From c7c0b86afa255983db3def0a15e1201455ade460 Mon Sep 17 00:00:00 2001 From: Tom Rondeau Date: Sat, 30 Oct 2010 16:29:27 -0400 Subject: [PATCH] Added a check in alsa sink if error has occurred due to blocking; if so, it will just drop samples and not get backed up. Patch taken from Marcus Leech 10/29/2010. --- gr-audio-alsa/src/audio_alsa_sink.cc | 12 +++++++++--- gr-audio-alsa/src/audio_alsa_sink.h | 1 + 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/gr-audio-alsa/src/audio_alsa_sink.cc b/gr-audio-alsa/src/audio_alsa_sink.cc index d6b7f84c..c28e23fe 100644 --- a/gr-audio-alsa/src/audio_alsa_sink.cc +++ b/gr-audio-alsa/src/audio_alsa_sink.cc @@ -90,7 +90,7 @@ audio_alsa_sink::audio_alsa_sink (int sampling_rate, d_period_size (0), d_buffer_size_bytes (0), d_buffer (0), d_worker (0), d_special_case_mono_to_stereo (false), - d_nunderuns (0), d_nsuspends (0) + d_nunderuns (0), d_nsuspends (0), d_ok_to_block(ok_to_block) { CHATTY_DEBUG = gr_prefs::singleton()->get_bool("audio_alsa", "verbose", false); @@ -100,6 +100,8 @@ audio_alsa_sink::audio_alsa_sink (int sampling_rate, // open the device for playback error = snd_pcm_open(&d_pcm_handle, d_device_name.c_str (), SND_PCM_STREAM_PLAYBACK, 0); + if (ok_to_block == false) + snd_pcm_nonblock(d_pcm_handle, !ok_to_block); if (error < 0){ fprintf (stderr, "audio_alsa_sink[%s]: %s\n", d_device_name.c_str(), snd_strerror(error)); @@ -287,7 +289,6 @@ audio_alsa_sink::check_topology (int ninputs, int noutputs) default: assert (0); } - return true; } @@ -489,7 +490,12 @@ audio_alsa_sink::write_buffer (const void *vbuffer, while (nframes > 0){ int r = snd_pcm_writei (d_pcm_handle, buffer, nframes); if (r == -EAGAIN) - continue; // try again + { + if (d_ok_to_block == true) + continue; // try again + + break; + } else if (r == -EPIPE){ // underrun d_nunderuns++; diff --git a/gr-audio-alsa/src/audio_alsa_sink.h b/gr-audio-alsa/src/audio_alsa_sink.h index d4b54038..f3007f60 100644 --- a/gr-audio-alsa/src/audio_alsa_sink.h +++ b/gr-audio-alsa/src/audio_alsa_sink.h @@ -83,6 +83,7 @@ class audio_alsa_sink : public gr_sync_block { // random stats int d_nunderuns; // count of underruns int d_nsuspends; // count of suspends + bool d_ok_to_block; // defaults to "true", controls blocking/non-block I/O void output_error_msg (const char *msg, int err); void bail (const char *msg, int err) throw (std::runtime_error); -- 2.30.2