/* GStreamer * Copyright (C) 1999,2000 Erik Walthinsen * 2000 Wim Taymans * 2005 Wim Taymans * 2005 Andy Wingo * 2005 Thomas Vander Stichele * * 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:gstbasetransform * @short_description: Base class for simple transform filters * @see_also: #GstBaseSrc, #GstBaseSink * * This base class is for filter elements that process data. * * It provides for: * * one sinkpad and one srcpad * * Possible formats on sink and source pad implemented * with custom transform_caps function. By default uses * same format on sink and source. * * Handles state changes * Does flushing * Push mode * * Pull mode if the sub-class transform can operate on arbitrary data * * * * Use Cases: * * * Passthrough mode * * Element has no interest in modifying the buffer. It may want to inspect it, * in which case the element should have a transform_ip function. If there * is no transform_ip function in passthrough mode, the buffer is pushed * intact. * * * On the GstBaseTransformClass is the passthrough_on_same_caps variable * which will automatically set/unset passthrough based on whether the * element negotiates the same caps on both pads. * * * passthrough_on_same_caps on an element that doesn't implement a transform_caps * function is useful for elements that only inspect data (such as level) * * * * Example elements * Level * Videoscale, audioconvert, ffmpegcolorspace, audioresample in certain modes. * * * * Modifications in-place - input buffer and output buffer are the same thing. * * The element must implement a transform_ip function. * * * Output buffer size must <= input buffer size * * * If the always_in_place flag is set, non-writable buffers will be copied and * passed to the transform_ip function, otherwise a new buffer will be created * and the transform function called. * * * Incoming writable buffers will be passed to the transform_ip function immediately. * * * only implementing transform_ip and not transform implies always_in_place = * TRUE * * * * Example elements * Volume * Audioconvert in certain modes (signed/unsigned conversion) * ffmpegcolorspace in certain modes (endianness swapping) * * * * Modifications only to the caps/metadata of a buffer * * The element does not require writable data, but non-writable buffers should * be subbuffered so that the meta-information can be replaced. * * * Elements wishing to operate in this mode should replace the * prepare_output_buffer method to create subbuffers of the input buffer and * set always_in_place to TRUE * * * * Example elements * Capsfilter when setting caps on outgoing buffers that have none. * identity when it is going to re-timestamp buffers by datarate. * * * * Normal mode * * always_in_place flag is not set, or there is no transform_ip function * * * Element will receive an input buffer and output buffer to operate on. * * * Output buffer is allocated by calling the prepare_output_buffer function. * * * * Example elements * Videoscale, ffmpegcolorspace, audioconvert when doing scaling/conversions * * * * Special output buffer allocations * * Elements which need to do special allocation of their output buffers other * than what gst_buffer_pad_alloc allows should implement a * prepare_output_buffer method, which calls the parent implementation and * passes the newly allocated buffer. * * * * Example elements * efence * * * * * Sub-class settable flags on GstBaseTransform * * passthrough * * Implies that in the current configuration, the sub-class is not * interested in modifying the buffers. * * * Elements which are always in passthrough mode whenever the same caps has * been negotiated on both pads can set the class variable * passthrough_on_same_caps to have this behaviour automatically. * * * * * always_in_place * * Determines whether a non-writable buffer will be copied before passing * to the transform_ip function. * * * Implied TRUE if no transform function is implemented. * * * Implied FALSE if ONLY transform function is implemented. * * * * * */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include "../../../gst/gst-i18n-lib.h" #include "gstbasetransform.h" #include GST_DEBUG_CATEGORY_STATIC (gst_base_transform_debug); #define GST_CAT_DEFAULT gst_base_transform_debug /* BaseTransform signals and args */ enum { /* FILL ME */ LAST_SIGNAL }; enum { PROP_0, }; static GstElementClass *parent_class = NULL; static void gst_base_transform_base_init (gpointer g_class); static void gst_base_transform_class_init (GstBaseTransformClass * klass); static void gst_base_transform_init (GstBaseTransform * trans, GstBaseTransformClass * klass); static GstFlowReturn gst_base_transform_prepare_output_buffer (GstBaseTransform * trans, GstBuffer * input, gint size, GstCaps * caps, GstBuffer ** buf); GType gst_base_transform_get_type (void) { static GType base_transform_type = 0; if (!base_transform_type) { static const GTypeInfo base_transform_info = { sizeof (GstBaseTransformClass), (GBaseInitFunc) gst_base_transform_base_init, NULL, (GClassInitFunc) gst_base_transform_class_init, NULL, NULL, sizeof (GstBaseTransform), 0, (GInstanceInitFunc) gst_base_transform_init, }; base_transform_type = g_type_register_static (GST_TYPE_ELEMENT, "GstBaseTransform", &base_transform_info, G_TYPE_FLAG_ABSTRACT); } return