1 files changed, 337 insertions, 0 deletions

diff --git a/src/modules/module-null-sink.c b/src/modules/module-null-sink.c
new file mode 100644
index 00000000..604ab158
--- /dev/null
+++ b/src/modules/module-null-sink.c
@@ -0,0 +1,337 @@
+/***
+  This file is part of PulseAudio.
+
+  Copyright 2004-2008 Lennart Poettering
+
+  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 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, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <limits.h>
+
+#include <pulse/timeval.h>
+#include <pulse/xmalloc.h>
+
+#include <pulsecore/macro.h>
+#include <pulsecore/sink.h>
+#include <pulsecore/module.h>
+#include <pulsecore/core-util.h>
+#include <pulsecore/core-error.h>
+#include <pulsecore/modargs.h>
+#include <pulsecore/log.h>
+#include <pulsecore/thread.h>
+#include <pulsecore/thread-mq.h>
+#include <pulsecore/rtpoll.h>
+#include <pulsecore/rtclock.h>
+
+#include "module-null-sink-symdef.h"
+
+PA_MODULE_AUTHOR("Lennart Poettering");
+PA_MODULE_DESCRIPTION("Clocked NULL sink");
+PA_MODULE_VERSION(PACKAGE_VERSION);
+PA_MODULE_LOAD_ONCE(FALSE);
+PA_MODULE_USAGE(
+        "format=<sample format> "
+        "channels=<number of channels> "
+        "rate=<sample rate> "
+        "sink_name=<name of sink> "
+        "channel_map=<channel map> "
+        "description=<description for the sink>");
+
+#define DEFAULT_SINK_NAME "null"
+#define MAX_LATENCY_USEC (PA_USEC_PER_SEC * 2)
+
+struct userdata {
+    pa_core *core;
+    pa_module *module;
+    pa_sink *sink;
+
+    pa_thread *thread;
+    pa_thread_mq thread_mq;
+    pa_rtpoll *rtpoll;
+
+    size_t block_size;
+
+    pa_usec_t block_usec;
+    pa_usec_t timestamp;
+};
+
+static const char* const valid_modargs[] = {
+    "rate",
+    "format",
+    "channels",
+    "sink_name",
+    "channel_map",
+    "description",
+    NULL
+};
+
+static int sink_process_msg(pa_msgobject *o, int code, void *data, int64_t offset, pa_memchunk *chunk) {
+    struct userdata *u = PA_SINK(o)->userdata;
+
+    switch (code) {
+        case PA_SINK_MESSAGE_SET_STATE:
+
+            if (PA_PTR_TO_UINT(data) == PA_SINK_RUNNING)
+                u->timestamp = pa_rtclock_usec();
+
+            break;
+
+        case PA_SINK_MESSAGE_GET_LATENCY: {
+            pa_usec_t now;
+
+            now = pa_rtclock_usec();
+            *((pa_usec_t*) data) = u->timestamp > now ? u->timestamp - now : 0;
+
+            return 0;
+        }
+    }
+
+    return pa_sink_process_msg(o, code, data, offset, chunk);
+}
+
+static void sink_update_requested_latency_cb(pa_sink *s) {
+    struct userdata *u;
+
+    pa_sink_assert_ref(s);
+    u = s->userdata;
+    pa_assert(u);
+
+    u->block_usec = pa_sink_get_requested_latency_within_thread(s);
+}
+
+static void process_rewind(struct userdata *u, pa_usec_t now) {
+    size_t rewind_nbytes, in_buffer;
+    pa_usec_t delay;
+
+    pa_assert(u);
+
+    /* Figure out how much we shall rewind and reset the counter */
+    rewind_nbytes = u->sink->thread_info.rewind_nbytes;
+    u->sink->thread_info.rewind_nbytes = 0;
+
+    pa_assert(rewind_nbytes > 0);
+    pa_log_debug("Requested to rewind %lu bytes.", (unsigned long) rewind_nbytes);
+
+    if (u->timestamp <= now)
+        return;
+
+    delay = u->timestamp - now;
+    in_buffer = pa_usec_to_bytes(delay, &u->sink->sample_spec);
+
+    if (in_buffer <= 0)
+        return;
+
+    if (rewind_nbytes > in_buffer)
+        rewind_nbytes = in_buffer;
+
+    pa_sink_process_rewind(u->sink, rewind_nbytes);
+    u->timestamp -= pa_bytes_to_usec(rewind_nbytes, &u->sink->sample_spec);
+
+    pa_log_debug("Rewound %lu bytes.", (unsigned long) rewind_nbytes);
+}
+
+static void process_render(struct userdata *u, pa_usec_t now) {
+    size_t ate = 0;
+
+    pa_assert(u);
+
+    /* This is the configured latency. Sink inputs connected to us
+    might not have a single frame more than the maxrequest value
+    queed. Hence: at maximum read this many bytes from the sink
+    inputs. */
+
+    /* Fill the buffer up the the latency size */
+    while (u->timestamp < now + u->block_usec) {
+        pa_memchunk chunk;
+
+        pa_sink_render(u->sink, u->sink->thread_info.max_request, &chunk);
+        pa_memblock_unref(chunk.memblock);
