+static int nearest_sample_index(float *data, float x, int low, int hi)
+{
+ int mid;
+ if (x < data[low])
+ return low;
+
+ if (x > data[hi])
+ return hi;
+
+ for (;;) {
+ av_assert0(x >= data[low]);
+ av_assert0(x <= data[hi]);
+ av_assert0((hi-low) > 0);
+
+ if (hi - low == 1)
+ return low;
+
+ mid = (low + hi) / 2;
+
+ if (x < data[mid])
+ hi = mid;
+ else
+ low = mid;
+ }
+
+ return 0;
+}
+
+#define NEXT_FLOAT_OR_GOTO(value, label) \
+ if (!fget_next_word(line, sizeof(line) ,f)) { \
+ ret = AVERROR_INVALIDDATA; \
+ goto label; \
+ } \
+ if (av_sscanf(line, "%f", &value) != 1) { \
+ ret = AVERROR_INVALIDDATA; \
+ goto label; \
+ }
+
+static int parse_cinespace(AVFilterContext *ctx, FILE *f)
+{
+ LUT3DContext *lut3d = ctx->priv;
+ char line[MAX_LINE_SIZE];
+ float in_min[3] = {0.0, 0.0, 0.0};
+ float in_max[3] = {1.0, 1.0, 1.0};
+ float out_min[3] = {0.0, 0.0, 0.0};
+ float out_max[3] = {1.0, 1.0, 1.0};
+ int inside_metadata = 0, size, size2;
+ int prelut = 0;
+ int ret = 0;
+
+ int prelut_sizes[3] = {0, 0, 0};
+ float *in_prelut[3] = {NULL, NULL, NULL};
+ float *out_prelut[3] = {NULL, NULL, NULL};
+
+ NEXT_LINE_OR_GOTO(skip_line(line), end);
+ if (strncmp(line, "CSPLUTV100", 10)) {
+ av_log(ctx, AV_LOG_ERROR, "Not cineSpace LUT format\n");
+ ret = AVERROR(EINVAL);
+ goto end;
+ }
+
+ NEXT_LINE_OR_GOTO(skip_line(line), end);
+ if (strncmp(line, "3D", 2)) {
+ av_log(ctx, AV_LOG_ERROR, "Not 3D LUT format\n");
+ ret = AVERROR(EINVAL);
+ goto end;
+ }
+
+ while (1) {
+ NEXT_LINE_OR_GOTO(skip_line(line), end);
+
+ if (!strncmp(line, "BEGIN METADATA", 14)) {
+ inside_metadata = 1;
+ continue;
+ }
+ if (!strncmp(line, "END METADATA", 12)) {
+ inside_metadata = 0;
+ continue;
+ }
+ if (inside_metadata == 0) {
+ int size_r, size_g, size_b;
+
+ for (int i = 0; i < 3; i++) {
+ int npoints = strtol(line, NULL, 0);
+
+ if (npoints > 2) {
+ float v,last;
+
+ if (npoints > PRELUT_SIZE) {
+ av_log(ctx, AV_LOG_ERROR, "Prelut size too large.\n");
+ ret = AVERROR_INVALIDDATA;
+ goto end;
+ }
+
+ if (in_prelut[i] || out_prelut[i]) {
+ av_log(ctx, AV_LOG_ERROR, "Invalid file has multiple preluts.\n");
+ ret = AVERROR_INVALIDDATA;
+ goto end;
+ }
+
+ in_prelut[i] = (float*)av_malloc(npoints * sizeof(float));
+ out_prelut[i] = (float*)av_malloc(npoints * sizeof(float));
+ if (!in_prelut[i] || !out_prelut[i]) {
+ ret = AVERROR(ENOMEM);
+ goto end;
+ }
+
+ prelut_sizes[i] = npoints;
+ in_min[i] = FLT_MAX;
+ in_max[i] = -FLT_MAX;
+ out_min[i] = FLT_MAX;
+ out_max[i] = -FLT_MAX;
+
+ for (int j = 0; j < npoints; j++) {
+ NEXT_FLOAT_OR_GOTO(v, end)
+ in_min[i] = FFMIN(in_min[i], v);
+ in_max[i] = FFMAX(in_max[i], v);
+ in_prelut[i][j] = v;
+ if (j > 0 && v < last) {
+ av_log(ctx, AV_LOG_ERROR, "Invalid file, non increasing prelut.\n");
+ ret = AVERROR(ENOMEM);
+ goto end;
+ }
