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1 /*
2 **
3 ** Copyright 2007, The Android Open Source Project
4 **
5 ** Licensed under the Apache License, Version 2.0 (the "License");
6 ** you may not use this file except in compliance with the License.
7 ** You may obtain a copy of the License at
8 **
9 **     http://www.apache.org/licenses/LICENSE-2.0
10 **
11 ** Unless required by applicable law or agreed to in writing, software
12 ** distributed under the License is distributed on an "AS IS" BASIS,
13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 ** See the License for the specific language governing permissions and
15 ** limitations under the License.
16 */
17 
18 #ifndef ANDROID_AUDIO_MIXER_H
19 #define ANDROID_AUDIO_MIXER_H
20 
21 #include <stdint.h>
22 #include <sys/types.h>
23 
24 #include <media/AudioBufferProvider.h>
25 #include <media/AudioResampler.h>
26 #include <media/AudioResamplerPublic.h>
27 #include <media/BufferProviders.h>
28 #include <media/nbaio/NBLog.h>
29 #include <system/audio.h>
30 #include <utils/Compat.h>
31 #include <utils/threads.h>
32 
33 // FIXME This is actually unity gain, which might not be max in future, expressed in U.12
34 #define MAX_GAIN_INT AudioMixer::UNITY_GAIN_INT
35 
36 namespace android {
37 
38 // ----------------------------------------------------------------------------
39 
40 class AudioMixer
41 {
42 public:
43                             AudioMixer(size_t frameCount, uint32_t sampleRate,
44                                        uint32_t maxNumTracks = MAX_NUM_TRACKS);
45 
46     /*virtual*/             ~AudioMixer();  // non-virtual saves a v-table, restore if sub-classed
47 
48 
49     // This mixer has a hard-coded upper limit of 32 active track inputs.
50     // Adding support for > 32 tracks would require more than simply changing this value.
51     static const uint32_t MAX_NUM_TRACKS = 32;
52     // maximum number of channels supported by the mixer
53 
54     // This mixer has a hard-coded upper limit of 8 channels for output.
55     static const uint32_t MAX_NUM_CHANNELS = 8;
56     static const uint32_t MAX_NUM_VOLUMES = 2; // stereo volume only
57     // maximum number of channels supported for the content
58     static const uint32_t MAX_NUM_CHANNELS_TO_DOWNMIX = AUDIO_CHANNEL_COUNT_MAX;
59 
60     static const uint16_t UNITY_GAIN_INT = 0x1000;
61     static const CONSTEXPR float UNITY_GAIN_FLOAT = 1.0f;
62 
63     enum { // names
64 
65         // track names (MAX_NUM_TRACKS units)
66         TRACK0          = 0x1000,
67 
68         // 0x2000 is unused
69 
70         // setParameter targets
71         TRACK           = 0x3000,
72         RESAMPLE        = 0x3001,
73         RAMP_VOLUME     = 0x3002, // ramp to new volume
74         VOLUME          = 0x3003, // don't ramp
75         TIMESTRETCH     = 0x3004,
76 
77         // set Parameter names
78         // for target TRACK
79         CHANNEL_MASK    = 0x4000,
80         FORMAT          = 0x4001,
81         MAIN_BUFFER     = 0x4002,
82         AUX_BUFFER      = 0x4003,
83         DOWNMIX_TYPE    = 0X4004,
84         MIXER_FORMAT    = 0x4005, // AUDIO_FORMAT_PCM_(FLOAT|16_BIT)
85         MIXER_CHANNEL_MASK = 0x4006, // Channel mask for mixer output
86         // for target RESAMPLE
87         SAMPLE_RATE     = 0x4100, // Configure sample rate conversion on this track name;
88                                   // parameter 'value' is the new sample rate in Hz.
89                                   // Only creates a sample rate converter the first time that
90                                   // the track sample rate is different from the mix sample rate.
91                                   // If the new sample rate is the same as the mix sample rate,
92                                   // and a sample rate converter already exists,
93                                   // then the sample rate converter remains present but is a no-op.
94         RESET           = 0x4101, // Reset sample rate converter without changing sample rate.
95                                   // This clears out the resampler's input buffer.
96         REMOVE          = 0x4102, // Remove the sample rate converter on this track name;
97                                   // the track is restored to the mix sample rate.
