1 files changed, 129 insertions, 0 deletions
diff --git a/audio/out/ao_null.c b/audio/out/ao_null.c
new file mode 100644
index 0000000000..87f11a51b6
--- /dev/null
+++ b/audio/out/ao_null.c
@@ -0,0 +1,129 @@
+/*
+ * null audio output driver
+ *
+ * This file is part of MPlayer.
+ *
+ * MPlayer is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * MPlayer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with MPlayer; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "talloc.h"
+
+#include "config.h"
+#include "osdep/timer.h"
+#include "libaf/format.h"
+#include "audio_out.h"
+
+struct priv {
+    unsigned last_time;
+    float buffered_bytes;
+};
+
+static void drain(struct ao *ao)
+{
+    struct priv *priv = ao->priv;
+
+    unsigned now = GetTimer();
+    priv->buffered_bytes -= (now - priv->last_time) / 1e6 * ao->bps;
+    if (priv->buffered_bytes < 0)
+        priv->buffered_bytes = 0;
+    priv->last_time = now;
+}
+
+static int init(struct ao *ao, char *params)
+{
+    struct priv *priv = talloc_zero(ao, struct priv);
+    ao->priv = priv;
+    int samplesize = af_fmt2bits(ao->format) / 8;
+    ao->outburst = 256 * ao->channels * samplesize;
+    // A "buffer" for about 0.2 seconds of audio
+    ao->buffersize = (int)(ao->samplerate * 0.2 / 256 + 1) * ao->outburst;
+    ao->bps = ao->channels * ao->samplerate * samplesize;
+    priv->last_time = GetTimer();
+
+    return 0;
+}
+
+// close audio device
+static void uninit(struct ao *ao, bool cut_audio)
+{
+}
+
+// stop playing and empty buffers (for seeking/pause)
+static void reset(struct ao *ao)
+{
+    struct priv *priv = ao->priv;
+    priv->buffered_bytes = 0;
+}
+
+// stop playing, keep buffers (for pause)
+static void pause(struct ao *ao)
+{
+    // for now, just call reset();
+    reset(ao);
+}
+
+// resume playing, after audio_pause()
+static void resume(struct ao *ao)
+{
+}
+
+static int get_space(struct ao *ao)
+{
+    struct priv *priv = ao->priv;
+
+    drain(ao);
+    return ao->buffersize - priv->buffered_bytes;
+}
+
+static int play(struct ao *ao, void *data, int len, int flags)
+{
+    struct priv *priv = ao->priv;
+
+    int maxbursts = (ao->buffersize - priv->buffered_bytes) / ao->outburst;
+    int playbursts = len / ao->outburst;
+    int bursts = playbursts > maxbursts ? maxbursts : playbursts;
+    priv->buffered_bytes += bursts * ao->outburst;
+    return bursts * ao->outburst;
+}
+
+static float get_delay(struct ao *ao)
+{
+    struct priv *priv = ao->priv;
+
+    drain(ao);
+    return priv->buffered_bytes / ao->bps;
+}
+
+const struct ao_driver audio_out_null = {
+    .is_new = true,
+    .info = &(const struct ao_info) {
+        "Null audio output",
+        "null",
+        "Tobias Diedrich <ranma+mplayer@tdiedrich.de>",
+        "",
+    },
+    .init      = init,
+    .uninit    = uninit,
+    .reset     = reset,
+    .get_space = get_space,
+    .play      = play,
+    .get_delay = get_delay,
+    .pause     = pause,
+    .resume    = resume,
+};
+