1.1 --- a/src/audio/SDL_audio.c Tue Aug 12 01:03:05 2008 +0000
1.2 +++ b/src/audio/SDL_audio.c Wed Aug 13 02:50:10 2008 +0000
1.3 @@ -319,6 +319,10 @@
1.4 void *udata;
1.5 void (SDLCALL * fill) (void *userdata, Uint8 * stream, int len);
1.6 int silence;
1.7 +
1.8 + /* For streaming when the buffer sizes don't match up */
1.9 + Uint8 *istream;
1.10 + int istream_len;
1.11
1.12 /* Perform any thread setup */
1.13 device->threadid = SDL_ThreadID();
1.14 @@ -341,52 +345,125 @@
1.15 }
1.16
1.17 /* Determine if the streamer is necessary here */
1.18 + if(device->use_streamer) {
1.19 + /* This code is almost the same as the old code. The difference is, instead of reding
1.20 + directly from the callback into "stream", then converting and sending the audio off,
1.21 + we go: callback -> "istream" -> (conversion) -> streamer -> stream -> device.
1.22 + However, reading and writing with streamer are done separately:
1.23 + - We only call the callback and write to the streamer when the streamer does not
1.24 + contain enough samples to output to the device.
1.25 + - We only read from the streamer and tell the device to play when the streamer
1.26 + does have enough samples to output.
1.27 + This allows us to perform resampling in the conversion step, where the output of the
1.28 + resampling process can be any number. We will have to see what a good size for the
1.29 + stream's maximum length is, but I suspect 2*max(len_cvt, stream_len) is a good figure.
1.30 + */
1.31 + while (device->enabled) {
1.32 + /* Only read in audio if the streamer doesn't have enough already (if it does not have enough samples to output) */
1.33 + if(SDL_StreamLength(&device->streamer) < stream_len) {
1.34 + /* Read from the callback into the _input_ stream */
1.35 + if (!device->paused) {
1.36 + SDL_mutexP(device->mixer_lock);
1.37 + (*fill) (udata, istream, istream_len);
1.38 + SDL_mutexV(device->mixer_lock);
1.39 + }
1.40 +
1.41 + /* Convert the audio if necessary and write to the streamer */
1.42 + if (device->convert.needed) {
1.43 + SDL_ConvertAudio(&device->convert);
1.44 + istream = current_audio.impl.GetDeviceBuf(device);
1.45 + if (istream == NULL) {
1.46 + istream = device->fake_stream;
1.47 + }
1.48 + SDL_memcpy(istream, device->convert.buf, device->convert.len_cvt);
1.49 + SDL_StreamWrite(&device->streamer, istream, device->convert.len_cvt);
1.50 + } else {
1.51 + SDL_StreamWrite(&device->streamer, istream, istream_len);
1.52 + }
1.53 + }
1.54 +
1.55 + /* Only output audio if the streamer has enough to output */
1.56 + if(SDL_StreamLength(&device->streamer) >= stream_len) {
1.57 + /* Set up the output stream */
1.58 + if (device->convert.needed) {
1.59 + if (device->convert.buf) {
1.60 + stream = device->convert.buf;
1.61 + } else {
1.62 + continue;
1.63 + }
1.64 + } else {
1.65 + stream = current_audio.impl.GetDeviceBuf(device);
1.66 + if (stream == NULL) {
1.67 + stream = device->fake_stream;
1.68 + }
1.69 + }
1.70 +
1.71 + /* Now read from the streamer */
1.72 + SDL_StreamRead(&device->streamer, stream, stream_len);
1.73 +
1.74 + /* Ready current buffer for play and change current buffer */
1.75 + if (stream != device->fake_stream) {
1.76 + current_audio.impl.PlayDevice(device);
1.77 + }
1.78
1.79 - /* Loop, filling the audio buffers */
1.80 - while (device->enabled) {
1.81 + /* Wait for an audio buffer to become available */