98         // for target RAMP_VOLUME and VOLUME (8 channels max)
99         // FIXME use float for these 3 to improve the dynamic range
100         VOLUME0         = 0x4200,
101         VOLUME1         = 0x4201,
102         AUXLEVEL        = 0x4210,
103         // for target TIMESTRETCH
104         PLAYBACK_RATE   = 0x4300, // Configure timestretch on this track name;
105                                   // parameter 'value' is a pointer to the new playback rate.
106     };
107 
108 
109     // For all APIs with "name": TRACK0 <= name < TRACK0 + MAX_NUM_TRACKS
110 
111     // Allocate a track name.  Returns new track name if successful, -1 on failure.
112     // The failure could be because of an invalid channelMask or format, or that
113     // the track capacity of the mixer is exceeded.
114     int         getTrackName(audio_channel_mask_t channelMask,
115                              audio_format_t format, int sessionId);
116 
117     // Free an allocated track by name
118     void        deleteTrackName(int name);
119 
120     // Enable or disable an allocated track by name
121     void        enable(int name);
122     void        disable(int name);
123 
124     void        setParameter(int name, int target, int param, void *value);
125 
126     void        setBufferProvider(int name, AudioBufferProvider* bufferProvider);
127     void        process();
128 
trackNames()129     uint32_t    trackNames() const { return mTrackNames; }
130 
131     size_t      getUnreleasedFrames(int name) const;
132 
isValidPcmTrackFormat(audio_format_t format)133     static inline bool isValidPcmTrackFormat(audio_format_t format) {
134         switch (format) {
135         case AUDIO_FORMAT_PCM_8_BIT:
136         case AUDIO_FORMAT_PCM_16_BIT:
137         case AUDIO_FORMAT_PCM_24_BIT_PACKED:
138         case AUDIO_FORMAT_PCM_32_BIT:
139         case AUDIO_FORMAT_PCM_FLOAT:
140             return true;
141         default:
142             return false;
143         }
144     }
145 
146 private:
147 
148     enum {
149         // FIXME this representation permits up to 8 channels
150         NEEDS_CHANNEL_COUNT__MASK   = 0x00000007,
151     };
152 
153     enum {
154         NEEDS_CHANNEL_1             = 0x00000000,   // mono
155         NEEDS_CHANNEL_2             = 0x00000001,   // stereo
156 
157         // sample format is not explicitly specified, and is assumed to be AUDIO_FORMAT_PCM_16_BIT
158 
159         NEEDS_MUTE                  = 0x00000100,
160         NEEDS_RESAMPLE              = 0x00001000,
161         NEEDS_AUX                   = 0x00010000,
162     };
163 
164     struct state_t;
165     struct track_t;
166 
167     typedef void (*hook_t)(track_t* t, int32_t* output, size_t numOutFrames, int32_t* temp,
168                            int32_t* aux);
169     static const int BLOCKSIZE = 16; // 4 cache lines
170 
171     struct track_t {
172         uint32_t    needs;
173 
174         // TODO: Eventually remove legacy integer volume settings
175         union {
176         int16_t     volume[MAX_NUM_VOLUMES]; // U4.12 fixed point (top bit should be zero)
177         int32_t     volumeRL;
178         };
179 
180         int32_t     prevVolume[MAX_NUM_VOLUMES];
181 
182         // 16-byte boundary
183 
184         int32_t     volumeInc[MAX_NUM_VOLUMES];
185         int32_t     auxInc;
186         int32_t     prevAuxLevel;
187 
188         // 16-byte boundary
189 
190         int16_t     auxLevel;       // 0 <= auxLevel <= MAX_GAIN_INT, but signed for mul performance
191         uint16_t    frameCount;
192 
193         uint8_t     channelCount;   // 1 or 2, redundant with (needs & NEEDS_CHANNEL_COUNT__MASK)
194         uint8_t     unused_padding; // formerly format, was always 16
195         uint16_t    enabled;        // actually bool
196         audio_channel_mask_t channelMask;
197 
198         // actual buffer provider used by the track hooks, see DownmixerBufferProvider below
199         //  for how the Track buffer provider is wrapped by another one when dowmixing is required
200         AudioBufferProvider*                bufferProvider;
201 
202         // 16-byte boundary
203 
204         mutable AudioBufferProvider::Buffer buffer; // 8 bytes
205 
206         hook_t      hook;
207         const void* in;             // current location in buffer
208 
209         // 16-byte boundary
210 
211         AudioResampler*     resampler;
212         uint32_t            sampleRate;
213         int32_t*           mainBuffer;
214         int32_t*           auxBuffer;
215 
216         // 16-byte boundary
217 
218         /* Buffer providers are constructed to translate the track input data as needed.
