mpd/src/output/plugins/JackOutputPlugin.cxx
Max Kellermann d0f6131ba4 output/Interface: allow Pause() to throw exception
Coverity discovered that the Pulse plugin could throw exceptions from
Pause(), but that method was marked "noexcept" because its caller was
not designed to catch exceptions.  So instead of avoiding exceptions
(by catching and logging them in each and every implementation), let's
allow them, and do the catch/log game in the MPD core.
2017-09-08 14:45:53 +02:00

680 lines
15 KiB
C++

/*
* Copyright 2003-2017 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include "JackOutputPlugin.hxx"
#include "../OutputAPI.hxx"
#include "config/ConfigError.hxx"
#include "util/ScopeExit.hxx"
#include "util/ConstBuffer.hxx"
#include "util/IterableSplitString.hxx"
#include "util/RuntimeError.hxx"
#include "util/Domain.hxx"
#include "Log.hxx"
#include <assert.h>
#include <jack/jack.h>
#include <jack/types.h>
#include <jack/ringbuffer.h>
#include <unistd.h> /* for usleep() */
#include <stdlib.h>
static constexpr unsigned MAX_PORTS = 16;
static constexpr size_t jack_sample_size = sizeof(jack_default_audio_sample_t);
struct JackOutput final : AudioOutput {
/**
* libjack options passed to jack_client_open().
*/
jack_options_t options = JackNullOption;
const char *name;
const char *const server_name;
/* configuration */
std::string source_ports[MAX_PORTS];
unsigned num_source_ports;
std::string destination_ports[MAX_PORTS];
unsigned num_destination_ports;
size_t ringbuffer_size;
/* the current audio format */
AudioFormat audio_format;
/* jack library stuff */
jack_port_t *ports[MAX_PORTS];
jack_client_t *client;
jack_ringbuffer_t *ringbuffer[MAX_PORTS];
bool shutdown;
/**
* While this flag is set, the "process" callback generates
* silence.
*/
bool pause;
explicit JackOutput(const ConfigBlock &block);
/**
* Connect the JACK client and performs some basic setup
* (e.g. register callbacks).
*
* Throws #std::runtime_error on error.
*/
void Connect();
/**
* Disconnect the JACK client.
*/
void Disconnect() noexcept;
void Shutdown() noexcept {
shutdown = true;
}
/**
* Throws #std::runtime_error on error.
*/
void Start();
void Stop() noexcept;
/**
* Determine the number of frames guaranteed to be available
* on all channels.
*/
gcc_pure
jack_nframes_t GetAvailable() const noexcept;
void Process(jack_nframes_t nframes);
/**
* @return the number of frames that were written
*/
size_t WriteSamples(const float *src, size_t n_frames);
/* virtual methods from class AudioOutput */
void Enable() override;
void Disable() noexcept override;
void Open(AudioFormat &new_audio_format) override;
void Close() noexcept override {
Stop();
}
std::chrono::steady_clock::duration Delay() const noexcept override {
return pause && !shutdown
? std::chrono::seconds(1)
: std::chrono::steady_clock::duration::zero();
}
size_t Play(const void *chunk, size_t size) override;
bool Pause() override;
};
static constexpr Domain jack_output_domain("jack_output");
/**
* Throws #std::runtime_error on error.
