ffmpeg/libavcodec/tests/mpeg12framerate.c
Mark Thompson 278c308cea mpeg12: Add a common function to find the best frame rate
This will be used later in both the mpeg2_metadata filter and the
VAAPI MPEG-2 encoder.  Also adds a unit test.

(cherry picked from commit b5859e0b04)
2017-10-17 20:56:30 +01:00

88 lines
3.3 KiB
C

/*
* 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 "libavcodec/mpeg12.h"
#include "libavcodec/mpeg12data.h"
int main(void)
{
int i;
#define TEST_MATCH(frame_rate, code, ext_n, ext_d) do { \
AVRational fr = frame_rate; \
int c, n, d; \
ff_mpeg12_find_best_frame_rate(fr, &c, &n, &d, 0); \
if (c != code || n != ext_n || d != ext_d) { \
av_log(NULL, AV_LOG_ERROR, "Failed to match %d/%d: " \
"code = %d, ext_n = %d, ext_d = %d.\n", \
fr.num, fr.den, c, n, d); \
return 1; \
} \
} while (0)
#define TEST_EXACT(frn, frd) do { \
AVRational fr = (AVRational) { frn, frd }; \
int c, n, d; \
ff_mpeg12_find_best_frame_rate(fr, &c, &n, &d, 0); \
if (av_cmp_q(fr, av_mul_q(ff_mpeg12_frame_rate_tab[c], \
(AVRational) { n + 1, d + 1 })) != 0) { \
av_log(NULL, AV_LOG_ERROR, "Failed to find exact %d/%d: " \
"code = %d, ext_n = %d, ext_d = %d.\n", \
fr.num, fr.den, c, n, d); \
return 1; \
} \
} while (0)
// Framerates in the table must be chosen exactly.
for (i = 1; i <= 8; i++)
TEST_MATCH(ff_mpeg12_frame_rate_tab[i], i, 0, 0);
// As should the same ones with small perturbations.
// (1/1000 used here to be smaller than half the difference
// between 24 and 24000/1001.)
for (i = 1; i <= 8; i++) {
TEST_MATCH(av_sub_q(ff_mpeg12_frame_rate_tab[i],
(AVRational) { 1, 1000 }), i, 0, 0);
TEST_MATCH(av_add_q(ff_mpeg12_frame_rate_tab[i],
(AVRational) { 1, 1000 }), i, 0, 0);
}
// Exactly constructable framerates should be exact. Note that some
// values can be made in multiple ways (e.g. 12 = 24 / 2 == 60 / 5),
// and there is no reason to favour any particular choice.
TEST_EXACT( 1, 1);
TEST_EXACT( 2, 1);
TEST_EXACT( 12, 1);
TEST_EXACT( 15000, 1001);
TEST_EXACT( 15, 1);
TEST_EXACT( 120, 1);
TEST_EXACT(120000, 1001);
TEST_EXACT( 200, 1);
TEST_EXACT( 240, 1);
// Values higher than 240 (the highest representable, as 60 * 4 / 1)
// should be mapped to 240.
for (i = 240; i < 1000; i += 10)
TEST_MATCH(((AVRational) { i, 1 }), 8, 3, 0);
// Values lower than 24000/32032 (the lowest representable, as
// 24000/1001 * 1 / 32) should be mapped to 24000/32032.
for (i = 74; i > 0; i--)
TEST_MATCH(((AVRational) { i, 100 }), 1, 0, 31);
return 0;
}