/*
  * 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
  */
 
 #include "libavutil/avassert.h"
 #include "libavutil/buffer.h"
 #include "libavutil/common.h"
 #include "libavutil/hwcontext.h"
 #include "libavutil/hwcontext_opencl.h"
 #include "libavutil/log.h"
 #include "libavutil/mathematics.h"
 #include "libavutil/mem.h"
 #include "libavutil/pixdesc.h"
 #include "libavutil/opt.h"
 
 #include "avfilter.h"
 #include "framesync.h"
 #include "internal.h"
 #include "opencl.h"
 #include "opencl_source.h"
 #include "video.h"
 
 typedef struct OverlayOpenCLContext {
     OpenCLFilterContext ocf;
 
     int              initialised;
     cl_kernel        kernel;
     cl_command_queue command_queue;
 
     FFFrameSync      fs;
 
     int              nb_planes;
     int              x_subsample;
     int              y_subsample;
     int              alpha_separate;
 
     int              x_position;
     int              y_position;
 } OverlayOpenCLContext;
 
 static int overlay_opencl_load(AVFilterContext *avctx,
                                enum AVPixelFormat main_format,
                                enum AVPixelFormat overlay_format)
 {
     OverlayOpenCLContext *ctx = avctx->priv;
     cl_int cle;
     const char *source = ff_opencl_source_overlay;
     const char *kernel;
     const AVPixFmtDescriptor *main_desc, *overlay_desc;
     int err, i, main_planes, overlay_planes;
 
     main_desc    = av_pix_fmt_desc_get(main_format);
     overlay_desc = av_pix_fmt_desc_get(overlay_format);
 
     main_planes = overlay_planes = 0;
     for (i = 0; i < main_desc->nb_components; i++)
         main_planes = FFMAX(main_planes,
                             main_desc->comp[i].plane + 1);
     for (i = 0; i < overlay_desc->nb_components; i++)
         overlay_planes = FFMAX(overlay_planes,
                                overlay_desc->comp[i].plane + 1);
 
     ctx->nb_planes = main_planes;
     ctx->x_subsample = 1 << main_desc->log2_chroma_w;
     ctx->y_subsample = 1 << main_desc->log2_chroma_h;
 
     if (ctx->x_position % ctx->x_subsample ||
         ctx->y_position % ctx->y_subsample) {
         av_log(avctx, AV_LOG_WARNING, "Warning: overlay position (%d, %d) "
                "does not match subsampling (%d, %d).\n",
                ctx->x_position, ctx->y_position,
                ctx->x_subsample, ctx->y_subsample);
     }
 
     if (main_planes == overlay_planes) {
         if (main_desc->nb_components == overlay_desc->nb_components)
             kernel = "overlay_no_alpha";
         else
             kernel = "overlay_internal_alpha";
         ctx->alpha_separate = 0;
     } else {
         kernel = "overlay_external_alpha";
         ctx->alpha_separate = 1;
     }
 
     av_log(avctx, AV_LOG_DEBUG, "Using kernel %s.\n", kernel);
 
     err = ff_opencl_filter_load_program(avctx, &source, 1);
     if (err < 0)
         goto fail;
 
     ctx->command_queue = clCreateCommandQueue(ctx->ocf.hwctx->context,
                                               ctx->ocf.hwctx->device_id,
                                               0, &cle);
     if (!ctx->command_queue) {
         av_log(avctx, AV_LOG_ERROR, "Failed to create OpenCL "
                "command queue: %d.\n", cle);
         err = AVERROR(EIO);
         goto fail;
     }
 
     ctx->kernel = clCreateKernel(ctx->ocf.program, kernel, &cle);
     if (!ctx->kernel) {
         av_log(avctx, AV_LOG_ERROR, "Failed to create kernel: %d.\n", cle);
         err = AVERROR(EIO);
         goto fail;
     }
 
     ctx->initialised = 1;
     return 0;
 
 fail:
     if (ctx->command_queue)
         clReleaseCommandQueue(ctx->command_queue);
     if (ctx->kernel)
         clReleaseKernel(ctx->kernel);
     return err;
 }
 
