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b68a05dbfa
Refactor the DVD subpicture compositing, switching it to 8-bit alpha calculations. Reuse some of the resulting code to implement PGS subpicture blending. Implement parsing and collecting of composition objects properly, but assuming a single active window and colour palette for now. I need more PGS samples.
94 lines
2.9 KiB
C
94 lines
2.9 KiB
C
/* GStreamer DVD Sub-Picture Unit
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* Copyright (C) 2007 Fluendo S.A. <info@fluendo.com>
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* Copyright (C) 2009 Jan Schmidt <thaytan@noraisin.net>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <string.h>
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#include <gst/gst.h>
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#include "gstdvdspu.h"
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GST_DEBUG_CATEGORY_EXTERN (dvdspu_debug);
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#define GST_CAT_DEFAULT dvdspu_debug
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void
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gstspu_clear_comp_buffers (SpuState * state)
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{
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/* The area to clear is the line inside the disp_rect, each entry 4 bytes,
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* of the sub-sampled UV planes. */
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gint16 left = state->comp_left / 2;
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gint16 right = state->comp_right / 2;
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gint16 uv_width = sizeof (guint32) * (right - left + 1);
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memset (state->comp_bufs[0] + left, 0, uv_width);
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memset (state->comp_bufs[1] + left, 0, uv_width);
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memset (state->comp_bufs[2] + left, 0, uv_width);
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}
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void
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gstspu_blend_comp_buffers (SpuState * state, guint8 * planes[3])
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{
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gint16 uv_end;
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gint16 left, x;
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guint8 *out_U;
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guint8 *out_V;
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guint32 *in_U;
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guint32 *in_V;
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guint32 *in_A;
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gint16 comp_last_x = state->comp_right;
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if (comp_last_x < state->comp_left)
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return; /* Didn't draw in the comp buffers, nothing to do... */
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#if 0
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GST_LOG ("Blending comp buffers from x=%d to x=%d",
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state->comp_left, state->comp_right);
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#endif
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/* Set up the output pointers */
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out_U = planes[1]; /* U plane */
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out_V = planes[2]; /* V plane */
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/* Input starts at the first pixel of the compositing buffer */
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in_U = state->comp_bufs[0]; /* U comp buffer */
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in_V = state->comp_bufs[1]; /* V comp buffer */
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in_A = state->comp_bufs[2]; /* A comp buffer */
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/* Calculate how many pixels to blend based on the maximum X value that was
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* drawn in the render_line function, divided by 2 (rounding up) to account
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* for UV sub-sampling */
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uv_end = (comp_last_x + 1) / 2;
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left = state->comp_left / 2;
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for (x = left; x < uv_end; x++) {
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guint32 tmp;
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/* Each entry in the compositing buffer is 4 summed pixels, so the
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* inverse alpha is (4 * 0xff) - in_A[x] */
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guint16 inv_A = (4 * 0xff) - in_A[x];
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tmp = in_U[x] + inv_A * out_U[x];
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out_U[x] = (guint8) (tmp / (4 * 0xff));
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tmp = in_V[x] + inv_A * out_V[x];
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out_V[x] = (guint8) (tmp / (4 * 0xff));
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}
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}
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