FFmpeg: tests/tiny_psnr.c Source File

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tiny_psnr.c

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1 /*

3 *

4 * This file is part of FFmpeg.

5 *

6 * FFmpeg is free software; you can redistribute it and/or

7 * modify it under the terms of the GNU Lesser General Public

8 * License as published by the Free Software Foundation; either

9 * version 2.1 of the License, or (at your option) any later version.

10 *

11 * FFmpeg is distributed in the hope that it will be useful,

12 * but WITHOUT ANY WARRANTY; without even the implied warranty of

13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

14 * Lesser General Public License for more details.

15 *

16 * You should have received a copy of the GNU Lesser General Public

17 * License along with FFmpeg; if not, write to the Free Software

18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

19 */

21 #include <stdio.h>

22 #include <stdlib.h>

23 #include <string.h>

24 #include <inttypes.h>

25 #include <math.h>

26 #include <float.h>

27 #include <limits.h>

29 #include "libavutil/intfloat.h"

30 #include "libavutil/intreadwrite.h"

32 #define FFMIN(a, b) ((a) > (b) ? (b) : (a))

33 #define F 100

34 #define SIZE 2048

36 uint64_t exp16_table[21] = {

37 65537,

38 65538,

39 65540,

40 65544,

41 65552,

42 65568,

43 65600,

44 65664,

45 65793,

46 66050,

47 66568,

48 67616,

49 69763,

50 74262,

51 84150,

52 108051,

53 178145,

54 484249,

55 3578144,

56 195360063,

57 582360139072LL,

58 };

60 #if 0

61 // 16.16 fixpoint exp()

62 static unsigned int exp16(unsigned int a){

63 int i;

64 int out= 1<<16;

66 for(i=19;i>=0;i--){

67 if(a&(1<<i))

68 out= (out*exp16_table[i] + (1<<15))>>16;

69 }

71 return out;

72 }

73 #endif

75 // 16.16 fixpoint log()

76 static int64_t log16(uint64_t a)

77 {

78 int i;

79 int out = 0;

81 if (a < 1 << 16)

82 return -log16((1LL << 32) / a);

83 a <<= 16;

85 for (i = 20; i >= 0; i--) {

86 int64_t b = exp16_table[i];

87 if (a < (b << 16))

88 continue;

89 out |= 1 << i;

90 a = ((a / b) << 16) + (((a % b) << 16) + b / 2) / b;

91 }

92 return out;

93 }

95 static uint64_t int_sqrt(uint64_t a)

96 {

97 uint64_t ret = 0;

98 uint64_t ret_sq = 0;

99 int s;

100

101 for (s = 31; s >= 0; s--) {

102 uint64_t b = ret_sq + (1ULL << (s * 2)) + (ret << s) * 2;

103 if (b <= a) {

104 ret_sq = b;

105 ret += 1ULL << s;

106 }

107 }

108 return ret;

109 }

110

111 static int16_t get_s16l(uint8_t *p)

112 {

113 union {

114 uint16_t u;

115 int16_t s;

116 } v;

117 v.u = p[0] | p[1] << 8;

118 return v.s;

119 }

120

121 static float get_f32l(uint8_t *p)

122 {

123 union av_intfloat32 v;

124 v.i = p[0] | p[1] << 8 | p[2] << 16 | p[3] << 24;

125 return v.f;

126 }

127

128 static double get_f64l(uint8_t *p)

129 {

130 return av_int2double(AV_RL64(p));

131 }

132

133 static int run_psnr(FILE *f[2], int len, int shift, int skip_bytes)

134 {

135 int i, j;

136 uint64_t sse = 0;

137 double sse_d = 0.0;

138 uint8_t buf[2][SIZE];

139 int64_t max = (1LL << (8 * len)) - 1;

140 int size0 = 0;

141 int size1 = 0;

142 uint64_t maxdist = 0;

143 double maxdist_d = 0.0;

144 int noseek;

145

146 noseek = fseek(f[0], 0, SEEK_SET) ||

147 fseek(f[1], 0, SEEK_SET);

148

149 if (!noseek) {

150 for (i = 0; i < 2; i++) {

151 uint8_t *p = buf[i];

152 if (fread(p, 1, 12, f[i]) != 12)

153 return 1;

154 if (!memcmp(p, "RIFF", 4) &&

155 !memcmp(p + 8, "WAVE", 4)) {

156 if (fread(p, 1, 8, f[i]) != 8)

157 return 1;

158 while (memcmp(p, "data", 4)) {

159 int s = p[4] | p[5] << 8 | p[6] << 16 | p[7] << 24;

160 fseek(f[i], s, SEEK_CUR);

161 if (fread(p, 1, 8, f[i]) != 8)

162 return 1;

163 }

164 } else {

165 fseek(f[i], -12, SEEK_CUR);

166 }

167 }

168

169 fseek(f[shift < 0], abs(shift), SEEK_CUR);

170

171 fseek(f[0], skip_bytes, SEEK_CUR);

172 fseek(f[1], skip_bytes, SEEK_CUR);

173 }

174

175 for (;;) {

176 int s0 = fread(buf[0], 1, SIZE, f[0]);