 static int overlay_opencl_blend(FFFrameSync *fs)
 {
     AVFilterContext    *avctx = fs->parent;
     AVFilterLink     *outlink = avctx->outputs[0];
     OverlayOpenCLContext *ctx = avctx->priv;
     AVFrame *input_main, *input_overlay;
     AVFrame *output;
     cl_mem mem;
     cl_int cle, x, y;
     size_t global_work[2];
     int kernel_arg = 0;
     int err, plane;
 
     err = ff_framesync_get_frame(fs, 0, &input_main, 0);
     if (err < 0)
         return err;
     err = ff_framesync_get_frame(fs, 1, &input_overlay, 0);
     if (err < 0)
         return err;
 
     if (!ctx->initialised) {
         AVHWFramesContext *main_fc =
             (AVHWFramesContext*)input_main->hw_frames_ctx->data;
         AVHWFramesContext *overlay_fc =
             (AVHWFramesContext*)input_overlay->hw_frames_ctx->data;
 
         err = overlay_opencl_load(avctx, main_fc->sw_format,
                                   overlay_fc->sw_format);
         if (err < 0)
             return err;
     }
 
     output = ff_get_video_buffer(outlink, outlink->w, outlink->h);
     if (!output) {
         err = AVERROR(ENOMEM);
         goto fail;
     }
 
     for (plane = 0; plane < ctx->nb_planes; plane++) {
         kernel_arg = 0;
 
         mem = (cl_mem)output->data[plane];
         cle = clSetKernelArg(ctx->kernel, kernel_arg++, sizeof(cl_mem), &mem);
         if (cle != CL_SUCCESS)
             goto fail_kernel_arg;
 
         mem = (cl_mem)input_main->data[plane];
         cle = clSetKernelArg(ctx->kernel, kernel_arg++, sizeof(cl_mem), &mem);
         if (cle != CL_SUCCESS)
             goto fail_kernel_arg;
 
         mem = (cl_mem)input_overlay->data[plane];
         cle = clSetKernelArg(ctx->kernel, kernel_arg++, sizeof(cl_mem), &mem);
         if (cle != CL_SUCCESS)
             goto fail_kernel_arg;
 
         if (ctx->alpha_separate) {
             mem = (cl_mem)input_overlay->data[ctx->nb_planes];
             cle = clSetKernelArg(ctx->kernel, kernel_arg++, sizeof(cl_mem), &mem);
             if (cle != CL_SUCCESS)
                 goto fail_kernel_arg;
         }
 
         x = ctx->x_position / (plane == 0 ? 1 : ctx->x_subsample);
         y = ctx->y_position / (plane == 0 ? 1 : ctx->y_subsample);
 
         cle = clSetKernelArg(ctx->kernel, kernel_arg++, sizeof(cl_int), &x);
         if (cle != CL_SUCCESS)
             goto fail_kernel_arg;
         cle = clSetKernelArg(ctx->kernel, kernel_arg++, sizeof(cl_int), &y);
         if (cle != CL_SUCCESS)
             goto fail_kernel_arg;
 
         if (ctx->alpha_separate) {
             cl_int alpha_adj_x = plane == 0 ? 1 : ctx->x_subsample;
             cl_int alpha_adj_y = plane == 0 ? 1 : ctx->y_subsample;
 
             cle = clSetKernelArg(ctx->kernel, kernel_arg++, sizeof(cl_int), &alpha_adj_x);
             if (cle != CL_SUCCESS)
                 goto fail_kernel_arg;
             cle = clSetKernelArg(ctx->kernel, kernel_arg++, sizeof(cl_int), &alpha_adj_y);
             if (cle != CL_SUCCESS)
                 goto fail_kernel_arg;
         }
 
         global_work[0] = output->width;
         global_work[1] = output->height;
 
         cle = clEnqueueNDRangeKernel(ctx->command_queue, ctx->kernel, 2, NULL,
                                      global_work, NULL, 0, NULL, NULL);
         if (cle != CL_SUCCESS) {
             av_log(avctx, AV_LOG_ERROR, "Failed to enqueue "
                    "overlay kernel for plane %d: %d.\n", cle, plane);
             err = AVERROR(EIO);
             goto fail;
         }
     }
 
