/* * tables and functions for demuxing SIPR audio muxed RealMedia style * * This file is part of FFmpeg. * * FFmpeg 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. * * FFmpeg 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 FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include <stdint.h> #include "rmsipr.h" const unsigned char ff_sipr_subpk_size[4] = { 29, 19, 37, 20 }; static const unsigned char sipr_swaps[38][2] = { { 0, 63 }, { 1, 22 }, { 2, 44 }, { 3, 90 }, { 5, 81 }, { 7, 31 }, { 8, 86 }, { 9, 58 }, { 10, 36 }, { 12, 68 }, { 13, 39 }, { 14, 73 }, { 15, 53 }, { 16, 69 }, { 17, 57 }, { 19, 88 }, { 20, 34 }, { 21, 71 }, { 24, 46 }, { 25, 94 }, { 26, 54 }, { 28, 75 }, { 29, 50 }, { 32, 70 }, { 33, 92 }, { 35, 74 }, { 38, 85 }, { 40, 56 }, { 42, 87 }, { 43, 65 }, { 45, 59 }, { 48, 79 }, { 49, 93 }, { 51, 89 }, { 55, 95 }, { 61, 76 }, { 67, 83 }, { 77, 80 } }; /* This can be optimized, e.g. use memcpy() if data blocks are aligned. */ void ff_rm_reorder_sipr_data(uint8_t *buf, int sub_packet_h, int framesize) { int n, bs = sub_packet_h * framesize * 2 / 96; // nibbles per subpacket for (n = 0; n < 38; n++) { int j; int i = bs * sipr_swaps[n][0]; int o = bs * sipr_swaps[n][1]; /* swap 4bit-nibbles of block 'i' with 'o' */ for (j = 0; j < bs; j++, i++, o++) { int x = (buf[i >> 1] >> (4 * (i & 1))) & 0xF, y = (buf[o >> 1] >> (4 * (o & 1))) & 0xF; buf[o >> 1] = (x << (4 * (o & 1))) | (buf[o >> 1] & (0xF << (4 * !(o & 1)))); buf[i >> 1] = (y << (4 * (i & 1))) | (buf[i >> 1] & (0xF << (4 * !(i & 1)))); } } }