diff options
author | Diego Biurrun <diego@biurrun.de> | 2012-10-15 01:41:12 +0400 |
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committer | Diego Biurrun <diego@biurrun.de> | 2012-10-15 15:34:07 +0400 |
commit | 7e68c91e247ba20fc8a08cf5a6cf2b75984f1aeb (patch) | |
tree | 7e5b3009d1916023e0a9cd2f38554e356398e79a /libavformat/rmsipr.c | |
parent | 95cd815c3663603871a1f2da95846e8f72d4ea96 (diff) |
rmdec: Move SIPR code shared with Matroska demuxer to a separate file
Diffstat (limited to 'libavformat/rmsipr.c')
-rw-r--r-- | libavformat/rmsipr.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/libavformat/rmsipr.c b/libavformat/rmsipr.c new file mode 100644 index 0000000000..89fbd0e398 --- /dev/null +++ b/libavformat/rmsipr.c @@ -0,0 +1,61 @@ +/* + * tables and functions for demuxing SIPR audio muxed RealMedia style + * + * This file is part of Libav. + * + * Libav 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. + * + * Libav 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 Libav; 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)))); + } + } +} |