/* GStreamer Tuner * Copyright (C) 2003 Ronald Bultje * * tuner.c: tuner design virtual class function wrappers * * 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. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include "tuner.h" #include /** * SECTION:gsttuner * @short_description: Interface for elements providing tuner operations * * * * The GstTuner interface is provided by elements that have the ability to * tune into multiple input signals, for example TV or radio capture cards. * * The interpretation of 'tuning into' an input stream depends on the element * implementing the interface. For v4lsrc, it might imply selection of an * input source and/or frequency to be configured on a TV card. Another * GstTuner implementation might be to allow selection of an active input pad * from multiple input pads. * * That said, the GstTuner interface functions are biased toward the * TV capture scenario. * * The general parameters provided are for configuration are: * * Selection of a current #GstTunerChannel. The current channel * represents the input source (e.g. Composite, S-Video etc for TV capture). * * The #GstTunerNorm for the channel. The norm chooses the * interpretation of the incoming signal for the current channel. For example, * PAL or NTSC, or more specific variants there-of. * * Channel frequency. If the current channel has the ability to tune * between multiple frequencies (if it has the GST_TUNER_CHANNEL_FREQUENCY flag) * then the frequency can be changed/retrieved via the * gst_tuner_set_frequency() and gst_tuner_get_frequency() methods. * * * * * Where applicable, the signal strength can be retrieved and/or monitored * via a signal. * * */ /* FIXME 0.11: check if we need to add API for sometimes-supportedness * (aka making up for GstImplementsInterface removal) */ /* FIXME 0.11: replace signals with messages (+ make API thread-safe) */ enum { NORM_CHANGED, CHANNEL_CHANGED, FREQUENCY_CHANGED, SIGNAL_CHANGED, LAST_SIGNAL }; static guint gst_tuner_signals[LAST_SIGNAL] = { 0 }; G_DEFINE_INTERFACE (GstTuner, gst_tuner, G_TYPE_INVALID); static void gst_tuner_default_init (GstTunerInterface * iface) { static gboolean initialized = FALSE; if (!initialized) { /** * GstTuner::norm-changed: * @tuner: The element providing the GstTuner interface * @norm: The new configured norm. * * Reports that the current #GstTunerNorm has changed. */ gst_tuner_signals[NORM_CHANGED] = g_signal_new ("norm-changed", GST_TYPE_TUNER, G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstTunerInterface, norm_changed), NULL, NULL, g_cclosure_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_TUNER_NORM); /** * GstTuner::channel-changed: * @tuner: The element providing the GstTuner interface * @channel: The new configured channel. * * Reports that the current #GstTunerChannel has changed. */ gst_tuner_signals[CHANNEL_CHANGED] = g_signal_new ("channel-changed", GST_TYPE_TUNER, G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstTunerInterface, channel_changed), NULL, NULL, g_cclosure_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_TUNER_CHANNEL); /** * GstTuner::frequency-changed: * @tuner: The element providing the GstTuner interface * @frequency: The new frequency (an unsigned long) * * Reports that the current frequency has changed. */ gst_tuner_signals[FREQUENCY_CHANGED] = g_signal_new ("frequency-changed", GST_TYPE_TUNER, G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstTunerInterface, frequency_changed), NULL, NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 2, GST_TYPE_TUNER_CHANNEL, G_TYPE_ULONG); /** * GstTuner::signal-changed: * @tuner: The element providing the GstTuner interface * @channel: The current #GstTunerChannel * @signal: The new signal strength (an integer) * * Reports that the signal strength has changed. * * See Also: gst_tuner_signal_strength() */ gst_tuner_signals[SIGNAL_CHANGED] = g_signal_new ("signal-changed", GST_TYPE_TUNER, G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstTunerInterface, signal_changed), NULL, NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 2, GST_TYPE_TUNER_CHANNEL, G_TYPE_INT); initialized = TRUE; } /* default virtual functions */ iface->list_channels = NULL; iface->set_channel = NULL; iface->get_channel = NULL; iface->list_norms = NULL; iface->set_norm = NULL; iface->get_norm = NULL; iface->set_frequency = NULL; iface->get_frequency = NULL; iface->signal_strength = NULL; } /** * gst_tuner_list_channels: * @tuner: the #GstTuner (a #GstElement) to get the channels from. * * Retrieve a #GList of #GstTunerChannels available * (e.g. 'composite', 's-video', ...) from the given tuner object. * * Returns: A list of channels available on this tuner. The list is * owned by the GstTuner and must not be freed. */ const GList * gst_tuner_list_channels (GstTuner * tuner) { GstTunerInterface *iface; g_return_val_if_fail (GST_IS_TUNER (tuner), NULL); iface = GST_TUNER_GET_INTERFACE (tuner); if (iface->list_channels) { return iface->list_channels (tuner); } return NULL; } /** * gst_tuner_set_channel: * @tuner: the #GstTuner (a #GstElement) that owns the channel. * @channel: the channel to tune to. * * Tunes the object to the given channel, which should be one of the * channels returned by gst_tuner_list_channels(). */ void gst_tuner_set_channel (GstTuner * tuner, GstTunerChannel * channel) { GstTunerInterface *iface; g_return_if_fail (GST_IS_TUNER (tuner)); iface = GST_TUNER_GET_INTERFACE (tuner); if (iface->set_channel) { iface->set_channel (tuner, channel); } } /** * gst_tuner_get_channel: * @tuner: the #GstTuner (a #GstElement) to get the current channel from. * * Retrieve the current channel from the tuner. * * Returns: the current channel of the tuner object. */ GstTunerChannel * gst_tuner_get_channel (GstTuner * tuner) { GstTunerInterface *iface; g_return_val_if_fail (GST_IS_TUNER (tuner), NULL); iface = GST_TUNER_GET_INTERFACE (tuner); if (iface->get_channel) { return iface->get_channel (tuner); } return NULL; } /** * gst_tuner_list_norms: * @tuner: the #GstTuner (*a #GstElement) to get the list of norms from. * * Retrieve a GList of available #GstTunerNorm settings for the currently * tuned channel on the given tuner object. * * Returns: A list of norms available on the current channel for this * tuner object. The list is owned by the GstTuner and must not * be freed. */ const GList * gst_tuner_list_norms (GstTuner * tuner) { GstTunerInterface *iface; g_return_val_if_fail (GST_IS_TUNER (tuner), NULL); iface = GST_TUNER_GET_INTERFACE (tuner); if (iface->list_norms) { return iface->list_norms (tuner); } return NULL; } /** * gst_tuner_set_norm: * @tuner: the #GstTuner (a #GstElement) to set the norm on. * @norm: the norm to use for the current channel. * * Changes the video norm on this tuner to the given norm, which should be * one of the norms returned by gst_tuner_list_norms(). */ void gst_tuner_set_norm (GstTuner * tuner, GstTunerNorm * norm) { GstTunerInterface *iface; g_return_if_fail (GST_IS_TUNER (tuner)); iface = GST_TUNER_GET_INTERFACE (tuner); if (iface->set_norm) { iface->set_norm (tuner, norm); } } /** * gst_tuner_get_norm: * @tuner: the #GstTuner (a #GstElement) to get the