/* GStreamer * Copyright (C) 1999,2000 Erik Walthinsen * 2005 Wim Taymans * * gstaudiobasesrc.c: * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, * Boston, MA 02110-1301, USA. */ /** * SECTION:gstaudiobasesrc * @title: GstAudioBaseSrc * @short_description: Base class for audio sources * @see_also: #GstAudioSrc, #GstAudioRingBuffer. * * This is the base class for audio sources. Subclasses need to implement the * ::create_ringbuffer vmethod. This base class will then take care of * reading samples from the ringbuffer, synchronisation and flushing. */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include "gstaudiobasesrc.h" #include GST_DEBUG_CATEGORY_STATIC (gst_audio_base_src_debug); #define GST_CAT_DEFAULT gst_audio_base_src_debug struct _GstAudioBaseSrcPrivate { /* the clock slaving algorithm in use */ GstAudioBaseSrcSlaveMethod slave_method; }; /* BaseAudioSrc signals and args */ enum { /* FILL ME */ LAST_SIGNAL }; /* FIXME: 2.0, handle BUFFER_TIME and LATENCY in nanoseconds */ #define DEFAULT_BUFFER_TIME ((200 * GST_MSECOND) / GST_USECOND) #define DEFAULT_LATENCY_TIME ((10 * GST_MSECOND) / GST_USECOND) #define DEFAULT_ACTUAL_BUFFER_TIME -1 #define DEFAULT_ACTUAL_LATENCY_TIME -1 #define DEFAULT_PROVIDE_CLOCK TRUE #define DEFAULT_SLAVE_METHOD GST_AUDIO_BASE_SRC_SLAVE_SKEW enum { PROP_0, PROP_BUFFER_TIME, PROP_LATENCY_TIME, PROP_ACTUAL_BUFFER_TIME, PROP_ACTUAL_LATENCY_TIME, PROP_PROVIDE_CLOCK, PROP_SLAVE_METHOD, PROP_LAST }; static void _do_init (GType type) { GST_DEBUG_CATEGORY_INIT (gst_audio_base_src_debug, "audiobasesrc", 0, "audiobasesrc element"); #ifdef ENABLE_NLS GST_DEBUG ("binding text domain %s to locale dir %s", GETTEXT_PACKAGE, LOCALEDIR); bindtextdomain (GETTEXT_PACKAGE, LOCALEDIR); bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8"); #endif /* ENABLE_NLS */ } #define gst_audio_base_src_parent_class parent_class G_DEFINE_TYPE_WITH_CODE (GstAudioBaseSrc, gst_audio_base_src, GST_TYPE_PUSH_SRC, G_ADD_PRIVATE (GstAudioBaseSrc) _do_init (g_define_type_id)); static void gst_audio_base_src_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec); static void gst_audio_base_src_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec); static void gst_audio_base_src_dispose (GObject * object); static GstStateChangeReturn gst_audio_base_src_change_state (GstElement * element, GstStateChange transition); static gboolean gst_audio_base_src_post_message (GstElement * element, GstMessage * message); static GstClock *gst_audio_base_src_provide_clock (GstElement * elem); static GstClockTime gst_audio_base_src_get_time (GstClock * clock, GstAudioBaseSrc * src); static GstFlowReturn gst_audio_base_src_create (GstBaseSrc * bsrc, guint64 offset, guint length, GstBuffer ** buf); static gboolean gst_audio_base_src_event (GstBaseSrc * bsrc, GstEvent * event); static void gst_audio_base_src_get_times (GstBaseSrc * bsrc, GstBuffer * buffer, GstClockTime * start, GstClockTime * end); static gboolean gst_audio_base_src_setcaps (GstBaseSrc * bsrc, GstCaps * caps); static gboolean gst_audio_base_src_query (GstBaseSrc * bsrc, GstQuery * query); static GstCaps *gst_audio_base_src_fixate (GstBaseSrc * bsrc, GstCaps * caps); /* static guint gst_audio_base_src_signals[LAST_SIGNAL] = { 0 }; */ static void gst_audio_base_src_class_init (GstAudioBaseSrcClass * klass) { GObjectClass *gobject_class; GstElementClass *gstelement_class; GstBaseSrcClass *gstbasesrc_class; gobject_class = (GObjectClass *) klass; gstelement_class = (GstElementClass *) klass; gstbasesrc_class = (GstBaseSrcClass *) klass; gobject_class->set_property = gst_audio_base_src_set_property; gobject_class->get_property = gst_audio_base_src_get_property; gobject_class->dispose = gst_audio_base_src_dispose; /* FIXME: 2.0, handle BUFFER_TIME and LATENCY in nanoseconds */ g_object_class_install_property (gobject_class, PROP_BUFFER_TIME, g_param_spec_int64 ("buffer-time", "Buffer Time", "Size of audio buffer in microseconds. This is the maximum amount " "of data that is buffered in the device and the maximum latency that " "the source reports. This value might be ignored by the element if " "necessary; see \"actual-buffer-time\"", 1, G_MAXINT64, DEFAULT_BUFFER_TIME, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_LATENCY_TIME, g_param_spec_int64 ("latency-time", "Latency