1.82 + if (stream == device->fake_stream) {
1.83 + SDL_Delay((device->spec.samples * 1000) / device->spec.freq);
1.84 + } else {
1.85 + current_audio.impl.WaitDevice(device);
1.86 + }
1.87 + }
1.88 +
1.89 + }
1.90 + } else {
1.91 + /* Otherwise, do not use the streamer. This is the old code. */
1.92 +
1.93 + /* Loop, filling the audio buffers */
1.94 + while (device->enabled) {
1.95
1.96 - /* Fill the current buffer with sound */
1.97 - if (device->convert.needed) {
1.98 - if (device->convert.buf) {
1.99 - stream = device->convert.buf;
1.100 - } else {
1.101 - continue;
1.102 - }
1.103 - } else {
1.104 - stream = current_audio.impl.GetDeviceBuf(device);
1.105 - if (stream == NULL) {
1.106 - stream = device->fake_stream;
1.107 - }
1.108 - }
1.109 + /* Fill the current buffer with sound */
1.110 + if (device->convert.needed) {
1.111 + if (device->convert.buf) {
1.112 + stream = device->convert.buf;
1.113 + } else {
1.114 + continue;
1.115 + }
1.116 + } else {
1.117 + stream = current_audio.impl.GetDeviceBuf(device);
1.118 + if (stream == NULL) {
1.119 + stream = device->fake_stream;
1.120 + }
1.121 + }
1.122
1.123 - if (!device->paused) {
1.124 - SDL_mutexP(device->mixer_lock);
1.125 - (*fill) (udata, stream, stream_len);
1.126 - SDL_mutexV(device->mixer_lock);
1.127 - }
1.128 + if (!device->paused) {
1.129 + SDL_mutexP(device->mixer_lock);
1.130 + (*fill) (udata, stream, stream_len);
1.131 + SDL_mutexV(device->mixer_lock);
1.132 + }
1.133
1.134 - /* Convert the audio if necessary */
1.135 - if (device->convert.needed) {
1.136 - SDL_ConvertAudio(&device->convert);
1.137 - stream = current_audio.impl.GetDeviceBuf(device);
1.138 - if (stream == NULL) {
1.139 - stream = device->fake_stream;
1.140 - }
1.141 - SDL_memcpy(stream, device->convert.buf, device->convert.len_cvt);
1.142 - }
1.143 + /* Convert the audio if necessary */
1.144 + if (device->convert.needed) {
1.145 + SDL_ConvertAudio(&device->convert);
1.146 + stream = current_audio.impl.GetDeviceBuf(device);
1.147 + if (stream == NULL) {
1.148 + stream = device->fake_stream;
1.149 + }
1.150 + SDL_memcpy(stream, device->convert.buf, device->convert.len_cvt);
1.151 + }
1.152
1.153 - /* Ready current buffer for play and change current buffer */
1.154 - if (stream != device->fake_stream) {
1.155 - current_audio.impl.PlayDevice(device);
1.156 - }
1.157 + /* Ready current buffer for play and change current buffer */
1.158 + if (stream != device->fake_stream) {
1.159 + current_audio.impl.PlayDevice(device);
1.160 + }
1.161
1.162 - /* Wait for an audio buffer to become available */
1.163 - if (stream == device->fake_stream) {
1.164 - SDL_Delay((device->spec.samples * 1000) / device->spec.freq);
1.165 - } else {
1.166 - current_audio.impl.WaitDevice(device);
1.167 - }
1.168 - }
1.169 + /* Wait for an audio buffer to become available */
1.170 + if (stream == device->fake_stream) {
1.171 + SDL_Delay((device->spec.samples * 1000) / device->spec.freq);
1.172 + } else {
1.173 + current_audio.impl.WaitDevice(device);
1.174 + }
1.175 + }
1.176 + }
1.177
1.178 /* Wait for the audio to drain.. */
1.179 current_audio.impl.WaitDone(device);
2.1 --- a/src/audio/SDL_sysaudio.h Tue Aug 12 01:03:05 2008 +0000
2.2 +++ b/src/audio/SDL_sysaudio.h Wed Aug 13 02:50:10 2008 +0000
2.3 @@ -68,6 +68,7 @@
2.4 SDL_AudioDriverImpl impl;
2.5 } SDL_AudioDriver;
2.6
2.7 +
2.8 /* Streamer */
2.9 typedef struct
2.10 {