avutil/csp: add av_csp_trc_inv_from_id()

Mathematical inverse of av_csp_trc_from_id(), plus testing to make sure it roundtrips correctly with the corresponding TRC.

Niklas Haas committed 1 year ago

Commit bf0a6c41 parent 28f21776 files · +470 −318Browse files

Unified · Split

6 files

doc/APIchanges +3 −0
libavutil/csp.c +145 −10
libavutil/csp.h +5 −0
libavutil/tests/color_utils.c +11 −2
libavutil/version.h +2 −2
tests/ref/fate/color_utils +304 −304

doc/APIchanges+3−0

@@ -2,6 +2,9 @@ The last version increases of all libraries were on 2024-03-07 · 1 unmodified line
2		2
3	API changes, most recent first:	3	API changes, most recent first:
4		4
		5	2024-12-05 - xxxxxxxxxx - lavu 59.48.100 - csp.h
		6	Add av_csp_trc_func_inv_from_id().
		7
5	2024-11-25 - xxxxxxxxxx - lsws 8.12.100 - swscale.h	8	2024-11-25 - xxxxxxxxxx - lsws 8.12.100 - swscale.h
6	Allow using sws_frame_scale() dynamically, without first initializing the	9	Allow using sws_frame_scale() dynamically, without first initializing the
7	SwsContext. Deprecate sws_init_context(). Add sws_frame_setup() instead.	10	SwsContext. Deprecate sws_init_context(). Add sws_frame_setup() instead.