Time", "The minimum amount of data to read in each iteration in " "microseconds. This is the minimum latency that the source reports. " "This value might be ignored by the element if necessary; see " "\"actual-latency-time\"", 1, G_MAXINT64, DEFAULT_LATENCY_TIME, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); /** * GstAudioBaseSrc:actual-buffer-time: * * Actual configured size of audio buffer in microseconds. **/ g_object_class_install_property (gobject_class, PROP_ACTUAL_BUFFER_TIME, g_param_spec_int64 ("actual-buffer-time", "Actual Buffer Time", "Actual configured size of audio buffer in microseconds", DEFAULT_ACTUAL_BUFFER_TIME, G_MAXINT64, DEFAULT_ACTUAL_BUFFER_TIME, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS)); /** * GstAudioBaseSrc:actual-latency-time: * * Actual configured audio latency in microseconds. **/ g_object_class_install_property (gobject_class, PROP_ACTUAL_LATENCY_TIME, g_param_spec_int64 ("actual-latency-time", "Actual Latency Time", "Actual configured audio latency in microseconds", DEFAULT_ACTUAL_LATENCY_TIME, G_MAXINT64, DEFAULT_ACTUAL_LATENCY_TIME, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_PROVIDE_CLOCK, g_param_spec_boolean ("provide-clock", "Provide Clock", "Provide a clock to be used as the global pipeline clock", DEFAULT_PROVIDE_CLOCK, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_SLAVE_METHOD, g_param_spec_enum ("slave-method", "Slave Method", "Algorithm used to match the rate of the masterclock", GST_TYPE_AUDIO_BASE_SRC_SLAVE_METHOD, DEFAULT_SLAVE_METHOD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_audio_base_src_change_state); gstelement_class->provide_clock = GST_DEBUG_FUNCPTR (gst_audio_base_src_provide_clock); gstelement_class->post_message = GST_DEBUG_FUNCPTR (gst_audio_base_src_post_message); gstbasesrc_class->set_caps = GST_DEBUG_FUNCPTR (gst_audio_base_src_setcaps); gstbasesrc_class->event = GST_DEBUG_FUNCPTR (gst_audio_base_src_event); gstbasesrc_class->query = GST_DEBUG_FUNCPTR (gst_audio_base_src_query); gstbasesrc_class->get_times = GST_DEBUG_FUNCPTR (gst_audio_base_src_get_times); gstbasesrc_class->create = GST_DEBUG_FUNCPTR (gst_audio_base_src_create); gstbasesrc_class->fixate = GST_DEBUG_FUNCPTR (gst_audio_base_src_fixate); /* ref class from a thread-safe context to work around missing bit of * thread-safety in GObject */ g_type_class_ref (GST_TYPE_AUDIO_CLOCK); g_type_class_ref (GST_TYPE_AUDIO_RING_BUFFER); } static void gst_audio_base_src_init (GstAudioBaseSrc * audiobasesrc) { audiobasesrc->priv = gst_audio_base_src_get_instance_private (audiobasesrc); audiobasesrc->buffer_time = DEFAULT_BUFFER_TIME; audiobasesrc->latency_time = DEFAULT_LATENCY_TIME; if (DEFAULT_PROVIDE_CLOCK) GST_OBJECT_FLAG_SET (audiobasesrc, GST_ELEMENT_FLAG_PROVIDE_CLOCK); else GST_OBJECT_FLAG_UNSET (audiobasesrc, GST_ELEMENT_FLAG_PROVIDE_CLOCK); audiobasesrc->priv->slave_method = DEFAULT_SLAVE_METHOD; /* reset blocksize we use latency time to calculate a more useful * value based on negotiated format. */ GST_BASE_SRC (audiobasesrc)->blocksize = 0; audiobasesrc->clock = gst_audio_clock_new ("GstAudioSrcClock", (GstAudioClockGetTimeFunc) gst_audio_base_src_get_time, audiobasesrc, NULL); /* we are always a live source */ gst_base_src_set_live (GST_BASE_SRC (audiobasesrc), TRUE); /* we operate in time */ gst_base_src_set_format (GST_BASE_SRC (audiobasesrc), GST_FORMAT_TIME); } static void gst_audio_base_src_dispose (GObject * object) { GstAudioBaseSrc *src; src = GST_AUDIO_BASE_SRC (object); GST_OBJECT_LOCK (src); if (src->clock) { gst_audio_clock_invalidate (GST_AUDIO_CLOCK (src->clock)); gst_object_unref (src->clock); src->clock = NULL; } if (src->ringbuffer) { gst_object_unparent (GST_OBJECT_CAST (src->ringbuffer)); src->ringbuffer = NULL; } GST_OBJECT_UNLOCK (src); G_OBJECT_CLASS (parent_class)->dispose (object); } static GstClock * gst_audio_base_src_provide_clock (GstElement * elem) { GstAudioBaseSrc *src; GstClock *clock; src = GST_AUDIO_BASE_SRC (elem); /* we have no ringbuffer (must be NULL state) */ if (src->ringbuffer == NULL) goto wrong_state; if (gst_audio_ring_buffer_is_flushing (src->ringbuffer)) goto wrong_state; GST_OBJECT_LOCK (src); if (!GST_OBJECT_FLAG_IS_SET (src, GST_ELEMENT_FLAG_PROVIDE_CLOCK)) goto clock_disabled; clock = GST_CLOCK_CAST (gst_object_ref (src->clock)); GST_OBJECT_UNLOCK (src); return clock; /* ERRORS */ wrong_state: { GST_DEBUG_OBJECT (src, "ringbuffer is flushing"); return NULL; } clock_disabled: { GST_DEBUG_OBJECT (src, "clock provide disabled"); GST_OBJECT_UNLOCK (src); return NULL; } } static GstClockTime gst_audio_base_src_get_time (GstClock * clock, GstAudioBaseSrc * src) { guint64 raw, samples; guint delay; GstClockTime result; GstAudioRingBuffer *ringbuffer; gint rate; ringbuffer = src->ringbuffer; if (!ringbuffer) return GST_CLOCK_TIME_NONE; rate = ringbuffer->spec.info.rate; if (rate == 0) return GST_CLOCK_TIME_NONE; raw = samples = gst_audio_ring_buffer_samples_done (ringbuffer); /* the number of samples not yet processed, this is still queued in the * device (not yet read for capture). */ delay = gst_audio_ring_buffer_delay (ringbuffer); samples += delay; result = gst_util_uint64_scale_int (samples, GST_SECOND, rate); GST_DEBUG_OBJECT (src, "processed samples: raw %" G_GUINT64_FORMAT ", delay %u, real %" G_GUINT64_FORMAT ", time %" GST_TIME_FORMAT, raw, delay, samples, GST_TIME_ARGS (result)); return result; } /** * gst_audio_base_src_set_provide_clock: * @src: a #GstAudioBaseSrc * @provide: new state * * Controls whether @src will provide a clock or not. If @provide is %TRUE, * gst_element_provide_clock() will return a clock that reflects the datarate * of @src. If @provide is %FALSE, gst_element_provide_clock() will return NULL. */ void gst_audio_base_src_set_provide_clock (GstAudioBaseSrc * src, gboolean provide) { g_return_if_fail (GST_IS_AUDIO_BASE_SRC (src)); GST_OBJECT_LOCK (src); if (provide) GST_OBJECT_FLAG_SET (src, GST_ELEMENT_FLAG_PROVIDE_CLOCK); else GST_OBJECT_FLAG_UNSET (src, GST_ELEMENT_FLAG_PROVIDE_CLOCK); GST_OBJECT_UNLOCK (src); } /** * gst_audio_base_src_get_provide_clock: * @src: a #GstAudioBaseSrc * * Queries whether @src will provide a clock or not. See also * gst_audio_base_src_set_provide_clock. * * Returns: %TRUE if @src will provide a clock. */ gboolean gst_audio_base_src_get_provide_clock (GstAudioBaseSrc * src) { gboolean result; g_return_val_if_fail (GST_IS_AUDIO_BASE_SRC (src), FALSE); GST_OBJECT_LOCK (src); result = GST_OBJECT_FLAG_IS_SET (src, GST_ELEMENT_FLAG_PROVIDE_CLOCK); GST_OBJECT_UNLOCK (src); return result; } /** * gst_audio_base_src_set_slave_method: * @src: a #GstAudioBaseSrc * @method: the new slave method * * Controls how clock slaving will be performed in @src. */ void gst_audio_base_src_set_slave_method (GstAudioBaseSrc * src, GstAudioBaseSrcSlaveMethod method) { g_return_if_fail (GST_IS_AUDIO_BASE_SRC (src)); GST_OBJECT_LOCK (src); src->priv->slave_method = method; GST_OBJECT_UNLOCK (src); } /** * gst_audio_base_src_get_slave_method: * @src: a #GstAudioBaseSrc * * Get the current slave method used by @src. * * Returns: The current slave method used by @src. */ GstAudioBaseSrcSlaveMethod gst_audio_base_src_get_slave_method (GstAudioBaseSrc * src) { GstAudioBaseSrcSlaveMethod result; g_return_val_if_fail (GST_IS_AUDIO_BASE_SRC (src), -1); GST_OBJECT_LOCK (src); result = src->priv->slave_method; GST_OBJECT_UNLOCK (src); return result; } static void gst_audio_base_src_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) { GstAudioBaseSrc *src; src = GST_AUDIO_BASE_SRC (object); switch (prop_id) { case PROP_BUFFER_TIME: src->buffer_time = g_value_get_int64 (value); break; case PROP_LATENCY_TIME: src->latency_time = g_value_get_int64 (value); break; case PROP_PROVIDE_CLOCK: gst_audio_base_src_set_provide_clock (src, g_value_get_boolean (value)); break; case PROP_SLAVE_METHOD: gst_audio_base_src_set_slave_method (src, g_value_get_enum (value)); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_audio_base_src_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) { GstAudioBaseSrc *src; src = GST_AUDIO_BASE_SRC (object); switch (prop_id) { case PROP_BUFFER_TIME: g_value_set_int64 (value, src->buffer_time); break; case PROP_LATENCY_TIME: g_value_set_int64 (value, src->latency_time); break; case PROP_ACTUAL_BUFFER_TIME: GST_OBJECT_LOCK (src); if (src->ringbuffer && src->ringbuffer->acquired) g_value_set_int64 (value, src->ringbuffer->spec.buffer_time); else g_value_set_int64 (value, DEFAULT_ACTUAL_BUFFER_TIME); GST_OBJECT_UNLOCK (src); break; case PROP_ACTUAL_LATENCY_TIME: GST_OBJECT_LOCK (src); if (src->ringbuffer && src->ringbuffer->acquired) g_value_set_int64 (value, src->ringbuffer->spec.latency_time); else g_value_set_int64 (value, DEFAULT_ACTUAL_LATENCY_TIME); GST_OBJECT_UNLOCK (src); break; case PROP_PROVIDE_CLOCK: g_value_set_boolean (value, gst_audio_base_src_get_provide_clock (src)); break; case PROP_SLAVE_METHOD: g_value_set_enum (value, gst_audio_base_src_get_slave_method (src)); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static GstCaps * gst_audio_base_src_fixate (GstBaseSrc * bsrc, GstCaps * caps) { GstStructure *s; caps = gst_caps_make_writable (caps); s = gst_caps_get_structure (caps, 0); /* fields for all formats */ gst_structure_fixate_field_nearest_int (s, "rate", GST_AUDIO_DEF_RATE); gst_structure_fixate_field_nearest_int (s, "channels", GST_AUDIO_DEF_CHANNELS); gst_structure_fixate_field_string (s, "format", GST_AUDIO_DEF_FORMAT); caps = GST_BASE_SRC_CLASS (parent_class)->fixate (bsrc, caps); return caps; } static gboolean gst_audio_base_src_setcaps (GstBaseSrc * bsrc, GstCaps * caps) { GstAudioBaseSrc *src = GST_AUDIO_BASE_SRC (bsrc); GstAudioRingBufferSpec *spec; gint bpf, rate; spec = &src->ringbuffer->spec; if (G_UNLIKELY (gst_audio_ring_buffer_is_acquired (src->ringbuffer) && gst_caps_is_equal (spec->caps, caps))) { GST_DEBUG_OBJECT (src, "Ringbuffer caps haven't changed, skipping reconfiguration"); return TRUE; } GST_DEBUG ("release old ringbuffer"); gst_audio_ring_buffer_release (src->ringbuffer); spec->buffer_time = src->buffer_time; spec->latency_time = src->latency_time; GST_OBJECT_LOCK (src); if (!gst_audio_ring_buffer_parse_caps (spec, caps)) { GST_OBJECT_UNLOCK (src); goto parse_error; } bpf = GST_AUDIO_INFO_BPF (&spec->info); rate = GST_AUDIO_INFO_RATE (&spec->info); /* calculate suggested segsize and segtotal */ spec->segsize = rate * bpf * spec->latency_time / GST_MSECOND; /* Round to an integer number of samples */ spec->segsize -= spec->segsize % bpf; spec->segtotal = spec->buffer_time / spec->latency_time; GST_OBJECT_UNLOCK (src); gst_audio_ring_buffer_debug_spec_buff (spec); GST_DEBUG ("acquire new ringbuffer"); if (!gst_audio_ring_buffer_acquire (src->ringbuffer, spec)) goto acquire_error; /* calculate actual latency and buffer times */ spec->latency_time = spec->segsize * GST_MSECOND / (rate * bpf); spec->buffer_time = spec->segtotal * spec->segsize * GST_MSECOND / (rate * bpf); gst_audio_ring_buffer_debug_spec_buff (spec); g_object_notify (G_OBJECT (src), "actual-buffer-time"); g_object_notify (G_OBJECT (src), "actual-latency-time"); gst_element_post_message (GST_ELEMENT_CAST (bsrc), gst_message_new_latency (GST_OBJECT (bsrc))); return TRUE; /* ERRORS */ parse_error: { GST_DEBUG ("could not parse caps"); return FALSE; } acquire_error: { GST_DEBUG ("could not acquire ringbuffer"); return FALSE; } } static void gst_audio_base_src_get_times (GstBaseSrc * bsrc, GstBuffer * buffer, GstClockTime * start, GstClockTime * end) { /* No need to sync to a clock here. We schedule the samples based * on our own clock for the moment. */ *start = GST_CLOCK_TIME_NONE; *end = GST_CLOCK_TIME_NONE; } static gboolean gst_audio_base_src_query (GstBaseSrc * bsrc, GstQuery * query) { GstAudioBaseSrc *src = GST_AUDIO_BASE_SRC (bsrc); gboolean res = FALSE; switch (GST_QUERY_TYPE (query)) { case GST_QUERY_LATENCY: { GstClockTime min_latency, max_latency; GstAudioRingBufferSpec *spec; gint bpf, rate; GST_OBJECT_LOCK (src); if (G_UNLIKELY (src->ringbuffer == NULL || src->ringbuffer->spec.info.rate == 0)) { GST_OBJECT_UNLOCK (src); goto done; } spec = &src->ringbuffer->spec; rate = GST_AUDIO_INFO_RATE (&spec->info); bpf = GST_AUDIO_INFO_BPF (&spec->info); /* we have at least 1 segment of latency */ min_latency = gst_util_uint64_scale_int (spec->segsize, GST_SECOND, rate * bpf); /* we cannot delay more than the buffersize else we lose data */ max_latency = gst_util_uint64_scale_int (spec->segtotal * spec->segsize, GST_SECOND, rate * bpf); GST_OBJECT_UNLOCK (src); GST_DEBUG_OBJECT (src, "report latency min %" GST_TIME_FORMAT " max %" GST_TIME_FORMAT, GST_TIME_ARGS (min_latency), GST_TIME_ARGS (max_latency)); /* we are always live, the min latency is 1 segment and the max latency is * the complete buffer of segments. */ gst_query_set_latency (query, TRUE, min_latency, max_latency); res = TRUE; break; } case