| /* GStreamer |
| * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu> |
| * Library <2002> Ronald Bultje <rbultje@ronald.bitfreak.net> |
| * Copyright (C) 2007 David A. Schleef <ds@schleef.org> |
| * |
| * 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 <string.h> |
| #include <stdio.h> |
| |
| #include "video.h" |
| #include "gstvideometa.h" |
| |
| /** |
| * SECTION:gstvideo |
| * @short_description: Support library for video operations |
| * |
| * <refsect2> |
| * <para> |
| * This library contains some helper functions and includes the |
| * videosink and videofilter base classes. |
| * </para> |
| * </refsect2> |
| */ |
| |
| /** |
| * gst_video_calculate_display_ratio: |
| * @dar_n: Numerator of the calculated display_ratio |
| * @dar_d: Denominator of the calculated display_ratio |
| * @video_width: Width of the video frame in pixels |
| * @video_height: Height of the video frame in pixels |
| * @video_par_n: Numerator of the pixel aspect ratio of the input video. |
| * @video_par_d: Denominator of the pixel aspect ratio of the input video. |
| * @display_par_n: Numerator of the pixel aspect ratio of the display device |
| * @display_par_d: Denominator of the pixel aspect ratio of the display device |
| * |
| * Given the Pixel Aspect Ratio and size of an input video frame, and the |
| * pixel aspect ratio of the intended display device, calculates the actual |
| * display ratio the video will be rendered with. |
| * |
| * Returns: A boolean indicating success and a calculated Display Ratio in the |
| * dar_n and dar_d parameters. |
| * The return value is FALSE in the case of integer overflow or other error. |
| */ |
| gboolean |
| gst_video_calculate_display_ratio (guint * dar_n, guint * dar_d, |
| guint video_width, guint video_height, |
| guint video_par_n, guint video_par_d, |
| guint display_par_n, guint display_par_d) |
| { |
| gint num, den; |
| gint tmp_n, tmp_d; |
| |
| g_return_val_if_fail (dar_n != NULL, FALSE); |
| g_return_val_if_fail (dar_d != NULL, FALSE); |
| |
| /* Calculate (video_width * video_par_n * display_par_d) / |
| * (video_height * video_par_d * display_par_n) */ |
| if (!gst_util_fraction_multiply (video_width, video_height, video_par_n, |
| video_par_d, &tmp_n, &tmp_d)) |
| goto error_overflow; |
| |
| if (!gst_util_fraction_multiply (tmp_n, tmp_d, display_par_d, display_par_n, |
| &num, &den)) |
| goto error_overflow; |
| |
| g_return_val_if_fail (num > 0, FALSE); |
| g_return_val_if_fail (den > 0, FALSE); |
| |
| *dar_n = num; |
| *dar_d = den; |
| |
| return TRUE; |
| |
| /* ERRORS */ |
| error_overflow: |
| { |
| GST_WARNING ("overflow in multiply"); |
| return FALSE; |
| } |
| } |
| |
| /** |
| * gst_video_alignment_reset: |
| * @align: a #GstVideoAlignment |
| * |
| * Set @align to its default values with no padding and no alignment. |
| */ |
| void |
| gst_video_alignment_reset (GstVideoAlignment * align) |
| { |
| gint i; |
| |
| g_return_if_fail (align != NULL); |
| |
| align->padding_top = 0; |
| align->padding_bottom = 0; |
| align->padding_left = 0; |
| align->padding_right = 0; |
| for (i = 0; i < GST_VIDEO_MAX_PLANES; i++) |
| align->stride_align[i] = 0; |
| } |