libavutil/csp.c+145−10

@@ -170,16 +170,36 @@ static double trc_bt709(double Lc) · 169 unmodified lines
170	: a * pow(Lc, 0.45) - (a - 1.0);	170	: a * pow(Lc, 0.45) - (a - 1.0);
171	}	171	}
172		172
		173	static double trc_bt709_inv(double E)
		174	{
		175	const double a = BT709_alpha;
		176	const double b = 4.500 * BT709_beta;
		177
		178	return (0.0 > E) ? 0.0
		179	: ( b > E) ? E / 4.500
		180	: pow((E + (a - 1.0)) / a, 1.0 / 0.45);
		181	}
		182
173	static double trc_gamma22(double Lc)	183	static double trc_gamma22(double Lc)
174	{	184	{
175	return (0.0 > Lc) ? 0.0 : pow(Lc, 1.0/ 2.2);	185	return (0.0 > Lc) ? 0.0 : pow(Lc, 1.0/ 2.2);
176	}	186	}
177		187
		188	static double trc_gamma22_inv(double E)
		189	{
		190	return (0.0 > E) ? 0.0 : pow(E, 2.2);
		191	}
		192
178	static double trc_gamma28(double Lc)	193	static double trc_gamma28(double Lc)
179	{	194	{
180	return (0.0 > Lc) ? 0.0 : pow(Lc, 1.0/ 2.8);	195	return (0.0 > Lc) ? 0.0 : pow(Lc, 1.0/ 2.8);
181	}	196	}
182		197
		198	static double trc_gamma28_inv(double E)
		199	{
		200	return (0.0 > E) ? 0.0 : pow(E, 2.8);
		201	}
		202
183	static double trc_smpte240M(double Lc)	203	static double trc_smpte240M(double Lc)
184	{	204	{
185	const double a = 1.1115;	205	const double a = 1.1115;
@@ -190,6 +210,16 @@ static double trc_smpte240M(double Lc) · 4 unmodified lines
190	: a * pow(Lc, 0.45) - (a - 1.0);	210	: a * pow(Lc, 0.45) - (a - 1.0);
191	}	211	}
192		212
		213	static double trc_smpte240M_inv(double E)
		214	{
		215	const double a = 1.1115;
		216	const double b = 4.000 * 0.0228;
		217
		218	return (0.0 > E) ? 0.0
		219	: ( b > E) ? E / 4.000
		220	: pow((E + (a - 1.0)) / a, 1.0 / 0.45);
		221	}
		222
193	static double trc_linear(double Lc)	223	static double trc_linear(double Lc)
194	{	224	{
195	return Lc;	225	return Lc;
@@ -200,12 +230,22 @@ static double trc_log(double Lc) · 4 unmodified lines
200	return (0.01 > Lc) ? 0.0 : 1.0 + log10(Lc) / 2.0;	230	return (0.01 > Lc) ? 0.0 : 1.0 + log10(Lc) / 2.0;
201	}	231	}
202		232
		233	static double trc_log_inv(double E)
		234	{
		235	return (0.0 > E) ? 0.01 : pow(10.0, 2.0 * (E - 1.0));
		236	}
		237
203	static double trc_log_sqrt(double Lc)	238	static double trc_log_sqrt(double Lc)
204	{	239	{
205	// sqrt(10) / 1000	240	// sqrt(10) / 1000
206	return (0.00316227766 > Lc) ? 0.0 : 1.0 + log10(Lc) / 2.5;	241	return (0.00316227766 > Lc) ? 0.0 : 1.0 + log10(Lc) / 2.5;
207	}	242	}
208		243
		244	static double trc_log_sqrt_inv(double E)
		245	{
		246	return (0.0 > E) ? 0.00316227766 : pow(10.0, 2.5 * (E - 1.0));
		247	}
		248
209	static double trc_iec61966_2_4(double Lc)	249	static double trc_iec61966_2_4(double Lc)
210	{	250	{
211	const double a = BT709_alpha;	251	const double a = BT709_alpha;
@@ -216,6 +256,16 @@ static double trc_iec61966_2_4(double Lc) · 4 unmodified lines
216	: a * pow( Lc, 0.45) - (a - 1.0);	256	: a * pow( Lc, 0.45) - (a - 1.0);
217	}	257	}
218		258
		259	static double trc_iec61966_2_4_inv(double E)
		260	{
		261	const double a = BT709_alpha;
		262	const double b = 4.500 * BT709_beta;
