/* GStreamer * Copyright (C) 2005 Wim Taymans * * 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., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ /** * SECTION:gstringbuffer * @short_description: Base class for audio ringbuffer implementations * @see_also: #GstBaseAudioSink, #GstAudioSink * * * * This object is the base class for audio ringbuffers used by the base * audio source and sink classes. * * * The ringbuffer abstracts a circular buffer of data. One reader and * one writer can operate on the data from different threads in a lockfree * manner. The base class is sufficiently flexible to be used as an * abstraction for DMA based ringbuffers as well as a pure software * implementations. * * * * Last reviewed on 2006-02-02 (0.10.4) */ #include #include "gstringbuffer.h" GST_DEBUG_CATEGORY_STATIC (gst_ring_buffer_debug); #define GST_CAT_DEFAULT gst_ring_buffer_debug static void gst_ring_buffer_class_init (GstRingBufferClass * klass); static void gst_ring_buffer_init (GstRingBuffer * ringbuffer); static void gst_ring_buffer_dispose (GObject * object); static void gst_ring_buffer_finalize (GObject * object); static gboolean gst_ring_buffer_pause_unlocked (GstRingBuffer * buf); static GstObjectClass *parent_class = NULL; /* ringbuffer abstract base class */ GType gst_ring_buffer_get_type (void) { static GType ringbuffer_type = 0; if (G_UNLIKELY (!ringbuffer_type)) { static const GTypeInfo ringbuffer_info = { sizeof (GstRingBufferClass), NULL, NULL, (GClassInitFunc) gst_ring_buffer_class_init, NULL, NULL, sizeof (GstRingBuffer), 0, (GInstanceInitFunc) gst_ring_buffer_init, NULL }; ringbuffer_type = g_type_register_static (GST_TYPE_OBJECT, "GstRingBuffer", &ringbuffer_info, G_TYPE_FLAG_ABSTRACT); GST_DEBUG_CATEGORY_INIT (gst_ring_buffer_debug, "ringbuffer", 0, "ringbuffer class"); } return ringbuffer_type; } static void gst_ring_buffer_class_init (GstRingBufferClass * klass) { GObjectClass *gobject_class; GstObjectClass *gstobject_class; gobject_class = (GObjectClass *) klass; gstobject_class = (GstObjectClass *) klass; parent_class = g_type_class_peek_parent (klass); gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_ring_buffer_dispose); gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_ring_buffer_finalize); } static void gst_ring_buffer_init (GstRingBuffer * ringbuffer) { ringbuffer->open = FALSE; ringbuffer->acquired = FALSE; ringbuffer->state = GST_RING_BUFFER_STATE_STOPPED; ringbuffer->cond = g_cond_new (); ringbuffer->waiting = 0; ringbuffer->empty_seg = NULL; ringbuffer->abidata.ABI.flushing = TRUE; } static void gst_ring_buffer_dispose (GObject * object) { GstRingBuffer *ringbuffer = GST_RING_BUFFER (object); gst_caps_replace (&ringbuffer->spec.caps, NULL); G_OBJECT_CLASS (parent_class)->dispose (G_OBJECT (ringbuffer)); } static void gst_ring_buffer_finalize (GObject * object) { GstRingBuffer *ringbuffer = GST_RING_BUFFER (object); g_cond_free (ringbuffer->cond); g_free (ringbuffer->empty_seg); G_OBJECT_CLASS (parent_class)->finalize (G_OBJECT (ringbuffer)); } typedef struct { const GstBufferFormat format; const guint8 silence[4]; } FormatDef; static const FormatDef linear_defs[4 * 2 * 2] = { {GST_S8, {0x00, 0x00, 0x00, 0x00}}, {GST_S8, {0x00, 0x00, 0x00, 0x00}}, {GST_U8, {0x80, 0x80, 0x80, 0x80}}, {GST_U8, {0x80, 0x80, 0x80, 0x80}}, {GST_S16_LE, {0x00, 0x00, 0x00, 0x00}}, {GST_S16_BE, {0x00, 0x00, 0x00, 0x00}}, {GST_U16_LE, {0x00, 0x80, 0x00, 0x80}}, {GST_U16_BE, {0x80, 0x00, 0x80, 0x00}}, {GST_S24_LE, {0x00, 0x00, 0x00, 0x00}}, {GST_S24_BE, {0x00, 0x00, 0x00, 0x00}}, {GST_U24_LE, {0x00, 0x00, 0x80, 0x00}}, {GST_U24_BE, {0x80, 0x00, 0x00, 0x00}}, {GST_S32_LE, {0x00, 0x00, 0x00, 0x00}}, {GST_S32_BE, {0x00, 0x00, 0x00, 0x00}}, {GST_U32_LE, {0x00, 0x00, 0x00, 0x80}}, {GST_U32_BE, {0x80, 0x00, 0x00, 0x00}} }; static const FormatDef linear24_defs[3 * 2 * 2] = { {GST_S24_3LE, {0x00, 0x00, 0x00, 0x00}}, {GST_S24_3BE, {0x00, 0x00, 0x00, 0x00}}, {GST_U24_3LE, {0x00, 0x00, 0x80, 0x00}}, {GST_U24_3BE, {0x80, 0x00, 0x00, 0x00}}, {GST_S20_3LE, {0x00, 0x00, 0x00, 0x00}}, {GST_S20_3BE, {0x00, 0x00, 0x00, 0x00}}, {GST_U20_3LE, {0x00, 0x00, 0x08, 0x00}}, {GST_U20_3BE, {0x08, 0x00, 0x00, 0x00}}, {GST_S18_3LE, {0x00, 0x00, 0x00, 0x00}}, {GST_S18_3BE, {0x00, 0x00, 0x00, 0x00}}, {GST_U18_3LE, {0x00, 0x00, 0x02, 0x00}}, {GST_U18_3BE, {0x02, 0x00, 0x00, 0x00}} }; static const FormatDef * build_linear_format (int depth, int width, int unsignd, int big_endian) { const FormatDef *formats; if (width == 24) { switch (depth) { case 24: formats = &linear24_defs[0]; break; case 20: formats = &linear24_defs[4]; break; case 18: formats = &linear24_defs[8]; break; default: return NULL; } } else { switch (depth) { case 8: formats = &linear_defs[0]; break; case 16: formats = &linear_defs[4]; break; case 24: formats = &linear_defs[8]; break; case 32: formats = &linear_defs[12]; break; default: return NULL; } } if (unsignd) formats += 2; if (big_endian) formats += 1; return formats; } /** * gst_ring_buffer_debug_spec_caps: * @spec: the spec to debug * * Print debug info about the parsed caps in @spec to the debug log. */ void gst_ring_buffer_debug_spec_caps (GstRingBufferSpec * spec) { gint i, bytes; GST_DEBUG ("spec caps: %p %" GST_PTR_FORMAT, spec->caps, spec->caps); GST_DEBUG ("parsed caps: type: %d", spec->type); GST_DEBUG ("parsed caps: format: %d", spec->format); GST_DEBUG ("parsed caps: width: %d", spec->width); GST_DEBUG ("parsed caps: depth: %d", spec->depth); GST_DEBUG ("parsed caps: sign: %d", spec->sign); GST_DEBUG ("parsed caps: bigend: %d", spec->bigend); GST_DEBUG ("parsed caps: rate: %d", spec->rate); GST_DEBUG ("parsed caps: channels: %d", spec->channels); GST_DEBUG ("parsed caps: sample bytes: %d", spec->bytes_per_sample); bytes = (spec->width >> 3) * spec->channels; for (i = 0; i < bytes; i++) { GST_DEBUG ("silence byte %d: %02x", i, spec->silence_sample[i]); } } /** * gst_ring_buffer_debug_spec_buff: * @spec: the spec to debug * * Print debug info about the buffer sized in @spec to the debug log. */ void gst_ring_buffer_debug_spec_buff (GstRingBufferSpec * spec) { GST_DEBUG ("acquire ringbuffer: buffer time: %" G_GINT64_FORMAT " usec", spec->buffer_time); GST_DEBUG ("acquire ringbuffer: latency time: %" G_GINT64_FORMAT " usec", spec->latency_time); GST_DEBUG ("acquire ringbuffer: total segments: %d", spec->segtotal); GST_DEBUG ("acquire ringbuffer: latency segments: %d", spec->seglatency); GST_DEBUG ("acquire ringbuffer: segment size: %d bytes = %d samples", spec->segsize, spec->segsize / spec->bytes_per_sample); GST_DEBUG ("acquire ringbuffer: buffer size: %d bytes = %d samples", spec->segsize * spec->segtotal, spec->segsize * spec->segtotal / spec->bytes_per_sample); } /** * gst_ring_buffer_parse_caps: * @spec: a spec * @caps: a #GstCaps * * Parse @caps into @spec. * * Returns: TRUE if the caps could be parsed. */ gboolean gst_ring_buffer_parse_caps (GstRingBufferSpec * spec, GstCaps * caps) { const gchar *mimetype; GstStructure *structure; gint i; structure = gst_caps_get_structure (caps, 0); /* we have to differentiate between int and float formats */ mimetype = gst_structure_get_name (structure); if (!strncmp (mimetype, "audio/x-raw-int", 15)) { gint endianness; const FormatDef *def; gint j, bytes; spec->type = GST_BUFTYPE_LINEAR; /* extract the needed information from the cap */ if (!(gst_structure_get_int (structure, "rate", &spec->rate) && gst_structure_get_int (structure, "channels", &spec->channels) && gst_structure_get_int (structure, "width", &spec->width) && gst_structure_get_int (structure, "depth", &spec->depth) && gst_structure_get_boolean (structure, "signed", &spec->sign))) goto parse_error; /* extract endianness if needed */ if (spec->width > 8) { if (!gst_structure_get_int (structure, "endianness", &endianness)) goto parse_error; } else { endianness = G_BYTE_ORDER; } spec->bigend = endianness == G_LITTLE_ENDIAN ? FALSE : TRUE; def = build_linear_format (spec->depth, spec->width, spec->sign ? 0 : 1, spec->bigend ? 1 : 0); if (def == NULL) goto parse_error; spec->format = def->format; bytes = spec->width >> 3; for (i = 0; i < spec->channels; i++) { for (j = 0; j < bytes; j++) { spec->silence_sample[i * bytes + j] = def->silence[j]; } } } else if (!strncmp (mimetype, "audio/x-raw-float", 17)) { spec->type = GST_BUFTYPE_FLOAT; /* extract the needed information from the cap */ if (!(gst_structure_get_int (structure, "rate", &spec->rate) && gst_structure_get_int (structure, "channels", &spec->channels) && gst_structure_get_int (structure, "width", &spec->width))) goto parse_error; /* match layout to format wrt to endianness */ switch (spec->width) { case 32: spec->format = G_BYTE_ORDER == G_LITTLE_ENDIAN ? GST_FLOAT32_LE : GST_FLOAT32_BE; break; case 64: spec->format = G_BYTE_ORDER == G_LITTLE_ENDIAN ? GST_FLOAT64_LE : GST_FLOAT64_BE; break; default: goto parse_error; } /* float silence is all zeros.. */ memset (spec->silence_sample, 0, 32); } else if (!strncmp (mimetype, "audio/x-alaw", 12)) { /* extract the needed information from the cap */ if (!(gst_structure_get_int (structure, "rate", &spec->rate) && gst_structure_get_int (structure, "channels", &spec->channels))) goto parse_error; spec->type = GST_BUFTYPE_A_LAW; spec->format = GST_A_LAW; spec->width = 8; spec->depth = 8; for (i = 0; i < spec->channels; i++) spec->silence_sample[i] = 0xd5; } else if (!strncmp (mimetype, "audio/x-mulaw", 13)) { /* extract the needed information from the cap */ if (!(gst_structure_get_int (structure, "rate", &spec->rate) && gst_structure_get_int (structure, "channels", &spec->channels))) goto parse_error; spec->type = GST_BUFTYPE_MU_LAW; spec->format = GST_MU_LAW; spec->width = 8; spec->depth = 8; for (i = 0; i < spec->channels; i++) spec->silence_sample[i] = 0xff; } else if (!strncmp (mimetype, "audio/x-iec958", 14)) { /* extract the needed information from the cap */ if (!(gst_structure_get_int (structure, "rate", &spec->rate))) goto parse_error; spec->type = GST_BUFTYPE_IEC958; spec->format = GST_IEC958; spec->width = 16; spec->depth = 16; spec->channels = 2; } else if (!strncmp (mimetype, "audio/x-ac3", 11)) { /* extract the needed information from the cap */ if (!(gst_structure_get_int (structure, "rate", &spec->rate))) goto parse_error; spec->type = GST_BUFTYPE_AC3; spec->format = GST_AC3; spec->width = 16; spec->depth = 16; spec->channels = 2; } else { goto parse_error; } spec->bytes_per_sample = (spec->width >> 3) * spec->channels; gst_caps_replace (&spec->caps, caps); g_return_val_if_fail (spec->latency_time != 0, FALSE); /* calculate suggested segsize and segtotal. segsize should be one unit * of 'latency_time' samples, scaling for the fact that latency_time is * currently stored in microseconds (FIXME: in 0.11) */ spec->segsize = gst_util_uint64_scale (spec->rate * spec->bytes_per_sample, spec->latency_time, GST_SECOND / GST_USECOND); /* Round to an integer number of samples */ spec->segsize -= spec->segsize % spec->bytes_per_sample; spec->segtotal = spec->buffer_time / spec->latency_time; /* leave the latency undefined now, implementations can change it but if it's * not changed, we assume the same value as segtotal */ spec->seglatency = -1; gst_ring_buffer_debug_spec_caps (spec); gst_ring_buffer_debug_spec_buff (spec); return TRUE; /* ERRORS */ parse_error: { GST_DEBUG ("could not parse caps"); return FALSE; } } /** * gst_ring_buffer_convert: * @buf: the #GstRingBuffer * @src_fmt: the source format * @src_val: the source value * @dest_fmt: the destination format * @dest_val: a location to store the converted value * * Convert @src_val in @src_fmt to the equivalent value in @dest_fmt. The result * will be put in @dest_val. * * Returns: TRUE if the conversion succeeded. * * Since: 0.10.22. */ gboolean gst_ring_buffer_convert (GstRingBuffer * buf, GstFormat src_fmt, gint64 src_val, GstFormat dest_fmt, gint64 * dest_val) { gboolean res = TRUE; gint bps, rate; GST_DEBUG ("converting value %" G_GINT64_FORMAT " from %s (%d) to %s (%d)", src_val, gst_format_get_name (src_fmt), src_fmt, gst_format_get_name (dest_fmt), dest_fmt); if (src_fmt == dest_fmt || src_val == -1) { *dest_val = src_val; goto done; } /* get important info */ GST_OBJECT_LOCK (buf); bps = buf->spec.bytes_per_sample; rate = buf->spec.rate; GST_OBJECT_UNLOCK (buf); if (bps == 0 || rate == 0) { GST_DEBUG ("no rate or bps configured"); res = FALSE; goto done; } switch (src_fmt) { case GST_FORMAT_BYTES: switch (dest_fmt) { case GST_FORMAT_TIME: *dest_val = gst_util_uint64_scale_int (src_val / bps, GST_SECOND, rate); break; case GST_FORMAT_DEFAULT: *dest_val = src_val / bps; break; default: res = FALSE; break; } break; case GST_FORMAT_DEFAULT: switch (dest_fmt) { case GST_FORMAT_TIME: *dest_val = gst_util_uint64_scale_int (src_val, GST_SECOND, rate); break; case GST_FORMAT_BYTES: *dest_val = src_val * bps; break; default: res = FALSE; break; } break; case GST_FORMAT_TIME: switch (dest_fmt) { case GST_FORMAT_DEFAULT: *dest_val = gst_util_uint64_scale_int (src_val, rate, GST_SECOND); break; case GST_FORMAT_BYTES: *dest_val = gst_util_uint64_scale_int (src_val, rate, GST_SECOND); *dest_val *= bps; break; default: res = FALSE; break; } break; default: res = FALSE; break; } done: GST_DEBUG ("ret=%d result %" G_GINT64_FORMAT, res, *dest_val); return res; } /** * gst_ring_buffer_set_callback: * @buf: the #GstRingBuffer to set the callback on * @cb: the callback to set * @user_data: user data passed to the callback * * Sets the given callback function on the buffer. This function * will be called every time a segment has been written to a device. * * MT safe. */ void gst_ring_buffer_set_callback (GstRingBuffer * buf, GstRingBufferCallback cb, gpointer user_data) { g_return_if_fail (GST_IS_RING_BUFFER (buf)); GST_OBJECT_LOCK (buf); buf->callback = cb; buf->cb_data = user_data; GST_OBJECT_UNLOCK (buf); } /** * gst_ring_buffer_open_device: * @buf: the #GstRingBuffer * * Open the audio device associated with the ring buffer. Does not perform any * setup on the device. You must open the device before acquiring the ring * buffer. * * Returns: TRUE if the device could be opened, FALSE on error. * * MT safe. */ gboolean gst_ring_buffer_open_device (GstRingBuffer * buf) { gboolean res = TRUE; GstRingBufferClass *rclass; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), FALSE); GST_DEBUG_OBJECT (buf, "opening device"); GST_OBJECT_LOCK (buf); if (G_UNLIKELY (buf->open)) goto was_opened; buf->open = TRUE; /* if this fails, something is wrong in this file */ g_assert (!buf->acquired); rclass = GST_RING_BUFFER_GET_CLASS (buf); if (G_LIKELY (rclass->open_device)) res = rclass->open_device (buf); if (G_UNLIKELY (!res)) goto open_failed; GST_DEBUG_OBJECT (buf, "opened device"); done: GST_OBJECT_UNLOCK (buf); return res; /* ERRORS */ was_opened: { GST_DEBUG_OBJECT (buf, "Device for ring buffer already open"); g_warning ("Device for ring buffer %p already open, fix your code", buf); res = TRUE; goto done; } open_failed: { buf->open = FALSE; GST_DEBUG_OBJECT (buf, "failed opening device"); goto done; } } /** * gst_ring_buffer_close_device: * @buf: the #GstRingBuffer * * Close the audio device associated with the ring buffer. The ring buffer * should already have been released via gst_ring_buffer_release(). * * Returns: TRUE if the device could be closed, FALSE on error. * * MT safe. */ gboolean gst_ring_buffer_close_device (GstRingBuffer * buf) { gboolean res = TRUE; GstRingBufferClass *rclass; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), FALSE); GST_DEBUG_OBJECT (buf, "closing device"); GST_OBJECT_LOCK (buf); if (G_UNLIKELY (!buf->open)) goto was_closed; if (G_UNLIKELY (buf->acquired)) goto was_acquired; buf->open = FALSE; rclass = GST_RING_BUFFER_GET_CLASS (buf); if (G_LIKELY (rclass->close_device)) res = rclass->close_device (buf); if (G_UNLIKELY (!res)) goto close_error; GST_DEBUG_OBJECT (buf, "closed device"); done: GST_OBJECT_UNLOCK (buf); return res; /* ERRORS */ was_closed: { GST_DEBUG_OBJECT (buf, "Device for ring buffer already closed"); g_warning ("Device for ring buffer %p already closed, fix your code", buf); res = TRUE; goto done; } was_acquired: { GST_DEBUG_OBJECT (buf, "Resources for ring buffer still acquired"); g_critical ("Resources for ring buffer %p still acquired", buf); res = FALSE; goto done; } close_error: { buf->open = TRUE; GST_DEBUG_OBJECT (buf, "error closing device"); goto done; } } /** * gst_ring_buffer_device_is_open: * @buf: the #GstRingBuffer * * Checks the status of the device associated with the ring buffer. * * Returns: TRUE if the device was open, FALSE if it was closed. * * MT safe. */ gboolean gst_ring_buffer_device_is_open (GstRingBuffer * buf) { gboolean res = TRUE; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), FALSE); GST_OBJECT_LOCK (buf); res = buf->open; GST_OBJECT_UNLOCK (buf); return res; } /** * gst_ring_buffer_acquire: * @buf: the #GstRingBuffer to acquire * @spec: the specs of the