FFmpeg/libavfilter/opencl.h

/*
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef AVFILTER_OPENCL_H
#define AVFILTER_OPENCL_H

// The intended target is OpenCL 1.2, so disable warnings for APIs
// deprecated after that.  This primarily applies to clCreateCommandQueue(),
// we can't use the replacement clCreateCommandQueueWithProperties() because
// it was introduced in OpenCL 2.0.
#define CL_USE_DEPRECATED_OPENCL_1_2_APIS

#include "libavutil/buffer.h"
#include "libavutil/hwcontext.h"
#include "libavutil/hwcontext_opencl.h"
#include "libavutil/pixfmt.h"

#include "avfilter.h"

typedef struct OpenCLFilterContext {
    const AVClass     *class;

    AVBufferRef       *device_ref;
    AVHWDeviceContext *device;
    AVOpenCLDeviceContext *hwctx;

    cl_program         program;

    enum AVPixelFormat output_format;
    int                output_width;
    int                output_height;
} OpenCLFilterContext;


/**
 * set argument to specific Kernel.
 * This macro relies on usage of local label "fail" and variables:
 * avctx, cle and err.
 */
#define CL_SET_KERNEL_ARG(kernel, arg_num, type, arg)          \
    cle = clSetKernelArg(kernel, arg_num, sizeof(type), arg);  \
    if (cle != CL_SUCCESS) {                                   \
        av_log(avctx, AV_LOG_ERROR, "Failed to set kernel "    \
               "argument %d: error %d.\n", arg_num, cle);      \
        err = AVERROR(EIO);                                    \
        goto fail;                                             \
    }

/**
 * A helper macro to handle OpenCL errors. It will assign errcode to
 * variable err, log error msg, and jump to fail label on error.
 */
#define CL_FAIL_ON_ERROR(errcode, ...) do {                    \
        if (cle != CL_SUCCESS) {                               \
            av_log(avctx, AV_LOG_ERROR, __VA_ARGS__);          \
            err = errcode;                                     \
            goto fail;                                         \
        }                                                      \
    } while(0)

/**
 * Return that all inputs and outputs support only AV_PIX_FMT_OPENCL.
 */
int ff_opencl_filter_query_formats(AVFilterContext *avctx);

/**
 * Check that the input link contains a suitable hardware frames
 * context and extract the device from it.
 */
int ff_opencl_filter_config_input(AVFilterLink *inlink);

/**
 * Create a suitable hardware frames context for the output.
 */
int ff_opencl_filter_config_output(AVFilterLink *outlink);

/**
 * Initialise an OpenCL filter context.
 */
int ff_opencl_filter_init(AVFilterContext *avctx);

/**
 * Uninitialise an OpenCL filter context.
 */
void ff_opencl_filter_uninit(AVFilterContext *avctx);

/**
 * Load a new OpenCL program from strings in memory.
 *
 * Creates a new program and compiles it for the current device.
 * Will log any build errors if compilation fails.
 */
int ff_opencl_filter_load_program(AVFilterContext *avctx,
                                  const char **program_source_array,
                                  int nb_strings);

/**
 * Load a new OpenCL program from a file.
 *
 * Same as ff_opencl_filter_load_program(), but from a file.
 */
int ff_opencl_filter_load_program_from_file(AVFilterContext *avctx,
                                            const char *filename);

/**
 * Find the work size needed needed for a given plane of an image.
 */
int ff_opencl_filter_work_size_from_image(AVFilterContext *avctx,
                                          size_t *work_size,
                                          AVFrame *frame, int plane,
                                          int block_alignment);

#endif /* AVFILTER_OPENCL_H */