virtual HRESULT RenderAudioSamples (bool preroll)
{
guint8 *ptr;
gint seg;
gint len;
gint bpf;
guint written, written_sum;
HRESULT res;
GST_LOG_OBJECT (m_ringbuffer->sink, "Writing audio samples (preroll: %d)",
preroll);
if (!gst_audio_ring_buffer_prepare_read (GST_AUDIO_RING_BUFFER_CAST
(m_ringbuffer), &seg, &ptr, &len)) {
GST_WARNING_OBJECT (m_ringbuffer->sink, "No segment available");
return E_FAIL;
}
bpf =
GST_AUDIO_INFO_BPF (&GST_AUDIO_RING_BUFFER_CAST (m_ringbuffer)->
spec.info);
len /= bpf;
GST_LOG_OBJECT (m_ringbuffer->sink,
"Write audio samples: %p size %d segment: %d", ptr, len, seg);
written_sum = 0;
do {
res =
m_ringbuffer->output->output->ScheduleAudioSamples (ptr, len,
0, 0, &written);
len -= written;
ptr += written * bpf;
written_sum += written;
} while (len > 0 && res == S_OK);
GST_LOG_OBJECT (m_ringbuffer->sink, "Wrote %u samples: 0x%08x", written_sum,
res);
gst_audio_ring_buffer_clear (GST_AUDIO_RING_BUFFER_CAST (m_ringbuffer),
seg);
gst_audio_ring_buffer_advance (GST_AUDIO_RING_BUFFER_CAST (m_ringbuffer),
1);
return res;
}
static GstAudioRingBuffer *
gst_decklink_audio_sink_create_ringbuffer (GstAudioBaseSink * absink)
{
GstAudioRingBuffer *ret;
GST_DEBUG_OBJECT (absink, "Creating ringbuffer");
ret =
GST_AUDIO_RING_BUFFER_CAST (g_object_new
(GST_TYPE_DECKLINK_AUDIO_SINK_RING_BUFFER, NULL));
GST_DECKLINK_AUDIO_SINK_RING_BUFFER_CAST (ret)->sink =
(GstDecklinkAudioSink *) gst_object_ref (absink);
return ret;
}
/* this is the callback of jack. This should RT-safe.
*/
static int
jack_process_cb (jack_nframes_t nframes, void *arg)
{
GstJackAudioSink *sink;
GstAudioRingBuffer *buf;
gint readseg, len;
guint8 *readptr;
gint i, j, flen, channels;
sample_t *data;
buf = GST_AUDIO_RING_BUFFER_CAST (arg);
sink = GST_JACK_AUDIO_SINK (GST_OBJECT_PARENT (buf));
channels = GST_AUDIO_INFO_CHANNELS (&buf->spec.info);
/* get target buffers */
for (i = 0; i < channels; i++) {
sink->buffers[i] =
(sample_t *) jack_port_get_buffer (sink->ports[i], nframes);
}
if (gst_audio_ring_buffer_prepare_read (buf, &readseg, &readptr, &len)) {
flen = len / channels;
/* the number of samples must be exactly the segment size */
if (nframes * sizeof (sample_t) != flen)
goto wrong_size;
GST_DEBUG_OBJECT (sink, "copy %d frames: %p, %d bytes, %d channels",
nframes, readptr, flen, channels);
data = (sample_t *) readptr;
/* the samples in the ringbuffer have the channels interleaved, we need to
* deinterleave into the jack target buffers */
for (i = 0; i < nframes; i++) {
for (j = 0; j < channels; j++) {
sink->buffers[j][i] = *data++;
}
}
/* clear written samples in the ringbuffer */
gst_audio_ring_buffer_clear (buf, readseg);
/* we wrote one segment */
gst_audio_ring_buffer_advance (buf, 1);
} else {
GST_DEBUG_OBJECT (sink, "write %d frames silence", nframes);
/* We are not allowed to read from the ringbuffer, write silence to all
* jack output buffers */
for (i = 0; i < channels; i++) {
memset (sink->buffers[i], 0, nframes * sizeof (sample_t));
}
}
return 0;
/* ERRORS */
wrong_size:
{
GST_ERROR_OBJECT (sink, "nbytes (%d) != flen (%d)",
(gint) (nframes * sizeof (sample_t)), flen);
return 1;
}
}