219          *
220          * TODO: perhaps make a single PlaybackConverterProvider class to move
221          * all pre-mixer track buffer conversions outside the AudioMixer class.
222          *
223          * 1) mInputBufferProvider: The AudioTrack buffer provider.
224          * 2) mReformatBufferProvider: If not NULL, performs the audio reformat to
225          *    match either mMixerInFormat or mDownmixRequiresFormat, if the downmixer
226          *    requires reformat. For example, it may convert floating point input to
227          *    PCM_16_bit if that's required by the downmixer.
228          * 3) downmixerBufferProvider: If not NULL, performs the channel remixing to match
229          *    the number of channels required by the mixer sink.
230          * 4) mPostDownmixReformatBufferProvider: If not NULL, performs reformatting from
231          *    the downmixer requirements to the mixer engine input requirements.
232          * 5) mTimestretchBufferProvider: Adds timestretching for playback rate
233          */
234         AudioBufferProvider*     mInputBufferProvider;    // externally provided buffer provider.
235         PassthruBufferProvider*  mReformatBufferProvider; // provider wrapper for reformatting.
236         PassthruBufferProvider*  downmixerBufferProvider; // wrapper for channel conversion.
237         PassthruBufferProvider*  mPostDownmixReformatBufferProvider;
238         PassthruBufferProvider*  mTimestretchBufferProvider;
239 
240         int32_t     sessionId;
241 
242         audio_format_t mMixerFormat;     // output mix format: AUDIO_FORMAT_PCM_(FLOAT|16_BIT)
243         audio_format_t mFormat;          // input track format
244         audio_format_t mMixerInFormat;   // mix internal format AUDIO_FORMAT_PCM_(FLOAT|16_BIT)
245                                          // each track must be converted to this format.
246         audio_format_t mDownmixRequiresFormat;  // required downmixer format
247                                                 // AUDIO_FORMAT_PCM_16_BIT if 16 bit necessary
248                                                 // AUDIO_FORMAT_INVALID if no required format
249 
250         float          mVolume[MAX_NUM_VOLUMES];     // floating point set volume
251         float          mPrevVolume[MAX_NUM_VOLUMES]; // floating point previous volume
252         float          mVolumeInc[MAX_NUM_VOLUMES];  // floating point volume increment
253 
254         float          mAuxLevel;                     // floating point set aux level
255         float          mPrevAuxLevel;                 // floating point prev aux level
256         float          mAuxInc;                       // floating point aux increment
257 
258         audio_channel_mask_t mMixerChannelMask;
259         uint32_t             mMixerChannelCount;
260 
261         AudioPlaybackRate    mPlaybackRate;
262 
needsRamptrack_t263         bool        needsRamp() { return (volumeInc[0] | volumeInc[1] | auxInc) != 0; }
264         bool        setResampler(uint32_t trackSampleRate, uint32_t devSampleRate);
doesResampletrack_t265         bool        doesResample() const { return resampler != NULL; }
resetResamplertrack_t266         void        resetResampler() { if (resampler != NULL) resampler->reset(); }
267         void        adjustVolumeRamp(bool aux, bool useFloat = false);
getUnreleasedFramestrack_t268         size_t      getUnreleasedFrames() const { return resampler != NULL ?
269                                                     resampler->getUnreleasedFrames() : 0; };
270 
271         status_t    prepareForDownmix();
272         void        unprepareForDownmix();
273         status_t    prepareForReformat();
274         void        unprepareForReformat();
275         bool        setPlaybackRate(const AudioPlaybackRate &playbackRate);
276         void        reconfigureBufferProviders();
277     };
278 
279     typedef void (*process_hook_t)(state_t* state);
280 
281     // pad to 32-bytes to fill cache line
282     struct state_t {
283         uint32_t        enabledTracks;
284         uint32_t        needsChanged;
285         size_t          frameCount;
286         process_hook_t  hook;   // one of process__*, never NULL
287         int32_t         *outputTemp;
288         int32_t         *resampleTemp;
289         NBLog::Writer*  mLog;
290         int32_t         reserved[1];
291         // FIXME allocate dynamically to save some memory when maxNumTracks < MAX_NUM_TRACKS
292         track_t         tracks[MAX_NUM_TRACKS] __attribute__((aligned(32)));
293     };
294 
295     // bitmask of allocated track names, where bit 0 corresponds to TRACK0 etc.
