Line data    Source code

       1             : /*
       2             :  *  Copyright (C) 2004-2025 Savoir-faire Linux Inc.
       3             :  *
       4             :  *  This program is free software: you can redistribute it and/or modify
       5             :  *  it under the terms of the GNU General Public License as published by
       6             :  *  the Free Software Foundation, either version 3 of the License, or
       7             :  *  (at your option) any later version.
       8             :  *
       9             :  *  This program is distributed in the hope that it will be useful,
      10             :  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
      11             :  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
      12             :  *  GNU General Public License for more details.
      13             :  *
      14             :  *  You should have received a copy of the GNU General Public License
      15             :  *  along with this program. If not, see <https://www.gnu.org/licenses/>.
      16             :  */
      17             : #pragma once
      18             : 
      19             : #include "audio/audiolayer.h"
      20             : #include "noncopyable.h"
      21             : 
      22             : #include <alsa/asoundlib.h>
      23             : 
      24             : #include <memory>
      25             : #include <thread>
      26             : 
      27             : #define PCM_DMIX "plug:dmix" /** Alsa plugin for software mixing */
      28             : 
      29             : // Error codes for error handling
      30             : #define ALSA_CAPTURE_DEVICE  0x0001 /** Error while opening capture device */
      31             : #define ALSA_PLAYBACK_DEVICE 0x0010 /** Error while opening playback device */
      32             : 
      33             : /**
      34             :  * @file  AlsaLayer.h
      35             :  * @brief Main sound class. Manages the data transfers between the application and the hardware.
      36             :  */
      37             : 
      38             : namespace jami {
      39             : 
      40             : class AlsaThread;
      41             : class RingBuffer;
      42             : class AudioPreference;
      43             : 
      44             : /** Associate a sound card index to its string description */
      45             : typedef std::pair<int, std::string> HwIDPair;
      46             : 
      47             : class AlsaLayer : public AudioLayer
      48             : {
      49             : public:
      50             :     /**
      51             :      * Constructor
      52             :      */
      53             :     AlsaLayer(const AudioPreference& pref);
      54             : 
      55             :     /**
      56             :      * Destructor
      57             :      */
      58             :     ~AlsaLayer();
      59             : 
      60             :     /**
      61             :      * Start the capture stream and prepare the playback stream.
      62             :      * The playback starts accordingly to its threshold
      63             :      * ALSA Library API
      64             :      */
      65             :     virtual void startStream(AudioDeviceType stream = AudioDeviceType::ALL);
      66             : 
      67             :     /**
      68             :      * Stop the playback and capture streams.
      69             :      * Drops the pending frames and put the capture and playback handles to PREPARED state
      70             :      * ALSA Library API
      71             :      */
      72             :     virtual void stopStream(AudioDeviceType stream = AudioDeviceType::ALL);
      73             : 
      74             :     /**
      75             :      * Concatenate two strings. Used to build a valid pcm device name.
      76             :      * @param plugin the alsa PCM name
      77             :      * @param card the sound card number
      78             :      * @return std::string the concatenated string
      79             :      */
      80             :     std::string buildDeviceTopo(const std::string& plugin, int card);
      81             : 
      82             :     /**
      83             :      * Scan the sound card available on the system
      84             :      * @return std::vector<std::string> The vector containing the string description of the card
      85             :      */
      86             :     virtual std::vector<std::string> getCaptureDeviceList() const;
      87             :     virtual std::vector<std::string> getPlaybackDeviceList() const;
      88             : 
      89             :     /**
      90             :      * Check if the given index corresponds to an existing sound card and supports the specified
      91             :      *streaming mode
      92             :      * @param card   An index
      93             :      * @param stream  The stream mode
      94             :      *            AudioDeviceType::CAPTURE
      95             :      *            AudioDeviceType::PLAYBACK
      96             :      *            AudioDeviceType::RINGTONE
      97             :      * @return bool True if it exists and supports the mode
      98             :      *              false otherwise
      99             :      */
     100             :     static bool soundCardIndexExists(int card, AudioDeviceType stream);
     101             : 
     102             :     /**
     103             :      * An index is associated with its string description
     104             :      * @param description The string description
     105             :      * @return  int       Its index
     106             :      */
     107             :     int getAudioDeviceIndex(const std::string& description, AudioDeviceType type) const;
     108             :     std::string getAudioDeviceName(int index, AudioDeviceType type) const;
     109             : 
     110             :     void playback();
     111             :     void ringtone();
     112             :     void capture();
     113             : 
     114             :     /**
     115             :      * Get the index of the audio card for capture
     116             :      * @return int The index of the card used for capture
     117             :      *                     0 for the first available card on the system, 1 ...
