " "source_output_properties= " "source_dont_move= " "sink_dont_move= " "remix= "); #define DEFAULT_LATENCY_MSEC 200 #define FILTER_PARAMETER 0.125 #define DEFAULT_ADJUST_THRESHOLD_USEC 250 #define MEMBLOCKQ_MAXLENGTH (1024*1024*32) #define MIN_DEVICE_LATENCY (2.5*PA_USEC_PER_MSEC) #define DEFAULT_ADJUST_TIME_USEC (1*PA_USEC_PER_SEC) typedef struct loopback_msg loopback_msg; struct userdata { pa_core *core; pa_module *module; loopback_msg *msg; pa_sink_input *sink_input; pa_source_output *source_output; pa_asyncmsgq *asyncmsgq; pa_memblockq *memblockq; pa_rtpoll_item *rtpoll_item_read, *rtpoll_item_write; pa_time_event *time_event; /* Variables used to calculate the average time between * subsequent calls of adjust_rates() */ pa_usec_t adjust_time_stamp; pa_usec_t real_adjust_time; pa_usec_t real_adjust_time_sum; /* Values from command line configuration */ pa_usec_t latency; pa_usec_t max_latency; pa_usec_t adjust_time; pa_usec_t fast_adjust_threshold; uint32_t adjust_threshold; uint32_t log_interval; /* Latency boundaries and current values */ pa_usec_t min_source_latency; pa_usec_t max_source_latency; pa_usec_t min_sink_latency; pa_usec_t max_sink_latency; pa_usec_t configured_sink_latency; pa_usec_t configured_source_latency; int64_t source_latency_offset; int64_t sink_latency_offset; pa_usec_t minimum_latency; /* State variable of the latency controller */ int32_t last_latency_difference; int64_t last_source_latency_offset; int64_t last_sink_latency_offset; int64_t next_latency_with_drift; int64_t next_latency_at_optimum_rate_with_drift; /* Filter varables used for 2nd order filter */ double drift_filter; double drift_compensation_rate; /* Variables for Kalman filter and error tracking*/ double latency_variance; double kalman_variance; double latency_error; /* lower latency limit found by underruns */ pa_usec_t underrun_latency_limit; /* Various counters */ uint32_t iteration_counter; uint32_t underrun_counter; uint32_t adjust_counter; uint32_t target_latency_cross_counter; uint32_t log_counter; /* Various booleans */ bool fixed_alsa_source; bool source_sink_changed; bool underrun_occured; bool source_latency_offset_changed; bool sink_latency_offset_changed; bool initial_adjust_pending; /* Used for sink input and source output snapshots */ struct { int64_t send_counter; int64_t source_latency; pa_usec_t source_timestamp; int64_t recv_counter; size_t loopback_memblockq_length; int64_t sink_latency; pa_usec_t sink_timestamp; } latency_snapshot; /* Input thread variable */ int64_t send_counter; /* Output thread variables */ struct { int64_t recv_counter; pa_usec_t effective_source_latency; /* Copied from main thread */ pa_usec_t minimum_latency; /* Various booleans */ bool in_pop; bool pop_called; bool pop_adjust; bool first_pop_done; bool push_called; } output_thread_info; }; struct loopback_msg { pa_msgobject parent; struct userdata *userdata; bool dead; }; PA_DEFINE_PRIVATE_CLASS(loopback_msg, pa_msgobject); #define LOOPBACK_MSG(o) (loopback_msg_cast(o)) static const char* const valid_modargs[] = { "source", "sink", "adjust_time", "latency_msec", "max_latency_msec", "log_interval", "fast_adjust_threshold_msec", "adjust_threshold_usec", "format", "rate", "channels", "channel_map", "sink_input_properties", "source_output_properties", "source_dont_move", "sink_dont_move", "remix", NULL, }; enum { SINK_INPUT_MESSAGE_POST = PA_SINK_INPUT_MESSAGE_MAX, SINK_INPUT_MESSAGE_REWIND, SINK_INPUT_MESSAGE_LATENCY_SNAPSHOT, SINK_INPUT_MESSAGE_SOURCE_CHANGED, SINK_INPUT_MESSAGE_SET_EFFECTIVE_SOURCE_LATENCY, SINK_INPUT_MESSAGE_UPDATE_MIN_LATENCY, SINK_INPUT_MESSAGE_FAST_ADJUST, }; enum { SOURCE_OUTPUT_MESSAGE_LATENCY_SNAPSHOT = PA_SOURCE_OUTPUT_MESSAGE_MAX, }; enum { LOOPBACK_MESSAGE_SOURCE_LATENCY_RANGE_CHANGED, LOOPBACK_MESSAGE_SINK_LATENCY_RANGE_CHANGED, LOOPBACK_MESSAGE_UNDERRUN, LOOPBACK_MESSAGE_ADJUST_DONE, }; static void enable_adjust_timer(struct userdata *u, bool enable); /* Called from main context */ static void teardown(struct userdata *u) { pa_assert(u); pa_assert_ctl_context(); u->adjust_time = 0; enable_adjust_timer(u, false); if (u->msg) u->msg->dead = true; /* Handling the asyncmsgq between the source output and the sink input * requires some care. When the source output is unlinked, nothing needs * to be done for the asyncmsgq, because the source output is the sending * end. But when the sink input is unlinked, we should ensure that the * asyncmsgq is emptied, because the messages in the queue hold references * to the sink input. Also, we need to ensure that new messages won't be * written to the queue after we have emptied it. * * Emptying the queue can be done in the state_change() callback of the * sink input, when the new state is "unlinked". * * Preventing new messages from being written to the queue can be achieved * by unlinking the source output before unlinking the sink input. There * are no other writers for that queue, so this is sufficient. */ if (u->source_output) { pa_source_output_unlink(u->source_output); pa_source_output_unref(u->source_output); u->source_output = NULL; } if (u->sink_input) { pa_sink_input_unlink(u->sink_input); pa_sink_input_unref(u->sink_input); u->sink_input = NULL; } } /* rate controller, called from main context * - maximum deviation from optimum rate for P-controller is less than 1% * - P-controller step size is limited to 2.01‰ * - will calculate an optimum rate */ static uint32_t rate_controller( struct userdata *u, uint32_t base_rate, uint32_t old_rate, int32_t latency_difference_at_optimum_rate, int32_t latency_difference_at_base_rate) { double new_rate, new_rate_1, new_rate_2; double min_cycles_1, min_cycles_2, drift_rate, latency_drift, controller_weight, min_weight; uint32_t base_rate_with_drift; base_rate_with_drift = (int)(base_rate + u->drift_compensation_rate); /* If we are less than 2‰ away from the optimum rate, lower weight of the * P-controller. The weight is determined by the fact that a correction * of 0.5 Hz needs to be applied by the controller when the latency * difference gets larger than the threshold. The weight follows * from the definition of the controller. The minimum will only * be reached when one adjust threshold away from the target. Start * using the weight after the target latency has been reached for the * second time to accelerate initial convergence. The second time has * been chosen because it takes a while before the smoother returns * reliable latencies. */ controller_weight = 1; min_weight = PA_CLAMP(0.5 / (double)base_rate * (100.0 + (double)u->real_adjust_time / u->adjust_threshold), 0, 1.0); if ((double)abs((int)(old_rate - base_rate_with_drift)) / base_rate_with_drift < 0.002 && u->target_latency_cross_counter >= 2) controller_weight = PA_CLAMP((double)abs(latency_difference_at_optimum_rate) / u->adjust_threshold * min_weight, min_weight, 1.0); /* Calculate next rate that is not more than 2‰ away from the last rate */ min_cycles_1 = (double)abs(latency_difference_at_optimum_rate) / u->real_adjust_time / 0.002 + 1; new_rate_1 = old_rate + base_rate * (double)latency_difference_at_optimum_rate / min_cycles_1 / u->real_adjust_time; /* Calculate best rate to correct the current latency offset, limit at * 1% difference from base_rate */ min_cycles_2 = (double)abs(latency_difference_at_optimum_rate) / u->real_adjust_time / 0.01 + 1; new_rate_2 = (double)base_rate * (1.0 + controller_weight * latency_difference_at_optimum_rate / min_cycles_2 / u->real_adjust_time); /* Choose the rate that is nearer to base_rate unless we are already near * to the desired latency and rate */ if (abs((int)(new_rate_1 - base_rate)) < abs((int)(new_rate_2 - base_rate)) && controller_weight > 0.99) new_rate = new_rate_1; else new_rate = new_rate_2; /* Calculate rate difference between source and sink. Skip calculation * after a source/sink change, an underrun or latency offset change */ if (!u->underrun_occured && !u->source_sink_changed && !u->source_latency_offset_changed && !u->sink_latency_offset_changed) { /* Latency difference between last iterations */ latency_drift = latency_difference_at_base_rate - u->last_latency_difference; /* Calculate frequency difference between source and sink */ drift_rate = latency_drift * old_rate / u->real_adjust_time + old_rate - base_rate; /* The maximum accepted sample rate difference between source and * sink is 1% of the base rate. If the result is larger, something * went wrong, so do not use it. Pass in 0 instead to allow the * filter to decay. */ if (abs((int)drift_rate) > base_rate / 100) drift_rate = 0; /* 2nd order lowpass filter */ u->drift_filter = (1 - FILTER_PARAMETER) * u->drift_filter + FILTER_PARAMETER * drift_rate; u->drift_compensation_rate = (1 - FILTER_PARAMETER) * u->drift_compensation_rate + FILTER_PARAMETER * u->drift_filter; } /* Use drift compensation. Though not likely, the rate might exceed the maximum allowed rate now. */ new_rate = new_rate + u->drift_compensation_rate + 0.5; if (new_rate > base_rate * 101 / 100) return base_rate * 101 / 100; else if (new_rate < base_rate * 99 / 100) return base_rate * 99 / 100; else return (int)new_rate; } /* Called from main thread. * It has been a matter of discussion how to correctly calculate the minimum * latency that module-loopback can deliver with a given source and sink. * The calculation has been placed in a separate function so that the definition * can easily be changed. The resulting estimate is not very exact because it * depends on the reported latency ranges. In cases were the lower bounds of * source and sink latency are not reported correctly (USB) the result will * be wrong. */ static void update_minimum_latency(struct userdata *u, pa_sink *sink, bool print_msg) { if (u->underrun_latency_limit) /* If we already detected a real latency limit because of underruns, use it */ u->minimum_latency = u->underrun_latency_limit; else { /* Calculate latency limit from latency ranges */ u->minimum_latency = u->min_sink_latency; if (u->fixed_alsa_source) /* If we are using an alsa source with fixed latency, we will get a wakeup when * one fragment is filled, and then we empty the source buffer, so the source * latency never grows much beyond one fragment (assuming that the CPU doesn't * cause a bottleneck). */ u->minimum_latency += u->core->default_fragment_size_msec * PA_USEC_PER_MSEC; else /* In all other cases the source will deliver new data at latest after one source latency. * Make sure there is enough data available that the sink can keep on playing until new * data is pushed. */ u->minimum_latency += u->min_source_latency; /* Multiply by 1.1 as a safety margin for delays that are proportional to the buffer sizes */ u->minimum_latency *= 1.1; /* Add 1.5 ms as a safety margin for delays not related to the buffer sizes */ u->minimum_latency += 1.5 * PA_USEC_PER_MSEC; } /* Add the latency offsets */ if (-(u->sink_latency_offset + u->source_latency_offset) <= (int64_t)u->minimum_latency) u->minimum_latency += u->sink_latency_offset + u->source_latency_offset; else u->minimum_latency = 0; /* If the sink is valid, send a message to update the minimum latency to * the output thread, else set the variable directly */ if (sink) pa_asyncmsgq_send(sink->asyncmsgq, PA_MSGOBJECT(u->sink_input), SINK_INPUT_MESSAGE_UPDATE_MIN_LATENCY, NULL, u->minimum_latency, NULL); else u->output_thread_info.minimum_latency = u->minimum_latency; if (print_msg) { pa_log_info("Minimum possible end to end latency: %0.2f ms", (double)u->minimum_latency / PA_USEC_PER_MSEC); if (u->latency < u->minimum_latency) pa_log_warn("Configured latency of %0.2f ms is smaller than minimum latency, using minimum instead", (double)u->latency / PA_USEC_PER_MSEC); } } /* Called from main context */ static void adjust_rates(struct userdata *u) { size_t buffer; uint32_t old_rate, base_rate, new_rate, run_hours; int32_t latency_difference; pa_usec_t current_buffer_latency, snapshot_delay; int64_t current_source_sink_latency, current_latency, latency_at_optimum_rate; pa_usec_t final_latency, now, time_passed; double filtered_latency, current_latency_error, latency_correction, base_rate_with_drift; pa_assert(u); pa_assert_ctl_context(); /* Runtime and counters since last change of source or sink * or source/sink latency */ run_hours = u->iteration_counter * u->real_adjust_time / PA_USEC_PER_SEC / 3600; u->iteration_counter +=1; /* If we are seeing underruns then the latency is too small */ if (u->underrun_counter > 2) { pa_usec_t target_latency; target_latency = PA_MAX(u->latency, u->minimum_latency) + 5 * PA_USEC_PER_MSEC; if (u->max_latency == 0 || target_latency < u->max_latency) { u->underrun_latency_limit = PA_CLIP_SUB((int64_t)target_latency, u->sink_latency_offset + u->source_latency_offset); pa_log_warn("Too many underruns, increasing latency to %0.2f ms", (double)target_latency / PA_USEC_PER_MSEC); } else { u->underrun_latency_limit = PA_CLIP_SUB((int64_t)u->max_latency, u->sink_latency_offset + u->source_latency_offset); pa_log_warn("Too many underruns, configured maximum latency of %0.2f ms is reached", (double)u->max_latency / PA_USEC_PER_MSEC); pa_log_warn("Consider increasing the max_latency_msec"); } update_minimum_latency(u, u->sink_input->sink, false); u->underrun_counter = 0; } /* Allow one underrun per hour */ if (u->iteration_counter * u->real_adjust_time / PA_USEC_PER_SEC / 3600 > run_hours) { u->underrun_counter = PA_CLIP_SUB(u->underrun_counter, 1u); pa_log_info("Underrun counter: %u", u->underrun_counter); } /* Calculate real adjust time if source or sink did not change and if the system has * not been suspended. If the time between two calls is more than 5% longer than the * configured adjust time, we assume that the system has been sleeping and skip the * calculation for this iteration. When source or sink changed or the system has been * sleeping, we need to reset the parameters for drift compensation. */ now = pa_rtclock_now(); time_passed = now - u->adjust_time_stamp; if (!u->source_sink_changed && time_passed < u->adjust_time * 1.05) { u->adjust_counter++; u->real_adjust_time_sum += time_passed; u->real_adjust_time = u->real_adjust_time_sum / u->adjust_counter; } else { u->drift_compensation_rate = 0; u->drift_filter = 0; /* Ensure that source_sink_changed is set, so that the Kalman filter parameters * will also be reset. */ u->source_sink_changed = true; } u->adjust_time_stamp = now; /* Rates and latencies */ old_rate = u->sink_input->sample_spec.rate; base_rate = u->source_output->sample_spec.rate; buffer = u->latency_snapshot.loopback_memblockq_length; if (u->latency_snapshot.recv_counter <= u->latency_snapshot.send_counter) buffer += (size_t) (u->latency_snapshot.send_counter - u->latency_snapshot.recv_counter); else buffer = PA_CLIP_SUB(buffer, (size_t) (u->latency_snapshot.recv_counter - u->latency_snapshot.send_counter)); current_buffer_latency = pa_bytes_to_usec(buffer, &u->sink_input->sample_spec); snapshot_delay = u->latency_snapshot.source_timestamp - u->latency_snapshot.sink_timestamp; current_source_sink_latency = u->latency_snapshot.sink_latency + u->latency_snapshot.source_latency - snapshot_delay; /* Current latency */ current_latency = current_source_sink_latency + current_buffer_latency; /* Latency at optimum rate and latency difference */ latency_at_optimum_rate = current_source_sink_latency + current_buffer_latency * old_rate / (u->drift_compensation_rate + base_rate); final_latency = PA_MAX(u->latency, u->minimum_latency); latency_difference = (int32_t)(current_latency - final_latency); /* Do not filter or calculate error if source or sink changed or if there was an underrun */ if (u->source_sink_changed || u->underrun_occured) { /* Initial conditions are very unsure, so use a high variance */ u->kalman_variance = 10000000; filtered_latency = latency_at_optimum_rate; u->next_latency_at_optimum_rate_with_drift = latency_at_optimum_rate; u->next_latency_with_drift = current_latency; } else { /* Correct predictions if one of the latency offsets changed between iterations */ u->next_latency_at_optimum_rate_with_drift += u->source_latency_offset - u->last_source_latency_offset; u->next_latency_at_optimum_rate_with_drift += u->sink_latency_offset - u->last_sink_latency_offset; u->next_latency_with_drift += u->source_latency_offset - u->last_source_latency_offset; u->next_latency_with_drift += u->sink_latency_offset - u->last_sink_latency_offset; /* Low pass filtered latency error. This value reflects how well the measured values match the prediction. */ u->latency_error = (1 - FILTER_PARAMETER) * u->latency_error + FILTER_PARAMETER * (double)abs((int32_t)(current_latency - u->next_latency_with_drift)); /* Low pass filtered latency variance */ current_latency_error = (double)abs((int32_t)(latency_at_optimum_rate - u->next_latency_at_optimum_rate_with_drift)); u->latency_variance = (1.0 - FILTER_PARAMETER) * u->latency_variance + FILTER_PARAMETER * current_latency_error * current_latency_error; /* Kalman filter */ filtered_latency = (latency_at_optimum_rate * u->kalman_variance + u->next_latency_at_optimum_rate_with_drift * u->latency_variance) / (u->kalman_variance + u->latency_variance); u->kalman_variance = u->kalman_variance * u->latency_variance / (u->kalman_variance + u->latency_variance) + u->latency_variance / 4 + 200; } /* Drop or insert samples if fast_adjust_threshold_msec was specified and the latency difference is too large. */ if (u->fast_adjust_threshold > 0 && abs(latency_difference) > u->fast_adjust_threshold) { pa_log_debug ("Latency difference larger than %" PRIu64 " msec, skipping or inserting samples.", u->fast_adjust_threshold / PA_USEC_PER_MSEC); pa_asyncmsgq_send(u->sink_input->sink->asyncmsgq, PA_MSGOBJECT(u->sink_input), SINK_INPUT_MESSAGE_FAST_ADJUST, NULL, current_source_sink_latency, NULL); /* Skip real adjust time calculation and reset drift compensation parameters on next iteration. */ u->source_sink_changed = true; /* We probably need to adjust again, reset cross_counter. */ u->target_latency_cross_counter = 0; return; } /* Calculate new rate */ new_rate = rate_controller(u, base_rate, old_rate, (int32_t)(filtered_latency - final_latency), latency_difference); /* Log every log_interval iterations if the log_interval parameter is set */ if (u->log_interval != 0) { u->log_counter--; if (u->log_counter == 0) { pa_log_debug("Loopback status %s to %s:\n Source latency: %0.2f ms\n Buffer: %0.2f ms\n Sink latency: %0.2f ms\n End-to-end latency: %0.2f ms\n" " Deviation from target latency at optimum rate: %0.2f usec\n Average prediction error: ± %0.2f usec\n Optimum rate: %0.2f Hz\n Deviation from base rate: %i Hz", u->source_output->source->name, u->sink_input->sink->name, (double) u->latency_snapshot.source_latency / PA_USEC_PER_MSEC, (double) current_buffer_latency / PA_USEC_PER_MSEC, (double) u->latency_snapshot.sink_latency / PA_USEC_PER_MSEC, (double) current_latency / PA_USEC_PER_MSEC, (double) latency_at_optimum_rate - final_latency, (double) u->latency_error, u->drift_compensation_rate + base_rate, (int32_t)(new_rate - base_rate)); u->log_counter = u->log_interval; } } /* If the latency difference changed sign, we have crossed the target latency. */ if ((int64_t)latency_difference * u->last_latency_difference < 0) u->target_latency_cross_counter++; /* Save current latency difference at new rate for next cycle and reset flags */ u->last_latency_difference = current_source_sink_latency + current_buffer_latency * old_rate / new_rate - final_latency; /* Set variables that may change between calls of adjust_rate() */ u->source_sink_changed = false; u->underrun_occured = false; u->last_source_latency_offset = u->source_latency_offset; u->last_sink_latency_offset = u->sink_latency_offset; u->source_latency_offset_changed = false; u->sink_latency_offset_changed = false; /* Predicton of next latency */ /* Evaluate optimum rate */ base_rate_with_drift = u->drift_compensation_rate + base_rate; /* Latency correction on next iteration */ latency_correction = (base_rate_with_drift - new_rate) * (int64_t)u->real_adjust_time / new_rate; if ((int)new_rate != (int)base_rate_with_drift || new_rate != old_rate) { /* While we are correcting, the next latency is determined by the current value and the difference * between the new sampling rate and the base rate*/ u->next_latency_with_drift = current_latency + latency_correction + ((double)old_rate / new_rate - 1) * current_buffer_latency; u->next_latency_at_optimum_rate_with_drift = filtered_latency + latency_correction * new_rate / base_rate_with_drift; } else { /* We are in steady state, now only the fractional drift should matter. * To make sure that we do not drift away due to errors in the fractional * drift, use a running average of the measured and predicted values */ u->next_latency_with_drift = (filtered_latency + u->next_latency_with_drift) / 2.0 + (1.0 - (double)(int)base_rate_with_drift / base_rate_with_drift) * (int64_t)u->real_adjust_time; /* We are at the optimum rate, so nothing to correct */ u->next_latency_at_optimum_rate_with_drift = u->next_latency_with_drift; } /* Set rate */ pa_sink_input_set_rate(u->sink_input, new_rate); } /* Called from main context */ static void time_callback(pa_mainloop_api *a, pa_time_event *e, const struct timeval *t, void *userdata) { struct userdata *u = userdata; pa_assert(u); pa_assert(a); pa_assert(u->time_event == e); /* Restart timer right away */ pa_core_rttime_restart(u->core, u->time_event, pa_rtclock_now() + u->adjust_time); /* If the initial latency adjustment has not been done yet, we have to skip * adjust_rates(). The estimation of the optimum rate cannot be done in that * situation */ if (u->initial_adjust_pending) return; /* Get sink and source latency snapshot */ pa_asyncmsgq_send(u->sink_input->sink->asyncmsgq, PA_MSGOBJECT(u->sink_input), SINK_INPUT_MESSAGE_LATENCY_SNAPSHOT, NULL, 0, NULL); pa_asyncmsgq_send(u->source_output->source->asyncmsgq, PA_MSGOBJECT(u->source_output), SOURCE_OUTPUT_MESSAGE_LATENCY_SNAPSHOT, NULL, 0, NULL); adjust_rates(u); } /* Called from main context * When source or sink changes, give it a third of a second to settle down, then call adjust_rates for the first time */ static void enable_adjust_timer(struct userdata *u, bool enable) { if (enable) { if (!u->adjust_time) return; if (u->time_event) u->core->mainloop->time_free(u->time_event); u->time_event = pa_core_rttime_new(u->core, pa_rtclock_now() + 333 * PA_USEC_PER_MSEC, time_callback, u); } else { if (!u->time_event) return; u->core->mainloop->time_free(u->time_event); u->time_event = NULL; } } /* Called from main context */ static void update_adjust_timer(struct userdata *u) { if (u->sink_input->state == PA_SINK_INPUT_CORKED || u->source_output->state == PA_SOURCE_OUTPUT_CORKED) enable_adjust_timer(u, false); else enable_adjust_timer(u, true); } /* Called from main thread * Calculates minimum and maximum possible latency for source and sink */ static void update_latency_boundaries(struct userdata *u, pa_source *source, pa_sink *sink) { const char *s; if (source) { /* Source latencies */ u->fixed_alsa_source = false; if (source->flags & PA_SOURCE_DYNAMIC_LATENCY) pa_source_get_latency_range(source, &u->min_source_latency, &u->max_source_latency); else { u->min_source_latency = pa_source_get_fixed_latency(source); u->max_source_latency = u->min_source_latency; if ((s = pa_proplist_gets(source->proplist, PA_PROP_DEVICE_API))) { if (pa_streq(s, "alsa")) u->fixed_alsa_source = true; } } /* Source offset */ u->source_latency_offset = source->port_latency_offset; /* Latencies below 2.5 ms cause problems, limit source latency if possible */ if (u->max_source_latency >= MIN_DEVICE_LATENCY) u->min_source_latency = PA_MAX(u->min_source_latency, MIN_DEVICE_LATENCY); else u->min_source_latency = u->max_source_latency; } if (sink) { /* Sink latencies */ if (sink->flags & PA_SINK_DYNAMIC_LATENCY) pa_sink_get_latency_range(sink, &u->min_sink_latency, &u->max_sink_latency); else { u->min_sink_latency = pa_sink_get_fixed_latency(sink); u->max_sink_latency = u->min_sink_latency; } /* Sink offset */ u->sink_latency_offset = sink->port_latency_offset; /* Latencies below 2.5 ms cause problems, limit sink latency if possible */ if (u->max_sink_latency >= MIN_DEVICE_LATENCY) u->min_sink_latency = PA_MAX(u->min_sink_latency, MIN_DEVICE_LATENCY); else u->min_sink_latency = u->max_sink_latency; } update_minimum_latency(u, sink, true); } /* Called from output context * Sets the memblockq to the configured latency corrected by latency_offset_usec */ static void memblockq_adjust(struct userdata *u, int64_t latency_offset_usec, bool allow_push) { size_t current_memblockq_length, requested_memblockq_length, buffer_correction; int64_t requested_buffer_latency; pa_usec_t final_latency, requested_sink_latency; final_latency = PA_MAX(u->latency, u->output_thread_info.minimum_latency); /* If source or sink have some large negative latency offset, we might want to * hold more than final_latency in the memblockq */ requested_buffer_latency = (int64_t)final_latency - latency_offset_usec; /* Keep at least one sink latency in the queue to make sure that the sink * never underruns initially */ requested_sink_latency = pa_sink_get_requested_latency_within_thread(u->sink_input->sink); if (requested_buffer_latency < (int64_t)requested_sink_latency) requested_buffer_latency = requested_sink_latency; requested_memblockq_length = pa_usec_to_bytes(requested_buffer_latency, &u->sink_input->sample_spec); current_memblockq_length = pa_memblockq_get_length(u->memblockq); if (current_memblockq_length > requested_memblockq_length) { /* Drop audio from queue */ buffer_correction = current_memblockq_length - requested_memblockq_length; pa_log_info("Dropping %" PRIu64 " usec of audio from queue", pa_bytes_to_usec(buffer_correction, &u->sink_input->sample_spec)); pa_memblockq_drop(u->memblockq, buffer_correction); } else if (current_memblockq_length < requested_memblockq_length && allow_push) { /* Add silence to queue */ buffer_correction = requested_memblockq_length - current_memblockq_length; pa_log_info("Adding %" PRIu64 " usec of silence to queue", pa_bytes_to_usec(buffer_correction, &u->sink_input->sample_spec)); pa_memblockq_seek(u->memblockq, (int64_t)buffer_correction, PA_SEEK_RELATIVE, true); } } /* Called from input thread context */ static void source_output_push_cb(pa_source_output *o, const pa_memchunk *chunk) { struct userdata *u; pa_usec_t push_time; int64_t current_source_latency; pa_source_output_assert_ref(o); pa_source_output_assert_io_context(o); pa_assert_se(u = o->userdata); /* Send current source latency and timestamp with the message */ push_time = pa_rtclock_now(); current_source_latency = pa_source_get_latency_within_thread(u->source_output->source, true); current_source_latency += pa_resampler_get_delay_usec(u->source_output->thread_info.resampler); pa_asyncmsgq_post(u->asyncmsgq, PA_MSGOBJECT(u->sink_input), SINK_INPUT_MESSAGE_POST, PA_INT_TO_PTR(current_source_latency), push_time, chunk, NULL); u->send_counter += (int64_t) chunk->length; } /* Called from input thread context */ static void source_output_process_rewind_cb(pa_source_output *o, size_t nbytes) { struct userdata *u; pa_source_output_assert_ref(o); pa_source_output_assert_io_context(o); pa_assert_se(u = o->userdata); pa_asyncmsgq_post(u->asyncmsgq, PA_MSGOBJECT(u->sink_input), SINK_INPUT_MESSAGE_REWIND, NULL, (int64_t) nbytes, NULL, NULL); u->send_counter -= (int64_t) nbytes; } /* Called from input thread context */ static int source_output_process_msg_cb(pa_msgobject *obj, int code, void *data, int64_t offset, pa_memchunk *chunk) { struct userdata *u = PA_SOURCE_OUTPUT(obj)->userdata; switch (code) { case SOURCE_OUTPUT_MESSAGE_LATENCY_SNAPSHOT: { size_t length; length = pa_memblockq_get_length(u->source_output->thread_info.delay_memblockq); u->latency_snapshot.send_counter = u->send_counter; /* Add content of delay memblockq to the source latency */ u->latency_snapshot.source_latency = pa_source_get_latency_within_thread(u->source_output->source, true) + pa_bytes_to_usec(length, &u->source_output->source->sample_spec); /* Add resampler latency */ u->latency_snapshot.source_latency += pa_resampler_get_delay_usec(u->source_output->thread_info.resampler); u->latency_snapshot.source_timestamp = pa_rtclock_now(); return 0; } } return pa_source_output_process_msg(obj, code, data, offset, chunk); } /* Called from main thread. * Get current effective latency of the source. If the source is in use with * smaller latency than the configured latency, it will continue running with * the smaller value when the source output is switched to the source. */ static void update_effective_source_latency(struct userdata *u, pa_source *source, pa_sink *sink) { pa_usec_t effective_source_latency; effective_source_latency = u->configured_source_latency; if (source) { effective_source_latency = pa_source_get_requested_latency(source); if (effective_source_latency == 0 || effective_source_latency > u->configured_source_latency) effective_source_latency = u->configured_source_latency; } /* If the sink is valid, send a message to the output thread, else set the variable directly */ if (sink) pa_asyncmsgq_send(sink->asyncmsgq, PA_MSGOBJECT(u->sink_input), SINK_INPUT_MESSAGE_SET_EFFECTIVE_SOURCE_LATENCY, NULL, (int64_t)effective_source_latency, NULL); else u->output_thread_info.effective_source_latency = effective_source_latency; } /* Called from main thread. * Set source output latency to one third of the overall latency if possible. * The choice of one third is rather arbitrary somewhere between the minimum * possible latency which would cause a lot of CPU load and half the configured * latency which would quickly lead to underruns */ static void set_source_output_latency(struct userdata *u, pa_source *source) { pa_usec_t latency, requested_latency; requested_latency = u->latency / 3; /* Normally we try to configure sink and source latency equally. If the * sink latency cannot match the requested source latency try to set the * source latency to a smaller value to avoid underruns */ if (u->min_sink_latency > requested_latency) { latency = PA_MAX(u->latency, u->minimum_latency); requested_latency = (latency - u->min_sink_latency) / 2; } latency = PA_CLAMP(requested_latency , u->min_source_latency, u->max_source_latency); u->configured_source_latency = pa_source_output_set_requested_latency(u->source_output, latency); if (u->configured_source_latency != requested_latency) pa_log_warn("Cannot set requested source latency of %0.2f ms, adjusting to %0.2f ms", (double)requested_latency / PA_USEC_PER_MSEC, (double)u->configured_source_latency / PA_USEC_PER_MSEC); } /* Called from input thread context */ static void source_output_attach_cb(pa_source_output *o) { struct userdata *u; pa_source_output_assert_ref(o); pa_source_output_assert_io_context(o); pa_assert_se(u = o->userdata); u->rtpoll_item_write = pa_rtpoll_item_new_asyncmsgq_write( o->source->thread_info.rtpoll, PA_RTPOLL_LATE, u->asyncmsgq); } /* Called from input thread context */ static void source_output_detach_cb(pa_source_output *o) { struct userdata *u; pa_source_output_assert_ref(o); pa_source_output_assert_io_context(o); pa_assert_se(u = o->userdata); if (u->rtpoll_item_write) { pa_rtpoll_item_free(u->rtpoll_item_write); u->rtpoll_item_write = NULL; } } /* Called from main thread */ static void source_output_kill_cb(pa_source_output *o) { struct userdata *u; pa_source_output_assert_ref(o); pa_assert_ctl_context(); pa_assert_se(u = o->userdata); teardown(u); pa_module_unload_request(u->module, true); } /* Called from main thread */ static bool source_output_may_move_to_cb(pa_source_output *o, pa_source *dest) { struct userdata *u; pa_source_output_assert_ref(o); pa_assert_ctl_context(); pa_assert_se(u = o->userdata); if (!u->sink_input || !u->sink_input->sink) return true; return dest != u->sink_input->sink->monitor_source; } /* Called from main thread */ static void source_output_moving_cb(pa_source_output *o, pa_source *dest) { struct userdata *u; char *input_description; const char *n; if (!dest) return; pa_source_output_assert_ref(o); pa_assert_ctl_context(); pa_assert_se(u = o->userdata); input_description = pa_sprintf_malloc("Loopback of %s", pa_strnull(pa_proplist_gets(dest->proplist, PA_PROP_DEVICE_DESCRIPTION))); pa_sink_input_set_property(u->sink_input, PA_PROP_MEDIA_NAME, input_description); pa_xfree(input_description); if ((n = pa_proplist_gets(dest->proplist, PA_PROP_DEVICE_ICON_NAME))) pa_sink_input_set_property(u->sink_input, PA_PROP_DEVICE_ICON_NAME, n); /* Set latency and calculate latency limits */ u->underrun_latency_limit = 0; u->last_source_latency_offset = dest->port_latency_offset; u->initial_adjust_pending = true; update_latency_boundaries(u, dest, u->sink_input->sink); set_source_output_latency(u, dest); update_effective_source_latency(u, dest, u->sink_input->sink); /* Uncork the sink input unless the destination is suspended for other * reasons than idle. */ if (dest->state == PA_SOURCE_SUSPENDED) pa_sink_input_cork(u->sink_input, (dest->suspend_cause != PA_SUSPEND_IDLE)); else pa_sink_input_cork(u->sink_input, false); update_adjust_timer(u); /* Reset counters */ u->iteration_counter = 0; u->underrun_counter = 0; /* Reset booleans, latency error and counters */ u->source_sink_changed = true; u->underrun_occured = false; u->source_latency_offset_changed = false; u->target_latency_cross_counter = 0; u->log_counter = u->log_interval; u->latency_error = 0; /* Send a mesage to the output thread that the source has changed. * If the sink is invalid here during a profile switching situation * we can safely set push_called to false directly. */ if (u->sink_input->sink) pa_asyncmsgq_send(u->sink_input->sink->asyncmsgq, PA_MSGOBJECT(u->sink_input), SINK_INPUT_MESSAGE_SOURCE_CHANGED, NULL, 0, NULL); else u->output_thread_info.push_called = false; /* The sampling rate may be far away from the default rate if we are still * recovering from a previous source or sink change, so reset rate to * default before moving the source. */ pa_sink_input_set_rate(u->sink_input, u->source_output->sample_spec.rate); } /* Called from main thread */ static void source_output_suspend_cb(pa_source_output *o, pa_source_state_t old_state, pa_suspend_cause_t old_suspend_cause) { struct userdata *u; bool suspended; pa_source_output_assert_ref(o); pa_assert_ctl_context(); pa_assert_se(u = o->userdata); /* State has not changed, nothing to do */ if (old_state == o->source->state) return; suspended = (o->source->state == PA_SOURCE_SUSPENDED); /* If the source has been suspended, we need to handle this like * a source change when the source is resumed */ if (suspended) { if (u->sink_input->sink) pa_asyncmsgq_send(u->sink_input->sink->asyncmsgq, PA_MSGOBJECT(u->sink_input), SINK_INPUT_MESSAGE_SOURCE_CHANGED, NULL, 0, NULL); else u->output_thread_info.push_called = false; } else /* Get effective source latency on unsuspend */ update_effective_source_latency(u, u->source_output->source, u->sink_input->sink); pa_sink_input_cork(u->sink_input, suspended); update_adjust_timer(u); } /* Called from input thread context */ static void update_source_latency_range_cb(pa_source_output *i) { struct userdata *u; pa_source_output_assert_ref(i); pa_source_output_assert_io_context(i); pa_assert_se(u = i->userdata); /* Source latency may have changed */ pa_asyncmsgq_post(pa_thread_mq_get()->outq, PA_MSGOBJECT(u->msg), LOOPBACK_MESSAGE_SOURCE_LATENCY_RANGE_CHANGED, NULL, 0, NULL, NULL); } /* Called from output thread context */ static int sink_input_pop_cb(pa_sink_input *i, size_t nbytes, pa_memchunk *chunk) { struct userdata *u; pa_sink_input_assert_ref(i); pa_sink_input_assert_io_context(i); pa_assert_se(u = i->userdata); pa_assert(chunk); /* It seems necessary to handle outstanding push messages here, though it is not clear * why. Removing this part leads to underruns when low latencies are configured. */ u->output_thread_info.in_pop = true; while (pa_asyncmsgq_process_one(u->asyncmsgq) > 0) ; u->output_thread_info.in_pop = false; /* While pop has not been called, latency adjustments in SINK_INPUT_MESSAGE_POST are * enabled. Disable them on second pop and enable the final adjustment during the * next push. The adjustment must be done on the next push, because there is no way * to retrieve the source latency here. We are waiting for the second pop, because * the first pop may be called before the sink is actually started. */ if (!u->output_thread_info.pop_called && u->output_thread_info.first_pop_done) { u->output_thread_info.pop_adjust = true; u->output_thread_info.pop_called = true; } u->output_thread_info.first_pop_done = true; if (pa_memblockq_peek(u->memblockq, chunk) < 0) { pa_log_info("Could not peek into queue"); return -1; } chunk->length = PA_MIN(chunk->length, nbytes); pa_memblockq_drop(u->memblockq, chunk->length); /* Adjust the memblockq to ensure that there is * enough data in the queue to avoid underruns. */ if (!u->output_thread_info.push_called) memblockq_adjust(u, 0, true); return 0; } /* Called from output thread context */ static void sink_input_process_rewind_cb(pa_sink_input *i, size_t nbytes) { struct userdata *u; pa_sink_input_assert_ref(i); pa_sink_input_assert_io_context(i); pa_assert_se(u = i->userdata); pa_memblockq_rewind(u->memblockq, nbytes); } /* Called from output thread context */ static int sink_input_process_msg_cb(pa_msgobject *obj, int code, void *data, int64_t offset, pa_memchunk *chunk) { struct userdata *u = PA_SINK_INPUT(obj)->userdata; pa_sink_input_assert_io_context(u->sink_input); switch (code) { case PA_SINK_INPUT_MESSAGE_GET_LATENCY: { pa_usec_t *r = data; *r = pa_bytes_to_usec(pa_memblockq_get_length(u->memblockq), &u->sink_input->sample_spec); /* Fall through, the default handler will add in the extra * latency added by the resampler */ break; } case SINK_INPUT_MESSAGE_POST: pa_memblockq_push_align(u->memblockq, chunk); /* If push has not been called yet, latency adjustments in sink_input_pop_cb() * are enabled. Disable them on first push and correct the memblockq. If pop * has not been called yet, wait until the pop_cb() requests the adjustment */ if (u->output_thread_info.pop_called && (!u->output_thread_info.push_called || u->output_thread_info.pop_adjust)) { int64_t time_delta; /* This is the source latency at the time push was called */ time_delta = PA_PTR_TO_INT(data); /* Add the time between push and post */ time_delta += pa_rtclock_now() - (pa_usec_t) offset; /* Add the sink and resampler latency */ time_delta += pa_sink_get_latency_within_thread(u->sink_input->sink, true); time_delta += pa_resampler_get_delay_usec(u->sink_input->thread_info.resampler); /* The source latency report includes the audio in the chunk, * but since we already pushed the chunk to the memblockq, we need * to subtract the chunk size from the source latency so that it * won't be counted towards both the memblockq latency and the * source latency. * * Sometimes the alsa source reports way too low latency (might * be a bug in the alsa source code). This seems to happen when * there's an overrun. As an attempt to detect overruns, we * check if the chunk size is larger than the configured source * latency. If so, we assume that the source should have pushed * a chunk whose size equals the configured latency, so we * modify time_delta only by that amount, which makes * memblockq_adjust() drop more data than it would otherwise. * This seems to work quite well, but it's possible that the * next push also contains too much data, and in that case the * resulting latency will be wrong. */ if (pa_bytes_to_usec(chunk->length, &u->sink_input->sample_spec) > u->output_thread_info.effective_source_latency) time_delta -= (int64_t)u->output_thread_info.effective_source_latency; else time_delta -= (int64_t)pa_bytes_to_usec(chunk->length, &u->sink_input->sample_spec); /* FIXME: We allow pushing silence here to fix up the latency. This * might lead to a gap in the stream */ memblockq_adjust(u, time_delta, true); /* Notify main thread when the initial adjustment is done. */ if (u->output_thread_info.pop_called) pa_asyncmsgq_post(pa_thread_mq_get()->outq, PA_MSGOBJECT(u->msg), LOOPBACK_MESSAGE_ADJUST_DONE, NULL, 0, NULL, NULL); u->output_thread_info.pop_adjust = false; u->output_thread_info.push_called = true; } /* If pop has not been called yet, make sure the latency does not grow too much. * Don't push any silence here, because we already have new data in the queue */ if (!u->output_thread_info.pop_called) memblockq_adjust(u, 0, false); /* Is this the end of an underrun? Then let's start things * right-away */ if (u->sink_input->sink->thread_info.state != PA_SINK_SUSPENDED && u->sink_input->thread_info.underrun_for > 0 && pa_memblockq_is_readable(u->memblockq) && u->output_thread_info.pop_called) { pa_asyncmsgq_post(pa_thread_mq_get()->outq, PA_MSGOBJECT(u->msg), LOOPBACK_MESSAGE_UNDERRUN, NULL, 0, NULL, NULL); /* If called from within the pop callback skip the rewind */ if (!u->output_thread_info.in_pop) { pa_log_debug("Requesting rewind due to end of underrun."); pa_sink_input_request_rewind(u->sink_input, (size_t) (u->sink_input->thread_info.underrun_for == (size_t) -1 ? 