     cle = clFinish(ctx->command_queue);
     if (cle != CL_SUCCESS) {
         av_log(avctx, AV_LOG_ERROR, "Failed to finish "
                "command queue: %d.\n", cle);
         err = AVERROR(EIO);
         goto fail;
     }
 
     err = av_frame_copy_props(output, input_main);
 
     av_log(avctx, AV_LOG_DEBUG, "Filter output: %s, %ux%u (%"PRId64").\n",
            av_get_pix_fmt_name(output->format),
            output->width, output->height, output->pts);
 
     return ff_filter_frame(outlink, output);
 
 fail_kernel_arg:
     av_log(avctx, AV_LOG_ERROR, "Failed to set kernel arg %d: %d.\n",
            kernel_arg, cle);
     err = AVERROR(EIO);
 fail:
     return err;
 }
 
 static int overlay_opencl_config_output(AVFilterLink *outlink)
 {
     AVFilterContext *avctx = outlink->src;
     OverlayOpenCLContext *ctx = avctx->priv;
     int err;
 
     err = ff_opencl_filter_config_output(outlink);
     if (err < 0)
         return err;
 
     err = ff_framesync_init_dualinput(&ctx->fs, avctx);
     if (err < 0)
         return err;
 
     return ff_framesync_configure(&ctx->fs);
 }
 
 static av_cold int overlay_opencl_init(AVFilterContext *avctx)
 {
     OverlayOpenCLContext *ctx = avctx->priv;
 
     ctx->fs.on_event = &overlay_opencl_blend;
 
     return ff_opencl_filter_init(avctx);
 }
 
 static int overlay_opencl_activate(AVFilterContext *avctx)
 {
     OverlayOpenCLContext *ctx = avctx->priv;
 
     return ff_framesync_activate(&ctx->fs);
 }
 
 static av_cold void overlay_opencl_uninit(AVFilterContext *avctx)
 {
     OverlayOpenCLContext *ctx = avctx->priv;
     cl_int cle;
 
     if (ctx->kernel) {
         cle = clReleaseKernel(ctx->kernel);
         if (cle != CL_SUCCESS)
             av_log(avctx, AV_LOG_ERROR, "Failed to release "
                    "kernel: %d.\n", cle);
     }
 
     if (ctx->command_queue) {
         cle = clReleaseCommandQueue(ctx->command_queue);
         if (cle != CL_SUCCESS)
             av_log(avctx, AV_LOG_ERROR, "Failed to release "
                    "command queue: %d.\n", cle);
     }
 
     ff_opencl_filter_uninit(avctx);
 
     ff_framesync_uninit(&ctx->fs);
 }
 
 #define OFFSET(x) offsetof(OverlayOpenCLContext, x)
 #define FLAGS (AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM)
 static const AVOption overlay_opencl_options[] = {
     { "x", "Overlay x position",
       OFFSET(x_position), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, .flags = FLAGS },
     { "y", "Overlay y position",
       OFFSET(y_position), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, .flags = FLAGS },
     { NULL },
 };
 
 AVFILTER_DEFINE_CLASS(overlay_opencl);
 
 static const AVFilterPad overlay_opencl_inputs[] = {
     {
         .name         = "main",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = &ff_opencl_filter_config_input,
     },
     {
         .name         = "overlay",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = &ff_opencl_filter_config_input,
     },
     { NULL }
 };
 
 static const AVFilterPad overlay_opencl_outputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_VIDEO,
         .config_props  = &overlay_opencl_config_output,
     },
     { NULL }
 };
 
 AVFilter ff_vf_overlay_opencl = {
     .name            = "overlay_opencl",
     .description     = NULL_IF_CONFIG_SMALL("Overlay one video on top of another"),
     .priv_size       = sizeof(OverlayOpenCLContext),
     .priv_class      = &overlay_opencl_class,
     .init            = &overlay_opencl_init,
     .uninit          = &overlay_opencl_uninit,
     .query_formats   = &ff_opencl_filter_query_formats,
     .activate        = &overlay_opencl_activate,
     .inputs          = overlay_opencl_inputs,
     .outputs         = overlay_opencl_outputs,
     .flags_internal  = FF_FILTER_FLAG_HWFRAME_AWARE,
 };