*/
static unsigned
parse_port_list(const char *source, std::string dest[])
{
unsigned n = 0;
for (auto i : IterableSplitString(source, ',')) {
if (n >= MAX_PORTS)
throw std::runtime_error("too many port names");
dest[n++] = std::string(i.data, i.size);
}
if (n == 0)
throw std::runtime_error("at least one port name expected");
return n;
}
JackOutput::JackOutput(const ConfigBlock &block)
:AudioOutput(FLAG_ENABLE_DISABLE|FLAG_PAUSE),
name(block.GetBlockValue("client_name", nullptr)),
server_name(block.GetBlockValue("server_name", nullptr))
{
if (name != nullptr)
options = jack_options_t(options | JackUseExactName);
else
/* if there's a no configured client name, we don't
care about the JackUseExactName option */
name = "Music Player Daemon";
if (server_name != nullptr)
options = jack_options_t(options | JackServerName);
if (!block.GetBlockValue("autostart", false))
options = jack_options_t(options | JackNoStartServer);
/* configure the source ports */
const char *value = block.GetBlockValue("source_ports", "left,right");
num_source_ports = parse_port_list(value, source_ports);
/* configure the destination ports */
value = block.GetBlockValue("destination_ports", nullptr);
if (value == nullptr) {
/* compatibility with MPD < 0.16 */
value = block.GetBlockValue("ports", nullptr);
if (value != nullptr)
FormatWarning(jack_output_domain,
"deprecated option 'ports' in line %d",
block.line);
}
if (value != nullptr) {
num_destination_ports =
parse_port_list(value, destination_ports);
} else {
num_destination_ports = 0;
}
if (num_destination_ports > 0 &&
num_destination_ports != num_source_ports)
FormatWarning(jack_output_domain,
"number of source ports (%u) mismatches the "
"number of destination ports (%u) in line %d",
num_source_ports, num_destination_ports,
block.line);
ringbuffer_size = block.GetBlockValue("ringbuffer_size", 32768u);
}
inline jack_nframes_t
JackOutput::GetAvailable() const noexcept
{
size_t min = jack_ringbuffer_read_space(ringbuffer[0]);
for (unsigned i = 1; i < audio_format.channels; ++i) {
size_t current = jack_ringbuffer_read_space(ringbuffer[i]);
if (current < min)
min = current;
}
assert(min % jack_sample_size == 0);
return min / jack_sample_size;
}
/**
* Call jack_ringbuffer_read_advance() on all buffers in the list.
*/
static void
MultiReadAdvance(ConstBuffer<jack_ringbuffer_t *> buffers,
size_t size)
{
for (auto *i : buffers)
jack_ringbuffer_read_advance(i, size);
}
/**
* Write a specific amount of "silence" to the given port.
*/
static void
WriteSilence(jack_port_t &port, jack_nframes_t nframes)
{
jack_default_audio_sample_t *out =
(jack_default_audio_sample_t *)
jack_port_get_buffer(&port, nframes);
if (out == nullptr)
/* workaround for libjack1 bug: if the server
connection fails, the process callback is invoked
anyway, but unable to get a buffer */
return;
std::fill_n(out, nframes, 0.0);
}
/**
* Write a specific amount of "silence" to all ports in the list.
*/
static void
MultiWriteSilence(ConstBuffer<jack_port_t *> ports, jack_nframes_t nframes)
{
for (auto *i : ports)
WriteSilence(*i, nframes);
}
/**
* Copy data from the buffer to the port. If the buffer underruns,
* fill with silence.
*/
static void
Copy(jack_port_t &dest, jack_nframes_t nframes,
jack_ringbuffer_t &src, jack_nframes_t available)
{
jack_default_audio_sample_t *out =
(jack_default_audio_sample_t *)
jack_port_get_buffer(&dest, nframes);
if (out == nullptr)