     118             :      */
     119           0 :     virtual int getIndexCapture() const { return indexIn_; }
     120             : 
     121             :     /**
     122             :      * Get the index of the audio card for playback
     123             :      * @return int The index of the card used for playback
     124             :      *                     0 for the first available card on the system, 1 ...
     125             :      */
     126          55 :     virtual int getIndexPlayback() const { return indexOut_; }
     127             : 
     128             :     /**
     129             :      * Get the index of the audio card for ringtone (could be differnet from playback)
     130             :      * @return int The index of the card used for ringtone
     131             :      *                 0 for the first available card on the system, 1 ...
     132             :      */
     133          55 :     virtual int getIndexRingtone() const { return indexRing_; }
     134             : 
     135             :     void run();
     136             : 
     137             : private:
     138             :     /**
     139             :      * Returns a map of audio device hardware description and index
     140             :      */
     141             :     std::vector<HwIDPair> getAudioDeviceIndexMap(bool getCapture) const;
     142             : 
     143             :     /**
     144             :      * Calls snd_pcm_open and retries if device is busy, since dmix plugin
     145             :      * will often hold on to a device temporarily after it has been opened
     146             :      * and closed.
     147             :      */
     148             :     bool openDevice(snd_pcm_t** pcm, const std::string& dev, snd_pcm_stream_t stream, AudioFormat& format);
     149             : 
     150             :     /**
     151             :      * Number of audio cards on which capture stream has been opened
     152             :      */
     153             :     int indexIn_;
     154             : 
     155             :     /**
     156             :      * Number of audio cards on which playback stream has been opened
     157             :      */
     158             :     int indexOut_;
     159             : 
     160             :     /**
     161             :      * Number of audio cards on which ringtone stream has been opened
     162             :      */
     163             :     int indexRing_;
     164             : 
     165             :     NON_COPYABLE(AlsaLayer);
     166             : 
     167             :     /**
     168             :      * Drop the pending frames and close the capture device
     169             :      * ALSA Library API
     170             :      */
     171             :     void closeCaptureStream();
     172             :     void stopCaptureStream();
     173             :     void startCaptureStream();
     174             :     void prepareCaptureStream();
     175             : 
     176             :     void closePlaybackStream();
     177             :     void stopPlaybackStream();
     178             :     void startPlaybackStream();
     179             :     void closeRingtoneStream();
     180             : 
     181             :     bool alsa_set_params(snd_pcm_t* pcm_handle, AudioFormat& format);
     182             : 
     183             :     void startThread();
     184             :     void stopThread();
     185             : 
     186             :     /**
     187             :      * Copy a data buffer in the internal ring buffer
     188             :      * ALSA Library API
     189             :      * @param buffer The non-interleaved data to be copied
     190             :      * @param frames Frames in the buffer
     191             :      */
     192             :     void write(const AudioFrame& buffer, snd_pcm_t* handle);
     193             : 
     194             :     /**
     195             :      * Read data from the internal ring buffer
     196             :      * ALSA Library API
     197             :      * @param buffer  The buffer to stock the read data
     198             :      * @param frames  The number of frames to get
     199             :      * @return int The number of frames actually read
     200             :      */
     201             :     std::unique_ptr<AudioFrame> read(unsigned frames);
     202             : 
     203             :     virtual void updatePreference(AudioPreference& pref, int index, AudioDeviceType type);
     204             : 
     205             :     /**
     206             :      * Handles to manipulate playback stream
     207             :      * ALSA Library API
     208             :      */
     209             :     snd_pcm_t* playbackHandle_ {nullptr};
     210             : 
     211             :     /**
     212             :      * Handles to manipulate ringtone stream
     213             :      *
     214             :      */
     215             :     snd_pcm_t* ringtoneHandle_ {nullptr};
     216             : 
     217             :     /**
     218             :      * Handles to manipulate capture stream
     219             :      * ALSA Library API
     220             :      */
     221             :     snd_pcm_t* captureHandle_ {nullptr};
     222             : 
     223             :     /**
     224             :      * name of the alsa audio plugin used
     225             :      */
     226             :     std::string audioPlugin_;
     227             : 
     228             :     bool is_capture_prepared_ {false};
     229             :     bool is_playback_running_ {false};
     230             :     bool is_capture_running_ {false};
     231             :     bool is_playback_open_ {false};
     232             :     bool is_capture_open_ {false};
     233             : 
     234             :     std::atomic_bool running_ {false};
     235             :     std::thread audioThread_;
     236             : };
     237             : 
     238             : } // namespace jami