| /* GStreamer |
| * Copyright (C) <2008> Wim Taymans <wim.taymans@gmail.com> |
| * |
| * 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 <string.h> |
| #include <stdlib.h> |
| |
| #include "gstrtpchannels.h" |
| |
| /* |
| * RTP channel positions as discussed in RFC 3551 and also RFC 3555 |
| * |
| * We can't really represent the described channel positions in GStreamer but we |
| * implement a (very rough) approximation here. |
| */ |
| |
| static gboolean |
| check_channels (const GstRTPChannelOrder * order, |
| const GstAudioChannelPosition * pos) |
| { |
| gint i, j; |
| gboolean res = TRUE; |
| |
| for (i = 0; i < order->channels; i++) { |
| for (j = 0; j < order->channels; j++) { |
| if (order->pos[j] == pos[i]) |
| break; |
| } |
| if (j == order->channels) |
| return FALSE; |
| } |
| return res; |
| } |
| |
| /** |
| * gst_rtp_channels_get_by_pos: |
| * @channels: the amount of channels |
| * @pos: a channel layout |
| * |
| * Return a description of the channel layout. |
| * |
| * Returns: a #GstRTPChannelOrder with the channel information or NULL when @pos |
| * is not a valid layout. |
| */ |
| const GstRTPChannelOrder * |
| gst_rtp_channels_get_by_pos (gint channels, const GstAudioChannelPosition * pos) |
| { |
| gint i; |
| const GstRTPChannelOrder *res = NULL; |
| |
| g_return_val_if_fail (pos != NULL, NULL); |
| |
| for (i = 0; channel_orders[i].pos; i++) { |
| if (channel_orders[i].channels != channels) |
| continue; |
| |
| if (check_channels (&channel_orders[i], pos)) { |
| res = &channel_orders[i]; |
| break; |
| } |
| } |
| return res; |
| } |
| |
| /** |
| * gst_rtp_channels_create_default: |
| * @channels: the amount of channels |
| * @order: a channel order |
| * |
| * Get the channel order info the @order and @channels. |
| * |
| * Returns: a #GstRTPChannelOrder with the channel information or NULL when |
| * @order is not a know layout for @channels. |
| */ |
| const GstRTPChannelOrder * |
| gst_rtp_channels_get_by_order (gint channels, const gchar * order) |
| { |
| gint i; |
| const GstRTPChannelOrder *res = NULL; |
| |
| for (i = 0; channel_orders[i].pos; i++) { |
| if (channel_orders[i].channels != channels) |
| continue; |
| |
| /* no name but channels match, continue */ |
| if (!channel_orders[i].name || !order) { |
| res = &channel_orders[i]; |
| break; |
| } |
| |
| /* compare names */ |
| if (g_ascii_strcasecmp (channel_orders[i].name, order)) { |
| res = &channel_orders[i]; |
| break; |
| } |
| } |
| return res; |
| } |
| |
| /** |
| * gst_rtp_channels_get_by_index: |
| * @channels: the amount of channels |
| * @idx: the channel index to retrieve |
| * |
| * Get the allowed channel order descriptions for @channels. @idx can be used to |
| * retrieve the desired index. |
| * |
| * Returns: a #GstRTPChannelOrder at @idx, NULL when there are no valid channel |
| * orders. |
| */ |
| const GstRTPChannelOrder * |
| gst_rtp_channels_get_by_index (gint channels, guint idx) |
| { |
| gint i; |
| const GstRTPChannelOrder *res = NULL; |
| |
| for (i = 0; channel_orders[i].pos; i++) { |
| if (channel_orders[i].channels != channels) |
| continue; |
| |
| if (idx == 0) { |
| res = &channel_orders[i]; |
| break; |
| } |
| idx--; |
| } |
| return res; |
| } |
| |
| |
| /** |
| * gst_rtp_channels_create_default: |
| * @channels: the amount of channels |
| * |
| * Create a default none channel mapping for @channels. |
| * |
| * Returns: a #GstAudioChannelPosition with all the channel position info set to |
| * #GST_AUDIO_CHANNEL_POSITION_NONE. |
| */ |
| void |
| gst_rtp_channels_create_default (gint channels, GstAudioChannelPosition * posn) |
| { |
| gint i; |
| |
| g_return_if_fail (channels > 0); |
| |
| for (i = 0; i < channels; i++) |
| posn[i] = GST_AUDIO_CHANNEL_POSITION_NONE; |
| } |