firmware/pcm_playback.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2005 by Linus Nielsen Feltzing
  11  *
  12  * All files in this archive are subject to the GNU General Public License.
  13  * See the file COPYING in the source tree root for full license agreement.
  14  *
  15  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  16  * KIND, either express or implied.
  17  *
  18  ****************************************************************************/
  19 #include "system.h"
  20 #include "kernel.h"
  21 #include "logf.h"
  22 #include "audio.h"
  23 #include "sound.h"
  24
  25 /**
  26  * APIs implemented in the target-specific portion:
  27  * Public -
  28  *      pcm_init
  29  *      pcm_get_bytes_waiting
  30  *      pcm_calculate_peaks
  31  * Semi-private -
  32  *      pcm_play_dma_start
  33  *      pcm_play_dma_stop
  34  *      pcm_play_pause_pause
  35  *      pcm_play_pause_unpause
  36  */
  37
  38 /** These items may be implemented target specifically or need to
  39     be shared semi-privately **/
  40
  41 /* the registered callback function to ask for more mp3 data */
  42 volatile pcm_more_callback_type pcm_callback_for_more = NULL;
  43 volatile bool                   pcm_playing           = false;
  44 volatile bool                   pcm_paused            = false;
  45
  46 void pcm_play_dma_start(const void *addr, size_t size);
  47 void pcm_play_dma_stop(void);
  48 void pcm_play_pause_pause(void);
  49 void pcm_play_pause_unpause(void);
  50
  51 /** Functions that require targeted implementation **/
  52
  53 #if defined(CPU_COLDFIRE) || (CONFIG_CPU == S3C2440) || (CONFIG_CPU == IMX31L)
  54 /* Implemented in target/... */
  55 #else
  56 /* dummy functions for those not actually supporting all this yet */
  57 void pcm_apply_settings(void)
  58 {
  59 }
  60 /** **/
  61
  62 void pcm_mute(bool mute)
  63 {
  64 #if defined(HAVE_WM8975) || defined(HAVE_WM8758) \
  65    || defined(HAVE_WM8731) || defined(HAVE_WM8721)
  66     audiohw_mute(mute);
  67 #endif
  68     if (mute)
  69         sleep(HZ/16);
  70 }
  71 #endif /* defined(CPU_COLDFIRE) || (CONFIG_CPU == S3C2440) */
  72
  73 #if defined(CPU_COLDFIRE) || (CONFIG_CPU == S3C2440) || defined(CPU_PP)
  74 /* Implemented in target/... */
  75 #else
  76 static int pcm_freq = HW_SAMPR_DEFAULT; /* 44.1 is default */
  77
  78 unsigned short* p IBSS_ATTR;
  79 size_t p_size IBSS_ATTR;
  80
  81 void pcm_play_dma_start(const void *addr, size_t size)
  82 {
  83     p = (unsigned short*)addr;
  84     p_size = size;
  85
  86     pcm_playing = true;
  87 }
  88
  89 void pcm_play_dma_stop(void)
  90 {
  91     pcm_playing = false;
  92     if (!audio_status())
  93         pcm_paused = false;
  94 }
  95
  96 void pcm_play_pause_pause(void)
  97 {
  98 }
  99
 100 void pcm_play_pause_unpause(void)
 101 {
 102 }
 103
 104 void pcm_postinit(void)
 105 {
 106     audiohw_postinit();
 107 }
 108
 109 void pcm_set_frequency(unsigned int frequency)
 110 {
 111     (void)frequency;
 112     pcm_freq = HW_SAMPR_DEFAULT;
 113 }
 114 size_t pcm_get_bytes_waiting(void)
 115 {
 116     return p_size;
 117 }
 118
 119 /*
 120  * This function goes directly into the DMA buffer to calculate the left and
 121  * right peak values. To avoid missing peaks it tries to look forward two full
 122  * peek periods (2/HZ sec, 100% overlap), although it's always possible that
 123  * the entire period will not be visible. To reduce CPU load it only looks at
 124  * every third sample, and this can be reduced even further if needed (even
 125  * every tenth sample would still be pretty accurate).
