From b2c7bb0b283dd2a80f345e26c042d6ffaf05209c Mon Sep 17 00:00:00 2001
From: chai <chaifix@163.com>
Date: Sun, 22 Jul 2018 12:28:03 +0800
Subject: update

---
 src/libjin/audio/sdl/audio.cpp | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

(limited to 'src/libjin/audio/sdl/audio.cpp')

diff --git a/src/libjin/audio/sdl/audio.cpp b/src/libjin/audio/sdl/audio.cpp
index be4caa2..79ca3f2 100644
--- a/src/libjin/audio/sdl/audio.cpp
+++ b/src/libjin/audio/sdl/audio.cpp
@@ -1,6 +1,7 @@
 #include <iostream>
 #include "audio.h"
 #include "source.h"
+#include "../../math/math.h"
 
 namespace jin
 {
@@ -8,9 +9,9 @@ namespace audio
 {
 
     /* 注意callback是在音频线程调用 */
-    void defaultCallback(void *userdata, Uint8 *stream, int size)
+    static void defaultCallback(void *userdata, Uint8 *stream, int size)
     {
-        SDLAudio* audio = static_cast<SDLAudio*>(userdata);
+        static SDLAudio* audio = static_cast<SDLAudio*>(userdata);
         audio->lock();
         audio->processCommands();
         audio->processSources(stream, size);
@@ -22,14 +23,21 @@ namespace audio
         if (SDL_Init(SDL_INIT_AUDIO) < 0)
             return false;
         SDL_AudioSpec spec;
-        spec.freq     = 44100;        // 44100 Hz
-        spec.format   = AUDIO_S16SYS; // signed 16bits
-        spec.channels = 2;            // 立体声
-        spec.samples  = 1 << 15;      // Uin16范围内最大的2的幂
+        Setting* setting = (Setting*)s;
+        if (setting == nullptr)
+            return false;
+
+        unsigned int samplerate = setting->samplerate;
+        unsigned int samples = clamp(setting->samples, 1, setting->samplerate);
+
+        spec.freq     = samplerate;        // 每秒采样的sample数,常用的有 11025, 22050, 44100 and 48000 Hz. 
+        spec.format   = AUDIO_S16SYS;      // signed 16-bit samples in native byte order
+        spec.channels = SDLAUDIO_CHANNELS; // 立体声
+        spec.samples  = samples;           // 每次采样时都一次性填充好，如果=setting->samplerate则每秒只调用1次
         spec.userdata = this;
         spec.callback = defaultCallback;
 
-        audioDevice = SDL_OpenAudioDevice(NULL, 0, &spec, NULL, 0); 
+        audioDevice = SDL_OpenAudioDevice(NULL, 0, &spec, NULL, 0);
         if (audioDevice == 0)
             return false;
         /* start audio */
-- 
cgit v1.1-26-g67d0