0 : u->sink_input->thread_info.underrun_for), false, true, false); } } u->output_thread_info.recv_counter += (int64_t) chunk->length; return 0; case SINK_INPUT_MESSAGE_REWIND: /* Do not try to rewind if no data was pushed yet */ if (u->output_thread_info.push_called) pa_memblockq_seek(u->memblockq, -offset, PA_SEEK_RELATIVE, true); u->output_thread_info.recv_counter -= offset; return 0; case SINK_INPUT_MESSAGE_LATENCY_SNAPSHOT: { size_t length; length = pa_memblockq_get_length(u->sink_input->thread_info.render_memblockq); u->latency_snapshot.recv_counter = u->output_thread_info.recv_counter; u->latency_snapshot.loopback_memblockq_length = pa_memblockq_get_length(u->memblockq); /* Add content of render memblockq to sink latency */ u->latency_snapshot.sink_latency = pa_sink_get_latency_within_thread(u->sink_input->sink, true) + pa_bytes_to_usec(length, &u->sink_input->sink->sample_spec); /* Add resampler latency */ u->latency_snapshot.sink_latency += pa_resampler_get_delay_usec(u->sink_input->thread_info.resampler); u->latency_snapshot.sink_timestamp = pa_rtclock_now(); return 0; } case SINK_INPUT_MESSAGE_SOURCE_CHANGED: u->output_thread_info.push_called = false; return 0; case SINK_INPUT_MESSAGE_SET_EFFECTIVE_SOURCE_LATENCY: u->output_thread_info.effective_source_latency = (pa_usec_t)offset; return 0; case SINK_INPUT_MESSAGE_UPDATE_MIN_LATENCY: u->output_thread_info.minimum_latency = (pa_usec_t)offset; return 0; case SINK_INPUT_MESSAGE_FAST_ADJUST: memblockq_adjust(u, offset, true); return 0; } return pa_sink_input_process_msg(obj, code, data, offset, chunk); } /* Called from main thread. * Set sink input latency to one third of the overall latency if possible. * The choice of one third is rather arbitrary somewhere between the minimum * possible latency which would cause a lot of CPU load and half the configured * latency which would quickly lead to underruns. */ static void set_sink_input_latency(struct userdata *u, pa_sink *sink) { pa_usec_t latency, requested_latency; requested_latency = u->latency / 3; /* Normally we try to configure sink and source latency equally. If the * source latency cannot match the requested sink latency try to set the * sink latency to a smaller value to avoid underruns */ if (u->min_source_latency > requested_latency) { latency = PA_MAX(u->latency, u->minimum_latency); requested_latency = (latency - u->min_source_latency) / 2; /* In the case of a fixed alsa source, u->minimum_latency is calculated from * the default fragment size while u->min_source_latency is the reported minimum * of the source latency (nr_of_fragments * fragment_size). This can lead to a * situation where u->minimum_latency < u->min_source_latency. We only fall * back to use the fragment size instead of min_source_latency if the calculation * above does not deliver a usable result. */ if (u->fixed_alsa_source && u->min_source_latency >= latency) requested_latency = (latency - u->core->default_fragment_size_msec * PA_USEC_PER_MSEC) / 2; } latency = PA_CLAMP(requested_latency , u->min_sink_latency, u->max_sink_latency); u->configured_sink_latency = pa_sink_input_set_requested_latency(u->sink_input, latency); if (u->configured_sink_latency != requested_latency) pa_log_warn("Cannot set requested sink latency of %0.2f ms, adjusting to %0.2f ms", (double)requested_latency / PA_USEC_PER_MSEC, (double)u->configured_sink_latency / PA_USEC_PER_MSEC); } /* Called from output thread context */ static void sink_input_attach_cb(pa_sink_input *i) { struct userdata *u; pa_sink_input_assert_ref(i); pa_sink_input_assert_io_context(i); pa_assert_se(u = i->userdata); u->rtpoll_item_read = pa_rtpoll_item_new_asyncmsgq_read( i->sink->thread_info.rtpoll, PA_RTPOLL_LATE, u->asyncmsgq); pa_memblockq_set_prebuf(u->memblockq, pa_sink_input_get_max_request(i)*2); pa_memblockq_set_maxrewind(u->memblockq, pa_sink_input_get_max_rewind(i)); } /* Called from output thread context */ static void sink_input_detach_cb(pa_sink_input *i) { struct userdata *u; pa_sink_input_assert_ref(i); pa_sink_input_assert_io_context(i); pa_assert_se(u = i->userdata); if (u->rtpoll_item_read) { pa_rtpoll_item_free(u->rtpoll_item_read); u->rtpoll_item_read = NULL; } } /* Called from output thread context */ static void sink_input_update_max_rewind_cb(pa_sink_input *i, size_t nbytes) { struct userdata *u; pa_sink_input_assert_ref(i); pa_sink_input_assert_io_context(i); pa_assert_se(u = i->userdata); pa_memblockq_set_maxrewind(u->memblockq, nbytes); } /* Called from output thread context */ static void sink_input_update_max_request_cb(pa_sink_input *i, size_t nbytes) { struct userdata *u; pa_sink_input_assert_ref(i); pa_sink_input_assert_io_context(i); pa_assert_se(u = i->userdata); pa_memblockq_set_prebuf(u->memblockq, nbytes*2); pa_log_info("Max request changed"); } /* Called from main thread */ static void sink_input_kill_cb(pa_sink_input *i) { struct userdata *u; pa_sink_input_assert_ref(i); pa_assert_ctl_context(); pa_assert_se(u = i->userdata); teardown(u); pa_module_unload_request(u->module, true); } /* Called from the output thread context */ static void sink_input_state_change_cb(pa_sink_input *i, pa_sink_input_state_t state) { struct userdata *u; pa_sink_input_assert_ref(i); pa_assert_se(u = i->userdata); if (state == PA_SINK_INPUT_UNLINKED) pa_asyncmsgq_flush(u->asyncmsgq, false); } /* Called from main thread */ static void sink_input_moving_cb(pa_sink_input *i, pa_sink *dest) { struct userdata *u; char *output_description; const char *n; if (!dest) return; pa_sink_input_assert_ref(i); pa_assert_ctl_context(); pa_assert_se(u = i->userdata); output_description = pa_sprintf_malloc("Loopback to %s", pa_strnull(pa_proplist_gets(dest->proplist, PA_PROP_DEVICE_DESCRIPTION))); pa_source_output_set_property(u->source_output, PA_PROP_MEDIA_NAME, output_description); pa_xfree(output_description); if ((n = pa_proplist_gets(dest->proplist, PA_PROP_DEVICE_ICON_NAME))) pa_source_output_set_property(u->source_output, PA_PROP_MEDIA_ICON_NAME, n); /* Set latency and calculate latency limits */ u->underrun_latency_limit = 0; u->last_sink_latency_offset = dest->port_latency_offset; u->initial_adjust_pending = true; update_latency_boundaries(u, NULL, dest); set_sink_input_latency(u, dest); update_effective_source_latency(u, u->source_output->source, dest); /* Uncork the source output unless the destination is suspended for other * reasons than idle */ if (dest->state == PA_SINK_SUSPENDED) pa_source_output_cork(u->source_output, (dest->suspend_cause != PA_SUSPEND_IDLE)); else pa_source_output_cork(u->source_output, false); update_adjust_timer(u); /* Reset counters */ u->iteration_counter = 0; u->underrun_counter = 0; /* Reset booleans, latency error and counters */ u->source_sink_changed = true; u->underrun_occured = false; u->sink_latency_offset_changed = false; u->target_latency_cross_counter = 0; u->log_counter = u->log_interval; u->latency_error = 0; u->output_thread_info.pop_called = false; u->output_thread_info.first_pop_done = false; /* Sample rate may be far away from the default rate if we are still * recovering from a previous source or sink change, so reset rate to * default before moving the sink. */ pa_sink_input_set_rate(u->sink_input, u->source_output->sample_spec.rate); } /* Called from main thread */ static bool sink_input_may_move_to_cb(pa_sink_input *i, pa_sink *dest) { struct userdata *u; pa_sink_input_assert_ref(i); pa_assert_ctl_context(); pa_assert_se(u = i->userdata); if (!u->source_output || !u->source_output->source) return true; return dest != u->source_output->source->monitor_of; } /* Called from main thread */ static void sink_input_suspend_cb(pa_sink_input *i, pa_sink_state_t old_state, pa_suspend_cause_t old_suspend_cause) { struct userdata *u; bool suspended; pa_sink_input_assert_ref(i); pa_assert_ctl_context(); pa_assert_se(u = i->userdata); /* State has not changed, nothing to do */ if (old_state == i->sink->state) return; suspended = (i->sink->state == PA_SINK_SUSPENDED); /* If the sink has been suspended, we need to handle this like * a sink change when the sink is resumed. Because the sink * is suspended, we can set the variables directly. */ if (suspended) { u->output_thread_info.pop_called = false; u->output_thread_info.first_pop_done = false; } else /* Set effective source latency on unsuspend */ update_effective_source_latency(u, u->source_output->source, u->sink_input->sink); pa_source_output_cork(u->source_output, suspended); update_adjust_timer(u); } /* Called from output thread context */ static void update_sink_latency_range_cb(pa_sink_input *i) { struct userdata *u; pa_sink_input_assert_ref(i); pa_sink_input_assert_io_context(i); pa_assert_se(u = i->userdata); /* Sink latency may have changed */ pa_asyncmsgq_post(pa_thread_mq_get()->outq, PA_MSGOBJECT(u->msg), LOOPBACK_MESSAGE_SINK_LATENCY_RANGE_CHANGED, NULL, 0, NULL, NULL); } /* Called