 126  */
 127
 128 /* Check for a peak every PEAK_STRIDE samples */
 129 #define PEAK_STRIDE   3
 130 /* Up to 1/50th of a second of audio for peak calculation */
 131 /* This should use NATIVE_FREQUENCY, or eventually an adjustable freq. value */
 132 #define PEAK_SAMPLES  (44100/50)
 133 void pcm_calculate_peaks(int *left, int *right)
 134 {
 135     short *addr;
 136     short *end;
 137     {
 138         size_t samples = p_size / 4;
 139         addr = p;
 140
 141         if (samples > PEAK_SAMPLES)
 142             samples = PEAK_SAMPLES - (PEAK_STRIDE - 1);
 143         else
 144             samples -= MIN(PEAK_STRIDE - 1, samples);
 145
 146         end = &addr[samples * 2];
 147     }
 148
 149     if (left && right) {
 150         int left_peak = 0, right_peak = 0;
 151
 152         while (addr < end) {
 153             int value;
 154             if ((value = addr [0]) > left_peak)
 155                 left_peak = value;
 156             else if (-value > left_peak)
 157                 left_peak = -value;
 158
 159             if ((value = addr [PEAK_STRIDE | 1]) > right_peak)
 160                 right_peak = value;
 161             else if (-value > right_peak)
 162                 right_peak = -value;
 163
 164             addr = &addr[PEAK_STRIDE * 2];
 165         }
 166
 167         *left = left_peak;
 168         *right = right_peak;
 169     }
 170     else if (left || right) {
 171         int peak_value = 0, value;
 172
 173         if (right)
 174             addr += (PEAK_STRIDE | 1);
 175
 176         while (addr < end) {
 177             if ((value = addr [0]) > peak_value)
 178                 peak_value = value;
 179             else if (-value > peak_value)
 180                 peak_value = -value;
 181
 182             addr += PEAK_STRIDE * 2;
 183         }
 184
 185         if (left)
 186             *left = peak_value;
 187         else
 188             *right = peak_value;
 189     }
 190 }
 191 #endif /* defined(CPU_COLDFIRE) || (CONFIG_CPU == S3C2440) || defined(CPU_PP) */
 192
 193 /****************************************************************************
 194  * Functions that do not require targeted implementation but only a targeted
 195  * interface
 196  */
 197
 198 /* Common code to pcm_play_data and pcm_play_pause
 199    Returns true if DMA playback was started, else false. */
 200 bool pcm_play_data_start(pcm_more_callback_type get_more,
 201                          unsigned char *start, size_t size)
 202 {
 203     if (!(start && size))
 204     {
 205         size = 0;
 206         if (get_more)
 207             get_more(&start, &size);
 208     }
 209
 210     if (start && size)
 211     {
 212         pcm_play_dma_start(start, size);
 213         return true;
 214     }
 215
 216     return false;
 217 }
 218
 219 void pcm_play_data(pcm_more_callback_type get_more,
 220                    unsigned char *start, size_t size)
 221 {
 222     pcm_callback_for_more = get_more;
 223
 224     if (pcm_play_data_start(get_more, start, size) && pcm_paused)
 225     {
 226         pcm_paused = false;
 227         pcm_play_pause(false);
 228     }
 229 }
 230
 231 void pcm_play_pause(bool play)
 232 {
 233     bool needs_change = pcm_paused == play;
 234
 235     /* This needs to be done ahead of the rest to prevent infinite
 236        recursion from pcm_play_data */
 237     pcm_paused = !play;
 238
 239     if (pcm_playing && needs_change)
 240     {
 241         if (play)
 242         {
 243             if (pcm_get_bytes_waiting())
 244             {
 245                 logf("unpause");
 246                 pcm_play_pause_unpause();
 247             }
 248             else
 249             {
 250                 logf("unpause, no data waiting");
 251                 if (!pcm_play_data_start(pcm_callback_for_more, NULL, 0))
 252                 {
 253                     pcm_play_dma_stop();
 254                     logf("unpause attempted, no data");
 255                 }
 256             }
 257         }
 258         else
 259         {
 260             logf("pause");
 261             pcm_play_pause_pause();
 262         }
 263     } /* pcm_playing && needs_change */
 264 }
 265
 266 void pcm_play_stop(void)
 267 {
 268     if (pcm_playing)
 269         pcm_play_dma_stop();
 270 }
 271
 272 bool pcm_is_playing(void)
 273 {
 274     return pcm_playing;
 275 }
 276
 277 bool pcm_is_paused(void)
 278 {
 279     return pcm_paused;
 280 }
 281