media/audio/linux/alsa_wrapper.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4 //
   5 // AlsaWrapper is a simple stateless class that wraps the alsa library commands
   6 // we want to use.  It's purpose is to allow injection of a mock so that the
   7 // higher level code is testable.
   8
   9 #include <alsa/asoundlib.h>
  10
  11 #include "base/basictypes.h"
  12 #include "media/base/media_export.h"
  13
  14 namespace media {
  15
  16 class MEDIA_EXPORT AlsaWrapper {
  17  public:
  18   AlsaWrapper();
  19   virtual ~AlsaWrapper();
  20
  21   virtual int DeviceNameHint(int card, const char* iface, void*** hints);
  22   virtual char* DeviceNameGetHint(const void* hint, const char* id);
  23   virtual int DeviceNameFreeHint(void** hints);
  24   virtual int CardNext(int* rcard);
  25
  26   virtual int PcmOpen(snd_pcm_t** handle, const char* name,
  27                       snd_pcm_stream_t stream, int mode);
  28   virtual int PcmClose(snd_pcm_t* handle);
  29   virtual int PcmPrepare(snd_pcm_t* handle);
  30   virtual int PcmDrop(snd_pcm_t* handle);
  31   virtual int PcmDelay(snd_pcm_t* handle, snd_pcm_sframes_t* delay);
  32   virtual snd_pcm_sframes_t PcmWritei(snd_pcm_t* handle,
  33                                       const void* buffer,
  34                                       snd_pcm_uframes_t size);
  35   virtual snd_pcm_sframes_t PcmReadi(snd_pcm_t* handle,
  36                                      void* buffer,
  37                                      snd_pcm_uframes_t size);
  38   virtual int PcmRecover(snd_pcm_t* handle, int err, int silent);
  39   virtual int PcmSetParams(snd_pcm_t* handle, snd_pcm_format_t format,
  40                            snd_pcm_access_t access, unsigned int channels,
  41                            unsigned int rate, int soft_resample,
  42                            unsigned int latency);
  43   virtual int PcmGetParams(snd_pcm_t* handle, snd_pcm_uframes_t* buffer_size,
  44                            snd_pcm_uframes_t* period_size);
  45   virtual const char* PcmName(snd_pcm_t* handle);
  46   virtual snd_pcm_sframes_t PcmAvailUpdate(snd_pcm_t* handle);
  47   virtual snd_pcm_state_t PcmState(snd_pcm_t* handle);
  48   virtual int PcmStart(snd_pcm_t* handle);
  49
  50   virtual int MixerOpen(snd_mixer_t** mixer, int mode);
  51   virtual int MixerAttach(snd_mixer_t* mixer, const char* name);
  52   virtual int MixerElementRegister(snd_mixer_t* mixer,
  53                                    struct snd_mixer_selem_regopt* options,
  54                                    snd_mixer_class_t** classp);
  55   virtual void MixerFree(snd_mixer_t* mixer);
  56   virtual int MixerDetach(snd_mixer_t* mixer, const char* name);
  57   virtual int MixerClose(snd_mixer_t* mixer);
  58   virtual int MixerLoad(snd_mixer_t* mixer);
  59   virtual snd_mixer_elem_t* MixerFirstElem(snd_mixer_t* mixer);
  60   virtual snd_mixer_elem_t* MixerNextElem(snd_mixer_elem_t* elem);
  61   virtual int MixerSelemIsActive(snd_mixer_elem_t* elem);
  62   virtual const char* MixerSelemName(snd_mixer_elem_t* elem);
  63   virtual int MixerSelemSetCaptureVolumeAll(snd_mixer_elem_t* elem, long value);
  64   virtual int MixerSelemGetCaptureVolume(snd_mixer_elem_t* elem,
  65                                          snd_mixer_selem_channel_id_t channel,
  66                                          long* value);
  67   virtual int MixerSelemHasCaptureVolume(snd_mixer_elem_t* elem);
  68   virtual int MixerSelemGetCaptureVolumeRange(snd_mixer_elem_t* elem,
  69                                               long* min, long* max);
  70
  71   virtual const char* StrError(int errnum);
  72
  73  private:
  74   int ConfigureHwParams(snd_pcm_t* handle, snd_pcm_hw_params_t* hw_params,
  75                         snd_pcm_format_t format, snd_pcm_access_t access,
  76                         unsigned int channels, unsigned int rate,
  77                         int soft_resample, unsigned int latency);
  78   DISALLOW_COPY_AND_ASSIGN(AlsaWrapper);
  79 };
  80
  81 }  // namespace media