diff options
author | Max Kellermann <max@duempel.org> | 2014-01-24 16:18:21 +0100 |
---|---|---|
committer | Max Kellermann <max@duempel.org> | 2014-01-24 16:33:33 +0100 |
commit | f8bfea8bae44134e8002db869fd4ec137d1c0d6e (patch) | |
tree | d370391baccbbc4c23306656aec3751a7ffc95ae /src/input/AlsaInputPlugin.cxx | |
parent | e199c33c6e9eb2f1aa588073f49f44de274985d5 (diff) | |
download | mpd-f8bfea8bae44134e8002db869fd4ec137d1c0d6e.tar.gz mpd-f8bfea8bae44134e8002db869fd4ec137d1c0d6e.tar.xz mpd-f8bfea8bae44134e8002db869fd4ec137d1c0d6e.zip |
Input*: move to input/
Diffstat (limited to 'src/input/AlsaInputPlugin.cxx')
-rw-r--r-- | src/input/AlsaInputPlugin.cxx | 431 |
1 files changed, 0 insertions, 431 deletions
diff --git a/src/input/AlsaInputPlugin.cxx b/src/input/AlsaInputPlugin.cxx deleted file mode 100644 index 29c6b2504..000000000 --- a/src/input/AlsaInputPlugin.cxx +++ /dev/null @@ -1,431 +0,0 @@ -/* - * Copyright (C) 2003-2014 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. - */ - -/* - * ALSA code based on an example by Paul Davis released under GPL here: - * http://equalarea.com/paul/alsa-audio.html - * and one by Matthias Nagorni, also GPL, here: - * http://alsamodular.sourceforge.net/alsa_programming_howto.html - */ - -#include "config.h" -#include "AlsaInputPlugin.hxx" -#include "InputPlugin.hxx" -#include "InputStream.hxx" -#include "util/Domain.hxx" -#include "util/Error.hxx" -#include "util/StringUtil.hxx" -#include "util/ReusableArray.hxx" -#include "util/Cast.hxx" -#include "Log.hxx" -#include "event/MultiSocketMonitor.hxx" -#include "event/DeferredMonitor.hxx" -#include "event/Call.hxx" -#include "thread/Mutex.hxx" -#include "thread/Cond.hxx" -#include "IOThread.hxx" - -#include <alsa/asoundlib.h> - -#include <assert.h> -#include <string.h> - -static constexpr Domain alsa_input_domain("alsa"); - -static constexpr const char *default_device = "hw:0,0"; - -// the following defaults are because the PcmDecoderPlugin forces CD format -static constexpr snd_pcm_format_t default_format = SND_PCM_FORMAT_S16; -static constexpr int default_channels = 2; // stereo -static constexpr unsigned int default_rate = 44100; // cd quality - -/** - * This value should be the same as the read buffer size defined in - * PcmDecoderPlugin.cxx:pcm_stream_decode(). - * We use it to calculate how many audio frames to buffer in the alsa driver - * before reading from the device. snd_pcm_readi() blocks until that many - * frames are ready. - */ -static constexpr size_t read_buffer_size = 4096; - -class AlsaInputStream final : MultiSocketMonitor, DeferredMonitor { - InputStream base; - snd_pcm_t *capture_handle; - size_t frame_size; - int frames_to_read; - bool eof; - - /** - * Is somebody waiting for data? This is set by method - * Available(). - */ - std::atomic_bool waiting; - - ReusableArray<pollfd> pfd_buffer; - -public: - AlsaInputStream(EventLoop &loop, - const char *uri, Mutex &mutex, Cond &cond, - snd_pcm_t *_handle, int _frame_size) - :MultiSocketMonitor(loop), - DeferredMonitor(loop), - base(input_plugin_alsa, uri, mutex, cond), - capture_handle(_handle), - frame_size(_frame_size), - eof(false) - { - assert(uri != nullptr); - assert(_handle != nullptr); - - /* this mime type forces use of the PcmDecoderPlugin. - Needs to be generalised when/if that decoder is - updated to support other audio formats */ - base.mime = "audio/x-mpd-cdda-pcm"; - base.seekable = false; - base.size = -1; - base.ready = true; - frames_to_read = read_buffer_size / frame_size; - - snd_pcm_start(capture_handle); - - DeferredMonitor::Schedule(); - } - - ~AlsaInputStream() { - snd_pcm_close(capture_handle); - } - - using DeferredMonitor::GetEventLoop; - - static InputStream *Create(const char *uri, Mutex &mutex, Cond &cond, - Error &error); - -#if GCC_CHECK_VERSION(4,6) || defined(__clang__) -#pragma GCC diagnostic push -#pragma GCC diagnostic ignored "-Winvalid-offsetof" -#endif - - static constexpr AlsaInputStream *Cast(InputStream *is) { - return ContainerCast(is, AlsaInputStream, base); - } - -#if GCC_CHECK_VERSION(4,6) || defined(__clang__) -#pragma GCC diagnostic pop -#endif - - bool Available() { - if (snd_pcm_avail(capture_handle) > frames_to_read) - return true; - - if (!waiting.exchange(true)) - SafeInvalidateSockets(); - - return false; - } - - size_t Read(void *ptr, size_t size, Error &error); - - bool IsEOF() { - return eof; - } - -private: - static snd_pcm_t *OpenDevice(const char *device, int rate, - snd_pcm_format_t format, int channels, - Error &error); - - int Recover(int err); - - void SafeInvalidateSockets() { - DeferredMonitor::Schedule(); - } - - virtual void RunDeferred() override { - InvalidateSockets(); - } - - virtual int PrepareSockets() override; - virtual void DispatchSockets() override; -}; - -inline InputStream * -AlsaInputStream::Create(const char *uri, Mutex &mutex, Cond &cond, - Error &error) -{ - const char *const scheme = "alsa://"; - if (!StringStartsWith(uri, scheme)) - return nullptr; - - const char *device = uri + strlen(scheme); - if (strlen(device) == 0) - device = default_device; - - /* placeholders - eventually user-requested audio format will - be passed via the URI. For now we just force the - defaults */ - int rate = default_rate; - snd_pcm_format_t format = default_format; - int channels = default_channels; - - snd_pcm_t *handle = OpenDevice(device, rate, format, channels, - error); - if (handle == nullptr) - return nullptr; - - int frame_size = snd_pcm_format_width(format) / 8 * channels; - AlsaInputStream *stream = new AlsaInputStream(io_thread_get(), - uri, mutex, cond, - handle, frame_size); - return &stream->base; -} - -inline size_t -AlsaInputStream::Read(void *ptr, size_t size, Error &error) -{ - assert(ptr != nullptr); - - int num_frames = size / frame_size; - int ret; - while ((ret = snd_pcm_readi(capture_handle, ptr, num_frames)) < 0) { - if (Recover(ret) < 0) { - eof = true; - error.Format(alsa_input_domain, - "PCM error - stream aborted"); - return 0; - } - } - - size_t nbytes = ret * frame_size; - base.offset += nbytes; - return nbytes; -} - -int -AlsaInputStream::PrepareSockets() -{ - if (!waiting) { - ClearSocketList(); - return -1; - } - - int count = snd_pcm_poll_descriptors_count(capture_handle); - if (count < 0) { - ClearSocketList(); - return -1; - } - - struct pollfd *pfds = pfd_buffer.Get(count); - - count = snd_pcm_poll_descriptors(capture_handle, pfds, count); - if (count < 0) - count = 0; - - ReplaceSocketList(pfds, count); - return -1; -} - -void -AlsaInputStream::DispatchSockets() -{ - waiting = false; - - const ScopeLock protect(base.mutex); - /* wake up the thread that is waiting for more data */ - base.cond.broadcast(); -} - -inline int -AlsaInputStream::Recover(int err) -{ - switch(err) { - case -EPIPE: - LogDebug(alsa_input_domain, "Buffer Overrun"); - // drop through - case -ESTRPIPE: - case -EINTR: - err = snd_pcm_recover(capture_handle, err, 1); - break; - default: - // something broken somewhere, give up - err = -1; - } - return err; -} - -inline snd_pcm_t * -AlsaInputStream::OpenDevice(const char *device, - int rate, snd_pcm_format_t format, int channels, - Error &error) -{ - snd_pcm_t *capture_handle; - int err; - if ((err = snd_pcm_open(&capture_handle, device, - SND_PCM_STREAM_CAPTURE, 0)) < 0) { - error.Format(alsa_input_domain, "Failed to open device: %s (%s)", device, snd_strerror(err)); - return nullptr; - } - - snd_pcm_hw_params_t *hw_params; - if ((err = snd_pcm_hw_params_malloc(&hw_params)) < 0) { - error.Format(alsa_input_domain, "Cannot allocate hardware parameter structure (%s)", snd_strerror(err)); - snd_pcm_close(capture_handle); - return nullptr; - } - - if ((err = snd_pcm_hw_params_any(capture_handle, hw_params)) < 0) { - error.Format(alsa_input_domain, "Cannot initialize hardware parameter structure (%s)", snd_strerror(err)); - snd_pcm_hw_params_free(hw_params); - snd_pcm_close(capture_handle); - return