diff options
Diffstat (limited to 'kopete/protocols/msn/webcam/libmimic/idct_dequant.c')
| -rw-r--r-- | kopete/protocols/msn/webcam/libmimic/idct_dequant.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/kopete/protocols/msn/webcam/libmimic/idct_dequant.c b/kopete/protocols/msn/webcam/libmimic/idct_dequant.c new file mode 100644 index 00000000..3512247e --- /dev/null +++ b/kopete/protocols/msn/webcam/libmimic/idct_dequant.c @@ -0,0 +1,134 @@ +/* Copyright (C) 2005 Ole Andr� Vadla Ravn�s <[email protected]> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "mimic-private.h" + +void _idct_dequant_block(MimCtx *ctx, gint *block, gboolean is_chrom) +{ + gdouble f; + gint i, *p; + + /* + * De-quantize. + */ + f = (10000 - ctx->quality) * 10.0 * (gfloat) 9.9999997e-5; + + if (f > 10.0) + f = 10.0; + + if (!is_chrom) { + if (f < 2.0) + f = 2.0; + } else { + if (f < 1.0) + f = 1.0; + } + + block[0] <<= 1; + block[1] <<= 2; + block[8] <<= 2; + + for (i = 2; i < 64; i++) { + if (i == 8) + continue; + + block[i] *= f; + } + + /* + * Inverse DCT, first pass (horizontal). + */ + p = block; + + for (i = 0; i < 8; i++) { + gint v1, v2, v3, v4, v5, v6, v7, v8; + gint va, vb; + + va = (p[0] << 11) + (p[4] << 11); + vb = ((p[2] << 2) * 392) + (((p[2] << 2) + (p[6] << 2)) * 277); + v1 = va + vb + 512; + v2 = va - vb + 512; + + va = (p[0] << 11) - (p[4] << 11); + vb = (((p[2] << 2) + (p[6] << 2)) * 277) - ((p[6] << 2) * 946); + v3 = va + vb + 512; + v4 = va - vb + 512; + + va = (p[1] << 9) + (p[3] * 724) + (p[7] << 9); + vb = (p[1] << 9) + (p[5] * 724) - (p[7] << 9); + v5 = (((va + vb) * 213) - (vb * 71)) >> 6; + v6 = (((va + vb) * 213) - (va * 355)) >> 6; + + va = (p[1] << 9) - (p[3] * 724) + (p[7] << 9); + vb = (p[1] << 9) - (p[5] * 724) - (p[7] << 9); + v7 = (((va + vb) * 251) - (va * 201)) >> 6; + v8 = (((va + vb) * 251) - (vb * 301)) >> 6; + + p[0] = (v1 + v5) >> 10; + p[1] = (v3 + v7) >> 10; + p[2] = (v4 + v8) >> 10; + p[3] = (v2 + v6) >> 10; + p[4] = (v2 - v6) >> 10; + p[5] = (v4 - v8) >> 10; + p[6] = (v3 - v7) >> 10; + p[7] = (v1 - v5) >> 10; + + p += 8; + } + + /* + * Inverse dct, second pass (vertical). + */ + p = block; + + for (i = 0; i < 8; i++) { + gint v1, v2, v3, v4, v5, v6, v7, v8; + gint va, vb; + + va = (p[0] << 9) + (p[32] << 9); + vb = ((p[16] + p[48]) * 277) + (p[16] * 392); + v1 = va + vb + 1024; + v2 = va - vb + 1024; + + va = (p[0] << 9) - (p[32] << 9); + vb = ((p[16] + p[48]) * 277) - (p[48] * 946); + v3 = va + vb + 1024; + v4 = va - vb + 1024; + + va = ((p[8] << 7) + (p[24] * 181) + (p[56] << 7)) >> 6; + vb = ((p[8] << 7) + (p[40] * 181) - (p[56] << 7)) >> 6; + v5 = ((va + vb) * 213) - (vb * 71); + v6 = ((va + vb) * 213) - (va * 355); + + va = ((p[8] << 7) - (p[24] * 181) + (p[56] << 7)) >> 6; + vb = ((p[8] << 7) - (p[40] * 181) - (p[56] << 7)) >> 6; + v7 = ((va + vb) * 251) - (va * 201); + v8 = ((va + vb) * 251) - (vb * 301); + + p[0] = (v1 + v5) >> 11; + p[8] = (v3 + v7) >> 11; + p[16] = (v4 + v8) >> 11; + p[24] = (v2 + v6) >> 11; + p[32] = (v2 - v6) >> 11; + p[40] = (v4 - v8) >> 11; + p[48] = (v3 - v7) >> 11; + p[56] = (v1 - v5) >> 11; + + p++; + } +} + |