ffmpeg/libavcodec/tests/bitstream_template.c

203 lines
6.0 KiB
C

/*
* cached bitstream reader test
* copyright (c) 2022 Anton Khirnov <anton@khirnov.net>
*
* 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
*/
#define ASSERT_LEVEL 2
#include "libavutil/avassert.h"
#include "libavutil/lfg.h"
#include "libavutil/random_seed.h"
#include "libavcodec/bitstream.h"
#include "libavcodec/defs.h"
#ifdef BITSTREAM_LE
#define BITSTREAM_WRITER_LE
#endif
#include "libavcodec/put_bits.h"
#define SIZE 157
enum Op {
OP_READ,
OP_READ_NZ,
OP_READ_BIT,
OP_READ_63,
OP_READ_64,
OP_READ_SIGNED,
OP_READ_SIGNED_NZ,
OP_APPLY_SIGN,
OP_ALIGN,
OP_NB,
};
int main(int argc, char **argv)
{
BitstreamContext bc;
PutBitContext pb;
AVLFG lfg;
uint8_t buf[SIZE + AV_INPUT_BUFFER_PADDING_SIZE];
uint8_t dst[SIZE + AV_INPUT_BUFFER_PADDING_SIZE];
uint32_t random_seed;
uint64_t val, val1;
int32_t sval, sval1;
unsigned count;
int ret;
/* generate random input, using a given or random seed */
if (argc > 1)
random_seed = strtoul(argv[1], NULL, 0);
else
random_seed = av_get_random_seed();
fprintf(stderr, "Testing with LFG seed: %"PRIu32"\n", random_seed);
av_lfg_init(&lfg, random_seed);
for (unsigned i = 0; i < SIZE; i++)
buf[i] = av_lfg_get(&lfg);
ret = bits_init8 (&bc, buf, SIZE);
av_assert0(ret >= 0);
init_put_bits(&pb, dst, SIZE);
/* use a random sequence of bitreading operations to transfer data
* from BitstreamContext to PutBitContext */
while (bits_left(&bc) > 0) {
enum Op op = av_lfg_get(&lfg) % OP_NB;
switch (op) {
case OP_READ:
count = av_lfg_get(&lfg) % FFMIN(33, bits_left(&bc) + 1);
val1 = bits_peek(&bc, count);
val = bits_read(&bc, count);
fprintf(stderr, "%d read %u: %"PRIu64"\n", bits_tell(&bc) - count, count, val);
av_assert0(val == val1);
put_bits64(&pb, count, val);
break;
case OP_READ_NZ:
count = av_lfg_get(&lfg) % FFMIN(33, bits_left(&bc) + 1);
count = FFMAX(count, 1);
val1 = bits_peek_nz(&bc, count);
val = bits_read_nz(&bc, count);
fprintf(stderr, "%d read_nz %u: %"PRIu64"\n", bits_tell(&bc) - count, count, val);
av_assert0(val == val1);
put_bits64(&pb, count, val);
break;
case OP_READ_BIT:
val = bits_read_bit(&bc);
fprintf(stderr, "%d read_bit: %"PRIu64"\n", bits_tell(&bc) - 1, val);
put_bits(&pb, 1, val);
break;
case OP_READ_63:
count = av_lfg_get(&lfg) % FFMIN(64, bits_left(&bc) + 1);
val = bits_read_63(&bc, count);
fprintf(stderr, "%d read_63 %u: %"PRIu64"\n", bits_tell(&bc) - count, count, val);
put_bits64(&pb, count, val);
break;
case OP_READ_64:
count = av_lfg_get(&lfg) % FFMIN(65, bits_left(&bc) + 1);
val = bits_read_64(&bc, count);
fprintf(stderr, "%d read_64 %u: %"PRIu64"\n", bits_tell(&bc) - count, count, val);
put_bits64(&pb, count, val);
break;
case OP_READ_SIGNED:
count = av_lfg_get(&lfg) % FFMIN(33, bits_left(&bc) + 1);
sval1 = bits_peek_signed(&bc, count);
sval = bits_read_signed(&bc, count);
fprintf(stderr, "%d read_signed %u: %"PRId32"\n", bits_tell(&bc) - count, count, sval);
av_assert0(sval == sval1);
if (count == 32) put_bits32(&pb, sval);
else put_sbits(&pb, count, sval);
break;
case OP_READ_SIGNED_NZ:
count = av_lfg_get(&lfg) % FFMIN(33, bits_left(&bc) + 1);
count = FFMAX(count, 1);
sval1 = bits_peek_signed_nz(&bc, count);
sval = bits_read_signed_nz(&bc, count);
fprintf(stderr, "%d read_signed_nz %u: %"PRId32"\n", bits_tell(&bc) - count, count, sval);
av_assert0(sval == sval1);
if (count == 32) put_bits32(&pb, sval);
else put_sbits(&pb, count, sval);
break;
case OP_ALIGN:
count = (bits_tell(&bc) + 7) / 8 * 8 - bits_tell(&bc);
fprintf(stderr, "%d align %u\n", bits_tell(&bc), count);
put_bits(&pb, count, bits_peek(&bc, count));
bits_align(&bc);
break;
case OP_APPLY_SIGN:
if (bits_left(&bc) < 2)
continue;
count = av_lfg_get(&lfg) % FFMIN(32, bits_left(&bc));
count = FFMAX(count, 1);
if (!bits_peek(&bc, count))
continue;
val = bits_read(&bc, count);
sval = bits_apply_sign(&bc, val);
fprintf(stderr, "%d apply_sign %u %"PRId32"\n",
bits_tell(&bc) - count - 1, count, sval);
put_bits64(&pb, count, FFABS(sval));
put_bits(&pb, 1, sval < 0);
break;
default:
av_assert0(0);
}
}
flush_put_bits(&pb);
for (unsigned i = 0; i < SIZE; i++)
if (buf[i] != dst[i]) {
fprintf(stderr, "Mismatch at byte %u: %hhu %hhu; seed %"PRIu32"\n",
i, buf[i], dst[i], random_seed);
return 1;
}
return 0;
}