GST_QUERY_SCHEDULING: { /* We allow limited pull base operation. Basically, pulling can be * done on any number of bytes as long as the offset is -1 or * sequentially increasing. */ gst_query_set_scheduling (query, GST_SCHEDULING_FLAG_SEQUENTIAL, 1, -1, 0); gst_query_add_scheduling_mode (query, GST_PAD_MODE_PULL); gst_query_add_scheduling_mode (query, GST_PAD_MODE_PUSH); res = TRUE; break; } default: res = GST_BASE_SRC_CLASS (parent_class)->query (bsrc, query); break; } done: return res; } static gboolean gst_audio_base_src_event (GstBaseSrc * bsrc, GstEvent * event) { GstAudioBaseSrc *src = GST_AUDIO_BASE_SRC (bsrc); gboolean res, forward; res = FALSE; forward = TRUE; switch (GST_EVENT_TYPE (event)) { case GST_EVENT_FLUSH_START: GST_DEBUG_OBJECT (bsrc, "flush-start"); gst_audio_ring_buffer_pause (src->ringbuffer); gst_audio_ring_buffer_clear_all (src->ringbuffer); break; case GST_EVENT_FLUSH_STOP: GST_DEBUG_OBJECT (bsrc, "flush-stop"); /* always resync on sample after a flush */ src->next_sample = -1; gst_audio_ring_buffer_clear_all (src->ringbuffer); break; case GST_EVENT_SEEK: GST_DEBUG_OBJECT (bsrc, "refuse to seek"); forward = FALSE; break; default: GST_DEBUG_OBJECT (bsrc, "forward event %p", event); break; } if (forward) res = GST_BASE_SRC_CLASS (parent_class)->event (bsrc, event); return res; } /* Get the next offset in the ringbuffer for reading samples. * If the next sample is too far away, this function will position itself to the * next most recent sample, creating discontinuity */ static guint64 gst_audio_base_src_get_offset (GstAudioBaseSrc * src) { guint64 sample; gint readseg, segdone, segtotal, sps; gint diff; /* assume we can append to the previous sample */ sample = src->next_sample; sps = src->ringbuffer->samples_per_seg; segtotal = src->ringbuffer->spec.segtotal; /* get the currently processed segment */ segdone = g_atomic_int_get (&src->ringbuffer->segdone) - src->ringbuffer->segbase; if (sample != -1) { GST_DEBUG_OBJECT (src, "at segment %d and sample %" G_GUINT64_FORMAT, segdone, sample); /* figure out the segment and the offset inside the segment where * the sample should be read from. */ readseg = sample / sps; /* See how far away it is from the read segment. Normally, segdone (where * new data is written in the ringbuffer) is bigger than readseg * (where we are reading). */ diff = segdone - readseg; if (diff >= segtotal) { GST_DEBUG_OBJECT (src, "dropped, align to segment %d", segdone); /* sample would be dropped, position to next playable position */ sample = ((guint64) (segdone)) * sps; } } else { /* no previous sample, go to the current position */ GST_DEBUG_OBJECT (src, "first sample, align to current %d", segdone); sample = ((guint64) (segdone)) * sps; readseg = segdone; } GST_DEBUG_OBJECT (src, "reading from %d, we are at %d, sample %" G_GUINT64_FORMAT, readseg, segdone, sample); return sample; } static GstFlowReturn gst_audio_base_src_create (GstBaseSrc * bsrc, guint64 offset, guint length, GstBuffer ** outbuf) { GstFlowReturn ret; GstAudioBaseSrc *src = GST_AUDIO_BASE_SRC (bsrc); GstBuffer *buf; GstMapInfo info; guint8 *ptr; guint samples, total_samples; guint64 sample; gint bpf, rate; GstAudioRingBuffer *ringbuffer; GstAudioRingBufferSpec *spec; guint read; GstClockTime timestamp, duration; GstClockTime rb_timestamp = GST_CLOCK_TIME_NONE; GstClock *clock; gboolean first; gboolean first_sample = src->next_sample == -1; ringbuffer = src->ringbuffer; spec = &ringbuffer->spec; if (G_UNLIKELY (!gst_audio_ring_buffer_is_acquired (ringbuffer))) goto wrong_state; bpf = GST_AUDIO_INFO_BPF (&spec->info); rate = GST_AUDIO_INFO_RATE (&spec->info); if ((length == 0 && bsrc->blocksize == 0) || length == -1) /* no length given, use the default segment size */ length = spec->segsize; else /* make sure we round down to an integral number of samples */ length -= length % bpf; /* figure out the offset in the ringbuffer */ if (G_UNLIKELY (offset != -1)) { sample = offset / bpf; /* if a specific offset was given it must be the next sequential * offset we expect or we fail for now. */ if (src->next_sample != -1 && sample != src->next_sample) goto wrong_offset; } else { /* Calculate the sequentially-next sample we need to read. This can jump and * create a DISCONT. */ sample = gst_audio_base_src_get_offset (src); } GST_DEBUG_OBJECT (src, "reading from sample %" G_GUINT64_FORMAT " length %u", sample, length); /* get the number of samples to read */ total_samples = samples = length / bpf; /* use the basesrc allocation code to use bufferpools or custom allocators */ ret = GST_BASE_SRC_CLASS (parent_class)->alloc (bsrc, offset, length, &buf); if (G_UNLIKELY (ret != GST_FLOW_OK)) goto alloc_failed; gst_buffer_map (buf, &info, GST_MAP_WRITE); ptr = info.data; first = TRUE; do { GstClockTime tmp_ts = GST_CLOCK_TIME_NONE; read = gst_audio_ring_buffer_read (ringbuffer, sample, ptr, samples, &tmp_ts); if (first && GST_CLOCK_TIME_IS_VALID (tmp_ts)) { first = FALSE; rb_timestamp = tmp_ts; } GST_DEBUG_OBJECT (src, "read %u of %u", read, samples); /* if we read all, we're done */ if (read == samples) break; if (g_atomic_int_get (&ringbuffer->state) == GST_AUDIO_RING_BUFFER_STATE_ERROR) goto got_error; /* else something interrupted us and we wait for playing again. */ GST_DEBUG_OBJECT (src, "wait playing"); if (gst_base_src_wait_playing (bsrc) != GST_FLOW_OK) goto stopped; GST_DEBUG_OBJECT (src, "continue playing"); /* read next samples */ sample += read; samples -= read; ptr += read * bpf; } while (TRUE); gst_buffer_unmap (buf, &info); /* mark discontinuity if needed */ if (G_UNLIKELY (sample != src->next_sample) && src->next_sample != -1) { GST_WARNING_OBJECT (src, "create DISCONT of %" G_GUINT64_FORMAT " samples at sample %" G_GUINT64_FORMAT, sample - src->next_sample, sample); GST_ELEMENT_WARNING (src, CORE, CLOCK, (_("Can't record audio fast enough")), ("Dropped %" G_GUINT64_FORMAT " samples. This is most likely because " "downstream can't keep up and is consuming samples too slowly.", sample - src->next_sample)); GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_DISCONT); } src->next_sample = sample + samples; /* get the normal timestamp to get the duration. */ timestamp = gst_util_uint64_scale_int (sample, GST_SECOND, rate); duration = gst_util_uint64_scale_int (src->next_sample, GST_SECOND, rate) - timestamp; GST_OBJECT_LOCK (src); if (!(clock = GST_ELEMENT_CLOCK (src))) goto no_sync; if (!GST_CLOCK_TIME_IS_VALID (rb_timestamp) && clock != src->clock) { /* we are slaved, check how to handle this */ switch (src->priv->slave_method) { case GST_AUDIO_BASE_SRC_SLAVE_RESAMPLE: /* Not implemented, use skew algorithm. This algorithm should * work on the readout pointer and produce more or less samples based * on the clock drift */ case GST_AUDIO_BASE_SRC_SLAVE_SKEW: { GstClockTime running_time; GstClockTime base_time; GstClockTime current_time; guint64 running_time_sample; gint running_time_segment; gint last_read_segment; gint segment_skew; gint sps; gint segments_written; gint last_written_segment; /* get the amount of segments written from the device by now */ segments_written = g_atomic_int_get (&ringbuffer->segdone); /* subtract the base to segments_written to get the number of the * last written segment in the ringbuffer * (one segment written = segment 0) */ last_written_segment = segments_written - ringbuffer->segbase - 1; /* samples per segment */ sps = ringbuffer->samples_per_seg; /* get the current time */ current_time = gst_clock_get_time (clock); /* get the basetime */ base_time = GST_ELEMENT_CAST (src)->base_time; /* get the running_time */ running_time = current_time - base_time; /* the running_time converted to a sample * (relative to the ringbuffer) */ running_time_sample = gst_util_uint64_scale_int (running_time, rate, GST_SECOND); /* the segmentnr corresponding to running_time, round down */ running_time_segment = running_time_sample / sps; /* the segment currently read from the ringbuffer */ last_read_segment = sample / sps; /* the skew we have between running_time and the ringbuffertime * (last written to) */ segment_skew = running_time_segment - last_written_segment; GST_DEBUG_OBJECT (bsrc, "\n running_time = %" GST_TIME_FORMAT "\n timestamp = %" GST_TIME_FORMAT "\n running_time_segment = %d" "\n last_written_segment = %d" "\n segment_skew (running time segment - last_written_segment) = %d" "\n last_read_segment = %d", GST_TIME_ARGS (running_time), GST_TIME_ARGS (timestamp), running_time_segment, last_written_segment, segment_skew, last_read_segment); /* Resync the ringbuffer if: * * 1. We are more than the length of the ringbuffer