/*

  * 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/buffer.h"
 #include "libavutil/hwcontext.h"
 #include "libavutil/hwcontext_internal.h"
 #include "libavutil/log.h"
 #include "libavutil/pixdesc.h"
 #include "libavutil/opt.h"
 
 #include "avfilter.h"
 #include "formats.h"
 #include "internal.h"
 #include "video.h"
 
 typedef struct HWUploadContext {
     const AVClass *class;
 
     AVBufferRef       *hwdevice_ref;
     AVHWDeviceContext *hwdevice;
 
     AVBufferRef       *hwframes_ref;
     AVHWFramesContext *hwframes;
 } HWUploadContext;
 
 static int hwupload_query_formats(AVFilterContext *avctx)
 {
     HWUploadContext *ctx = avctx->priv;
     AVHWFramesConstraints *constraints = NULL;
     const enum AVPixelFormat *input_pix_fmts, *output_pix_fmts;
     AVFilterFormats *input_formats = NULL;
     int err, i;
 
     if (!avctx->hw_device_ctx) {
         av_log(ctx, AV_LOG_ERROR, "A hardware device reference is required "
                "to upload frames to.\n");
         return AVERROR(EINVAL);
     }
 
     ctx->hwdevice_ref = av_buffer_ref(avctx->hw_device_ctx);
     if (!ctx->hwdevice_ref)
         return AVERROR(ENOMEM);
     ctx->hwdevice = (AVHWDeviceContext*)ctx->hwdevice_ref->data;
 
     constraints = av_hwdevice_get_hwframe_constraints(ctx->hwdevice_ref, NULL);
     if (!constraints) {
         err = AVERROR(EINVAL);
         goto fail;
     }
 
     input_pix_fmts  = constraints->valid_sw_formats;
     output_pix_fmts = constraints->valid_hw_formats;
 
     input_formats = ff_make_format_list(output_pix_fmts);
     if (!input_formats) {
         err = AVERROR(ENOMEM);
         goto fail;
     }
     if (input_pix_fmts) {
         for (i = 0; input_pix_fmts[i] != AV_PIX_FMT_NONE; i++) {
             err = ff_add_format(&input_formats, input_pix_fmts[i]);

             if (err < 0)

                 goto fail;
         }
     }
 

     if ((err = ff_formats_ref(input_formats, &avctx->inputs[0]->out_formats)) < 0 ||
         (err = ff_formats_ref(ff_make_format_list(output_pix_fmts),
                               &avctx->outputs[0]->in_formats)) < 0)
         goto fail;

 
     av_hwframe_constraints_free(&constraints);
     return 0;
 
 fail:
     av_buffer_unref(&ctx->hwdevice_ref);
     av_hwframe_constraints_free(&constraints);
     return err;
 }
 
 static int hwupload_config_output(AVFilterLink *outlink)
 {
     AVFilterContext *avctx = outlink->src;
     AVFilterLink   *inlink = avctx->inputs[0];
     HWUploadContext   *ctx = avctx->priv;
     int err;
 
     av_buffer_unref(&ctx->hwframes_ref);
 
     if (inlink->format == outlink->format) {
         // The input is already a hardware format, so we just want to
         // pass through the input frames in their own hardware context.
         if (!inlink->hw_frames_ctx) {
             av_log(ctx, AV_LOG_ERROR, "No input hwframe context.\n");
             return AVERROR(EINVAL);
         }
 
         outlink->hw_frames_ctx = av_buffer_ref(inlink->hw_frames_ctx);
         if (!outlink->hw_frames_ctx)
             return AVERROR(ENOMEM);
 
         return 0;
     }
 
     ctx->hwframes_ref = av_hwframe_ctx_alloc(ctx->hwdevice_ref);
     if (!ctx->hwframes_ref)
         return AVERROR(ENOMEM);
 
     ctx->hwframes = (AVHWFramesContext*)ctx->hwframes_ref->data;
 
     av_log(ctx, AV_LOG_DEBUG, "Surface format is %s.\n",
            av_get_pix_fmt_name(inlink->format));
 
     ctx->hwframes->format    = outlink->format;
     ctx->hwframes->sw_format = inlink->format;
     ctx->hwframes->width     = inlink->w;
     ctx->hwframes->height    = inlink->h;
 
     err = av_hwframe_ctx_init(ctx->hwframes_ref);
     if (err < 0)
         goto fail;
 
     outlink->hw_frames_ctx = av_buffer_ref(ctx->hwframes_ref);
     if (!outlink->hw_frames_ctx) {
         err = AVERROR(ENOMEM);
         goto fail;
     }
 
     return 0;
 
 fail:
     av_buffer_unref(&ctx->hwframes_ref);
     return err;
 }
 
 static int hwupload_filter_frame(AVFilterLink *link, AVFrame *input)
 {
     AVFilterContext *avctx = link->dst;
     AVFilterLink  *outlink = avctx->outputs[0];
     HWUploadContext   *ctx = avctx->priv;
     AVFrame *output = NULL;
     int err;
 
     if (input->format == outlink->format)
         return ff_filter_frame(outlink, input);
 

     output = ff_get_video_buffer(outlink, outlink->w, outlink->h);

     if (!output) {
         av_log(ctx, AV_LOG_ERROR, "Failed to allocate frame to upload to.\n");

         err = AVERROR(ENOMEM);

         goto fail;
     }
 
     output->width  = input->width;
     output->height = input->height;
 
     err = av_hwframe_transfer_data(output, input, 0);
     if (err < 0) {
         av_log(ctx, AV_LOG_ERROR, "Failed to upload frame: %d.\n", err);
         goto fail;
     }
 
     err = av_frame_copy_props(output, input);
     if (err < 0)
         goto fail;
 
     av_frame_free(&input);
 
     return ff_filter_frame(outlink, output);
 
 fail:
     av_frame_free(&input);
     av_frame_free(&output);
     return err;
 }
 
 static av_cold void hwupload_uninit(AVFilterContext *avctx)
 {
     HWUploadContext *ctx = avctx->priv;
 
     av_buffer_unref(&ctx->hwframes_ref);
     av_buffer_unref(&ctx->hwdevice_ref);
 }
 
 static const AVClass hwupload_class = {
     .class_name = "hwupload",
     .item_name  = av_default_item_name,
     .option     = NULL,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 
 static const AVFilterPad hwupload_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = hwupload_filter_frame,
     },
     { NULL }
 };
 
 static const AVFilterPad hwupload_outputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = hwupload_config_output,
     },
     { NULL }
 };
 
 AVFilter ff_vf_hwupload = {
     .name          = "hwupload",
     .description   = NULL_IF_CONFIG_SMALL("Upload a normal frame to a hardware frame"),
     .uninit        = hwupload_uninit,
     .query_formats = hwupload_query_formats,
     .priv_size     = sizeof(HWUploadContext),
     .priv_class    = &hwupload_class,
     .inputs        = hwupload_inputs,
     .outputs       = hwupload_outputs,

     .flags_internal = FF_FILTER_FLAG_HWFRAME_AWARE,

 };