current norm from. * * Get the current video norm from the given tuner object for the * currently selected channel. * * Returns: the current norm. */ GstTunerNorm * gst_tuner_get_norm (GstTuner * tuner) { GstTunerInterface *iface; g_return_val_if_fail (GST_IS_TUNER (tuner), NULL); iface = GST_TUNER_GET_INTERFACE (tuner); if (iface->get_norm) { return iface->get_norm (tuner); } return NULL; } /** * gst_tuner_set_frequency: * @tuner: The #GstTuner (a #GstElement) that owns the given channel. * @channel: The #GstTunerChannel to set the frequency on. * @frequency: The frequency to tune in to. * * Sets a tuning frequency on the given tuner/channel. Note that this * requires the given channel to be a "tuning" channel, which can be * checked using GST_TUNER_CHANNEL_HAS_FLAG (), with the proper flag * being GST_TUNER_CHANNEL_FREQUENCY. * * The frequency is in Hz, with minimum steps indicated by the * frequency_multiplicator provided in the #GstTunerChannel. The * valid range is provided in the min_frequency and max_frequency properties * of the #GstTunerChannel. */ void gst_tuner_set_frequency (GstTuner * tuner, GstTunerChannel * channel, gulong frequency) { GstTunerInterface *iface; g_return_if_fail (GST_IS_TUNER (tuner)); g_return_if_fail (GST_IS_TUNER_CHANNEL (channel)); g_return_if_fail (GST_TUNER_CHANNEL_HAS_FLAG (channel, GST_TUNER_CHANNEL_FREQUENCY)); iface = GST_TUNER_GET_INTERFACE (tuner); if (iface->set_frequency) { iface->set_frequency (tuner, channel, frequency); } } /** * gst_tuner_get_frequency: * @tuner: The #GstTuner (a #GstElement) that owns the given channel. * @channel: The #GstTunerChannel to retrieve the frequency from. * * Retrieve the current frequency from the given channel. As for * gst_tuner_set_frequency(), the #GstTunerChannel must support frequency * operations, as indicated by the GST_TUNER_CHANNEL_FREQUENCY flag. * * Returns: The current frequency, or 0 on error. */ gulong gst_tuner_get_frequency (GstTuner * tuner, GstTunerChannel * channel) { GstTunerInterface *iface; g_return_val_if_fail (GST_IS_TUNER (tuner), 0); g_return_val_if_fail (GST_IS_TUNER_CHANNEL (channel), 0); g_return_val_if_fail (GST_TUNER_CHANNEL_HAS_FLAG (channel, GST_TUNER_CHANNEL_FREQUENCY), 0); iface = GST_TUNER_GET_INTERFACE (tuner); if (iface->get_frequency) { return iface->get_frequency (tuner, channel); } return 0; } /** * gst_tuner_signal_strength: * @tuner: the #GstTuner (a #GstElement) that owns the given channel. * @channel: the #GstTunerChannel to get the signal strength from. * * Get the strength of the signal on this channel. Note that this * requires the current channel to be a "tuning" channel, i.e. a * channel on which frequency can be set. This can be checked using * GST_TUNER_CHANNEL_HAS_FLAG (), and the appropriate flag to check * for is GST_TUNER_CHANNEL_FREQUENCY. * * The valid range of the signal strength is indicated in the * min_signal and max_signal properties of the #GstTunerChannel. * * Returns: Signal strength, or 0 on error. */ gint gst_tuner_signal_strength (GstTuner * tuner, GstTunerChannel * channel) { GstTunerInterface *iface; g_return_val_if_fail (GST_IS_TUNER (tuner), 0); g_return_val_if_fail (GST_IS_TUNER_CHANNEL (channel), 0); g_return_val_if_fail (GST_TUNER_CHANNEL_HAS_FLAG (channel, GST_TUNER_CHANNEL_FREQUENCY), 0); iface = GST_TUNER_GET_INTERFACE (tuner); if (iface->signal_strength) { return iface->signal_strength (tuner, channel); } return 0; } /** * gst_tuner_find_norm_by_name: * @tuner: A #GstTuner instance * @norm: A string containing the name of a #GstTunerNorm * * Look up a #GstTunerNorm by