/* workaround for libjack1 bug: if the server
connection fails, the process callback is
invoked anyway, but unable to get a
buffer */
return;
/* copy from buffer to port */
jack_ringbuffer_read(&src, (char *)out,
available * jack_sample_size);
/* ringbuffer underrun, fill with silence */
std::fill(out + available, out + nframes, 0.0);
}
inline void
JackOutput::Process(jack_nframes_t nframes)
{
if (nframes <= 0)
return;
jack_nframes_t available = GetAvailable();
const unsigned n_channels = audio_format.channels;
if (pause) {
/* empty the ring buffers */
MultiReadAdvance({ringbuffer, n_channels},
available * jack_sample_size);
/* generate silence while MPD is paused */
MultiWriteSilence({ports, n_channels}, nframes);
return;
}
if (available > nframes)
available = nframes;
for (unsigned i = 0; i < n_channels; ++i)
Copy(*ports[i], nframes, *ringbuffer[i], available);
/* generate silence for the unused source ports */
MultiWriteSilence({ports + n_channels, num_source_ports - n_channels},
nframes);
}
static int
mpd_jack_process(jack_nframes_t nframes, void *arg)
{
JackOutput &jo = *(JackOutput *) arg;
jo.Process(nframes);
return 0;
}
static void
mpd_jack_shutdown(void *arg)
{
JackOutput &jo = *(JackOutput *) arg;
jo.Shutdown();
}
static void
set_audioformat(JackOutput *jd, AudioFormat &audio_format)
{
audio_format.sample_rate = jack_get_sample_rate(jd->client);
if (jd->num_source_ports == 1)
audio_format.channels = 1;
else if (audio_format.channels > jd->num_source_ports)
audio_format.channels = 2;
/* JACK uses 32 bit float in the range [-1 .. 1] - just like
MPD's SampleFormat::FLOAT*/
static_assert(jack_sample_size == sizeof(float), "Expected float32");
audio_format.format = SampleFormat::FLOAT;
}
static void
mpd_jack_error(const char *msg)
{
LogError(jack_output_domain, msg);
}
#ifdef HAVE_JACK_SET_INFO_FUNCTION
static void
mpd_jack_info(const char *msg)
{
LogDefault(jack_output_domain, msg);
}
#endif
void
JackOutput::Disconnect() noexcept
{
assert(client != nullptr);
jack_deactivate(client);
jack_client_close(client);
client = nullptr;
}
void
JackOutput::Connect()
{
shutdown = false;
jack_status_t status;
client = jack_client_open(name, options, &status, server_name);
if (client == nullptr)
throw FormatRuntimeError("Failed to connect to JACK server, status=%d",
status);
jack_set_process_callback(client, mpd_jack_process, this);
jack_on_shutdown(client, mpd_jack_shutdown, this);
for (unsigned i = 0; i < num_source_ports; ++i) {
ports[i] = jack_port_register(client,
source_ports[i].c_str(),
JACK_DEFAULT_AUDIO_TYPE,
JackPortIsOutput, 0);
if (ports[i] == nullptr) {
Disconnect();
throw FormatRuntimeError("Cannot register output port \"%s\"",
source_ports[i].c_str());
}
}
}
static bool
mpd_jack_test_default_device(void)
{
return true;
}
inline void
JackOutput::Enable()
{
for (unsigned i = 0; i < num_source_ports; ++i)
ringbuffer[i] = nullptr;
Connect();
}
inline void
JackOutput::Disable() noexcept
{
if (client != nullptr)
Disconnect();
for (unsigned i = 0; i < num_source_ports; ++i) {
if (ringbuffer[i] != nullptr) {
jack_ringbuffer_free(ringbuffer[i]);
ringbuffer[i] = nullptr;
}
}
}
static AudioOutput *
mpd_jack_init(EventLoop &, const ConfigBlock &block)
{
jack_set_error_function(mpd_jack_error);
#ifdef HAVE_JACK_SET_INFO_FUNCTION
jack_set_info_function(mpd_jack_info);
#endif
return new JackOutput(block);
}
/**
* Stops the playback on the JACK connection.
