/* GStreamer * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu> * * 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. */ #include "audio.h" int gst_audio_frame_byte_size (GstPad* pad) { /* calculate byte size of an audio frame * this should be moved closer to the gstreamer core * and be implemented for every mime type IMO * returns -1 if there's an error (to avoid division by zero), * or the byte size if everything's ok */ int width = 0; int channels = 0; GstCaps *caps = NULL; /* get caps of pad */ caps = GST_PAD_CAPS (pad); if (caps == NULL) { /* ERROR: could not get caps of pad */ g_warning ("gstaudio: could not get caps of pad %s:%s\n", GST_ELEMENT_NAME (gst_pad_get_parent (pad)), GST_PAD_NAME (pad)); return 0; } gst_caps_get_int (caps, "width", &width); gst_caps_get_int (caps, "channels", &channels); return (width / 8) * channels; } long gst_audio_frame_length (GstPad* pad, GstBuffer* buf) /* calculate length of buffer in frames * this should be moved closer to the gstreamer core * and be implemented for every mime type IMO * returns 0 if there's an error, or the number of frames if everything's ok */ { int frame_byte_size = 0; frame_byte_size = gst_audio_frame_byte_size (pad); if (frame_byte_size == 0) /* error */ return 0; /* FIXME: this function assumes the buffer size to be a whole multiple * of the frame byte size */ return GST_BUFFER_SIZE (buf) / frame_byte_size; } long gst_audio_frame_rate (GstPad *pad) /* * calculate frame rate (based on caps of pad) * returns 0 if failed, rate if success */ { GstCaps *caps = NULL; gint rate; /* get caps of pad */ caps = GST_PAD_CAPS (pad); if (caps == NULL) { /* ERROR: could not get caps of pad */ g_warning ("gstaudio: could not get caps of pad %s:%s\n", GST_ELEMENT_NAME (gst_pad_get_parent (pad)), GST_PAD_NAME (pad)); return 0; } else { gst_caps_get_int (caps, "rate", &rate); return rate; } } double gst_audio_length (GstPad* pad, GstBuffer* buf) { /* calculate length in seconds * of audio buffer buf * based on capabilities of pad */ long bytes = 0; int width = 0; int channels = 0; int rate = 0; double length; GstCaps *caps = NULL; g_assert (GST_IS_BUFFER (buf)); /* get caps of pad */ caps = GST_PAD_CAPS (pad); if (caps == NULL) { /* ERROR: could not get caps of pad */ g_warning ("gstaudio: could not get caps of pad %s:%s\n", GST_ELEMENT_NAME (gst_pad_get_parent (pad)), GST_PAD_NAME (pad)); length = 0.0; } else { bytes = GST_BUFFER_SIZE (buf); gst_caps_get_int (caps, "width", &width); gst_caps_get_int (caps, "channels", &channels); gst_caps_get_int (caps, "rate", &rate); g_assert (bytes != 0); g_assert (width != 0); g_assert (channels != 0); g_assert (rate != 0); length = (bytes * 8.0) / (double) (rate * channels * width); } /* g_print ("DEBUG: audio: returning length of %f\n", length); */ return length; } long gst_audio_highest_sample_value (GstPad* pad) /* calculate highest possible sample value * based on capabilities of pad */ { gboolean is_signed = FALSE; gint width = 0; GstCaps *caps = NULL; caps = GST_PAD_CAPS (pad); if (caps == NULL) { g_warning ("gstaudio: could not get caps of pad %s:%s\n", GST_ELEMENT_NAME (gst_pad_get_parent (pad)), GST_PAD_NAME (pad)); } gst_caps_get_int (caps, "width", &width); gst_caps_get_boolean (caps, "signed", &is_signed); if (is_signed) --width; /* example : 16 bit, signed : samples between -32768 and 32767 */ return ((long) (1 << width)); } gboolean gst_audio_is_buffer_framed (GstPad* pad, GstBuffer* buf) /* check if the buffer size is a whole multiple of the frame size */ { if (GST_BUFFER_SIZE (buf) % gst_audio_frame_byte_size (pad) == 0) return TRUE; else return FALSE; } static gboolean plugin_init (GModule *module, GstPlugin *plugin) { gst_plugin_set_longname (plugin, "Support services for audio plugins"); return TRUE; } GstPluginDesc plugin_desc = { GST_VERSION_MAJOR, GST_VERSION_MINOR, "gstaudio", plugin_init };