177 int s1 = fread(buf[1], 1, SIZE, f[1]);

178

179 for (j = 0; j < FFMIN(s0, s1); j += len) {

180 switch (len) {

181 case 1:

182 case 2: {

183 int64_t a = buf[0][j];

184 int64_t b = buf[1][j];

185 int dist;

186 if (len == 2) {

187 a = get_s16l(buf[0] + j);

188 b = get_s16l(buf[1] + j);

189 } else {

190 a = buf[0][j];

191 b = buf[1][j];

192 }

193 sse += (a - b) * (a - b);

194 dist = abs(a - b);

195 if (dist > maxdist)

196 maxdist = dist;

197 break;

198 }

199 case 4:

200 case 8: {

201 double dist, a, b;

202 if (len == 8) {

203 a = get_f64l(buf[0] + j);

204 b = get_f64l(buf[1] + j);

205 } else {

206 a = get_f32l(buf[0] + j);

207 b = get_f32l(buf[1] + j);

208 }

209 dist = fabs(a - b);

210 sse_d += (a - b) * (a - b);

211 if (dist > maxdist_d)

212 maxdist_d = dist;

213 break;

214 }

215 }

216 }

217 size0 += s0;

218 size1 += s1;

219 if (s0 + s1 <= 0)

220 break;

221 }

222

223 i = FFMIN(size0, size1) / len;

224 if (!i)

225 i = 1;

226 switch (len) {

227 case 1:

228 case 2: {

229 uint64_t psnr;

230 uint64_t dev = int_sqrt(((sse / i) * F * F) + (((sse % i) * F * F) + i / 2) / i);

231 if (sse)

232 psnr = ((2 * log16(max << 16) + log16(i) - log16(sse)) *

233 284619LL * F + (1LL << 31)) / (1LL << 32);

234 else

235 psnr = 1000 * F - 1; // floating point free infinity :)

236

237 printf("stddev:%5d.%02d PSNR:%3d.%02d MAXDIFF:%5"PRIu64" bytes:%9d/%9d\n",

238 (int)(dev / F), (int)(dev % F),

239 (int)(psnr / F), (int)(psnr % F),

240 maxdist, size0, size1);

241 return psnr;

242 }

243 case 4:

244 case 8: {

245 char psnr_str[64];

246 double psnr = INT_MAX;

247 double dev = sqrt(sse_d / i);

248 uint64_t scale = (len == 4) ? (1ULL << 24) : (1ULL << 32);

249

250 if (sse_d) {

251 psnr = 2 * log(DBL_MAX) - log(i / sse_d);

252 snprintf(psnr_str, sizeof(psnr_str), "%5.02f", psnr);

253 } else

254 snprintf(psnr_str, sizeof(psnr_str), "inf");

255

256 maxdist = maxdist_d * scale;

257

258 printf("stddev:%10.2f PSNR:%s MAXDIFF:%10"PRIu64" bytes:%9d/%9d\n",

259 dev * scale, psnr_str, maxdist, size0, size1);

260 return psnr;

261 }

262 }

263 return -1;

264 }

265

266 int main(int argc, char *argv[])

267 {

268 FILE *f[2];

269 int len = 1;

270 int shift_first= argc < 5 ? 0 : atoi(argv[4]);

271 int skip_bytes = argc < 6 ? 0 : atoi(argv[5]);

272 int shift_last = shift_first + (argc < 7 ? 0 : atoi(argv[6]));

273 int shift;

274 int max_psnr = -1;

275 int max_psnr_shift = 0;

276

277 if (argc > 3) {

278 if (!strcmp(argv[3], "u8")) {

279 len = 1;

280 } else if (!strcmp(argv[3], "s16")) {

281 len = 2;

282 } else if (!strcmp(argv[3], "f32")) {

283 len = 4;

284 } else if (!strcmp(argv[3], "f64")) {

285 len = 8;

286 } else {

287 char *end;

288 len = strtol(argv[3], &end, 0);

289 if (*end || len < 1 || len > 2) {

290 fprintf(stderr, "Unsupported sample format: %s\n", argv[3]);

291 return 1;

292 }

293 }

294 }

295

296 if (argc < 3) {

297 printf("tiny_psnr <file1> <file2> [<elem size> [<shift> [<skip bytes> [<shift search range>]]]]\n");

298 printf("WAV headers are skipped automatically.\n");

299 return 1;

300 }

301

302 f[0] = fopen(argv[1], "rb");

303 f[1] = fopen(argv[2], "rb");

304 if (!f[0] || !f[1]) {

305 fprintf(stderr, "Could not open input files.\n");

306 return 1;

307 }

308

309 for (shift = shift_first; shift <= shift_last; shift++) {

310 int psnr = run_psnr(f, len, shift, skip_bytes);

311 if (psnr > max_psnr || (shift < 0 && psnr == max_psnr)) {

312 max_psnr = psnr;

313 max_psnr_shift = shift;

314 }

315 }

316 if (shift_last > shift_first)

317 printf("Best PSNR is %3d.%02d for shift %i\n", (int)(max_psnr / F), (int)(max_psnr % F), max_psnr_shift);

318 return 0;

319 }

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