nullptr; - } - - if ((err = snd_pcm_hw_params_set_access(capture_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) { - error.Format(alsa_input_domain, "Cannot set access type (%s)", snd_strerror (err)); - snd_pcm_hw_params_free(hw_params); - snd_pcm_close(capture_handle); - return nullptr; - } - - if ((err = snd_pcm_hw_params_set_format(capture_handle, hw_params, format)) < 0) { - snd_pcm_hw_params_free(hw_params); - snd_pcm_close(capture_handle); - error.Format(alsa_input_domain, "Cannot set sample format (%s)", snd_strerror (err)); - return nullptr; - } - - if ((err = snd_pcm_hw_params_set_channels(capture_handle, hw_params, channels)) < 0) { - snd_pcm_hw_params_free(hw_params); - snd_pcm_close(capture_handle); - error.Format(alsa_input_domain, "Cannot set channels (%s)", snd_strerror (err)); - return nullptr; - } - - if ((err = snd_pcm_hw_params_set_rate(capture_handle, hw_params, rate, 0)) < 0) { - snd_pcm_hw_params_free(hw_params); - snd_pcm_close(capture_handle); - error.Format(alsa_input_domain, "Cannot set sample rate (%s)", snd_strerror (err)); - return nullptr; - } - - /* period needs to be big enough so that poll() doesn't fire too often, - * but small enough that buffer overruns don't occur if Read() is not - * invoked often enough. - * the calculation here is empirical; however all measurements were - * done using 44100:16:2. When we extend this plugin to support - * other audio formats then this may need to be revisited */ - snd_pcm_uframes_t period = read_buffer_size * 2; - int direction = -1; - if ((err = snd_pcm_hw_params_set_period_size_near(capture_handle, hw_params, - &period, &direction)) < 0) { - error.Format(alsa_input_domain, "Cannot set period size (%s)", - snd_strerror(err)); - snd_pcm_hw_params_free(hw_params); - snd_pcm_close(capture_handle); - return nullptr; - } - - if ((err = snd_pcm_hw_params(capture_handle, hw_params)) < 0) { - error.Format(alsa_input_domain, "Cannot set parameters (%s)", - snd_strerror(err)); - snd_pcm_hw_params_free(hw_params); - snd_pcm_close(capture_handle); - return nullptr; - } - - snd_pcm_hw_params_free (hw_params); - - snd_pcm_sw_params_t *sw_params; - - snd_pcm_sw_params_malloc(&sw_params); - snd_pcm_sw_params_current(capture_handle, sw_params); - - if ((err = snd_pcm_sw_params_set_start_threshold(capture_handle, sw_params, - period)) < 0) { - error.Format(alsa_input_domain, - "unable to set start threshold (%s)", snd_strerror(err)); - snd_pcm_sw_params_free(sw_params); - snd_pcm_close(capture_handle); - return nullptr; - } - - if ((err = snd_pcm_sw_params(capture_handle, sw_params)) < 0) { - error.Format(alsa_input_domain, - "unable to install sw params (%s)", snd_strerror(err)); - snd_pcm_sw_params_free(sw_params); - snd_pcm_close(capture_handle); - return nullptr; - } - - snd_pcm_sw_params_free(sw_params); - - snd_pcm_prepare(capture_handle); - - return capture_handle; -} - -/*######################### Plugin Functions ##############################*/ - -static InputStream * -alsa_input_open(const char *uri, Mutex &mutex, Cond &cond, Error &error) -{ - return AlsaInputStream::Create(uri, mutex, cond, error); -} - -static void -alsa_input_close(InputStream *is) -{ - AlsaInputStream *ais = AlsaInputStream::Cast(is); - delete ais; -} - -static bool -alsa_input_available(InputStream *is) -{ - AlsaInputStream *ais = AlsaInputStream::Cast(is); - return ais->Available(); -} - -static size_t -alsa_input_read(InputStream *is, void *ptr, size_t size, Error &error) -{ - AlsaInputStream *ais = AlsaInputStream::Cast(is); - return ais->Read(ptr, size, error); -} - -static bool -alsa_input_eof(gcc_unused InputStream *is) -{ - AlsaInputStream *ais = AlsaInputStream::Cast(is); - return ais->IsEOF(); -} - -const struct InputPlugin input_plugin_alsa = { - "alsa", - nullptr, - nullptr, - alsa_input_open, - alsa_input_close, - nullptr, - nullptr, - nullptr, - alsa_input_available, - alsa_input_read, - alsa_input_eof, - nullptr, -}; |