buffer * * Allocate the resources for the ringbuffer. This function fills * in the data pointer of the ring buffer with a valid #GstBuffer * to which samples can be written. * * Returns: TRUE if the device could be acquired, FALSE on error. * * MT safe. */ gboolean gst_ring_buffer_acquire (GstRingBuffer * buf, GstRingBufferSpec * spec) { gboolean res = FALSE; GstRingBufferClass *rclass; gint i, j; gint segsize, bps; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), FALSE); GST_DEBUG_OBJECT (buf, "acquiring device"); GST_OBJECT_LOCK (buf); if (G_UNLIKELY (!buf->open)) goto not_opened; if (G_UNLIKELY (buf->acquired)) goto was_acquired; buf->acquired = TRUE; rclass = GST_RING_BUFFER_GET_CLASS (buf); if (G_LIKELY (rclass->acquire)) res = rclass->acquire (buf, spec); if (G_UNLIKELY (!res)) goto acquire_failed; if (G_UNLIKELY ((bps = buf->spec.bytes_per_sample) == 0)) goto invalid_bps; /* if the seglatency was overwritten with something else than -1, use it, else * assume segtotal as the latency */ if (buf->spec.seglatency == -1) buf->spec.seglatency = buf->spec.segtotal; segsize = buf->spec.segsize; buf->samples_per_seg = segsize / bps; /* create an empty segment */ g_free (buf->empty_seg); buf->empty_seg = g_malloc (segsize); /* FIXME, we only have 32 silence samples, which might not be enough to * represent silence in all channels */ bps = MIN (bps, 32); for (i = 0, j = 0; i < segsize; i++) { buf->empty_seg[i] = buf->spec.silence_sample[j]; j = (j + 1) % bps; } GST_DEBUG_OBJECT (buf, "acquired device"); done: GST_OBJECT_UNLOCK (buf); return res; /* ERRORS */ not_opened: { GST_DEBUG_OBJECT (buf, "device not opened"); g_critical ("Device for %p not opened", buf); res = FALSE; goto done; } was_acquired: { res = TRUE; GST_DEBUG_OBJECT (buf, "device was acquired"); goto done; } acquire_failed: { buf->acquired = FALSE; GST_DEBUG_OBJECT (buf, "failed to acquire device"); goto done; } invalid_bps: { g_warning ("invalid bytes_per_sample from acquire ringbuffer, fix the element"); buf->acquired = FALSE; res = FALSE; goto done; } } /** * gst_ring_buffer_release: * @buf: the #GstRingBuffer to release * * Free the resources of the ringbuffer. * * Returns: TRUE if the device could be released, FALSE on error. * * MT safe. */ gboolean gst_ring_buffer_release (GstRingBuffer * buf) { gboolean res = FALSE; GstRingBufferClass *rclass; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), FALSE); GST_DEBUG_OBJECT (buf, "releasing device"); gst_ring_buffer_stop (buf); GST_OBJECT_LOCK (buf); if (G_UNLIKELY (!buf->acquired)) goto was_released; buf->acquired = FALSE; /* if this fails, something is wrong in this file */ g_assert (buf->open == TRUE); rclass = GST_RING_BUFFER_GET_CLASS (buf); if (G_LIKELY (rclass->release)) res = rclass->release (buf); /* signal any waiters */ GST_DEBUG_OBJECT (buf, "signal waiter"); GST_RING_BUFFER_SIGNAL (buf); if (G_UNLIKELY (!res)) goto release_failed; g_free (buf->empty_seg); buf->empty_seg = NULL; GST_DEBUG_OBJECT (buf, "released device"); done: GST_OBJECT_UNLOCK (buf); return res; /* ERRORS */ was_released: { res = TRUE; GST_DEBUG_OBJECT (buf, "device was released"); goto done; } release_failed: { buf->acquired = TRUE; GST_DEBUG_OBJECT (buf, "failed to release device"); goto done; } } /** * gst_ring_buffer_is_acquired: * @buf: the #GstRingBuffer to check * * Check if the ringbuffer is acquired and ready to use. * * Returns: TRUE if the ringbuffer is acquired, FALSE on error. * * MT safe. */ gboolean gst_ring_buffer_is_acquired (GstRingBuffer * buf) { gboolean res; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), FALSE); GST_OBJECT_LOCK (buf); res = buf->acquired; GST_OBJECT_UNLOCK (buf); return res; } /** * gst_ring_buffer_activate: * @buf: the #GstRingBuffer to activate * @active: the new mode * * Activate @buf to start or stop pulling data. * * Returns: TRUE if the device could be activated in the requested mode, * FALSE on error. * * Since: 0.10.22. * * MT safe. */ gboolean gst_ring_buffer_activate (GstRingBuffer * buf, gboolean active) { gboolean res = FALSE; GstRingBufferClass *rclass; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), FALSE); GST_DEBUG_OBJECT (buf, "activate device"); GST_OBJECT_LOCK (buf); if (G_UNLIKELY (active && !buf->acquired)) goto not_acquired; if (G_UNLIKELY (buf->abidata.ABI.active == active)) goto was_active; rclass = GST_RING_BUFFER_GET_CLASS (buf); /* if there is no activate function we assume it was started/released * in the acquire method */ if (G_LIKELY (rclass->activate)) res = rclass->activate (buf, active); else res = TRUE; if (G_UNLIKELY (!res)) goto activate_failed; buf->abidata.ABI.active = active; done: GST_OBJECT_UNLOCK (buf); return res; /* ERRORS */ not_acquired: { GST_DEBUG_OBJECT (buf, "device not acquired"); g_critical ("Device for %p not acquired", buf); res = FALSE; goto done; } was_active: { res = TRUE; GST_DEBUG_OBJECT (buf, "device was active in mode %d", active); goto done; } activate_failed: { GST_DEBUG_OBJECT (buf, "failed to activate device"); goto done; } } /** * gst_ring_buffer_is_active: * @buf: the #GstRingBuffer * * Check if @buf is activated. * * Returns: TRUE if the device is active. * * Since: 0.10.22. * * MT safe. */ gboolean gst_ring_buffer_is_active (GstRingBuffer * buf) { gboolean res; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), FALSE); GST_OBJECT_LOCK (buf); res = buf->abidata.ABI.active; GST_OBJECT_UNLOCK (buf); return res; } /** * gst_ring_buffer_set_flushing: * @buf: the #GstRingBuffer to flush * @flushing: the new mode * * Set the ringbuffer to flushing mode or normal mode. * * MT safe. */ void gst_ring_buffer_set_flushing (GstRingBuffer * buf, gboolean flushing) { g_return_if_fail (GST_IS_RING_BUFFER (buf)); GST_OBJECT_LOCK (buf); buf->abidata.ABI.flushing = flushing; gst_ring_buffer_clear_all (buf); if (flushing) { gst_ring_buffer_pause_unlocked (buf); } GST_OBJECT_UNLOCK (buf); } /** * gst_ring_buffer_start: * @buf: the #GstRingBuffer to start * * Start processing samples from the ringbuffer. * * Returns: TRUE if the device could be started, FALSE on error. * * MT safe. */ gboolean gst_ring_buffer_start (GstRingBuffer * buf) { gboolean res = FALSE; GstRingBufferClass *rclass; gboolean resume = FALSE; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), FALSE); GST_DEBUG_OBJECT (buf, "starting ringbuffer"); GST_OBJECT_LOCK (buf); if (G_UNLIKELY (buf->abidata.ABI.flushing)) goto flushing; if (G_UNLIKELY (!buf->acquired)) goto not_acquired; /* if stopped, set to started */ res = g_atomic_int_compare_and_exchange (&buf->state, GST_RING_BUFFER_STATE_STOPPED, GST_RING_BUFFER_STATE_STARTED); if (!res) { GST_DEBUG_OBJECT (buf, "was not stopped, try paused"); /* was not stopped, try from paused */ res = g_atomic_int_compare_and_exchange (&buf->state, GST_RING_BUFFER_STATE_PAUSED, GST_RING_BUFFER_STATE_STARTED); if (!res) { /* was not paused either, must be started then */ res = TRUE; GST_DEBUG_OBJECT (buf, "was not paused, must have been started"); goto done; } resume = TRUE; GST_DEBUG_OBJECT (buf, "resuming"); } rclass = GST_RING_BUFFER_GET_CLASS (buf); if (resume) { if (G_LIKELY (rclass->resume)) res = rclass->resume (buf); } else { if (G_LIKELY (rclass->start)) res = rclass->start (buf); } if (G_UNLIKELY (!res)) { buf->state = GST_RING_BUFFER_STATE_PAUSED; GST_DEBUG_OBJECT (buf, "failed to start"); } else { GST_DEBUG_OBJECT (buf, "started"); } done: GST_OBJECT_UNLOCK (buf); return res; flushing: { GST_DEBUG_OBJECT (buf, "we are flushing"); GST_OBJECT_UNLOCK (buf); return FALSE; } not_acquired: { GST_DEBUG_OBJECT (buf, "we are not acquired"); GST_OBJECT_UNLOCK (buf); return FALSE; } } static gboolean gst_ring_buffer_pause_unlocked (GstRingBuffer * buf) { gboolean res = FALSE; GstRingBufferClass *rclass; GST_DEBUG_OBJECT (buf, "pausing ringbuffer"); /* if started, set to paused */ res = g_atomic_int_compare_and_exchange (&buf->state, GST_RING_BUFFER_STATE_STARTED, GST_RING_BUFFER_STATE_PAUSED); if (!res) goto not_started; /* signal any waiters */ GST_DEBUG_OBJECT (buf, "signal waiter"); GST_RING_BUFFER_SIGNAL (buf); rclass = GST_RING_BUFFER_GET_CLASS (buf); if (G_LIKELY (rclass->pause)) res = rclass->pause (buf); if (G_UNLIKELY (!res)) { buf->state = GST_RING_BUFFER_STATE_STARTED; GST_DEBUG_OBJECT (buf, "failed to pause"); } else { GST_DEBUG_OBJECT (buf, "paused"); } return res; not_started: { /* was not started */ GST_DEBUG_OBJECT (buf, "was not started"); return TRUE; } } /** * gst_ring_buffer_pause: * @buf: the #GstRingBuffer to pause * * Pause processing samples from the ringbuffer. * * Returns: TRUE if the device could be paused, FALSE on error. * * MT safe. */ gboolean gst_ring_buffer_pause (GstRingBuffer * buf) { gboolean res = FALSE; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), FALSE); GST_OBJECT_LOCK (buf); if (G_UNLIKELY (buf->abidata.ABI.flushing)) goto flushing; if (G_UNLIKELY (!buf->acquired)) goto not_acquired; res = gst_ring_buffer_pause_unlocked (buf); GST_OBJECT_UNLOCK (buf); return res; /* ERRORS */ flushing: { GST_DEBUG_OBJECT (buf, "we are flushing"); GST_OBJECT_UNLOCK (buf); return FALSE; } not_acquired: { GST_DEBUG_OBJECT (buf, "not acquired"); GST_OBJECT_UNLOCK (buf); return FALSE; } } /** * gst_ring_buffer_stop: * @buf: the #GstRingBuffer to stop * * Stop processing samples from the ringbuffer. * * Returns: TRUE if the device could be stopped, FALSE on error. * * MT safe. */ gboolean gst_ring_buffer_stop (GstRingBuffer * buf) { gboolean res = FALSE; GstRingBufferClass *rclass; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), FALSE); GST_DEBUG_OBJECT (buf, "stopping"); GST_OBJECT_LOCK (buf); /* if started, set to stopped */ res = g_atomic_int_compare_and_exchange (&buf->state, GST_RING_BUFFER_STATE_STARTED, GST_RING_BUFFER_STATE_STOPPED); if (!res) { GST_DEBUG_OBJECT (buf, "was not started, try paused"); /* was not started, try from paused */ res = g_atomic_int_compare_and_exchange (&buf->state, GST_RING_BUFFER_STATE_PAUSED, GST_RING_BUFFER_STATE_STOPPED); if (!res) { /* was not paused either, must have been stopped then */ res = TRUE; GST_DEBUG_OBJECT (buf, "was not paused, must have been stopped"); goto done; } } /* signal any waiters */ GST_DEBUG_OBJECT (buf, "signal waiter"); GST_RING_BUFFER_SIGNAL (buf); rclass = GST_RING_BUFFER_GET_CLASS (buf); if (G_LIKELY (rclass->stop)) res = rclass->stop (buf); if (G_UNLIKELY (!res)) { buf->state = GST_RING_BUFFER_STATE_STARTED; GST_DEBUG_OBJECT (buf, "failed to stop"); } else { GST_DEBUG_OBJECT (buf, "stopped"); } done: GST_OBJECT_UNLOCK (buf); return res; } /** * gst_ring_buffer_delay: * @buf: the #GstRingBuffer to query * * Get the number of samples queued in the audio device. This is * usually less than the segment size but can be bigger when the * implementation uses another internal buffer between the audio * device. * * For playback ringbuffers this is the amount of samples transfered from the * ringbuffer to the device but still not played. * * For capture ringbuffers this is the amount of samples in the device that are * not yet transfered to the ringbuffer. * * Returns: The number of samples queued in the audio device. * * MT safe. */ guint gst_ring_buffer_delay (GstRingBuffer * buf) { GstRingBufferClass *rclass; guint res; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), 