void end_audio_frame() {
if (frame_offset == 0)
// No audio added; blip_end_frame() dislikes being called with an
// offset of 0
return;
assert(!(is_backwards_frame && frame_offset != get_frame_len()));
// Bring the signal level at the end of the frame to zero as outlined in
// set_audio_signal_level()
set_audio_signal_level(0);
blip_end_frame(blip, frame_offset);
if (playback_started) {
// Fudge playback rate by an amount proportional to the difference
// between the desired and current buffer fill levels to try to steer
// towards it
double const fudge_factor = 1.0 + 2*max_adjust*(0.5 - fill_level());
blip_set_rates(blip, cpu_clock_rate, sample_rate*fudge_factor);
}
else {
if (fill_level() >= 0.5) {
start_audio_playback();
playback_started = true;
}
}
int const n_samples = blip_read_samples(blip, blip_samples, ARRAY_LEN(blip_samples), 0);
// We expect to read all samples from blip_buf. If something goes wrong and
// we don't, clear the buffer to prevent data piling up in blip_buf's
// buffer (which lacks bounds checking).
int const avail = blip_samples_avail(blip);
if (avail != 0) {
printf("Warning: didn't read all samples from blip_buf (%d samples remain) - dropping samples\n",
avail);
blip_clear(blip);
}
#ifdef RECORD_MOVIE
add_movie_audio_frame(blip_samples, n_samples);
#endif
// Save the samples to the audio ring buffer
lock_audio();
write_samples(blip_samples, n_samples);
unlock_audio();
}
static void feed_data(GstElement * appsrc, guint size_hint, void *unused)
{
(void)size_hint;
(void)unused;
lock_audio();
/* Make sure we don't trigger a gst_element_set_state() call
from inside gstreamer's stream thread as it will deadlock */
inside_feed_data = 1;
pcm_play_get_more_callback((void **)&pcm_data, &pcm_data_size);
if (pcm_data_size != 0)
{
GstBuffer *buffer = gst_buffer_new ();
GstFlowReturn ret;
GST_BUFFER_DATA (buffer) = pcm_data;
GST_BUFFER_SIZE (buffer) = pcm_data_size;
g_signal_emit_by_name (appsrc, "push-buffer", buffer, &ret);
gst_buffer_unref (buffer);
if (ret != 0)
DEBUGF("push-buffer error result: %d\n", ret);
pcm_play_dma_started_callback();
} else
{
DEBUGF("feed_data: No Data.\n");
g_signal_emit_by_name (appsrc, "end-of-stream", NULL);
}
inside_feed_data = 0;
unlock_audio();
}
void pcm_play_unlock(void)
{
if (--audio_locked == 0)
unlock_audio();
}