+ last = v;
+ }
+
+ for (int j = 0; j < npoints; j++) {
+ NEXT_FLOAT_OR_GOTO(v, end)
+ out_min[i] = FFMIN(out_min[i], v);
+ out_max[i] = FFMAX(out_max[i], v);
+ out_prelut[i][j] = v;
+ }
+
+ } else if (npoints == 2) {
+ NEXT_LINE_OR_GOTO(skip_line(line), end);
+ if (av_sscanf(line, "%f %f", &in_min[i], &in_max[i]) != 2) {
+ ret = AVERROR_INVALIDDATA;
+ goto end;
+ }
+ NEXT_LINE_OR_GOTO(skip_line(line), end);
+ if (av_sscanf(line, "%f %f", &out_min[i], &out_max[i]) != 2) {
+ ret = AVERROR_INVALIDDATA;
+ goto end;
+ }
+
+ } else {
+ av_log(ctx, AV_LOG_ERROR, "Unsupported number of pre-lut points.\n");
+ ret = AVERROR_PATCHWELCOME;
+ goto end;
+ }
+
+ NEXT_LINE_OR_GOTO(skip_line(line), end);
+ }
+
+ if (av_sscanf(line, "%d %d %d", &size_r, &size_g, &size_b) != 3) {
+ ret = AVERROR(EINVAL);
+ goto end;
+ }
+ if (size_r != size_g || size_r != size_b) {
+ av_log(ctx, AV_LOG_ERROR, "Unsupported size combination: %dx%dx%d.\n", size_r, size_g, size_b);
+ ret = AVERROR_PATCHWELCOME;
+ goto end;
+ }
+
+ size = size_r;
+ size2 = size * size;
+
+ if (prelut_sizes[0] && prelut_sizes[1] && prelut_sizes[2])
+ prelut = 1;
+
+ ret = allocate_3dlut(ctx, size, prelut);
+ if (ret < 0)
+ return ret;
+
+ for (int k = 0; k < size; k++) {
+ for (int j = 0; j < size; j++) {
+ for (int i = 0; i < size; i++) {
+ struct rgbvec *vec = &lut3d->lut[i * size2 + j * size + k];
+
+ NEXT_LINE_OR_GOTO(skip_line(line), end);
+ if (av_sscanf(line, "%f %f %f", &vec->r, &vec->g, &vec->b) != 3) {
+ ret = AVERROR_INVALIDDATA;
+ goto end;
+ }
+
+ vec->r *= out_max[0] - out_min[0];
+ vec->g *= out_max[1] - out_min[1];
+ vec->b *= out_max[2] - out_min[2];
+ }
+ }
+ }
+
+ break;
+ }
+ }
+
+ if (prelut) {
+ for (int c = 0; c < 3; c++) {
+
+ lut3d->prelut.min[c] = in_min[c];
+ lut3d->prelut.max[c] = in_max[c];
+ lut3d->prelut.scale[c] = (1.0f / (float)(in_max[c] - in_min[c])) * (lut3d->prelut.size - 1);
+
+ for (int i = 0; i < lut3d->prelut.size; ++i) {
+ float mix = (float) i / (float)(lut3d->prelut.size - 1);
+ float x = lerpf(in_min[c], in_max[c], mix), a, b;
+
+ int idx = nearest_sample_index(in_prelut[c], x, 0, prelut_sizes[c]-1);
+ av_assert0(idx + 1 < prelut_sizes[c]);
+
+ a = out_prelut[c][idx + 0];
+ b = out_prelut[c][idx + 1];
+ mix = x - in_prelut[c][idx];
+
+ lut3d->prelut.lut[c][i] = sanitizef(lerpf(a, b, mix));
+ }
+ }
+ lut3d->scale.r = 1.00f;
+ lut3d->scale.g = 1.00f;
+ lut3d->scale.b = 1.00f;
+
+ } else {
+ lut3d->scale.r = av_clipf(1. / (in_max[0] - in_min[0]), 0.f, 1.f);
+ lut3d->scale.g = av_clipf(1. / (in_max[1] - in_min[1]), 0.f, 1.f);
+ lut3d->scale.b = av_clipf(1. / (in_max[2] - in_min[2]), 0.f, 1.f);
+ }
+
+end:
+ for (int c = 0; c < 3; c++) {
+ av_freep(&in_prelut[c]);
+ av_freep(&out_prelut[c]);
+ }
+ return ret;
+}
+
+static int set_identity_matrix(AVFilterContext *ctx, int size)