arts: backed out audio capture support.

Turns out that libartsc isn't thread-safe, so if we run a capture and playback
device at the same time, it often crashes in arts's internal event loop.

We could throw mutexes around the read/write calls, but these are meant to
block, so one device could cause serious latency and stutter in the other.

Since this audio target isn't in high-demand (Ubuntu hasn't offered a libartsc
package for years), I'm just backing out the capture support. If someone needs
it, they can pull it out of the revision history.

src/audio/arts/SDL_artsaudio.c

@@ -54,16 +54,12 @@ static void (*SDL_NAME(arts_free)) (void);
 static arts_stream_t(*SDL_NAME(arts_play_stream)) (int rate, int bits,
                                                    int channels,
                                                    const char *name);
-static arts_stream_t(*SDL_NAME(arts_record_stream)) (int rate, int bits,
-                                                   int channels,
-                                                   const char *name);
 static int (*SDL_NAME(arts_stream_set)) (arts_stream_t s,
                                          arts_parameter_t param, int value);
 static int (*SDL_NAME(arts_stream_get)) (arts_stream_t s,
                                          arts_parameter_t param);
 static int (*SDL_NAME(arts_write)) (arts_stream_t s, const void *buffer,
                                     int count);
-static int (*SDL_NAME(arts_read)) (arts_stream_t s, void *buffer, int count);
 static void (*SDL_NAME(arts_close_stream)) (arts_stream_t s);
 static int (*SDL_NAME(arts_suspend))(void);
 static int (*SDL_NAME(arts_suspended)) (void);
@@ -79,11 +75,9 @@ static struct
     SDL_ARTS_SYM(arts_init),
     SDL_ARTS_SYM(arts_free),
     SDL_ARTS_SYM(arts_play_stream),
-    SDL_ARTS_SYM(arts_record_stream),
     SDL_ARTS_SYM(arts_stream_set),
     SDL_ARTS_SYM(arts_stream_get),
     SDL_ARTS_SYM(arts_write),
-    SDL_ARTS_SYM(arts_read),
     SDL_ARTS_SYM(arts_close_stream),
     SDL_ARTS_SYM(arts_suspend),
     SDL_ARTS_SYM(arts_suspended),
@@ -205,27 +199,6 @@ ARTS_GetDeviceBuf(_THIS)
     return (this->hidden->mixbuf);
 }
 
-static int
-ARTS_CaptureFromDevice(_THIS, void *buffer, int buflen)
-{
-    return SDL_NAME(arts_read) (this->hidden->stream, buffer, buflen);
-}
-
-static void
-ARTS_FlushCapture(_THIS)
-{
-    arts_stream_t stream = this->hidden->stream;
-    int remain = SDL_NAME(arts_stream_get)(stream, ARTS_P_BUFFER_SPACE);
-    Uint8 buf[512];
-    while (remain > 0) {
-        const int len = SDL_min(sizeof (buf), remain);
-        const int br = SDL_NAME(arts_read)(stream, buf, len);
-        if (br <= 0) {
-            return;  /* oh well. */
-        }
-        remain -= br;
-    }
-}
 
 static void
 ARTS_CloseDevice(_THIS)
@@ -305,20 +278,19 @@ ARTS_OpenDevice(_THIS, void *handle, const char *devname, int iscapture)
                             SDL_NAME(arts_error_text) (rc));
     }
 
-    if (iscapture) {
-        this->hidden->stream = SDL_NAME(arts_record_stream) (this->spec.freq,
-                                                             bits,
-                                                             this->spec.channels,
-                                                             "SDL");
-    } else {
-        this->hidden->stream = SDL_NAME(arts_play_stream) (this->spec.freq,
-                                                           bits,
-                                                           this->spec.channels,
-                                                           "SDL");
-        /* Play nothing so we have at least one write (server bug workaround). */
-        SDL_NAME(arts_write) (this->hidden->stream, "", 0);
+    if (!ARTS_Suspend()) {
+        ARTS_CloseDevice(this);
+        return SDL_SetError("ARTS can not open audio device");
     }
 
+    this->hidden->stream = SDL_NAME(arts_play_stream) (this->spec.freq,
+                                                       bits,
+                                                       this->spec.channels,
+                                                       "SDL");
+
+    /* Play nothing so we have at least one write (server bug workaround). */
+    SDL_NAME(arts_write) (this->hidden->stream, "", 0);
+
     /* Calculate the final parameters for this audio specification */
     SDL_CalculateAudioSpec(&this->spec);
 
@@ -397,12 +369,7 @@ ARTS_Init(SDL_AudioDriverImpl * impl)
     impl->CloseDevice = ARTS_CloseDevice;
     impl->WaitDone = ARTS_WaitDone;
     impl->Deinitialize = ARTS_Deinitialize;
-    impl->CaptureFromDevice = ARTS_CaptureFromDevice;
-    impl->FlushCapture = ARTS_FlushCapture;
-
     impl->OnlyHasDefaultOutputDevice = 1;
-    impl->OnlyHasDefaultInputDevice = 1;
-    impl->HasCaptureSupport = 1;
 
     return 1;   /* this audio target is available. */
 }