base_transform_type; } static void gst_base_transform_finalize (GObject * object); static void gst_base_transform_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec); static void gst_base_transform_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec); static gboolean gst_base_transform_src_activate_pull (GstPad * pad, gboolean active); static gboolean gst_base_transform_sink_activate_push (GstPad * pad, gboolean active); static gboolean gst_base_transform_get_unit_size (GstBaseTransform * trans, GstCaps * caps, guint * size); static GstStateChangeReturn gst_base_transform_change_state (GstElement * element, GstStateChange transition); static gboolean gst_base_transform_event (GstPad * pad, GstEvent * event); static gboolean gst_base_transform_eventfunc (GstBaseTransform * trans, GstEvent * event); static GstFlowReturn gst_base_transform_getrange (GstPad * pad, guint64 offset, guint length, GstBuffer ** buffer); static GstFlowReturn gst_base_transform_chain (GstPad * pad, GstBuffer * buffer); static GstCaps *gst_base_transform_getcaps (GstPad * pad); static gboolean gst_base_transform_setcaps (GstPad * pad, GstCaps * caps); static GstFlowReturn gst_base_transform_buffer_alloc (GstPad * pad, guint64 offset, guint size, GstCaps * caps, GstBuffer ** buf); /* static guint gst_base_transform_signals[LAST_SIGNAL] = { 0 }; */ static void gst_base_transform_base_init (gpointer g_class) { GST_DEBUG_CATEGORY_INIT (gst_base_transform_debug, "basetransform", 0, "basetransform element"); } static void gst_base_transform_finalize (GObject * object) { GstBaseTransform *trans; trans = GST_BASE_TRANSFORM (object); g_mutex_free (trans->transform_lock); G_OBJECT_CLASS (parent_class)->finalize (object); } static void gst_base_transform_class_init (GstBaseTransformClass * klass) { GObjectClass *gobject_class; GstElementClass *gstelement_class; gobject_class = G_OBJECT_CLASS (klass); gstelement_class = GST_ELEMENT_CLASS (klass); parent_class = g_type_class_peek_parent (klass); gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_base_transform_set_property); gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_base_transform_get_property); gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_base_transform_finalize); gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_base_transform_change_state); klass->passthrough_on_same_caps = FALSE; klass->event = GST_DEBUG_FUNCPTR (gst_base_transform_eventfunc); } static void gst_base_transform_init (GstBaseTransform * trans, GstBaseTransformClass * bclass) { GstPadTemplate *pad_template; GST_DEBUG ("gst_base_transform_init"); pad_template = gst_element_class_get_pad_template (GST_ELEMENT_CLASS (bclass), "sink"); g_return_if_fail (pad_template != NULL); trans->sinkpad = gst_pad_new_from_template (pad_template, "sink"); gst_pad_set_getcaps_function (trans->sinkpad, GST_DEBUG_FUNCPTR (gst_base_transform_getcaps)); gst_pad_set_setcaps_function (trans->sinkpad, GST_DEBUG_FUNCPTR (gst_base_transform_setcaps)); gst_pad_set_event_function (trans->sinkpad, GST_DEBUG_FUNCPTR (gst_base_transform_event)); gst_pad_set_chain_function (trans->sinkpad, GST_DEBUG_FUNCPTR (gst_base_transform_chain)); gst_pad_set_activatepush_function (trans->sinkpad, GST_DEBUG_FUNCPTR (gst_base_transform_sink_activate_push)); gst_pad_set_bufferalloc_function (trans->sinkpad, GST_DEBUG_FUNCPTR (gst_base_transform_buffer_alloc)); gst_element_add_pad (GST_ELEMENT (trans), trans->sinkpad); pad_template = gst_element_class_get_pad_template (GST_ELEMENT_CLASS (bclass), "src"); g_return_if_fail (pad_template != NULL); trans->srcpad = gst_pad_new_from_template (pad_template, "src"); gst_pad_set_getcaps_function (trans->srcpad, GST_DEBUG_FUNCPTR (gst_base_transform_getcaps)); gst_pad_set_setcaps_function (trans->srcpad, GST_DEBUG_FUNCPTR (gst_base_transform_setcaps)); gst_pad_set_getrange_function (trans->srcpad, GST_DEBUG_FUNCPTR (gst_base_transform_getrange)); gst_pad_set_activatepull_function (trans->srcpad, GST_DEBUG_FUNCPTR (gst_base_transform_src_activate_pull)); gst_element_add_pad (GST_ELEMENT (trans), trans->srcpad); trans->transform_lock = g_mutex_new (); trans->delay_configure = FALSE; trans->pending_configure = FALSE; trans->cache_caps1 = NULL; trans->cache_caps2 = NULL; trans->passthrough = FALSE; if (bclass->transform == NULL) { /* If no transform function, always_in_place is TRUE */ GST_DEBUG_OBJECT (trans, "setting in_place TRUE"); trans->always_in_place = TRUE; if (bclass->transform_ip == NULL) trans->passthrough = TRUE; } } /* given @caps on the src or sink pad (given by @direction) * calculate the possible caps on the other pad. * * Returns new caps, unref after usage. */ static GstCaps * gst_base_transform_transform_caps (GstBaseTransform * trans, GstPadDirection direction, GstCaps * caps) { GstCaps *ret; GstBaseTransformClass *klass; klass = GST_BASE_TRANSFORM_GET_CLASS (trans); /* if there is a custom transform function, use this */ if (klass->transform_caps) { GstCaps *temp; gint i; /* start with empty caps */ ret = gst_caps_new_empty (); if (gst_caps_is_any (caps)) { /* for any caps we still have to call the transform function */ GST_DEBUG_OBJECT (trans, "from ANY:"); temp = klass->transform_caps (trans, direction, caps); GST_DEBUG_OBJECT (trans, " to: %" GST_PTR_FORMAT, temp); temp = gst_caps_make_writable (temp); gst_caps_append (ret, temp); } else { /* we send caps with just one structure to the transform * function as this is easier for the element */ for (i = 0; i < gst_caps_get_size (caps); i++) { GstCaps *nth; nth = gst_caps_copy_nth (caps, i); GST_DEBUG_OBJECT (trans, "from[%d]: %" GST_PTR_FORMAT, i, nth); temp = klass->transform_caps (trans, direction, nth); gst_caps_unref (nth); GST_DEBUG_OBJECT (trans, " to[%d]: %" GST_PTR_FORMAT, i, temp); temp = gst_caps_make_writable (temp); gst_caps_append (ret, temp); } } } else { /* else use the identity transform */ ret = gst_caps_ref (caps); } GST_DEBUG_OBJECT (trans, "to: %" GST_PTR_FORMAT, ret); return ret; } static gboolean gst_base_transform_transform_size (GstBaseTransform * trans, GstPadDirection direction, GstCaps * caps, guint size, GstCaps * othercaps, guint * othersize) { guint inunitsize, outunitsize, units; GstBaseTransformClass *klass; gboolean ret; klass = GST_BASE_TRANSFORM_GET_CLASS (trans); GST_DEBUG_OBJECT (trans, "asked to transform size %d for caps %" GST_PTR_FORMAT " to size for caps %" GST_PTR_FORMAT " in direction %s", size, caps, othercaps, direction == GST_PAD_SRC ? "SRC" : "SINK"); /* if there is a custom transform function, use this */ if (klass->transform_size) { ret = klass->transform_size (trans, direction, caps, size, othercaps, othersize); } else { if (!gst_base_transform_get_unit_size (trans, caps, &inunitsize)) goto no_in_size; GST_DEBUG_OBJECT (trans, "input size %d, input unit size %d", size, inunitsize); if (inunitsize == 0 || (size % inunitsize != 0)) goto no_multiple; units = size / inunitsize; if (!gst_base_transform_get_unit_size (trans, othercaps, &outunitsize)) goto no_out_size; *othersize = units * outunitsize; GST_DEBUG_OBJECT (trans, "transformed size to %d", *othersize); ret = TRUE; } return ret; /* ERRORS */ no_in_size: { GST_DEBUG_OBJECT (trans, "could not get in_size"); g_warning ("could not get in_size"); return FALSE; } no_multiple: { GST_DEBUG_OBJECT (trans, "Size %u is not a multiple of unit size %u", size, inunitsize); g_warning ("Size %u is not a multiple of unit size %u", size, inunitsize); return FALSE; } no_out_size: { GST_DEBUG_OBJECT (trans, "could not get out_size"); g_warning ("could not get out_size"); return FALSE; } } static GstCaps * gst_base_transform_getcaps (GstPad * pad) { GstBaseTransform *trans; GstPad *otherpad; GstCaps *caps; trans = GST_BASE_TRANSFORM (gst_pad_get_parent (pad)); otherpad = (pad == trans->srcpad) ? trans->sinkpad : trans->srcpad; /* we can do what the peer can */ caps = gst_pad_peer_get_caps (otherpad); if (caps) { GstCaps *temp; const GstCaps *templ; GST_DEBUG_OBJECT (pad, "peer caps %" GST_PTR_FORMAT, caps); /* filtered against our padtemplate */ templ = gst_pad_get_pad_template_caps (otherpad); GST_DEBUG_OBJECT (pad, "our template %" GST_PTR_FORMAT, templ); temp = gst_caps_intersect (caps, templ); GST_DEBUG_OBJECT (pad, "intersected %" GST_PTR_FORMAT, temp); gst_caps_unref (caps); /* then see what we can transform this to */ caps = gst_base_transform_transform_caps (trans, GST_PAD_DIRECTION (otherpad), temp); GST_DEBUG_OBJECT (pad, "transformed %" GST_PTR_FORMAT, caps); gst_caps_unref (temp); if (caps == NULL) goto done; /* and filter against the template again */ templ = gst_pad_get_pad_template_caps (pad); GST_DEBUG_OBJECT (pad, "our template %" GST_PTR_FORMAT, templ); temp = gst_caps_intersect (caps, templ); GST_DEBUG_OBJECT (pad, "intersected %" GST_PTR_FORMAT, temp); gst_caps_unref (caps); /* this is what we can do */ caps = temp; } else { /* no peer, our padtemplate is enough then */ caps = gst_caps_copy (gst_pad_get_pad_template_caps (pad)); } done: GST_DEBUG_OBJECT (trans, "returning %" GST_PTR_FORMAT, caps); gst_object_unref (trans); return caps; } /* function triggered when the in and out caps are negotiated and need * to be configured in the subclass. */ static gboolean gst_base_transform_configure_caps (GstBaseTransform * trans, GstCaps * in, GstCaps * out) { gboolean ret = TRUE; GstBaseTransformClass *klass; klass = GST_BASE_TRANSFORM_GET_CLASS (trans); /* clear the cache */ gst_caps_replace (&trans->cache_caps1, NULL); gst_caps_replace (&trans->cache_caps2, NULL); /* If we've a transform_ip method and same input/output caps, set in_place * by default. If for some reason the sub-class prefers using a transform * function, it can clear the in place flag in the set_caps */ gst_base_transform_set_in_place (trans, klass->transform_ip && trans->have_same_caps); /* Set the passthrough if the class wants passthrough_on_same_caps * and we have the same caps on each pad */ if (klass->passthrough_on_same_caps) gst_base_transform_set_passthrough (trans, trans->have_same_caps); /* now configure the element with the caps */ if (klass->set_caps) { GST_DEBUG_OBJECT (trans, "Calling set_caps method to setup caps"); ret = klass->set_caps (trans, in, out); } trans->negotiated = ret; return ret; } /* called when new caps arrive on the sink or source pad */ static gboolean gst_base_transform_setcaps (GstPad * pad, GstCaps * caps) { GstBaseTransform *trans; GstBaseTransformClass *klass; GstPad *otherpad, *otherpeer; GstCaps *othercaps = NULL; gboolean ret = TRUE; gboolean peer_checked = FALSE; trans = GST_BASE_TRANSFORM (gst_pad_get_parent (pad)); klass = GST_BASE_TRANSFORM_GET_CLASS (trans); otherpad = (pad == trans->srcpad) ? trans->sinkpad : trans->srcpad; otherpeer = gst_pad_get_peer (otherpad); /* if we get called recursively, we bail out now to avoid an * infinite loop. */ if (GST_PAD_IS_IN_SETCAPS (otherpad)) goto done; /* caps must be fixed here */ if (!gst_caps_is_fixed (caps)) goto unfixed_caps; /* see how we can transform the input caps. */ othercaps = gst_base_transform_transform_caps (trans, GST_PAD_DIRECTION (pad), caps); /* The caps we can actually output is the intersection of the transformed * caps with the pad template for the pad */ if (othercaps) { GstCaps *intersect; const GstCaps *templ_caps; templ_caps = gst_pad_get_pad_template_caps (otherpad); intersect = gst_caps_intersect (othercaps, templ_caps); gst_caps_unref (othercaps); othercaps = intersect; } /* check if transform is empty */ if (!othercaps || gst_caps_is_empty (othercaps)) goto no_transform; /* if the othercaps are not fixed, we need to fixate them, first attempt * is by attempting passthrough if the othercaps are a superset of caps. */ if (!gst_caps_is_fixed (othercaps)) { GstCaps *temp; GST_DEBUG_OBJECT (trans, "transform returned non fixed %" GST_PTR_FORMAT, othercaps); /* see if the target caps are a superset of the source caps, in this * case we can try to perform passthrough */ temp = gst_caps_intersect (othercaps, caps); GST_DEBUG_OBJECT (trans, "intersect returned %" GST_PTR_FORMAT, temp); if (temp) { if (!gst_caps_is_empty (temp) && otherpeer) { GST_DEBUG_OBJECT (trans, "try passthrough with %" GST_PTR_FORMAT, caps); /* try passthrough. we know it's fixed, because caps is fixed */ if (gst_pad_accept_caps (otherpeer, caps)) { GST_DEBUG_OBJECT (trans, "peer accepted %" GST_PTR_FORMAT, caps); /* peer accepted unmodified caps, we free the original non-fixed * caps and work with the passthrough caps */ gst_caps_unref (othercaps); othercaps = gst_caps_ref (caps); /* mark that we checked othercaps with the peer, this * makes sure we don't call accept_caps again with these same * caps */ peer_checked = TRUE; } else { GST_DEBUG_OBJECT (trans, "peer did not accept %" GST_PTR_FORMAT, caps); } } gst_caps_unref (temp); } } /* second attempt at fixation is done by intersecting with * the peer caps */ if (!gst_caps_is_fixed (othercaps) && otherpeer) { /* intersect against what the peer can do */ GstCaps *peercaps; GstCaps *intersect; GST_DEBUG_OBJECT (trans, "othercaps now %" GST_PTR_FORMAT, othercaps); peercaps = gst_pad_get_caps (otherpeer); intersect = gst_caps_intersect (peercaps, othercaps); gst_caps_unref (peercaps); gst_caps_unref (othercaps); othercaps = intersect; peer_checked = FALSE; GST_DEBUG_OBJECT (trans, "filtering against peer yields %" GST_PTR_FORMAT, othercaps); } if (gst_caps_is_empty (othercaps)) goto no_transform_possible; /* third attempt at fixation, call the fixate vmethod and * ultimately call the pad fixate function. */ if (!gst_caps_is_fixed (othercaps)) { GstCaps *temp; GST_DEBUG_OBJECT (trans, "trying to fixate %" GST_PTR_FORMAT " on pad %s:%s", othercaps, GST_DEBUG_PAD_NAME (otherpad)); /* since we have no other way to fixate left, we might as well just take * the first of the caps list and fixate that */ /* FIXME: when fixating using the vmethod, it might make sense to fixate * each of the caps; but Wim doesn't see a use case for that yet */ temp = gst_caps_copy_nth (othercaps, 0); gst_caps_unref (othercaps); othercaps = temp; peer_checked = FALSE; if (klass->fixate_caps) { GST_DEBUG_OBJECT (trans, "trying to fixate %" GST_PTR_FORMAT " using caps %" GST_PTR_FORMAT " on pad %s:%s using fixate_caps vmethod", othercaps, caps, GST_DEBUG_PAD_NAME (otherpad)); klass->fixate_caps (trans, GST_PAD_DIRECTION (pad), caps, othercaps); } /* if still not fixed, no other option but to let the default pad fixate * function do its job */ if (!gst_caps_is_fixed (othercaps)) { GST_DEBUG_OBJECT (trans, "trying to fixate %" GST_PTR_FORMAT " on pad %s:%s using gst_pad_fixate_caps", othercaps, GST_DEBUG_PAD_NAME (otherpad)); gst_pad_fixate_caps (otherpad, othercaps); } GST_DEBUG_OBJECT (trans, "after fixating %" GST_PTR_FORMAT, othercaps); } /* caps should be fixed now, if not we have to fail. */ if (!gst_caps_is_fixed (othercaps)) goto could_not_fixate; /* and peer should accept, don't check again if we already checked the * othercaps against the peer. */ if (!peer_checked && otherpeer && !gst_pad_accept_caps (otherpeer, othercaps)) goto peer_no_accept; GST_DEBUG_OBJECT (trans, "got final caps %" GST_PTR_FORMAT, othercaps); trans->have_same_caps = gst_caps_is_equal (caps, othercaps); GST_DEBUG_OBJECT (trans, "have_same_caps: %d", trans->have_same_caps); /* see if we have to configure the element now */ if (!trans->delay_configure) { GstCaps *incaps, *outcaps; /* make sure in and out caps are correct */ if (pad == trans->sinkpad) { incaps = caps; outcaps = othercaps; } else { incaps = othercaps; outcaps = caps; } /* call configure now */ if (!