		263
		264	return (-b >= E) ? -pow((-E + (a - 1.0)) / a, 1.0 / 0.45)
		265	: ( b > E) ? E / 4.500
		266	: pow(( E + (a - 1.0)) / a, 1.0 / 0.45);
		267	}
		268
219	static double trc_bt1361(double Lc)	269	static double trc_bt1361(double Lc)
220	{	270	{
221	const double a = BT709_alpha;	271	const double a = BT709_alpha;
@@ -226,6 +276,16 @@ static double trc_bt1361(double Lc) · 4 unmodified lines
226	: a * pow( Lc, 0.45) - (a - 1.0);	276	: a * pow( Lc, 0.45) - (a - 1.0);
227	}	277	}
228		278
		279	static double trc_bt1361_inv(double E)
		280	{
		281	const double a = BT709_alpha;
		282	const double b = 4.500 * BT709_beta;
		283
		284	return (-0.02025 >= E) ? -pow((-4.0 * E - (a - 1.0)) / a, 1.0 / 0.45) / 4.0
		285	: ( b > E) ? E / 4.500
		286	: pow(( E + (a - 1.0)) / a, 1.0 / 0.45);
		287	}
		288
229	static double trc_iec61966_2_1(double Lc)	289	static double trc_iec61966_2_1(double Lc)
230	{	290	{
231	const double a = 1.055;	291	const double a = 1.055;
@@ -236,13 +296,30 @@ static double trc_iec61966_2_1(double Lc) · 4 unmodified lines
236	: a * pow(Lc, 1.0 / 2.4) - (a - 1.0);	296	: a * pow(Lc, 1.0 / 2.4) - (a - 1.0);
237	}	297	}
238		298
		299	static double trc_iec61966_2_1_inv(double E)
		300	{
		301	const double a = 1.055;
		302	const double b = 12.92 * 0.0031308;
		303
		304	return (0.0 > E) ? 0.0
		305	: ( b > E) ? E / 12.92
		306	: pow((E + (a - 1.0)) / a, 2.4);
		307	return E;
		308	}
		309
		310	#define PQ_c1 ( 3424.0 / 4096.0) /* c3-c2 + 1 */
		311	#define PQ_c2 ( 32.0 * 2413.0 / 4096.0)
		312	#define PQ_c3 ( 32.0 * 2392.0 / 4096.0)
		313	#define PQ_m (128.0 * 2523.0 / 4096.0)
		314	#define PQ_n ( 0.25 * 2610.0 / 4096.0)
		315
239	static double trc_smpte_st2084(double Lc)	316	static double trc_smpte_st2084(double Lc)
240	{	317	{
241	const double c1 = 3424.0 / 4096.0; // c3-c2 + 1	318	const double c1 = PQ_c1;
242	const double c2 = 32.0 * 2413.0 / 4096.0;	319	const double c2 = PQ_c2;
243	const double c3 = 32.0 * 2392.0 / 4096.0;	320	const double c3 = PQ_c3;
244	const double m = 128.0 * 2523.0 / 4096.0;	321	const double m = PQ_m;
245	const double n = 0.25 * 2610.0 / 4096.0;	322	const double n = PQ_n;
246	const double L = Lc / 10000.0;	323	const double L = Lc / 10000.0;
247	const double Ln = pow(L, n);	324	const double Ln = pow(L, n);
248		325
@@ -251,24 +328,56 @@ static double trc_smpte_st2084(double Lc) · 2 unmodified lines
251		328
252	}	329	}
253		330
		331	static double trc_smpte_st2084_inv(double E)
		332	{
		333	const double c1 = PQ_c1;
		334	const double c2 = PQ_c2;
		335	const double c3 = PQ_c3;
		336	const double m = PQ_m;
		337	const double n = PQ_n;
		338	const double Em = pow(E, 1.0 / m);
		339
		340	return (c1 > Em) ? 0.0
		341	: 10000.0 * pow((Em - c1) / (c2 - c3 * Em), 1.0 / n);
		342	}
		343
		344	#define DCI_L 48.00
		345	#define DCI_P 52.37
		346
254	static double trc_smpte_st428_1(double Lc)	347	static double trc_smpte_st428_1(double Lc)
255	{	348	{
256	return (0.0 > Lc) ? 0.0	349	return (0.0 > Lc) ? 0.0 : pow(DCI_L / DCI_P * Lc, 1.0 / 2.6);