*/
void
JackOutput::Stop() noexcept
{
if (client == nullptr)
return;
if (shutdown)
/* the connection has failed; close it */
Disconnect();
else
/* the connection is alive: just stop playback */
jack_deactivate(client);
}
inline void
JackOutput::Start()
{
assert(client != nullptr);
assert(audio_format.channels <= num_source_ports);
/* allocate the ring buffers on the first open(); these
persist until MPD exits. It's too unsafe to delete them
because we can never know when mpd_jack_process() gets
called */
for (unsigned i = 0; i < num_source_ports; ++i) {
if (ringbuffer[i] == nullptr)
ringbuffer[i] =
jack_ringbuffer_create(ringbuffer_size);
/* clear the ring buffer to be sure that data from
previous playbacks are gone */
jack_ringbuffer_reset(ringbuffer[i]);
}
if ( jack_activate(client) ) {
Stop();
throw std::runtime_error("cannot activate client");
}
const char *dports[MAX_PORTS], **jports;
unsigned num_dports;
if (num_destination_ports == 0) {
/* no output ports were configured - ask libjack for
defaults */
jports = jack_get_ports(client, nullptr, nullptr,
JackPortIsPhysical | JackPortIsInput);
if (jports == nullptr) {
Stop();
throw std::runtime_error("no ports found");
}
assert(*jports != nullptr);
for (num_dports = 0; num_dports < MAX_PORTS &&
jports[num_dports] != nullptr;
++num_dports) {
FormatDebug(jack_output_domain,
"destination_port[%u] = '%s'\n",
num_dports,
jports[num_dports]);
dports[num_dports] = jports[num_dports];
}
} else {
/* use the configured output ports */
num_dports = num_destination_ports;
for (unsigned i = 0; i < num_dports; ++i)
dports[i] = destination_ports[i].c_str();
jports = nullptr;
}
AtScopeExit(jports) { free(jports); };
assert(num_dports > 0);
const char *duplicate_port = nullptr;
if (audio_format.channels >= 2 && num_dports == 1) {
/* mix stereo signal on one speaker */
std::fill(dports + num_dports, dports + audio_format.channels,
dports[0]);
} else if (num_dports > audio_format.channels) {
if (audio_format.channels == 1 && num_dports > 2) {
/* mono input file: connect the one source
channel to the both destination channels */
duplicate_port = dports[1];
num_dports = 1;
} else
/* connect only as many ports as we need */
num_dports = audio_format.channels;
}
assert(num_dports <= num_source_ports);
for (unsigned i = 0; i < num_dports; ++i) {
int ret = jack_connect(client, jack_port_name(ports[i]),
dports[i]);
if (ret != 0) {
Stop();
throw FormatRuntimeError("Not a valid JACK port: %s",
dports[i]);
}
}
if (duplicate_port != nullptr) {
/* mono input file: connect the one source channel to
the both destination channels */
int ret;
ret = jack_connect(client, jack_port_name(ports[0]),
duplicate_port);
if (ret != 0) {
Stop();
throw FormatRuntimeError("Not a valid JACK port: %s",
duplicate_port);
}
}
}
inline void
JackOutput::Open(AudioFormat &new_audio_format)
{
pause = false;
if (client != nullptr && shutdown)
Disconnect();
if (client == nullptr)
Connect();
set_audioformat(this, new_audio_format);
audio_format = new_audio_format;
Start();
}
inline size_t
JackOutput::WriteSamples(const float *src, size_t n_frames)
{
assert(n_frames > 0);
const unsigned n_channels = audio_format.channels;
float *dest[MAX_CHANNELS];
size_t space = -1;
for (unsigned i = 0; i < n_channels; ++i) {
jack_ringbuffer_data_t d[2];
jack_ringbuffer_get_write_vector(ringbuffer[i], d);
/* choose the first non-empty writable area */
const jack_ringbuffer_data_t &e = d[d[0].len == 0];
if (e.len < space)
/* send data symmetrically */
space = e.len;
dest[i] = (float *)e.buf;
}
space /= jack_sample_size;
if (space == 0)
return 0;
const size_t result = n_frames = std::min(space, n_frames);
while (n_frames-- > 0)
for (unsigned i = 0; i < n_channels; ++i)
*dest[i]++ = *src++;
const size_t per_channel_advance = result * jack_sample_size;
for (unsigned i = 0; i < n_channels; ++i)
jack_ringbuffer_write_advance(ringbuffer[i],
per_channel_advance);
return result;
}
inline size_t
JackOutput::Play(const void *chunk, size_t size)
{
pause = false;
const size_t frame_size = audio_format.GetFrameSize();
assert(size % frame_size == 0);
size /= frame_size;
while (true) {
if (shutdown)
throw std::runtime_error("Refusing to play, because "
"there is no client thread");
size_t frames_written =
WriteSamples((const float *)chunk, size);
if (frames_written > 0)
return frames_written * frame_size;
/* XXX do something more intelligent to
synchronize */
usleep(1000);
}
}
inline bool
JackOutput::Pause()
{
if (shutdown)
return false;
pause = true;
return true;
}
const struct AudioOutputPlugin jack_output_plugin = {
"jack",
mpd_jack_test_default_device,
mpd_jack_init,
nullptr,
};