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Diffstat (limited to 'third_party/aom/aom_dsp/flow_estimation/corner_detect.h')
-rw-r--r-- | third_party/aom/aom_dsp/flow_estimation/corner_detect.h | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/third_party/aom/aom_dsp/flow_estimation/corner_detect.h b/third_party/aom/aom_dsp/flow_estimation/corner_detect.h new file mode 100644 index 0000000000..d05846ce5d --- /dev/null +++ b/third_party/aom/aom_dsp/flow_estimation/corner_detect.h @@ -0,0 +1,80 @@ +/* + * Copyright (c) 2016, Alliance for Open Media. All rights reserved + * + * This source code is subject to the terms of the BSD 2 Clause License and + * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License + * was not distributed with this source code in the LICENSE file, you can + * obtain it at www.aomedia.org/license/software. If the Alliance for Open + * Media Patent License 1.0 was not distributed with this source code in the + * PATENTS file, you can obtain it at www.aomedia.org/license/patent. + */ + +#ifndef AOM_AOM_DSP_FLOW_ESTIMATION_CORNER_DETECT_H_ +#define AOM_AOM_DSP_FLOW_ESTIMATION_CORNER_DETECT_H_ + +#include <stdio.h> +#include <stdlib.h> +#include <stdbool.h> +#include <memory.h> + +#include "aom_dsp/pyramid.h" +#include "aom_util/aom_thread.h" + +#ifdef __cplusplus +extern "C" { +#endif + +#define MAX_CORNERS 4096 + +typedef struct corner_list { +#if CONFIG_MULTITHREAD + // Mutex which is used to prevent the corner list from being computed twice + // at the same time + // + // Semantics: + // * This mutex must be held whenever reading or writing the `valid` flag + // + // * This mutex must also be held while computing the image pyramid, + // to ensure that only one thread may do so at a time. + // + // * However, once you have read the valid flag and seen a true value, + // it is safe to drop the mutex and read from the remaining fields. + // This is because, once the image pyramid is computed, its contents + // will not be changed until the parent frame buffer is recycled, + // which will not happen until there are no more outstanding references + // to the frame buffer. + pthread_mutex_t mutex; +#endif // CONFIG_MULTITHREAD + // Flag indicating whether the corner list contains valid data + bool valid; + // Number of corners found + int num_corners; + // (x, y) coordinates of each corner + int corners[2 * MAX_CORNERS]; +} CornerList; + +size_t av1_get_corner_list_size(void); + +CornerList *av1_alloc_corner_list(void); + +bool av1_compute_corner_list(const ImagePyramid *pyr, CornerList *corners); + +#ifndef NDEBUG +// Check if a corner list has already been computed. +// This is mostly a debug helper - as it is necessary to hold corners->mutex +// while reading the valid flag, we cannot just write: +// assert(corners->valid); +// This function allows the check to be correctly written as: +// assert(aom_is_corner_list_valid(corners)); +bool aom_is_corner_list_valid(CornerList *corners); +#endif + +void av1_invalidate_corner_list(CornerList *corners); + +void av1_free_corner_list(CornerList *corners); + +#ifdef __cplusplus +} +#endif + +#endif // AOM_AOM_DSP_FLOW_ESTIMATION_CORNER_DETECT_H_ |