257	: pow(48.0 * Lc / 52.37, 1.0 / 2.6);
258	}	350	}
259		351
		352	static double trc_smpte_st428_1_inv(double E)
		353	{
		354	return (0.0 > E) ? 0.0 : DCI_P / DCI_L * pow(E, 2.6);
		355	}
		356
		357	#define HLG_a 0.17883277
		358	#define HLG_b 0.28466892
		359	#define HLG_c 0.55991073
260		360
261	static double trc_arib_std_b67(double Lc) {	361	static double trc_arib_std_b67(double Lc) {
262	// The function uses the definition from HEVC, which assumes that the peak	362	// The function uses the definition from HEVC, which assumes that the peak
263	// white is input level = 1. (this is equivalent to scaling E = Lc * 12 and	363	// white is input level = 1. (this is equivalent to scaling E = Lc * 12 and
264	// using the definition from the ARIB STD-B67 spec)	364	// using the definition from the ARIB STD-B67 spec)
265	const double a = 0.17883277;	365	const double a = HLG_a;
266	const double b = 0.28466892;	366	const double b = HLG_b;
267	const double c = 0.55991073;	367	const double c = HLG_c;
268	return (0.0 > Lc) ? 0.0 :	368	return (0.0 > Lc) ? 0.0 :
269	(Lc <= 1.0 / 12.0 ? sqrt(3.0 * Lc) : a * log(12.0 * Lc - b) + c);	369	(Lc <= 1.0 / 12.0 ? sqrt(3.0 * Lc) : a * log(12.0 * Lc - b) + c);
270	}	370	}
271		371
		372	static double trc_arib_std_b67_inv(double E)
		373	{
		374	const double a = HLG_a;
		375	const double b = HLG_b;
		376	const double c = HLG_c;
		377	return (0.0 > E) ? 0.0 :
		378	(E <= 0.5 ? E * E / 3.0 : (exp((E - c) / a) + b) / 12.0);
		379	}
		380
272	static const av_csp_trc_function trc_funcs[AVCOL_TRC_NB] = {	381	static const av_csp_trc_function trc_funcs[AVCOL_TRC_NB] = {
273	[AVCOL_TRC_BT709] = trc_bt709,	382	[AVCOL_TRC_BT709] = trc_bt709,
274	[AVCOL_TRC_GAMMA22] = trc_gamma22,	383	[AVCOL_TRC_GAMMA22] = trc_gamma22,
@@ -294,3 +403,29 @@ av_csp_trc_function av_csp_trc_func_from_id(enum AVColorTransferCharacteristic t · 19 unmodified lines
294	return NULL;	403	return NULL;
295	return trc_funcs[trc];	404	return trc_funcs[trc];
296	}	405	}
		406
		407	static const av_csp_trc_function trc_inv_funcs[AVCOL_TRC_NB] = {
		408	[AVCOL_TRC_BT709] = trc_bt709_inv,
		409	[AVCOL_TRC_GAMMA22] = trc_gamma22_inv,
		410	[AVCOL_TRC_GAMMA28] = trc_gamma28_inv,
		411	[AVCOL_TRC_SMPTE170M] = trc_bt709_inv,
		412	[AVCOL_TRC_SMPTE240M] = trc_smpte240M_inv,
		413	[AVCOL_TRC_LINEAR] = trc_linear,
		414	[AVCOL_TRC_LOG] = trc_log_inv,
		415	[AVCOL_TRC_LOG_SQRT] = trc_log_sqrt_inv,
		416	[AVCOL_TRC_IEC61966_2_4] = trc_iec61966_2_4_inv,
		417	[AVCOL_TRC_BT1361_ECG] = trc_bt1361_inv,
		418	[AVCOL_TRC_IEC61966_2_1] = trc_iec61966_2_1_inv,
		419	[AVCOL_TRC_BT2020_10] = trc_bt709_inv,
		420	[AVCOL_TRC_BT2020_12] = trc_bt709_inv,
		421	[AVCOL_TRC_SMPTE2084] = trc_smpte_st2084_inv,
		422	[AVCOL_TRC_SMPTE428] = trc_smpte_st428_1_inv,
		423	[AVCOL_TRC_ARIB_STD_B67] = trc_arib_std_b67_inv,
		424	};
		425
		426	av_csp_trc_function av_csp_trc_func_inv_from_id(enum AVColorTransferCharacteristic trc)
		427	{
		428	if (trc >= AVCOL_TRC_NB)
		429	return NULL;
		430	return trc_inv_funcs[trc];
		431	}