from main context */ static int loopback_process_msg_cb(pa_msgobject *o, int code, void *userdata, int64_t offset, pa_memchunk *chunk) { struct loopback_msg *msg; struct userdata *u; pa_usec_t current_latency; pa_assert(o); pa_assert_ctl_context(); msg = LOOPBACK_MSG(o); /* If messages are processed after a module unload request, they * must be ignored. */ if (msg->dead) return 0; pa_assert_se(u = msg->userdata); switch (code) { case LOOPBACK_MESSAGE_SOURCE_LATENCY_RANGE_CHANGED: update_effective_source_latency(u, u->source_output->source, u->sink_input->sink); current_latency = pa_source_get_requested_latency(u->source_output->source); if (current_latency > u->configured_source_latency) { /* The minimum latency has changed to a value larger than the configured latency, so * the source latency has been increased. The case that the minimum latency changes * back to a smaller value is not handled because this never happens with the current * source implementations. */ pa_log_warn("Source minimum latency increased to %0.2f ms", (double)current_latency / PA_USEC_PER_MSEC); u->configured_source_latency = current_latency; update_latency_boundaries(u, u->source_output->source, u->sink_input->sink); /* We re-start counting when the latency has changed */ u->iteration_counter = 0; u->underrun_counter = 0; } return 0; case LOOPBACK_MESSAGE_SINK_LATENCY_RANGE_CHANGED: current_latency = pa_sink_get_requested_latency(u->sink_input->sink); if (current_latency > u->configured_sink_latency) { /* The minimum latency has changed to a value larger than the configured latency, so * the sink latency has been increased. The case that the minimum latency changes back * to a smaller value is not handled because this never happens with the current sink * implementations. */ pa_log_warn("Sink minimum latency increased to %0.2f ms", (double)current_latency / PA_USEC_PER_MSEC); u->configured_sink_latency = current_latency; update_latency_boundaries(u, u->source_output->source, u->sink_input->sink); /* We re-start counting when the latency has changed */ u->iteration_counter = 0; u->underrun_counter = 0; } return 0; case LOOPBACK_MESSAGE_UNDERRUN: u->underrun_counter++; u->underrun_occured = true; u->target_latency_cross_counter = 0; pa_log_debug("Underrun detected, counter incremented to %u", u->underrun_counter); return 0; case LOOPBACK_MESSAGE_ADJUST_DONE: u->initial_adjust_pending = false; return 0; } return 0; } /* Called from main thread */ static pa_hook_result_t sink_port_latency_offset_changed_cb(pa_core *core, pa_sink *sink, struct userdata *u) { if (sink != u->sink_input->sink) return PA_HOOK_OK; if (!u->sink_latency_offset_changed) u->last_sink_latency_offset = u->sink_latency_offset; u->sink_latency_offset_changed = true; u->sink_latency_offset = sink->port_latency_offset; update_minimum_latency(u, sink, true); /* We might need to adjust again, reset counter */ u->target_latency_cross_counter = 0; return PA_HOOK_OK; } /* Called from main thread */ static pa_hook_result_t source_port_latency_offset_changed_cb(pa_core *core, pa_source *source, struct userdata *u) { if (source != u->source_output->source) return PA_HOOK_OK; if (!u->source_latency_offset_changed) u->last_source_latency_offset = u->source_latency_offset; u->source_latency_offset_changed = true; u->source_latency_offset = source->port_latency_offset; update_minimum_latency(u, u->sink_input->sink, true); /* We might need to adjust again, reset counter */ u->target_latency_cross_counter = 0; return PA_HOOK_OK; } int pa__init(pa_module *m) { pa_modargs *ma = NULL; struct userdata *u; pa_sink *sink = NULL; pa_sink_input_new_data sink_input_data; bool sink_dont_move; pa_source *source = NULL; pa_source_output_new_data source_output_data; bool source_dont_move; uint32_t latency_msec; uint32_t max_latency_msec; uint32_t fast_adjust_threshold; uint32_t adjust_threshold; pa_sample_spec ss; pa_channel_map map; bool format_set = false; bool rate_set = false; bool channels_set = false; pa_memchunk silence; double adjust_time_sec; double log_interval_sec; const char *n; bool remix = true; pa_assert(m); if (!(ma = pa_modargs_new(m->argument, valid_modargs))) { pa_log("Failed to parse module arguments"); goto fail; } n = pa_modargs_get_value(ma, "source", NULL); if (n && !(source = pa_namereg_get(m->core, n, PA_NAMEREG_SOURCE))) { pa_log("No such source."); goto fail; } n = pa_modargs_get_value(ma, "sink", NULL); if (n && !(sink = pa_namereg_get(m->core, n, PA_NAMEREG_SINK))) { pa_log("No such sink."); goto fail; } if (pa_modargs_get_value_boolean(ma, "remix", &remix) < 0) { pa_log("Invalid boolean remix parameter"); goto fail; } if (source) { ss = source->sample_spec; map = source->channel_map; format_set = true; rate_set = true; channels_set = true; } else if (sink) { ss = sink->sample_spec; map = sink->channel_map; format_set = true; rate_set = true; channels_set = true; } else { /* FIXME: Dummy stream format, needed because pa_sink_input_new() * requires valid sample spec and channel map even when all the FIX_* * stream flags are specified. pa_sink_input_new() should be changed * to ignore the sample spec and channel map when the FIX_* flags are * present. */ ss.format = PA_SAMPLE_U8; ss.rate = 8000; ss.channels = 1; map.channels = 1; map.map[0] = PA_CHANNEL_POSITION_MONO; } if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) { pa_log("Invalid sample format specification or channel map"); goto fail; } if (ss.rate < 4000 || ss.rate > PA_RATE_MAX) { pa_log("Invalid rate specification, valid range is 4000 Hz to %i Hz", PA_RATE_MAX); goto fail; } if (pa_modargs_get_value(ma, "format", NULL)) format_set = true; if (pa_modargs_get_value(ma, "rate", NULL)) rate_set = true; if (pa_modargs_get_value(ma, "channels", NULL) || pa_modargs_get_value(ma, "channel_map", NULL)) channels_set = true; adjust_threshold = DEFAULT_ADJUST_THRESHOLD_USEC; if (pa_modargs_get_value_u32(ma, "adjust_threshold_usec", &adjust_threshold) < 0 || adjust_threshold < 1 || adjust_threshold > 10000) { pa_log_info("Invalid adjust threshold specification"); goto fail; } latency_msec = DEFAULT_LATENCY_MSEC; if (pa_modargs_get_value_u32(ma, "latency_msec", &latency_msec) < 0 || latency_msec < 1 || latency_msec > 30000) { pa_log("Invalid latency specification"); goto fail; } fast_adjust_threshold = 0; if (pa_modargs_get_value_u32(ma, "fast_adjust_threshold_msec", &fast_adjust_threshold) < 0 || (fast_adjust_threshold != 0 && fast_adjust_threshold < 100)) { pa_log("Invalid fast adjust threshold specification"); goto fail; } max_latency_msec = 0; if (pa_modargs_get_value_u32(ma, "max_latency_msec", &max_latency_msec) < 0) { pa_log("Invalid maximum latency specification"); goto fail; } if (max_latency_msec > 0 && max_latency_msec < latency_msec) { pa_log_warn("Configured maximum latency is smaller than latency, using latency instead"); max_latency_msec = latency_msec; } m->userdata = u = pa_xnew0(struct userdata, 1); u->core = m->core; u->module = m; u->latency = (pa_usec_t) latency_msec * PA_USEC_PER_MSEC; u->max_latency = (pa_usec_t) max_latency_msec * PA_USEC_PER_MSEC; u->output_thread_info.pop_called = false; u->output_thread_info.pop_adjust = false; u->output_thread_info.push_called = false; u->iteration_counter = 0; u->underrun_counter = 0; u->underrun_latency_limit = 0; u->source_sink_changed = true; u->real_adjust_time_sum = 0; u->adjust_counter = 0; u->fast_adjust_threshold = fast_adjust_threshold * PA_USEC_PER_MSEC; u->underrun_occured = false; u->source_latency_offset_changed = false; u->sink_latency_offset_changed = false; u->latency_error = 0; u->adjust_threshold = adjust_threshold; u->target_latency_cross_counter = 0; u->initial_adjust_pending = true; adjust_time_sec = DEFAULT_ADJUST_TIME_USEC / PA_USEC_PER_SEC; if (pa_modargs_get_value_double(ma, "adjust_time", &adjust_time_sec) < 0) { pa_log("Failed to parse adjust_time value"); goto fail; } /* Allow values >= 0.1 and also 0 which means no adjustment */ if (adjust_time_sec < 0.1) { if (adjust_time_sec < 0 || adjust_time_sec > 0) { pa_log("Failed to parse adjust_time value"); goto fail; } } u->adjust_time = adjust_time_sec * PA_USEC_PER_SEC; u->real_adjust_time = u->adjust_time; pa_source_output_new_data_init(&source_output_data); source_output_data.driver = __FILE__; source_output_data.module = m; if (source) pa_source_output_new_data_set_source(&source_output_data, source, false, true); if (pa_modargs_get_proplist(ma, "source_output_properties", source_output_data.proplist, PA_UPDATE_REPLACE) < 0) { pa_log("Failed to parse the source_output_properties value."); pa_source_output_new_data_done(&source_output_data); goto fail; } if (!pa_proplist_contains(source_output_data.proplist, PA_PROP_MEDIA_ROLE)) pa_proplist_sets(source_output_data.proplist, PA_PROP_MEDIA_ROLE, "abstract"); pa_source_output_new_data_set_sample_spec(&source_output_data, &ss); pa_source_output_new_data_set_channel_map(&source_output_data, &map); source_output_data.flags = PA_SOURCE_OUTPUT_START_CORKED; if (!remix) source_output_data.flags |= PA_SOURCE_OUTPUT_NO_REMIX; if (!format_set) source_output_data.flags |= PA_SOURCE_OUTPUT_FIX_FORMAT; if (!rate_set) source_output_data.flags |= PA_SOURCE_OUTPUT_FIX_RATE; if (!channels_set) source_output_data.flags |= PA_SOURCE_OUTPUT_FIX_CHANNELS; source_dont_move = false; if (pa_modargs_get_value_boolean(ma, "source_dont_move", &source_dont_move) < 0) { pa_log("source_dont_move= expects a boolean argument."); goto fail; } if (source_dont_move) source_output_data.flags |= PA_SOURCE_OUTPUT_DONT_MOVE; pa_source_output_new(&u->source_output, m->core, &source_output_data); pa_source_output_new_data_done(&source_output_data); if (!u->source_output) goto fail; u->source_output->parent.process_msg = source_output_process_msg_cb; u->source_output->push = source_output_push_cb; u->source_output->process_rewind = source_output_process_rewind_cb; u->source_output->kill = source_output_kill_cb; u->source_output->attach = source_output_attach_cb; u->source_output->detach = source_output_detach_cb; u->source_output->may_move_to = source_output_may_move_to_cb; u->source_output->moving = source_output_moving_cb; u->source_output->suspend = source_output_suspend_cb; u->source_output->update_source_latency_range = update_source_latency_range_cb; u->source_output->update_source_fixed_latency = update_source_latency_range_cb; u->source_output->userdata = u; /* If format, rate or channels were originally unset, they are set now * after the pa_source_output_new() call. */ ss = u->source_output->sample_spec; map = u->source_output->channel_map; /* Get log interval, default is 0, which means no logging */ log_interval_sec = 0; if (pa_modargs_get_value_double(ma, "log_interval", &log_interval_sec) < 0) { pa_log_info("Invalid log interval specification"); goto fail; } /* Allow values >= 0.1 and also 0 */ if (log_interval_sec < 0.1) { if (log_interval_sec < 0 || log_interval_sec > 0) { pa_log("Failed to parse log_interval value"); goto fail; } } /* Estimate number of iterations for logging. */ u->log_interval = 0; if (u->adjust_time != 0 && log_interval_sec != 0) { u->log_interval = (int)(log_interval_sec * PA_USEC_PER_SEC / u->adjust_time + 0.5); /* Logging was specified, but log interval parameter was too small, * therefore log on every iteration */ if (u->log_interval == 0) u->log_interval = 1; } u->log_counter = u->log_interval; pa_sink_input_new_data_init(&sink_input_data); sink_input_data.driver = __FILE__; sink_input_data.module = m; if (sink) pa_sink_input_new_data_set_sink(&sink_input_data, sink, false, true); if (pa_modargs_get_proplist(ma, "sink_input_properties", sink_input_data.proplist, PA_UPDATE_REPLACE) < 0) { pa_log("Failed to parse the sink_input_properties value."); pa_sink_input_new_data_done(&sink_input_data); goto fail; } if (!pa_proplist_contains(sink_input_data.proplist, PA_PROP_MEDIA_ROLE)) pa_proplist_sets(sink_input_data.proplist, PA_PROP_MEDIA_ROLE, "abstract"); pa_sink_input_new_data_set_sample_spec(&sink_input_data, &ss); pa_sink_input_new_data_set_channel_map(&sink_input_data, &map); sink_input_data.flags = PA_SINK_INPUT_VARIABLE_RATE | PA_SINK_INPUT_START_CORKED; if (!remix) sink_input_data.flags |= PA_SINK_INPUT_NO_REMIX; sink_dont_move = false; if (pa_modargs_get_value_boolean(ma, "sink_dont_move", &sink_dont_move) < 0) { pa_log("sink_dont_move= expects a boolean argument."); goto fail; } if (sink_dont_move) sink_input_data.flags |= PA_SINK_INPUT_DONT_MOVE; pa_sink_input_new(&u->sink_input, m->core, &sink_input_data); pa_sink_input_new_data_done(&sink_input_data); if (!u->sink_input) goto fail; u->sink_input->parent.process_msg = sink_input_process_msg_cb; u->sink_input->pop = sink_input_pop_cb; u->sink_input->process_rewind = sink_input_process_rewind_cb; u->sink_input->kill = sink_input_kill_cb; u->sink_input->state_change = sink_input_state_change_cb; u->sink_input->attach = sink_input_attach_cb; u->sink_input->detach = sink_input_detach_cb; u->sink_input->update_max_rewind = sink_input_update_max_rewind_cb; u->sink_input->update_max_request = sink_input_update_max_request_cb; u->sink_input->may_move_to = sink_input_may_move_to_cb; u->sink_input->moving = sink_input_moving_cb; u->sink_input->suspend = sink_input_suspend_cb; u->sink_input->update_sink_latency_range = update_sink_latency_range_cb; u->sink_input->update_sink_fixed_latency = update_sink_latency_range_cb; u->sink_input->userdata = u; u->last_source_latency_offset = u->source_output->source->port_latency_offset; u->last_sink_latency_offset = u->sink_input->sink->port_latency_offset; update_latency_boundaries(u, u->source_output->source, u->sink_input->sink); set_sink_input_latency(u, u->sink_input->sink); set_source_output_latency(u, u->source_output->source); pa_sink_input_get_silence(u->sink_input, &silence); u->memblockq = pa_memblockq_new( "module-loopback memblockq", 0, /* idx */ MEMBLOCKQ_MAXLENGTH, /* maxlength */ MEMBLOCKQ_MAXLENGTH, /* tlength */ &ss, /* sample_spec */ 0, /* prebuf */ 0, /* minreq */ 0, /* maxrewind */ &silence); /* silence frame */ pa_memblock_unref(silence.memblock); /* Fill the memblockq with silence */ pa_memblockq_seek(u->memblockq, pa_usec_to_bytes(u->latency, &u->sink_input->sample_spec), PA_SEEK_RELATIVE, true); u->asyncmsgq = pa_asyncmsgq_new(0); if (!u->asyncmsgq) { pa_log("pa_asyncmsgq_new() failed."); goto fail; } if (!pa_proplist_contains(u->source_output->proplist, PA_PROP_MEDIA_NAME)) pa_proplist_setf(u->source_output->proplist, PA_PROP_MEDIA_NAME, "Loopback to %s", pa_strnull(pa_proplist_gets(u->sink_input->sink->proplist, PA_PROP_DEVICE_DESCRIPTION))); if (!pa_proplist_contains(u->source_output->proplist, PA_PROP_MEDIA_ICON_NAME) && (n = pa_proplist_gets(u->sink_input->sink->proplist, PA_PROP_DEVICE_ICON_NAME))) pa_proplist_sets(u->source_output->proplist, PA_PROP_MEDIA_ICON_NAME, n); if (!pa_proplist_contains(u->sink_input->proplist, PA_PROP_MEDIA_NAME)) pa_proplist_setf(u->sink_input->proplist, PA_PROP_MEDIA_NAME, "Loopback from %s", pa_strnull(pa_proplist_gets(u->source_output->source->proplist, PA_PROP_DEVICE_DESCRIPTION))); if (source && !pa_proplist_contains(u->sink_input->proplist, PA_PROP_MEDIA_ICON_NAME) && (n = pa_proplist_gets(u->source_output->source->proplist, PA_PROP_DEVICE_ICON_NAME))) pa_proplist_sets(u->sink_input->proplist, PA_PROP_MEDIA_ICON_NAME, n); /* Hooks to track changes of latency offsets */ pa_module_hook_connect(m, &m->core->hooks[PA_CORE_HOOK_SINK_PORT_LATENCY_OFFSET_CHANGED], PA_HOOK_NORMAL, (pa_hook_cb_t) sink_port_latency_offset_changed_cb, u); pa_module_hook_connect(m, &m->core->hooks[PA_CORE_HOOK_SOURCE_PORT_LATENCY_OFFSET_CHANGED], PA_HOOK_NORMAL, (pa_hook_cb_t) source_port_latency_offset_changed_cb, u); /* Setup message handler for main thread */ u->msg = pa_msgobject_new(loopback_msg); u->msg->parent.process_msg = loopback_process_msg_cb; u->msg->userdata = u; u->msg->dead = false; /* The output thread is not yet running, set effective_source_latency directly */ update_effective_source_latency(u, u->source_output->source, NULL); pa_sink_input_put(u->sink_input); pa_source_output_put(u->source_output); if (u->source_output->source->state != PA_SOURCE_SUSPENDED) pa_sink_input_cork(u->sink_input, false); if (u->sink_input->sink->state != PA_SINK_SUSPENDED) pa_source_output_cork(u->source_output, false); update_adjust_timer(u); pa_modargs_free(ma); return 0; fail: if (ma) pa_modargs_free(ma); pa__done(m); return -1; } void pa__done(pa_module*m) { struct userdata *u; pa_assert(m); if (!(u = m->userdata)) return; teardown(u); if (u->memblockq) pa_memblockq_free(u->memblockq); if (u->asyncmsgq) pa_asyncmsgq_unref(u->asyncmsgq); if (u->msg) loopback_msg_unref(u->msg); pa_xfree(u); }