behind. * The length of the ringbuffer then gets to dictate * the threshold for what is considered "too late" * * 2. If this is our first buffer. * We know that we should catch up to running_time * the first time we are ran. */ if ((segment_skew >= ringbuffer->spec.segtotal) || (last_read_segment == 0) || first_sample) { gint new_read_segment; gint segment_diff; guint64 new_sample; /* the difference between running_time and the last written segment */ segment_diff = running_time_segment - last_written_segment; /* advance the ringbuffer */ gst_audio_ring_buffer_advance (ringbuffer, segment_diff); /* we move the new read segment to the last known written segment */ new_read_segment = g_atomic_int_get (&ringbuffer->segdone) - ringbuffer->segbase; /* we calculate the new sample value */ new_sample = ((guint64) new_read_segment) * sps; /* and get the relative time to this -> our new timestamp */ timestamp = gst_util_uint64_scale_int (new_sample, GST_SECOND, rate); /* we update the next sample accordingly */ src->next_sample = new_sample + samples; GST_DEBUG_OBJECT (bsrc, "Timeshifted the ringbuffer with %d segments: " "Updating the timestamp to %" GST_TIME_FORMAT ", " "and src->next_sample to %" G_GUINT64_FORMAT, segment_diff, GST_TIME_ARGS (timestamp), src->next_sample); } break; } case GST_AUDIO_BASE_SRC_SLAVE_RE_TIMESTAMP: { GstClockTime base_time, latency; /* We are slaved to another clock. Take running time of the pipeline * clock and timestamp against it. Somebody else in the pipeline should * figure out the clock drift. We keep the duration we calculated * above. */ timestamp = gst_clock_get_time (clock); base_time = GST_ELEMENT_CAST (src)->base_time; if (GST_CLOCK_DIFF (timestamp, base_time) < 0) timestamp -= base_time; else timestamp = 0; /* subtract latency */ latency = gst_util_uint64_scale_int (total_samples, GST_SECOND, rate); if (timestamp > latency) timestamp -= latency; else timestamp = 0; } case GST_AUDIO_BASE_SRC_SLAVE_NONE: break; } } else { GstClockTime base_time; if (GST_CLOCK_TIME_IS_VALID (rb_timestamp)) { /* the read method returned a timestamp so we use this instead */ timestamp = rb_timestamp; } else { /* to get the timestamp against the clock we also need to add our * offset */ timestamp = gst_audio_clock_adjust (GST_AUDIO_CLOCK (clock), timestamp); } /* we are not slaved, subtract base_time */ base_time = GST_ELEMENT_CAST (src)->base_time; if (GST_CLOCK_DIFF (timestamp, base_time) < 0) { timestamp -= base_time; GST_LOG_OBJECT (src, "buffer timestamp %" GST_TIME_FORMAT " (base_time %" GST_TIME_FORMAT ")", GST_TIME_ARGS (timestamp), GST_TIME_ARGS (base_time)); } else { GST_LOG_OBJECT (src, "buffer timestamp 0, ts %" GST_TIME_FORMAT " <= base_time %" GST_TIME_FORMAT, GST_TIME_ARGS (timestamp), GST_TIME_ARGS (base_time)); timestamp = 0; } } no_sync: GST_OBJECT_UNLOCK (src); GST_BUFFER_PTS (buf) = timestamp; GST_BUFFER_DURATION (buf) = duration; GST_BUFFER_OFFSET (buf) = sample; GST_BUFFER_OFFSET_END (buf) = sample + samples; *outbuf = buf; GST_LOG_OBJECT (src, "Pushed buffer timestamp %" GST_TIME_FORMAT, GST_TIME_ARGS (GST_BUFFER_PTS (buf))); return GST_FLOW_OK; /* ERRORS */ wrong_state: { GST_DEBUG_OBJECT (src, "ringbuffer in wrong state"); return GST_FLOW_FLUSHING; } wrong_offset: { GST_ELEMENT_ERROR (src, RESOURCE, SEEK, (NULL), ("resource can only be operated on sequentially but offset %" G_GUINT64_FORMAT " was given", offset)); return GST_FLOW_ERROR; } alloc_failed: { GST_DEBUG_OBJECT (src, "alloc failed: %s", gst_flow_get_name (ret)); return ret; } stopped: { gst_buffer_unmap (buf, &info); gst_buffer_unref (buf); GST_DEBUG_OBJECT (src, "ringbuffer stopped"); return GST_FLOW_FLUSHING; } got_error: { gst_buffer_unmap (buf, &info); gst_buffer_unref (buf); GST_DEBUG_OBJECT (src, "ringbuffer was in error state, bailing out"); return GST_FLOW_ERROR; } } /** * gst_audio_base_src_create_ringbuffer: * @src: a #GstAudioBaseSrc. * * Create and return the #GstAudioRingBuffer for @src. This function will call * the ::create_ringbuffer vmethod and will set @src as the parent of the * returned buffer (see gst_object_set_parent()). * * Returns: (transfer none): The new ringbuffer of @src. */ GstAudioRingBuffer * gst_audio_base_src_create_ringbuffer (GstAudioBaseSrc * src) { GstAudioBaseSrcClass *bclass; GstAudioRingBuffer *buffer = NULL; bclass = GST_AUDIO_BASE_SRC_GET_CLASS (src); if (bclass->create_ringbuffer) buffer = bclass->create_ringbuffer (src); if (G_LIKELY (buffer)) gst_object_set_parent (GST_OBJECT_CAST (buffer), GST_OBJECT_CAST (src)); return buffer; } static GstStateChangeReturn gst_audio_base_src_change_state (GstElement * element, GstStateChange transition) { GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS; GstAudioBaseSrc *src = GST_AUDIO_BASE_SRC (element); switch (transition) { case GST_STATE_CHANGE_NULL_TO_READY:{ GstAudioRingBuffer *rb; GST_DEBUG_OBJECT (src, "NULL->READY"); gst_audio_clock_reset (GST_AUDIO_CLOCK (src->clock), 0); rb = gst_audio_base_src_create_ringbuffer (src); if (rb == NULL) goto create_failed; GST_OBJECT_LOCK (src); src->ringbuffer = rb; GST_OBJECT_UNLOCK (src); if (!gst_audio_ring_buffer_open_device (src->ringbuffer)) { GST_OBJECT_LOCK (src); gst_object_unparent (GST_OBJECT_CAST (src->ringbuffer)); src->ringbuffer = NULL; GST_OBJECT_UNLOCK (src); goto open_failed; } break; } case GST_STATE_CHANGE_READY_TO_PAUSED: GST_DEBUG_OBJECT (src, "READY->PAUSED"); src->next_sample = -1; gst_audio_ring_buffer_set_flushing (src->ringbuffer, FALSE); gst_audio_ring_buffer_may_start (src->ringbuffer, FALSE); /* Only post clock-provide messages if this is the clock that * we've created. If the subclass has overridden it the subclass * should post this messages whenever necessary */ if (src->clock && GST_IS_AUDIO_CLOCK (src->clock) && GST_AUDIO_CLOCK_CAST (src->clock)->func == (GstAudioClockGetTimeFunc) gst_audio_base_src_get_time) gst_element_post_message (element, gst_message_new_clock_provide (GST_OBJECT_CAST (element), src->clock, TRUE)); break; case GST_STATE_CHANGE_PAUSED_TO_PLAYING: GST_DEBUG_OBJECT (src, "PAUSED->PLAYING"); gst_audio_ring_buffer_may_start (src->ringbuffer, TRUE); break; case GST_STATE_CHANGE_PLAYING_TO_PAUSED: GST_DEBUG_OBJECT (src, "PLAYING->PAUSED"); gst_audio_ring_buffer_may_start (src->ringbuffer, FALSE); gst_audio_ring_buffer_pause (src->ringbuffer); break; case GST_STATE_CHANGE_PAUSED_TO_READY: GST_DEBUG_OBJECT (src, "PAUSED->READY"); /* Only post clock-lost messages if this is the clock that * we've created. If the subclass has overridden it the subclass * should post this messages whenever necessary */ if (src->clock && GST_IS_AUDIO_CLOCK (src->clock) && GST_AUDIO_CLOCK_CAST (src->clock)->func == (GstAudioClockGetTimeFunc) gst_audio_base_src_get_time) gst_element_post_message (element, gst_message_new_clock_lost (GST_OBJECT_CAST (element), src->clock)); gst_audio_ring_buffer_set_flushing (src->ringbuffer, TRUE); break; default: break; } ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition); switch (transition) { case GST_STATE_CHANGE_PAUSED_TO_READY: GST_DEBUG_OBJECT (src, "PAUSED->READY"); gst_audio_ring_buffer_release (src->ringbuffer); break; case GST_STATE_CHANGE_READY_TO_NULL: GST_DEBUG_OBJECT (src, "READY->NULL"); gst_audio_ring_buffer_close_device (src->ringbuffer); GST_OBJECT_LOCK (src); gst_object_unparent (GST_OBJECT_CAST (src->ringbuffer)); src->ringbuffer = NULL; GST_OBJECT_UNLOCK (src); break; default: break; } return ret; /* ERRORS */ create_failed: { /* subclass must post a meaningful error message */ GST_DEBUG_OBJECT (src, "create failed"); return GST_STATE_CHANGE_FAILURE; } open_failed: { /* subclass must post a meaningful error message */ GST_DEBUG_OBJECT (src, "open failed"); return GST_STATE_CHANGE_FAILURE; } } static gboolean gst_audio_base_src_post_message (GstElement * element, GstMessage * message) { GstAudioBaseSrc *src = GST_AUDIO_BASE_SRC (element); gboolean ret; if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_ERROR && src->ringbuffer) { GstAudioRingBuffer *ringbuffer; GST_INFO_OBJECT (element, "subclass posted error"); ringbuffer = gst_object_ref (src->ringbuffer); /* post message first before signalling the error to the ringbuffer, to * make sure it ends up on the bus before the generic basesrc internal * flow error message */ ret = GST_ELEMENT_CLASS (parent_class)->post_message (element, message); g_atomic_int_set (&ringbuffer->state, GST_AUDIO_RING_BUFFER_STATE_ERROR); GST_AUDIO_RING_BUFFER_SIGNAL (ringbuffer); gst_object_unref (ringbuffer); } else { ret = GST_ELEMENT_CLASS (parent_class)->post_message (element, message); } return ret; }