libavutil/csp.h+5−0

  */
 av_csp_trc_function av_csp_trc_func_from_id(enum AVColorTransferCharacteristic trc);
+/**
+ * Returns the mathematical inverse of the corresponding TRC function.
+ */
+av_csp_trc_function av_csp_trc_func_inv_from_id(enum AVColorTransferCharacteristic trc);
 /**
  * @}
  */

libavutil/tests/color_utils.c+11−2

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
+#include <math.h>
 #include <stdio.h>
 #include "libavutil/csp.h"
 #include "libavutil/macros.h"
 #include "libavutil/pixdesc.h"
     for (enum AVColorTransferCharacteristic trc = 0; trc < AVCOL_TRC_NB; trc++) {
         av_csp_trc_function func = av_csp_trc_func_from_id(trc);
+        av_csp_trc_function func_inv = av_csp_trc_func_inv_from_id(trc);
         const char *name = av_color_transfer_name(trc);
         if (!func)
             continue;
         for (int i = 0; i < FF_ARRAY_ELEMS(test_data); i++) {
             double result = func(test_data[i]);
-            printf("trc=%s calling func(%f) expected=%f\n",
+            double roundtrip = func_inv(result);
-                    name, test_data[i], result);
+            printf("trc=%s calling func(%f) expected=%f roundtrip=%f\n",
+                    name, test_data[i], result, roundtrip);
+            if (result > 0.0 && fabs(roundtrip - test_data[i]) > 1e-8) {
+                printf("  FAIL\n");
+                return 1;
+            }
         }
     }
 }

libavutil/version.h+2−2

@@ -79,8 +79,8 @@ · 78 unmodified lines
79	*/	79	*/
80		80
81	#define LIBAVUTIL_VERSION_MAJOR 59	81	#define LIBAVUTIL_VERSION_MAJOR 59
82	#define LIBAVUTIL_VERSION_MINOR 47	82	#define LIBAVUTIL_VERSION_MINOR 48
83	#define LIBAVUTIL_VERSION_MICRO 101	83	#define LIBAVUTIL_VERSION_MICRO 100
84		84
85	#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \	85	#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
86	LIBAVUTIL_VERSION_MINOR, \	86	LIBAVUTIL_VERSION_MINOR, \

tests/ref/fate/color_utils+304−304

avutil/csp: add av_csp_trc_inv_from_id()

