[vlc-devel] [vlc-commits] pulse: follow PulseAudio write requests
Thomas Guillem
thomas at gllm.fr
Tue Mar 19 18:56:25 CET 2019
On Tue, Mar 19, 2019, at 18:17, Thomas Guillem wrote:
>
> On Tue, Mar 19, 2019, at 17:22, Thomas Guillem wrote:
> > Reverted with a force push, this cause an underflow on startup (just
> > after a flush).
>
> OK, it was a small problem: when 2 flush were called in a row, the
> second one reseted the write_request count to 0.
Naup, it's still not good with some input: reverted until I found the real issue.
>
> >
> > On Tue, Mar 19, 2019, at 16:03, Thomas Guillem wrote:
> > > vlc | branch: master | Thomas Guillem <thomas at gllm.fr> | Tue Mar 19
> > > 13:51:15 2019 +0100| [e8633b41c86516e2f5c91b2eec05f99e1d3ecd8a] |
> > > committer: Thomas Guillem
> > >
> > > pulse: follow PulseAudio write requests
> > >
> > > Wait from Play() if the server don't ask for more data (like every other aout
> > > modules).
> > >
> > > Note: tlength (target length of the buffer) is increased from 120ms to 2s.
> > > Before this commit, the average audio delay (time_get) was around 500ms (file
> > > caching and input dependant). If we don't increase it, the delay of the stream
> > > will be arround 120ms (since we now follow PulseAudio write requests). Setting
> > > tlength to 2sec will restore the previous time_get behavior: delay of arround
> > > 500ms, and always lower than 2sec (when file-caching is increased). This fixes
> > > potential overflow.
> > >
> > > > http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=e8633b41c86516e2f5c91b2eec05f99e1d3ecd8a
> > > ---
> > >
> > > modules/audio_output/pulse.c | 27 ++++++++++++++++++++++++++-
> > > 1 file changed, 26 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/modules/audio_output/pulse.c b/modules/audio_output/pulse.c
> > > index cc4af1e8c0..961fa7129a 100644
> > > --- a/modules/audio_output/pulse.c
> > > +++ b/modules/audio_output/pulse.c
> > > @@ -69,6 +69,7 @@ typedef struct
> > > pa_time_event *trigger; /**< Deferred stream trigger */
> > > pa_cvolume cvolume; /**< actual sink input volume */
> > > vlc_tick_t last_date; /**< Play system timestamp of last buffer */
> > > + size_t write_request; /**< Write request from PulseAudio */
> > >
> > > pa_volume_t volume_force; /**< Forced volume (stream must be NULL)
> > > */
> > > pa_stream_flags_t flags_force; /**< Forced flags (stream must be
> > > NULL) */
> > > @@ -357,6 +358,15 @@ static void stream_underflow_cb(pa_stream *s, void
> > > *userdata)
> > > (void) s;
> > > }
> > >
> > > +static void stream_request_cb(pa_stream *s, size_t nbytes, void
> > > *userdata)
> > > +{
> > > + audio_output_t *aout = userdata;
> > > + aout_sys_t *sys = aout->sys;
> > > +
> > > + sys->write_request = nbytes;
> > > + pa_threaded_mainloop_signal(sys->mainloop, 0);
> > > +}
> > > +
> > > static int stream_wait(pa_stream *stream, pa_threaded_mainloop
> > > *mainloop)
> > > {
> > > pa_stream_state_t state;
> > > @@ -491,6 +501,13 @@ static void Play(audio_output_t *aout, block_t
> > > *block, vlc_tick_t date)
> > > void *ptr;
> > > size_t len = block->i_buffer;
> > >
> > > + while (sys->write_request == 0)
> > > + pa_threaded_mainloop_wait(sys->mainloop);
> > > +
> > > + if (len > sys->write_request)
> > > + len = sys->write_request;
> > > + sys->write_request -= len;
> > > +
> > > if (pa_stream_begin_write(s, &ptr, &len))
> > > vlc_pa_error(aout, "cannot begin write", sys->context);
> > >
> > > @@ -540,6 +557,8 @@ static void Flush(audio_output_t *aout)
> > >
> > > pa_threaded_mainloop_lock(sys->mainloop);
> > >
> > > + sys->write_request = 0;
> > > +
> > > pa_operation *op = pa_stream_flush(s, NULL, NULL);
> > > if (op != NULL)
> > > pa_operation_unref(op);
> > > @@ -555,6 +574,9 @@ static void Drain(audio_output_t *aout)
> > > pa_stream *s = sys->stream;
> > >
> > > pa_threaded_mainloop_lock(sys->mainloop);
> > > +
> > > + sys->write_request = 0;
> > > +
> > > pa_operation *op = pa_stream_drain(s, NULL, NULL);
> > > if (op != NULL)
> > > pa_operation_unref(op);
> > > @@ -778,7 +800,7 @@ static int Start(audio_output_t *aout,
> > > audio_sample_format_t *restrict fmt)
> > > /* PulseAudio goes berserk if the target length (tlength) is not
> > > * significantly longer than 2 periods (minreq), or when the
> > > period length
> > > * is unspecified and the target length is short. */
> > > - attr.tlength = pa_usec_to_bytes(3 * AOUT_MIN_PREPARE_TIME, &ss);
> > > + attr.tlength = pa_usec_to_bytes(AOUT_MAX_PREPARE_TIME, &ss);
> > > attr.prebuf = 0; /* trigger manually */
> > > attr.minreq = pa_usec_to_bytes(AOUT_MIN_PREPARE_TIME, &ss);
> > > attr.fragsize = 0; /* not used for output */
> > > @@ -790,6 +812,7 @@ static int Start(audio_output_t *aout,
> > > audio_sample_format_t *restrict fmt)
> > > pa_cvolume_set(cvolume, ss.channels, sys->volume_force);
> > > }
> > >
> > > + sys->write_request = 0;
> > > sys->trigger = NULL;
> > > pa_cvolume_init(&sys->cvolume);
> > > sys->last_date = VLC_TICK_INVALID;
> > > @@ -919,6 +942,7 @@ static int Start(audio_output_t *aout,
> > > audio_sample_format_t *restrict fmt)
> > > pa_stream_set_started_callback(s, stream_started_cb, aout);
> > > pa_stream_set_suspended_callback(s, stream_suspended_cb, aout);
> > > pa_stream_set_underflow_callback(s, stream_underflow_cb, aout);
> > > + pa_stream_set_write_callback(s, stream_request_cb, aout);
> > >
> > > if (pa_stream_connect_playback(s, sys->sink_force, &attr, flags,
> > > cvolume, NULL) < 0
> > > @@ -976,6 +1000,7 @@ static void Stop(audio_output_t *aout)
> > > pa_stream_set_started_callback(s, NULL, NULL);
> > > pa_stream_set_suspended_callback(s, NULL, NULL);
> > > pa_stream_set_underflow_callback(s, NULL, NULL);
> > > + pa_stream_set_write_callback(s, NULL, NULL);
> > >
> > > pa_stream_unref(s);
> > > sys->stream = NULL;
> > >
> > > _______________________________________________
> > > vlc-commits mailing list
> > > vlc-commits at videolan.org
> > > https://mailman.videolan.org/listinfo/vlc-commits
> > >
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