1/*
2 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
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 */
20
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>
28
29#include "libavutil/intfloat.h"
30#include "libavutil/intreadwrite.h"
31
32#define FFMIN(a, b) ((a) > (b) ? (b) : (a))
33#define F 100
34#define SIZE 2048
35
36uint64_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};
59
60#if 0
61// 16.16 fixpoint exp()
62static unsigned int exp16(unsigned int a){
63    int i;
64    int out= 1<<16;
65
66    for(i=19;i>=0;i--){
67        if(a&(1<<i))
68            out= (out*exp16_table[i] + (1<<15))>>16;
69    }
70
71    return out;
72}
73#endif
74
75// 16.16 fixpoint log()
76static int64_t log16(uint64_t a)
77{
78    int i;
79    int out = 0;
80
81    if (a < 1 << 16)
82        return -log16((1LL << 32) / a);
83    a <<= 16;
84
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}
94
95static 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
111static 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
121static 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
128static double get_f64l(uint8_t *p)
129{
130    return av_int2double(AV_RL64(p));
131}
132
133static 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
266int 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\nSupported: u8, s16, f32, f64\n", argv[3]);
291                return 1;
292            }
293        }
294    }
295
296    if (argc < 3) {
297        printf("tiny_psnr <file1> <file2> [<elem size>|u8|s16|f32|f64 [<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}
320