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@@ -1,304 +1,304 @@
1	trc=bt709 calling func(-0.100000) expected=0.000000	1	trc=bt709 calling func(-0.100000) expected=0.000000 roundtrip=0.000000
2	trc=bt709 calling func(-0.018054) expected=0.000000	2	trc=bt709 calling func(-0.018054) expected=0.000000 roundtrip=0.000000
3	trc=bt709 calling func(-0.010000) expected=0.000000	3	trc=bt709 calling func(-0.010000) expected=0.000000 roundtrip=0.000000
4	trc=bt709 calling func(-0.004490) expected=0.000000	4	trc=bt709 calling func(-0.004490) expected=0.000000 roundtrip=0.000000
5	trc=bt709 calling func(0.000000) expected=0.000000	5	trc=bt709 calling func(0.000000) expected=0.000000 roundtrip=0.000000
6	trc=bt709 calling func(0.003162) expected=0.014230	6	trc=bt709 calling func(0.003162) expected=0.014230 roundtrip=0.003162
7	trc=bt709 calling func(0.005000) expected=0.022500	7	trc=bt709 calling func(0.005000) expected=0.022500 roundtrip=0.005000
8	trc=bt709 calling func(0.009000) expected=0.040500	8	trc=bt709 calling func(0.009000) expected=0.040500 roundtrip=0.009000
9	trc=bt709 calling func(0.015000) expected=0.067500	9	trc=bt709 calling func(0.015000) expected=0.067500 roundtrip=0.015000
10	trc=bt709 calling func(0.100000) expected=0.290748	10	trc=bt709 calling func(0.100000) expected=0.290748 roundtrip=0.100000
11	trc=bt709 calling func(1.000000) expected=1.000000	11	trc=bt709 calling func(1.000000) expected=1.000000 roundtrip=1.000000
12	trc=bt709 calling func(52.370000) expected=6.427531	12	trc=bt709 calling func(52.370000) expected=6.427531 roundtrip=52.370000
13	trc=bt709 calling func(125.098765) expected=9.558517	13	trc=bt709 calling func(125.098765) expected=9.558517 roundtrip=125.098765
14	trc=bt709 calling func(1999.111230) expected=33.512490	14	trc=bt709 calling func(1999.111230) expected=33.512490 roundtrip=1999.111230
15	trc=bt709 calling func(6945.443000) expected=58.768794	15	trc=bt709 calling func(6945.443000) expected=58.768794 roundtrip=6945.443000
16	trc=bt709 calling func(15123.456700) expected=83.452916	16	trc=bt709 calling func(15123.456700) expected=83.452916 roundtrip=15123.456700
17	trc=bt709 calling func(19845.889230) expected=94.321297	17	trc=bt709 calling func(19845.889230) expected=94.321297 roundtrip=19845.889230
18	trc=bt709 calling func(98678.423100) expected=194.219568	18	trc=bt709 calling func(98678.423100) expected=194.219568 roundtrip=98678.423100
19	trc=bt709 calling func(99999.899998) expected=195.386306	19	trc=bt709 calling func(99999.899998) expected=195.386306 roundtrip=99999.899998
20	trc=bt470m calling func(-0.100000) expected=0.000000	20	trc=bt470m calling func(-0.100000) expected=0.000000 roundtrip=0.000000
21	trc=bt470m calling func(-0.018054) expected=0.000000	21	trc=bt470m calling func(-0.018054) expected=0.000000 roundtrip=0.000000
22	trc=bt470m calling func(-0.010000) expected=0.000000	22	trc=bt470m calling func(-0.010000) expected=0.000000 roundtrip=0.000000
23	trc=bt470m calling func(-0.004490) expected=0.000000	23	trc=bt470m calling func(-0.004490) expected=0.000000 roundtrip=0.000000
24	trc=bt470m calling func(0.000000) expected=0.000000	24	trc=bt470m calling func(0.000000) expected=0.000000 roundtrip=0.000000
25	trc=bt470m calling func(0.003162) expected=0.073053	25	trc=bt470m calling func(0.003162) expected=0.073053 roundtrip=0.003162
26	trc=bt470m calling func(0.005000) expected=0.089966	26	trc=bt470m calling func(0.005000) expected=0.089966 roundtrip=0.005000
27	trc=bt470m calling func(0.009000) expected=0.117520	27	trc=bt470m calling func(0.009000) expected=0.117520 roundtrip=0.009000
28	trc=bt470m calling func(0.015000) expected=0.148235	28	trc=bt470m calling func(0.015000) expected=0.148235 roundtrip=0.015000
29	trc=bt470m calling func(0.100000) expected=0.351119	29	trc=bt470m calling func(0.100000) expected=0.351119 roundtrip=0.100000
30	trc=bt470m calling func(1.000000) expected=1.000000	30	trc=bt470m calling func(1.000000) expected=1.000000 roundtrip=1.000000
31	trc=bt470m calling func(52.370000) expected=6.045068	31	trc=bt470m calling func(52.370000) expected=6.045068 roundtrip=52.370000
32	trc=bt470m calling func(125.098765) expected=8.980424	32	trc=bt470m calling func(125.098765) expected=8.980424 roundtrip=125.098765
33	trc=bt470m calling func(1999.111230) expected=31.650490	33	trc=bt470m calling func(1999.111230) expected=31.650490 roundtrip=1999.111230
34	trc=bt470m calling func(6945.443000) expected=55.747738	34	trc=bt470m calling func(6945.443000) expected=55.747738 roundtrip=6945.443000
35	trc=bt470m calling func(15123.456700) expected=79.403820	35	trc=bt470m calling func(15123.456700) expected=79.403820 roundtrip=15123.456700
36	trc=bt470m calling func(19845.889230) expected=89.843491	36	trc=bt470m calling func(19845.889230) expected=89.843491 roundtrip=19845.889230
37	trc=bt470m calling func(98678.423100) expected=186.252024	37	trc=bt470m calling func(98678.423100) expected=186.252024 roundtrip=98678.423100
38	trc=bt470m calling func(99999.899998) expected=187.381657	38	trc=bt470m calling func(99999.899998) expected=187.381657 roundtrip=99999.899998
39	trc=bt470bg calling func(-0.100000) expected=0.000000	39	trc=bt470bg calling func(-0.100000) expected=0.000000 roundtrip=0.000000