+
+/*         pa_log_debug("Ate %lu bytes.", (unsigned long) chunk.length); */
+        u->timestamp += pa_bytes_to_usec(chunk.length, &u->sink->sample_spec);
+
+        ate += chunk.length;
+
+        if (ate >= u->sink->thread_info.max_request)
+            break;
+    }
+
+/*     pa_log_debug("Ate in sum %lu bytes (of %lu)", (unsigned long) ate, (unsigned long) nbytes); */
+}
+
+static void thread_func(void *userdata) {
+    struct userdata *u = userdata;
+
+    pa_assert(u);
+
+    pa_log_debug("Thread starting up");
+
+    pa_thread_mq_install(&u->thread_mq);
+    pa_rtpoll_install(u->rtpoll);
+
+    u->timestamp = pa_rtclock_usec();
+
+    for (;;) {
+        int ret;
+
+        /* Render some data and drop it immediately */
+        if (PA_SINK_IS_OPENED(u->sink->thread_info.state)) {
+            pa_usec_t now;
+
+            now = pa_rtclock_usec();
+
+            if (u->sink->thread_info.rewind_nbytes > 0)
+                process_rewind(u, now);
+
+            if (u->timestamp <= now)
+                process_render(u, now);
+
+            pa_rtpoll_set_timer_absolute(u->rtpoll, u->timestamp);
+        } else
+            pa_rtpoll_set_timer_disabled(u->rtpoll);
+
+        /* Hmm, nothing to do. Let's sleep */
+        if ((ret = pa_rtpoll_run(u->rtpoll, TRUE)) < 0)
+            goto fail;
+
+        if (ret == 0)
+            goto finish;
+    }
+
+fail:
+    /* If this was no regular exit from the loop we have to continue
+     * processing messages until we received PA_MESSAGE_SHUTDOWN */
+    pa_asyncmsgq_post(u->thread_mq.outq, PA_MSGOBJECT(u->core), PA_CORE_MESSAGE_UNLOAD_MODULE, u->module, 0, NULL, NULL);
+    pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);
+
+finish:
+    pa_log_debug("Thread shutting down");
+}
+
+int pa__init(pa_module*m) {
+    struct userdata *u = NULL;
+    pa_sample_spec ss;
+    pa_channel_map map;
+    pa_modargs *ma = NULL;
+    pa_sink_new_data data;
+
+    pa_assert(m);
+
+    if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
+        pa_log("Failed to parse module arguments.");
+        goto fail;
+    }
+
+    ss = m->core->default_sample_spec;
+    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;
+    }
+
+    m->userdata = u = pa_xnew0(struct userdata, 1);
+    u->core = m->core;
+    u->module = m;
+    u->rtpoll = pa_rtpoll_new();
+    pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll);
+
+    pa_sink_new_data_init(&data);
+    data.driver = __FILE__;
+    data.module = m;
+    pa_sink_new_data_set_name(&data, pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME));
+    pa_sink_new_data_set_sample_spec(&data, &ss);
+    pa_sink_new_data_set_channel_map(&data, &map);
+    pa_proplist_sets(data.proplist, PA_PROP_DEVICE_DESCRIPTION, pa_modargs_get_value(ma, "description", "Null Output"));
+    pa_proplist_sets(data.proplist, PA_PROP_DEVICE_CLASS, "abstract");
+
+    u->sink = pa_sink_new(m->core, &data, PA_SINK_LATENCY);
+    pa_sink_new_data_done(&data);
+
+    if (!u->sink) {
+        pa_log("Failed to create sink object.");
+        goto fail;
+    }
+
+    u->sink->parent.process_msg = sink_process_msg;
+    u->sink->update_requested_latency = sink_update_requested_latency_cb;
+    u->sink->userdata = u;
+
+    pa_sink_set_asyncmsgq(u->sink, u->thread_mq.inq);
+    pa_sink_set_rtpoll(u->sink, u->rtpoll);
+
+    pa_sink_set_latency_range(u->sink, (pa_usec_t) -1, MAX_LATENCY_USEC);
+    u->block_usec = u->sink->thread_info.max_latency;
+
+    u->sink->thread_info.max_rewind =
+        u->sink->thread_info.max_request =
+        pa_usec_to_bytes(u->block_usec, &u->sink->sample_spec);
+
+    if (!(u->thread = pa_thread_new(thread_func, u))) {
+        pa_log("Failed to create thread.");
+        goto fail;
+    }
+
+    pa_sink_put(u->sink);
+
+    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;
+
+    if (u->sink)
+        pa_sink_unlink(u->sink);
+
+    if (u->thread) {
+        pa_asyncmsgq_send(u->thread_mq.inq, NULL, PA_MESSAGE_SHUTDOWN, NULL, 0, NULL);
+        pa_thread_free(u->thread);
+    }
+
+    pa_thread_mq_done(&u->thread_mq);
+
+    if (u->sink)
+        pa_sink_unref(u->sink);
+
+    if (u->rtpoll)
+        pa_rtpoll_free(u->rtpoll);
+
+    pa_xfree(u);
+}