0); /* buffer must be acquired */ if (G_UNLIKELY (!gst_ring_buffer_is_acquired (buf))) goto not_acquired; rclass = GST_RING_BUFFER_GET_CLASS (buf); if (G_LIKELY (rclass->delay)) res = rclass->delay (buf); else res = 0; return res; not_acquired: { GST_DEBUG_OBJECT (buf, "not acquired"); return 0; } } /** * gst_ring_buffer_samples_done: * @buf: the #GstRingBuffer to query * * Get the number of samples that were processed by the ringbuffer * since it was last started. This does not include the number of samples not * yet processed (see gst_ring_buffer_delay()). * * Returns: The number of samples processed by the ringbuffer. * * MT safe. */ guint64 gst_ring_buffer_samples_done (GstRingBuffer * buf) { gint segdone; guint64 samples; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), 0); /* get the amount of segments we processed */ segdone = g_atomic_int_get (&buf->segdone); /* convert to samples */ samples = ((guint64) segdone) * buf->samples_per_seg; return samples; } /** * gst_ring_buffer_set_sample: * @buf: the #GstRingBuffer to use * @sample: the sample number to set * * Make sure that the next sample written to the device is * accounted for as being the @sample sample written to the * device. This value will be used in reporting the current * sample position of the ringbuffer. * * This function will also clear the buffer with silence. * * MT safe. */ void gst_ring_buffer_set_sample (GstRingBuffer * buf, guint64 sample) { g_return_if_fail (GST_IS_RING_BUFFER (buf)); if (sample == -1) sample = 0; if (G_UNLIKELY (buf->samples_per_seg == 0)) return; /* FIXME, we assume the ringbuffer can restart at a random * position, round down to the beginning and keep track of * offset when calculating the processed samples. */ buf->segbase = buf->segdone - sample / buf->samples_per_seg; gst_ring_buffer_clear_all (buf); GST_DEBUG_OBJECT (buf, "set sample to %llu, segbase %d", sample, buf->segbase); } /** * gst_ring_buffer_clear_all: * @buf: the #GstRingBuffer to clear * * Fill the ringbuffer with silence. * * MT safe. */ void gst_ring_buffer_clear_all (GstRingBuffer * buf) { gint i; g_return_if_fail (GST_IS_RING_BUFFER (buf)); /* not fatal, we just are not negotiated yet */ if (G_UNLIKELY (buf->spec.segtotal <= 0)) return; GST_DEBUG_OBJECT (buf, "clear all segments"); for (i = 0; i < buf->spec.segtotal; i++) { gst_ring_buffer_clear (buf, i); } } static gboolean wait_segment (GstRingBuffer * buf) { /* buffer must be started now or we deadlock since nobody is reading */ if (G_UNLIKELY (g_atomic_int_get (&buf->state) != GST_RING_BUFFER_STATE_STARTED)) { /* see if we are allowed to start it */ if (G_UNLIKELY (g_atomic_int_get (&buf->abidata.ABI.may_start) == FALSE)) goto no_start; GST_DEBUG_OBJECT (buf, "start!"); gst_ring_buffer_start (buf); } /* take lock first, then update our waiting flag */ GST_OBJECT_LOCK (buf); if (G_UNLIKELY (buf->abidata.ABI.flushing)) goto flushing; if (G_UNLIKELY (g_atomic_int_get (&buf->state) != GST_RING_BUFFER_STATE_STARTED)) goto not_started; if (g_atomic_int_compare_and_exchange (&buf->waiting, 0, 1)) { GST_DEBUG_OBJECT (buf, "waiting.."); GST_RING_BUFFER_WAIT (buf); if (G_UNLIKELY (buf->abidata.ABI.flushing)) goto flushing; if (G_UNLIKELY (g_atomic_int_get (&buf->state) != GST_RING_BUFFER_STATE_STARTED)) goto not_started; } GST_OBJECT_UNLOCK (buf); return TRUE; /* ERROR */ not_started: { g_atomic_int_compare_and_exchange (&buf->waiting, 1, 0); GST_DEBUG_OBJECT (buf, "stopped processing"); GST_OBJECT_UNLOCK (buf); return FALSE; } flushing: { g_atomic_int_compare_and_exchange (&buf->waiting, 1, 0); GST_DEBUG_OBJECT (buf, "flushing"); GST_OBJECT_UNLOCK (buf); return FALSE; } no_start: { GST_DEBUG_OBJECT (buf, "not allowed to start"); return FALSE; } } #define FWD_SAMPLES(s,se,d,de) \ G_STMT_START { \ /* no rate conversion */ \ guint towrite = MIN (se + bps - s, de - d); \ /* simple copy */ \ if (!skip) \ memcpy (d, s, towrite); \ in_samples -= towrite / bps; \ out_samples -= towrite / bps; \ s += towrite; \ GST_DEBUG ("copy %u bytes", towrite); \ } G_STMT_END /* in_samples >= out_samples, rate > 1.0 */ #define FWD_UP_SAMPLES(s,se,d,de) \ G_STMT_START { \ guint8 *sb = s, *db = d; \ while (s <= se && d < de) { \ if (!skip) \ memcpy (d, s, bps); \ s += bps; \ *accum += outr; \ if ((*accum << 1) >= inr) { \ *accum -= inr; \ d += bps; \ } \ } \ in_samples -= (s - sb)/bps; \ out_samples -= (d - db)/bps; \ GST_DEBUG ("fwd_up end %d/%d",*accum,*toprocess); \ } G_STMT_END /* out_samples > in_samples, for rates smaller than 1.0 */ #define FWD_DOWN_SAMPLES(s,se,d,de) \ G_STMT_START { \ guint8 *sb = s, *db = d; \ while (s <= se && d < de) { \ if (!skip) \ memcpy (d, s, bps); \ d += bps; \ *accum += inr; \ if ((*accum << 1) >= outr) { \ *accum -= outr; \ s += bps; \ } \ } \ in_samples -= (s - sb)/bps; \ out_samples -= (d - db)/bps; \ GST_DEBUG ("fwd_down end %d/%d",*accum,*toprocess); \ } G_STMT_END #define REV_UP_SAMPLES(s,se,d,de) \ G_STMT_START { \ guint8 *sb = se, *db = d; \ while (s <= se && d < de) { \ if (!skip) \ memcpy (d, se, bps); \ se -= bps; \ *accum += outr; \ while ((*accum << 1) >= inr) { \ *accum -= inr; \ d += bps; \ } \ } \ in_samples -= (sb - se)/bps; \ out_samples -= (d - db)/bps; \ GST_DEBUG ("rev_up end %d/%d",*accum,*toprocess); \ } G_STMT_END #define REV_DOWN_SAMPLES(s,se,d,de) \ G_STMT_START { \ guint8 *sb = se, *db = d; \ while (s <= se && d < de) { \ if (!skip) \ memcpy (d, se, bps); \ d += bps; \ *accum += inr; \ while ((*accum << 1) >= outr) { \ *accum -= outr; \ se -= bps; \ } \ } \ in_samples -= (sb - se)/bps; \ out_samples -= (d - db)/bps; \ GST_DEBUG ("rev_down end %d/%d",*accum,*toprocess); \ } G_STMT_END /** * gst_ring_buffer_commit_full: * @buf: the #GstRingBuffer to commit * @sample: the sample position of the data * @data: the data to commit * @in_samples: the number of samples in the data to commit * @out_samples: the number of samples to write to the ringbuffer * @accum: accumulator for rate conversion. * * Commit @in_samples samples pointed to by @data to the ringbuffer @buf. * * @in_samples and @out_samples define the rate conversion to perform on the the * samples in @data. For negative rates, @out_samples must be negative and * @in_samples positive. * * When @out_samples is positive, the first sample will be written at position @sample * in the ringbuffer. When @out_samples is negative, the last sample will be written to * @sample in reverse order. * * @out_samples does not need to be a multiple of the segment size of the ringbuffer * although it is recommended for optimal performance. * * @accum will hold a temporary accumulator used in rate conversion and should be * set to 0 when this function is first called. In case the commit operation is * interrupted, one can resume the processing by passing the previously returned * @accum value back to this function. * * Returns: The number of samples written to the ringbuffer or -1 on error. The * number of samples written can be less than @out_samples when @buf was interrupted * with a flush or stop. * * Since: 0.10.11. * * MT safe. */ guint gst_ring_buffer_commit_full (GstRingBuffer * buf, guint64 * sample, guchar * data, gint in_samples, gint out_samples, gint * accum) { gint segdone; gint segsize, segtotal, bps, sps; guint8 *dest, *data_end; gint writeseg, sampleoff; gint *toprocess; gint inr, outr; gboolean reverse; if (G_UNLIKELY (in_samples == 0 || out_samples == 0)) return in_samples; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), -1); g_return_val_if_fail (buf->data != NULL, -1); g_return_val_if_fail (data != NULL, -1); dest = GST_BUFFER_DATA (buf->data); segsize = buf->spec.segsize; segtotal = buf->spec.segtotal; bps = buf->spec.bytes_per_sample; sps = buf->samples_per_seg; reverse = out_samples < 0; out_samples = ABS (out_samples); if (in_samples >= out_samples) toprocess = &in_samples; else toprocess = &out_samples; inr = in_samples - 1; outr = out_samples - 1; /* data_end points to the last sample we have to write, not past it. This is * needed to properly handle reverse playback: it points to the last sample. */ data_end = data + (bps * inr); /* figure out the segment and the offset inside the segment where * the first sample should be written. */ writeseg = *sample / sps; sampleoff = (*sample % sps) * bps; /* write out all samples */ while (*toprocess > 0) { gint avail; guint8 *d, *d_end; gint ws; gboolean skip; while (TRUE) { gint diff; /* get the currently processed segment */ segdone = g_atomic_int_get (&buf->segdone) - buf->segbase; /* see how far away it is from the write segment */ diff = writeseg - segdone; GST_DEBUG ("pointer at %d, write to %d-%d, diff %d, segtotal %d, segsize %d", segdone, writeseg, sampleoff, diff, segtotal, segsize); /* segment too far ahead, writer too slow, we need to drop, hopefully UNLIKELY */ if (G_UNLIKELY (diff < 0)) { /* we need to drop one segment at a time, pretend we wrote a * segment. */ skip = TRUE; break; } /* write segment is within writable range, we can break the loop and * start writing the data. */ if (diff < segtotal) { skip = FALSE; break; } /* else we need to wait for the segment to become writable. */ if (!wait_segment (buf)) goto not_started; } /* we can write now */ ws = writeseg % segtotal; avail = MIN (segsize - sampleoff, bps * out_samples); d = dest + (ws * segsize) + sampleoff; d_end = d + avail; *sample += avail / bps; GST_DEBUG_OBJECT (buf, "write @%p seg %d, sps %d, off %d, avail %d", dest + ws * segsize, ws, sps, sampleoff, avail); if (G_LIKELY (inr == outr && !reverse)) { /* no rate conversion, simply copy samples */ FWD_SAMPLES (data, data_end, d, d_end); } else if (!reverse) { if (inr >= outr) /* forward speed up */ FWD_UP_SAMPLES (data, data_end, d, d_end); else /* forward slow down */ FWD_DOWN_SAMPLES (data, data_end, d, d_end); } else { if (inr >= outr) /* reverse speed up */ REV_UP_SAMPLES (data, data_end, d, d_end); else /* reverse slow down */ REV_DOWN_SAMPLES (data, data_end, d, d_end); } /* for the next iteration we write to the next segment at the beginning. */ writeseg++; sampleoff = 0; } /* we consumed all samples here */ data = data_end + bps; done: return inr - ((data_end - data) / bps); /* ERRORS */ not_started: { GST_DEBUG_OBJECT (buf, "stopped processing"); goto done; } } /** * gst_ring_buffer_commit: * @buf: the #GstRingBuffer to commit * @sample: the sample position of the data * @data: the data to commit * @len: the number of samples in the data to commit * * Same as gst_ring_buffer_commit_full() but with a in_samples and out_samples * equal to @len, ignoring accum. * * Returns: The number of samples written to the ringbuffer or -1 on * error. * * MT safe. */ guint gst_ring_buffer_commit (GstRingBuffer * buf, guint64 sample, guchar * data, guint len) { guint res; guint64 samplep = sample; res = gst_ring_buffer_commit_full (buf, &samplep, data, len, len, NULL); return res; } /** * gst_ring_buffer_read: * @buf: the #GstRingBuffer to read from * @sample: the sample position of the data * @data: where the data should be read * @len: the number of samples in data to read * * Read @len samples from the ringbuffer into the memory pointed * to by @data. * The first sample should be read from position @sample in * the ringbuffer. * * @len should not be a multiple of the segment size