2 * This file is part of FFmpeg.
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/lfg.h"
23 #include "libavutil/log.h"
25 #include "libavcodec/rangecoder.h"
30 * Check if at the current position there is a valid looking termination
31 * @param version version 0 requires the decoder to know the data size in bytes
32 * version 1 needs about 1 bit more space but does not need to
33 * carry the size from encoder to decoder
34 * @returns negative AVERROR code on error or non negative.
36 static int rac_check_termination(RangeCoder *c, int version)
40 get_rac(c, (uint8_t[]) { 129 });
42 if (c->bytestream == tmp.bytestream && c->bytestream > c->bytestream_start)
43 tmp.low -= *--tmp.bytestream;
44 tmp.bytestream_end = tmp.bytestream;
46 if (get_rac(&tmp, (uint8_t[]) { 129 }))
47 return AVERROR_INVALIDDATA;
49 if (c->bytestream_end != c->bytestream)
50 return AVERROR_INVALIDDATA;
58 uint8_t b[9 * SIZE] = {0};
60 int i, p, actual_length, version;
64 av_lfg_init(&prng, 1);
65 for (version = 0; version < 2; version++) {
66 for (p = 0; p< 1024; p++) {
67 ff_init_range_encoder(&c, b, SIZE);
68 ff_build_rac_states(&c, (1LL << 32) / 20, 128 + 64 + 32 + 16);
70 memset(state, 128, sizeof(state));
72 for (i = 0; i < SIZE; i++)
73 r[i] = av_lfg_get(&prng) % 7;
75 for (i = 0; i < SIZE; i++)
76 put_rac(&c, state, r[i] & 1);
78 actual_length = ff_rac_terminate(&c, version);
80 ff_init_range_decoder(&c, b, version ? SIZE : actual_length);
82 memset(state, 128, sizeof(state));
84 for (i = 0; i < SIZE; i++)
85 if ((r[i] & 1) != get_rac(&c, state)) {
86 av_log(NULL, AV_LOG_ERROR, "rac failure at %d pass %d version %d\n", i, p, version);
90 if (rac_check_termination(&c, version) < 0) {
91 av_log(NULL, AV_LOG_ERROR, "rac failure at termination pass %d version %d\n", p, version);
94 if (c.bytestream - c.bytestream_start - actual_length != version) {
95 av_log(NULL, AV_LOG_ERROR, "rac failure at pass %d version %d\n", p, version);