name. * * Returns: A #GstTunerNorm, or NULL if no norm with the provided name * is available. */ GstTunerNorm * gst_tuner_find_norm_by_name (GstTuner * tuner, gchar * norm) { GList *walk; g_return_val_if_fail (GST_IS_TUNER (tuner), NULL); g_return_val_if_fail (norm != NULL, NULL); walk = (GList *) gst_tuner_list_norms (tuner); while (walk) { if (strcmp (GST_TUNER_NORM (walk->data)->label, norm) == 0) return GST_TUNER_NORM (walk->data); walk = g_list_next (walk); } return NULL; } /** * gst_tuner_find_channel_by_name: * @tuner: A #GstTuner instance * @channel: A string containing the name of a #GstTunerChannel * * Look up a #GstTunerChannel by name. * * Returns: A #GstTunerChannel, or NULL if no channel with the provided name * is available. */ GstTunerChannel * gst_tuner_find_channel_by_name (GstTuner * tuner, gchar * channel) { GList *walk; g_return_val_if_fail (GST_IS_TUNER (tuner), NULL); g_return_val_if_fail (channel != NULL, NULL); walk = (GList *) gst_tuner_list_channels (tuner); while (walk) { if (strcmp (GST_TUNER_CHANNEL (walk->data)->label, channel) == 0) return GST_TUNER_CHANNEL (walk->data); walk = g_list_next (walk); } return NULL; } /** * gst_tuner_channel_changed: * @tuner: A #GstTuner instance * @channel: A #GstTunerChannel instance * * Called by elements implementing the #GstTuner interface when the * current channel changes. Fires the #GstTuner::channel-changed signal. */ void gst_tuner_channel_changed (GstTuner * tuner, GstTunerChannel * channel) { g_return_if_fail (GST_IS_TUNER (tuner)); g_return_if_fail (GST_IS_TUNER_CHANNEL (channel)); g_signal_emit (G_OBJECT (tuner), gst_tuner_signals[CHANNEL_CHANGED], 0, channel); } /** * gst_tuner_norm_changed: * @tuner: A #GstTuner instance * @norm: A #GstTunerNorm instance * * Called by elements implementing the #GstTuner interface when the * current norm changes. Fires the #GstTuner::norm-changed signal. * */ void gst_tuner_norm_changed (GstTuner * tuner, GstTunerNorm * norm) { g_return_if_fail (GST_IS_TUNER (tuner)); g_return_if_fail (GST_IS_TUNER_NORM (norm)); g_signal_emit (G_OBJECT (tuner), gst_tuner_signals[NORM_CHANGED], 0, norm); } /** * gst_tuner_frequency_changed: * @tuner: A #GstTuner instance * @channel: The current #GstTunerChannel * @frequency: The new frequency setting * * Called by elements implementing the #GstTuner interface when the * configured frequency changes. Fires the #GstTuner::frequency-changed * signal on the tuner, and the #GstTunerChannel::frequency-changed signal * on the channel. */ void gst_tuner_frequency_changed (GstTuner * tuner, GstTunerChannel * channel, gulong frequency) { g_return_if_fail (GST_IS_TUNER (tuner)); g_return_if_fail (GST_IS_TUNER_CHANNEL (channel)); g_signal_emit (G_OBJECT (tuner), gst_tuner_signals[FREQUENCY_CHANGED], 0, channel, frequency); g_signal_emit_by_name (G_OBJECT (channel), "frequency_changed", frequency); } /** * gst_tuner_signal_changed: * @tuner: A #GstTuner instance * @channel: The current #GstTunerChannel * @signal: The new signal strength * * Called by elements implementing the #GstTuner interface when the * incoming signal strength changes. Fires the #GstTuner::signal-changed * signal on the tuner and the #GstTunerChannel::signal-changed signal on * the channel. */ void gst_tuner_signal_changed (GstTuner * tuner, GstTunerChannel * channel, gint signal) { g_return_if_fail (GST_IS_TUNER (tuner)); g_return_if_fail (GST_IS_TUNER_CHANNEL (channel)); g_signal_emit (G_OBJECT (tuner), gst_tuner_signals[SIGNAL_CHANGED], 0, channel, signal); g_signal_emit_by_name (G_OBJECT (channel), "signal_changed", signal); }