of the ringbuffer * although it is recommended. * * Returns: The number of samples read from the ringbuffer or -1 on * error. * * MT safe. */ guint gst_ring_buffer_read (GstRingBuffer * buf, guint64 sample, guchar * data, guint len) { gint segdone; gint segsize, segtotal, bps, sps; guint8 *dest; guint to_read; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), -1); g_return_val_if_fail (buf->data != NULL, -1); g_return_val_if_fail (data != NULL, -1); dest = GST_BUFFER_DATA (buf->data); segsize = buf->spec.segsize; segtotal = buf->spec.segtotal; bps = buf->spec.bytes_per_sample; sps = buf->samples_per_seg; to_read = len; /* read enough samples */ while (to_read > 0) { gint sampleslen; gint readseg, sampleoff; /* figure out the segment and the offset inside the segment where * the sample should be read from. */ readseg = sample / sps; sampleoff = (sample % sps); while (TRUE) { gint diff; /* get the currently processed segment */ segdone = g_atomic_int_get (&buf->segdone) - buf->segbase; /* see how far away it is from the read segment, normally segdone (where * the hardware is writing) is bigger than readseg (where software is * reading) */ diff = segdone - readseg; GST_DEBUG ("pointer at %d, sample %llu, read from %d-%d, to_read %d, diff %d, segtotal %d, segsize %d", segdone, sample, readseg, sampleoff, to_read, diff, segtotal, segsize); /* segment too far ahead, reader too slow */ if (G_UNLIKELY (diff >= segtotal)) { /* pretend we read an empty segment. */ sampleslen = MIN (sps, to_read); memcpy (data, buf->empty_seg, sampleslen * bps); goto next; } /* read segment is within readable range, we can break the loop and * start reading the data. */ if (diff > 0) break; /* else we need to wait for the segment to become readable. */ if (!wait_segment (buf)) goto not_started; } /* we can read now */ readseg = readseg % segtotal; sampleslen = MIN (sps - sampleoff, to_read); GST_DEBUG_OBJECT (buf, "read @%p seg %d, off %d, sampleslen %d", dest + readseg * segsize, readseg, sampleoff, sampleslen); memcpy (data, dest + (readseg * segsize) + (sampleoff * bps), (sampleslen * bps)); next: to_read -= sampleslen; sample += sampleslen; data += sampleslen * bps; } return len - to_read; /* ERRORS */ not_started: { GST_DEBUG_OBJECT (buf, "stopped processing"); return len - to_read; } } /** * gst_ring_buffer_prepare_read: * @buf: the #GstRingBuffer to read from * @segment: the segment to read * @readptr: the pointer to the memory where samples can be read * @len: the number of bytes to read * * Returns a pointer to memory where the data from segment @segment * can be found. This function is mostly used by subclasses. * * Returns: FALSE if the buffer is not started. * * MT safe. */ gboolean gst_ring_buffer_prepare_read (GstRingBuffer * buf, gint * segment, guint8 ** readptr, gint * len) { guint8 *data; gint segdone; g_return_val_if_fail (GST_IS_RING_BUFFER (buf), FALSE); g_return_val_if_fail (buf->data != NULL, FALSE); g_return_val_if_fail (segment != NULL, FALSE); g_return_val_if_fail (readptr != NULL, FALSE); g_return_val_if_fail (len != NULL, FALSE); data = GST_BUFFER_DATA (buf->data); if (buf->callback == NULL) { /* push mode, fail when nothing is started */ if (g_atomic_int_get (&buf->state) != GST_RING_BUFFER_STATE_STARTED) return FALSE; } /* get the position of the pointer */ segdone = g_atomic_int_get (&buf->segdone); *segment = segdone % buf->spec.segtotal; *len = buf->spec.segsize; *readptr = data + *segment * *len; GST_LOG ("prepare read from segment %d (real %d) @%p", *segment, segdone, *readptr); /* callback to fill the memory with data, for pull based * scheduling. */ if (buf->callback) buf->callback (buf, *readptr, *len, buf->cb_data); return TRUE; } /** * gst_ring_buffer_advance: * @buf: the #GstRingBuffer to advance * @advance: the number of segments written * * Subclasses should call this function to notify the fact that * @advance segments are now processed by the device. * * MT safe. */ void gst_ring_buffer_advance (GstRingBuffer * buf, guint advance) { g_return_if_fail (GST_IS_RING_BUFFER (buf)); /* update counter */ g_atomic_int_add (&buf->segdone, advance); /* the lock is already taken when the waiting flag is set, * we grab the lock as well to make sure the waiter is actually * waiting for the signal */ if (g_atomic_int_compare_and_exchange (&buf->waiting, 1, 0)) { GST_OBJECT_LOCK (buf); GST_DEBUG_OBJECT (buf, "signal waiter"); GST_RING_BUFFER_SIGNAL (buf); GST_OBJECT_UNLOCK (buf); } } /** * gst_ring_buffer_clear: * @buf: the #GstRingBuffer to clear * @segment: the segment to clear * * Clear the given segment of the buffer with silence samples. * This function is used by subclasses. * * MT safe. */ void gst_ring_buffer_clear (GstRingBuffer * buf, gint segment) { guint8 *data; g_return_if_fail (GST_IS_RING_BUFFER (buf)); /* no data means it's already cleared */ if (G_UNLIKELY (buf->data == NULL)) return; /* no empty_seg means it's not opened */ if (G_UNLIKELY (buf->empty_seg == NULL)) return; segment %= buf->spec.segtotal; data = GST_BUFFER_DATA (buf->data); data += segment * buf->spec.segsize; GST_LOG ("clear segment %d @%p", segment, data); memcpy (data, buf->empty_seg, buf->spec.segsize); } /** * gst_ring_buffer_may_start: * @buf: the #GstRingBuffer * @allowed: the new value * * Tell the ringbuffer that it is allowed to start playback when * the ringbuffer is filled with samples. * * Since: 0.10.6 * * MT safe. */ void gst_ring_buffer_may_start (GstRingBuffer * buf, gboolean allowed) { g_return_if_fail (GST_IS_RING_BUFFER (buf)); GST_LOG_OBJECT (buf, "may start: %d", allowed); g_atomic_int_set (&buf->abidata.ABI.may_start, allowed); }