296     uint32_t        mTrackNames;
297 
298     // bitmask of configured track names; ~0 if maxNumTracks == MAX_NUM_TRACKS,
299     // but will have fewer bits set if maxNumTracks < MAX_NUM_TRACKS
300     const uint32_t  mConfiguredNames;
301 
302     const uint32_t  mSampleRate;
303 
304     NBLog::Writer   mDummyLog;
305 public:
306     void            setLog(NBLog::Writer* log);
307 private:
308     state_t         mState __attribute__((aligned(32)));
309 
310     // Call after changing either the enabled status of a track, or parameters of an enabled track.
311     // OK to call more often than that, but unnecessary.
312     void invalidateState(uint32_t mask);
313 
314     bool setChannelMasks(int name,
315             audio_channel_mask_t trackChannelMask, audio_channel_mask_t mixerChannelMask);
316 
317     static void track__genericResample(track_t* t, int32_t* out, size_t numFrames, int32_t* temp,
318             int32_t* aux);
319     static void track__nop(track_t* t, int32_t* out, size_t numFrames, int32_t* temp, int32_t* aux);
320     static void track__16BitsStereo(track_t* t, int32_t* out, size_t numFrames, int32_t* temp,
321             int32_t* aux);
322     static void track__16BitsMono(track_t* t, int32_t* out, size_t numFrames, int32_t* temp,
323             int32_t* aux);
324     static void volumeRampStereo(track_t* t, int32_t* out, size_t frameCount, int32_t* temp,
325             int32_t* aux);
326     static void volumeStereo(track_t* t, int32_t* out, size_t frameCount, int32_t* temp,
327             int32_t* aux);
328 
329     static void process__validate(state_t* state);
330     static void process__nop(state_t* state);
331     static void process__genericNoResampling(state_t* state);
332     static void process__genericResampling(state_t* state);
333     static void process__OneTrack16BitsStereoNoResampling(state_t* state);
334 
335     static pthread_once_t   sOnceControl;
336     static void             sInitRoutine();
337 
338     /* multi-format volume mixing function (calls template functions
339      * in AudioMixerOps.h).  The template parameters are as follows:
340      *
341      *   MIXTYPE     (see AudioMixerOps.h MIXTYPE_* enumeration)
342      *   USEFLOATVOL (set to true if float volume is used)
343      *   ADJUSTVOL   (set to true if volume ramp parameters needs adjustment afterwards)
344      *   TO: int32_t (Q4.27) or float
345      *   TI: int32_t (Q4.27) or int16_t (Q0.15) or float
346      *   TA: int32_t (Q4.27)
347      */
348     template <int MIXTYPE, bool USEFLOATVOL, bool ADJUSTVOL,
349         typename TO, typename TI, typename TA>
350     static void volumeMix(TO *out, size_t outFrames,
351             const TI *in, TA *aux, bool ramp, AudioMixer::track_t *t);
352 
353     // multi-format process hooks
354     template <int MIXTYPE, typename TO, typename TI, typename TA>
355     static void process_NoResampleOneTrack(state_t* state);
356 
357     // multi-format track hooks
358     template <int MIXTYPE, typename TO, typename TI, typename TA>
359     static void track__Resample(track_t* t, TO* out, size_t frameCount,
360             TO* temp __unused, TA* aux);
361     template <int MIXTYPE, typename TO, typename TI, typename TA>
362     static void track__NoResample(track_t* t, TO* out, size_t frameCount,
363             TO* temp __unused, TA* aux);
364 
365     static void convertMixerFormat(void *out, audio_format_t mixerOutFormat,
366             void *in, audio_format_t mixerInFormat, size_t sampleCount);
367 
368     // hook types
369     enum {
370         PROCESSTYPE_NORESAMPLEONETRACK,
371     };
372     enum {
373         TRACKTYPE_NOP,
374         TRACKTYPE_RESAMPLE,
375         TRACKTYPE_NORESAMPLE,
376         TRACKTYPE_NORESAMPLEMONO,
377     };
378 
379     // functions for determining the proper process and track hooks.
380     static process_hook_t getProcessHook(int processType, uint32_t channelCount,
381             audio_format_t mixerInFormat, audio_format_t mixerOutFormat);
382     static hook_t getTrackHook(int trackType, uint32_t channelCount,
383             audio_format_t mixerInFormat, audio_format_t mixerOutFormat);
384 };
385 
386 // ----------------------------------------------------------------------------
387 } // namespace android
388 
389 #endif // ANDROID_AUDIO_MIXER_H
390