(ret = gst_base_transform_configure_caps (trans, incaps, outcaps))) goto failed_configure; } else { /* set pending configure, the configure will happen later with the * caps we set on the pads above. */ trans->pending_configure = TRUE; } /* we know this will work, we implement the setcaps */ gst_pad_set_caps (otherpad, othercaps); done: if (otherpeer) gst_object_unref (otherpeer); if (othercaps) gst_caps_unref (othercaps); trans->negotiated = ret; gst_object_unref (trans); return ret; /* ERRORS */ unfixed_caps: { GST_DEBUG_OBJECT (trans, "caps are not fixed %" GST_PTR_FORMAT, caps); ret = FALSE; goto done; } no_transform: { GST_DEBUG_OBJECT (trans, "transform returned useless %" GST_PTR_FORMAT, othercaps); ret = FALSE; goto done; } no_transform_possible: { GST_DEBUG_OBJECT (trans, "transform could not transform %" GST_PTR_FORMAT " in anything we support", caps); ret = FALSE; goto done; } could_not_fixate: { GST_ERROR_OBJECT (trans, "FAILED to fixate %" GST_PTR_FORMAT, othercaps); ret = FALSE; goto done; } peer_no_accept: { GST_DEBUG_OBJECT (trans, "FAILED to get peer of %" GST_PTR_FORMAT " to accept %" GST_PTR_FORMAT, otherpad, othercaps); ret = FALSE; goto done; } failed_configure: { GST_DEBUG_OBJECT (trans, "FAILED to configure caps %" GST_PTR_FORMAT " to accept %" GST_PTR_FORMAT, otherpad, othercaps); ret = FALSE; goto done; } } /* Allocate a buffer using gst_pad_alloc_buffer * * This function does not do renegotiation on the source pad */ static GstFlowReturn gst_base_transform_prepare_output_buffer (GstBaseTransform * trans, GstBuffer * in_buf, gint out_size, GstCaps * out_caps, GstBuffer ** out_buf) { GstBaseTransformClass *bclass; GstFlowReturn ret = GST_FLOW_OK; gboolean copy_inbuf = FALSE; bclass = GST_BASE_TRANSFORM_GET_CLASS (trans); /* we cannot reconfigure the element yet as we are still processing * the old buffer. We will therefore delay the reconfiguration of the * element until we have processed this last buffer. */ trans->delay_configure = TRUE; /* out_caps is the caps of the src pad gathered through the GST_PAD_CAPS macro. If a set_caps occurs during this function this caps will become invalid. We want to keep them during preparation of the output buffer. */ if (out_caps) gst_caps_ref (out_caps); /* see if the subclass wants to alloc a buffer */ if (bclass->prepare_output_buffer) { ret = bclass->prepare_output_buffer (trans, in_buf, out_size, out_caps, out_buf); if (ret != GST_FLOW_OK) goto done; } /* See if we want to prepare the buffer for in place output */ if (*out_buf == NULL && GST_BUFFER_SIZE (in_buf) == out_size && bclass->transform_ip) { if (gst_buffer_is_writable (in_buf)) { if (trans->have_same_caps) { /* Input buffer is already writable and caps are the same, just ref and return it */ *out_buf = in_buf; gst_buffer_ref (in_buf); } else { /* Writable buffer, but need to change caps => subbuffer */ *out_buf = gst_buffer_create_sub (in_buf, 0, GST_BUFFER_SIZE (in_buf)); gst_caps_replace (&GST_BUFFER_CAPS (*out_buf), out_caps); } goto done; } else { /* Make a writable buffer below and copy the data */ copy_inbuf = TRUE; } } if (*out_buf == NULL) { /* Sub-class didn't already provide a buffer for us. Make one */ ret = gst_pad_alloc_buffer (trans->srcpad, GST_BUFFER_OFFSET (in_buf), out_size, out_caps, out_buf); if (ret != GST_FLOW_OK || *out_buf == NULL) goto done; /* allocated buffer could be of different caps than what we requested */ if (G_UNLIKELY (!gst_caps_is_equal (out_caps, GST_BUFFER_CAPS (*out_buf)))) { /* FIXME, it is possible we can reconfigure the transform with new caps at this * point but for now we just create a buffer ourselves */ gst_buffer_unref (*out_buf); *out_buf = gst_buffer_new_and_alloc (out_size); gst_buffer_set_caps (*out_buf, out_caps); } } /* If the output buffer metadata is modifiable, copy timestamps and * buffer flags */ if (*out_buf != in_buf && gst_buffer_is_metadata_writable (*out_buf)) { if (copy_inbuf && gst_buffer_is_writable (*out_buf)) memcpy (GST_BUFFER_DATA (*out_buf), GST_BUFFER_DATA (in_buf), out_size); gst_buffer_stamp (*out_buf, in_buf); GST_BUFFER_FLAGS (*out_buf) |= GST_BUFFER_FLAGS (in_buf) & (GST_BUFFER_FLAG_PREROLL | GST_BUFFER_FLAG_DISCONT | GST_BUFFER_FLAG_IN_CAPS | GST_BUFFER_FLAG_DELTA_UNIT); } done: if (out_caps) gst_caps_unref (out_caps); trans->delay_configure = FALSE; return ret; } /* Given @caps calcultate the size of one unit. * * For video caps, this is the size of one frame (and thus one buffer). * For audio caps, this is the size of one sample. * * These values are cached since they do not change and the calculation * potentially involves parsing caps and other expensive stuff. * * We have two cache locations to store the size, one for the source caps * and one for the sink caps. * * this function returns FALSE if no size could be calculated. */ static gboolean gst_base_transform_get_unit_size (GstBaseTransform * trans, GstCaps * caps, guint * size) { gboolean res = FALSE; GstBaseTransformClass *bclass; /* see if we have the result cached */ if (trans->cache_caps1 == caps) { *size = trans->cache_caps1_size; GST_DEBUG_OBJECT (trans, "returned %d from first cache", *size); return TRUE; } if (trans->cache_caps2 == caps) { *size = trans->cache_caps2_size; GST_DEBUG_OBJECT (trans, "returned %d from second cached", *size); return TRUE; } bclass = GST_BASE_TRANSFORM_GET_CLASS (trans); if (bclass->get_unit_size) { res = bclass->get_unit_size (trans, caps, size); GST_DEBUG_OBJECT (trans, "caps %" GST_PTR_FORMAT ") has unit size %d, result %s", caps, *size, res ? "TRUE" : "FALSE"); if (res) { /* and cache the values */ if (trans->cache_caps1 == NULL) { gst_caps_replace (&trans->cache_caps1, caps); trans->cache_caps1_size = *size; GST_DEBUG_OBJECT (trans, "caching %d in first cache", *size); } else if (trans->cache_caps2 == NULL) { gst_caps_replace (&trans->cache_caps2, caps); trans->cache_caps2_size = *size; GST_DEBUG_OBJECT (trans, "caching %d in second cache", *size); } else { GST_DEBUG_OBJECT (trans, "no free spot to cache unit_size"); } } } else { GST_DEBUG_OBJECT (trans, "Sub-class does not implement get_unit_size"); } return res; } /* your upstream peer wants to send you a buffer * that buffer has the given offset, size and caps * you're requested to allocate a buffer */ static GstFlowReturn gst_base_transform_buffer_alloc (GstPad * pad, guint64 offset, guint size, GstCaps * caps, GstBuffer ** buf) { GstBaseTransform *trans; GstFlowReturn res; guint new_size; trans = GST_BASE_TRANSFORM (gst_pad_get_parent (pad)); /* we cannot run this when we are transforming data and as such doing * another negotiation in the transform method. */ g_mutex_lock (trans->transform_lock); *buf = NULL; GST_DEBUG_OBJECT (trans, "allocating a buffer of size %d ...", size); if (offset == GST_BUFFER_OFFSET_NONE) GST_DEBUG_OBJECT (trans, "... and offset NONE"); else GST_DEBUG_OBJECT (trans, "... and offset %" G_GUINT64_FORMAT, offset); /* before any buffers are pushed, have_same_caps is TRUE; allocating can trigger * a renegotiation and change that to FALSE */ if (trans->have_same_caps) { /* request a buffer with the same caps */ GST_DEBUG_OBJECT (trans, "requesting buffer with same caps, size %d", size); res = gst_pad_alloc_buffer_and_set_caps (trans->srcpad, offset, size, caps, buf); } else { /* if we are configured, request a buffer with the src caps */ GstCaps *srccaps = gst_pad_get_negotiated_caps (trans->srcpad); GstCaps *sinkcaps = gst_pad_get_negotiated_caps (trans->sinkpad); if (!srccaps) goto not_configured; if (sinkcaps != NULL) { if (sinkcaps != caps || !gst_caps_is_equal (sinkcaps, caps)) { gst_caps_unref (sinkcaps); gst_caps_unref (srccaps); goto not_configured; } gst_caps_unref (sinkcaps); } GST_DEBUG_OBJECT (trans, "calling transform_size"); if (!gst_base_transform_transform_size (trans, GST_PAD_DIRECTION (pad), caps, size, srccaps, &new_size)) { gst_caps_unref (srccaps); goto unknown_size; } res = gst_pad_alloc_buffer_and_set_caps (trans->srcpad, offset, new_size, srccaps, buf); gst_caps_unref (srccaps); } if (res == GST_FLOW_OK && !trans->have_same_caps) { /* note that we might have had same caps before, but calling the alloc_buffer caused setcaps to switch us out of in_place -- in any case the alloc_buffer served to transmit caps information but we can't use the buffer. fall through and allocate a buffer corresponding to our sink caps, if any */ GstCaps *sinkcaps = gst_pad_get_negotiated_caps (trans->sinkpad); GstCaps *srccaps = gst_pad_get_negotiated_caps (trans->srcpad); if (!sinkcaps) goto not_configured; if (!gst_base_transform_transform_size (trans, GST_PAD_DIRECTION (trans->srcpad), srccaps, GST_BUFFER_SIZE (*buf), sinkcaps, &new_size)) { gst_caps_unref (srccaps); gst_caps_unref (sinkcaps); goto unknown_size; } gst_buffer_unref (*buf); *buf = gst_buffer_new_and_alloc (new_size); gst_buffer_set_caps (*buf, sinkcaps); GST_BUFFER_OFFSET (*buf) = offset; res = GST_FLOW_OK; gst_caps_unref (srccaps); gst_caps_unref (sinkcaps); } done: g_mutex_unlock (trans->transform_lock); gst_object_unref (trans); return res; not_configured: { /* let the default allocator handle it */ GST_DEBUG_OBJECT (trans, "not configured"); gst_buffer_replace (buf, NULL); res = GST_FLOW_OK; goto done; } unknown_size: { /* let the default allocator handle it */ GST_DEBUG_OBJECT (trans, "unknown size"); gst_buffer_replace (buf, NULL); res = GST_FLOW_OK; goto done; } } static gboolean gst_base_transform_event (GstPad * pad, GstEvent * event) { GstBaseTransform *trans; GstBaseTransformClass *bclass; gboolean ret = TRUE; trans = GST_BASE_TRANSFORM (gst_pad_get_parent (pad)); bclass = GST_BASE_TRANSFORM_GET_CLASS (trans); if (bclass->event) ret = bclass->event (trans, event); /* FIXME, do this in the default event handler so the subclass can do * something different. */ if (ret) ret = gst_pad_event_default (pad, event); gst_object_unref (trans); return ret; } static gboolean gst_base_transform_eventfunc (GstBaseTransform * trans, GstEvent * event) { switch (GST_EVENT_TYPE (event)) { case GST_EVENT_FLUSH_START: break; case GST_EVENT_FLUSH_STOP: /* we need new segment info after the flush. */ gst_segment_init (&trans->segment, GST_FORMAT_UNDEFINED); break; case GST_EVENT_EOS: break; case GST_EVENT_TAG: break; case GST_EVENT_NEWSEGMENT: { GstFormat format; gdouble rate; gint64 start, stop, time; gboolean update; gst_event_parse_new_segment (event, &update, &rate, &format, &start, &stop, &time); if (trans->segment.format != format) gst_segment_init (&trans->segment, format); gst_segment_set_newsegment (&trans->segment, update, rate, format, start, stop, time); trans->have_newsegment = TRUE; if (format == GST_FORMAT_TIME) { GST_DEBUG_OBJECT (trans, "received NEW_SEGMENT %" GST_TIME_FORMAT " -- %" GST_TIME_FORMAT ", time %" GST_TIME_FORMAT ", accum %" GST_TIME_FORMAT, GST_TIME_ARGS (trans->segment.start), GST_TIME_ARGS (trans->segment.stop), GST_TIME_ARGS (trans->segment.time), GST_TIME_ARGS (trans->segment.accum)); } else { GST_DEBUG_OBJECT (trans, "received NEW_SEGMENT %" G_GINT64_FORMAT " -- %" G_GINT64_FORMAT ", time %" G_GINT64_FORMAT ", accum %" G_GINT64_FORMAT, trans->segment.start, trans->segment.stop, trans->segment.time, trans->segment.accum); } break; } default: break; } return TRUE; } static GstFlowReturn gst_base_transform_handle_buffer (GstBaseTransform * trans, GstBuffer * inbuf, GstBuffer ** outbuf) { GstBaseTransformClass *bclass; GstFlowReturn ret = GST_FLOW_OK; guint out_size; gboolean want_in_place; bclass = GST_BASE_TRANSFORM_GET_CLASS (trans); if (GST_BUFFER_OFFSET_IS_VALID (inbuf)) GST_LOG_OBJECT (trans, "handling buffer %p of size %d and offset %" G_GUINT64_FORMAT, inbuf, GST_BUFFER_SIZE (inbuf), GST_BUFFER_OFFSET (inbuf)); else GST_LOG_OBJECT (trans, "handling buffer %p of size %d and offset NONE", inbuf, GST_BUFFER_SIZE (inbuf)); /* Don't allow buffer handling before negotiation, except in passthrough mode * or if the class doesn't implement a set_caps function (in which case it doesn't * care about caps) */ if (!trans->negotiated && !trans->passthrough && (bclass->set_caps != NULL)) goto not_negotiated; if (trans->passthrough) { /* In passthrough mode, give transform_ip a look at the * buffer, without making it writable, or just push the * data through */ GST_LOG_OBJECT (trans, "element is in passthrough mode"); if (bclass->transform_ip) ret = bclass->transform_ip (trans, inbuf); *outbuf = inbuf; return ret; } want_in_place = (bclass->transform_ip != NULL) && trans->always_in_place; *outbuf = NULL; if (want_in_place) { /* If want_in_place is TRUE, we may need to prepare a new output buffer * Sub-classes can implement a prepare_output_buffer function as they * wish. */ GST_LOG_OBJECT (trans, "doing inplace transform"); ret = gst_base_transform_prepare_output_buffer (trans, inbuf, GST_BUFFER_SIZE (inbuf), GST_PAD_CAPS (trans->srcpad), outbuf); if (G_UNLIKELY (ret != GST_FLOW_OK)) goto no_buffer; ret = bclass->transform_ip (trans, *outbuf); } else { GST_LOG_OBJECT (trans, "doing non-inplace transform"); /* not transforming inplace, figure out the output size */ if (trans->always_in_place) { out_size = GST_BUFFER_SIZE (inbuf); } else { if (!gst_base_transform_transform_size (trans, GST_PAD_DIRECTION (trans->sinkpad), GST_PAD_CAPS (trans->sinkpad), GST_BUFFER_SIZE (inbuf), GST_PAD_CAPS (trans->srcpad), &out_size)) { /* we have an error */ goto no_size; } } /* no in place transform, get buffer, this might renegotiate. */ ret = gst_base_transform_prepare_output_buffer (trans, inbuf, out_size, GST_PAD_CAPS (trans->srcpad), outbuf); if (ret != GST_FLOW_OK) goto no_buffer; if (bclass->transform) ret = bclass->transform (trans, inbuf, *outbuf); else ret = GST_FLOW_NOT_SUPPORTED; } /* if we got renegotiated we can configure now */ if (trans->pending_configure) { gboolean success; success = gst_base_transform_configure_caps (trans, GST_PAD_CAPS (trans->sinkpad), GST_PAD_CAPS (trans->srcpad)); trans->pending_configure = FALSE; if (!success) goto configure_failed; } gst_buffer_unref (inbuf); return ret; /* ERRORS */ not_negotiated: { gst_buffer_unref (inbuf); GST_ELEMENT_ERROR (trans, STREAM, NOT_IMPLEMENTED, ("not negotiated"), ("not negotiated")); return GST_FLOW_NOT_NEGOTIATED; } no_size: { gst_buffer_unref (inbuf); GST_ELEMENT_ERROR (trans, STREAM, NOT_IMPLEMENTED, ("subclass did not specify output size"), ("subclass did not specify output size")); return GST_FLOW_ERROR; } no_buffer: { gst_buffer_unref (inbuf); GST_DEBUG_OBJECT (trans, "could not get buffer from pool: %s", gst_flow_get_name (ret)); return ret; } configure_failed: { gst_buffer_unref (inbuf); GST_DEBUG_OBJECT (trans, "could not negotiate"); return GST_FLOW_NOT_NEGOTIATED; } } /* FIXME, getrange is broken, need to pull range from the other * end based on the transform_size result. */ static GstFlowReturn gst_base_transform_getrange (GstPad * pad, guint64 offset, guint length, GstBuffer ** buffer) { GstBaseTransform *trans; GstFlowReturn ret; GstBuffer *inbuf; trans = GST_BASE_TRANSFORM (gst_pad_get_parent (pad)); ret = gst_pad_pull_range (trans->sinkpad, offset, length, &inbuf); if (ret == GST_FLOW_OK) { g_mutex_lock (trans->transform_lock); ret = gst_base_transform_handle_buffer (trans, inbuf, buffer); g_mutex_unlock (trans->transform_lock); } gst_object_unref (trans); return ret; } static GstFlowReturn gst_base_transform_chain (GstPad * pad, GstBuffer * buffer) { GstBaseTransform *trans; GstFlowReturn ret; GstBuffer *outbuf = NULL; trans = GST_BASE_TRANSFORM (gst_pad_get_parent (pad)); /* protect transform method and concurrent buffer alloc */ g_mutex_lock (trans->transform_lock); ret = gst_base_transform_handle_buffer (trans, buffer, &outbuf); g_mutex_unlock (trans->transform_lock); if (ret == GST_FLOW_OK) { ret = gst_pad_push (trans->srcpad, outbuf); } else if (outbuf != NULL) gst_buffer_unref (outbuf); gst_object_unref (trans); return ret; } static void gst_base_transform_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) { GstBaseTransform *trans; trans = GST_BASE_TRANSFORM (object); switch (prop_id) { default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_base_transform_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) { GstBaseTransform *trans; trans = GST_BASE_TRANSFORM (object); switch (prop_id) { default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static gboolean gst_base_transform_sink_activate_push (GstPad * pad, gboolean active) { gboolean result = TRUE; GstBaseTransform *trans; GstBaseTransformClass *bclass; trans = GST_BASE_TRANSFORM (gst_pad_get_parent (pad)); bclass = GST_BASE_TRANSFORM_GET_CLASS (trans); if (active) { if (bclass->start) result = bclass->start (trans); } gst_object_unref (trans); return result; } static gboolean gst_base_transform_src_activate_pull (GstPad * pad, gboolean active) { gboolean result = FALSE; GstBaseTransform *trans; GstBaseTransformClass *bclass; trans = GST_BASE_TRANSFORM (gst_pad_get_parent (pad)); bclass = GST_BASE_TRANSFORM_GET_CLASS (trans); result = gst_pad_activate_pull (trans->sinkpad, active); if (active) { if (result && bclass->start) result &= bclass->start (trans); } gst_object_unref (trans); return result; } static GstStateChangeReturn gst_base_transform_change_state (GstElement * element, GstStateChange transition) { GstBaseTransform *trans; GstBaseTransformClass *bclass; GstStateChangeReturn result; trans = GST_BASE_TRANSFORM (element); bclass = GST_BASE_TRANSFORM_GET_CLASS (trans); switch (transition) { case GST_STATE_CHANGE_NULL_TO_READY: break; case GST_STATE_CHANGE_READY_TO_PAUSED: GST_OBJECT_LOCK (trans); if (GST_PAD_CAPS (trans->sinkpad) && GST_PAD_CAPS (trans->srcpad)) trans->have_same_caps = gst_caps_is_equal (GST_PAD_CAPS (trans->sinkpad), GST_PAD_CAPS (trans->srcpad)) || trans->passthrough; else trans->have_same_caps = trans->passthrough; GST_DEBUG_OBJECT (trans, "have_same_caps %d", trans->have_same_caps); trans->negotiated = FALSE; trans->have_newsegment = FALSE; gst_segment_init (&trans->segment, GST_FORMAT_UNDEFINED); GST_OBJECT_UNLOCK (trans); break; case GST_STATE_CHANGE_PAUSED_TO_PLAYING: break; default: break; } result = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition); switch (transition) { case GST_STATE_CHANGE_PLAYING_TO_PAUSED: break; case GST_STATE_CHANGE_PAUSED_TO_READY: trans->have_same_caps = FALSE; /* We can only reset the passthrough mode if the instance told us to handle it in configure_caps */ if (bclass->passthrough_on_same_caps) { gst_base_transform_set_passthrough (trans, FALSE); } gst_caps_replace (&trans->cache_caps1, NULL); gst_caps_replace (&trans->cache_caps2, NULL); if (bclass->stop) result = bclass->stop (trans); break; case GST_STATE_CHANGE_READY_TO_NULL: break; default: break; } return result; } /** * gst_base_transform_set_passthrough: * @trans: the #GstBaseTransform to set * @passthrough: boolean indicating passthrough mode. * * Set passthrough mode for this filter by default. This is mostly * useful for filters that do not care about negotiation. * * Always TRUE for filters which don't implement either a transform * or transform_ip method. * * MT safe. */ void gst_base_transform_set_passthrough (GstBaseTransform * trans, gboolean passthrough) { GstBaseTransformClass *bclass; g_return_if_fail (trans != NULL); bclass = GST_BASE_TRANSFORM_GET_CLASS (trans); GST_OBJECT_LOCK (trans); if (passthrough == FALSE) { if (bclass->transform_ip || bclass->transform) trans->passthrough = FALSE; } else { trans->passthrough = TRUE; } GST_DEBUG_OBJECT (trans, "set passthrough %d", trans->passthrough); GST_OBJECT_UNLOCK (trans); } /** * gst_base_transform_is_passthrough: * @trans: the #GstBaseTransform to query * * See if @trans is configured as a passthrough transform. * * Returns: TRUE is the transform is configured in passthrough mode. * * MT safe. */ gboolean gst_base_transform_is_passthrough (GstBaseTransform * trans) { gboolean result; g_return_val_if_fail (trans != NULL, FALSE); GST_OBJECT_LOCK (trans); result = trans->passthrough; GST_OBJECT_UNLOCK (trans); return result; } /** * gst_base_transform_set_in_place: * @trans: the #GstBaseTransform to modify * @in_place: Boolean value indicating that we would like to operate * on in_place buffers. * * Determines whether a non-writable buffer will be copied before passing * to the transform_ip function. * * Always TRUE if no transform function is implemented. * Always FALSE if ONLY transform_ip function is implemented. * * * MT safe. */ void gst_base_transform_set_in_place (GstBaseTransform * trans, gboolean in_place) { GstBaseTransformClass *bclass; g_return_if_fail (trans != NULL); bclass = GST_BASE_TRANSFORM_GET_CLASS (trans); GST_OBJECT_LOCK (trans); if (in_place) { if (bclass->transform_ip) { GST_DEBUG_OBJECT (trans, "setting in_place TRUE"); trans->always_in_place = TRUE; } } else { if (bclass->transform) { GST_DEBUG_OBJECT (trans, "setting in_place FALSE"); trans->always_in_place = FALSE; } } GST_OBJECT_UNLOCK (trans); } /** * gst_base_transform_is_in_place: * @trans: the #GstBaseTransform to query * * See if @trans is configured as a in_place transform. * * Returns: TRUE is the transform is configured in in_place mode. * * MT safe. */ gboolean gst_base_transform_is_in_place (GstBaseTransform * trans) { gboolean result; g_return_val_if_fail (trans != NULL, FALSE); GST_OBJECT_LOCK (trans); result = trans->always_in_place; GST_OBJECT_UNLOCK (trans); return result; }