/*

  * 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 "buffer.h"
 #include "common.h"
 #include "hwcontext.h"
 #include "hwcontext_internal.h"
 #include "hwcontext_cuda.h"
 #include "mem.h"
 #include "pixdesc.h"
 #include "pixfmt.h"
 
 typedef struct CUDAFramesContext {
     int shift_width, shift_height;
 } CUDAFramesContext;
 
 static const enum AVPixelFormat supported_formats[] = {
     AV_PIX_FMT_NV12,
     AV_PIX_FMT_YUV420P,
     AV_PIX_FMT_YUV444P,
 };
 
 static void cuda_buffer_free(void *opaque, uint8_t *data)
 {
     AVHWFramesContext *ctx = opaque;
     AVCUDADeviceContext *hwctx = ctx->device_ctx->hwctx;
 
     CUcontext dummy;
 
     cuCtxPushCurrent(hwctx->cuda_ctx);
 
     cuMemFree((CUdeviceptr)data);
 
     cuCtxPopCurrent(&dummy);
 }
 
 static AVBufferRef *cuda_pool_alloc(void *opaque, int size)
 {
     AVHWFramesContext     *ctx = opaque;
     AVCUDADeviceContext *hwctx = ctx->device_ctx->hwctx;
 
     AVBufferRef *ret = NULL;
     CUcontext dummy = NULL;
     CUdeviceptr data;
     CUresult err;
 
     err = cuCtxPushCurrent(hwctx->cuda_ctx);
     if (err != CUDA_SUCCESS) {
         av_log(ctx, AV_LOG_ERROR, "Error setting current CUDA context\n");
         return NULL;
     }
 
     err = cuMemAlloc(&data, size);
     if (err != CUDA_SUCCESS)
         goto fail;
 
     ret = av_buffer_create((uint8_t*)data, size, cuda_buffer_free, ctx, 0);
     if (!ret) {
         cuMemFree(data);
         goto fail;
     }
 
 fail:
     cuCtxPopCurrent(&dummy);
     return ret;
 }
 
 static int cuda_frames_init(AVHWFramesContext *ctx)
 {
     CUDAFramesContext *priv = ctx->internal->priv;
     int i;
 
     for (i = 0; i < FF_ARRAY_ELEMS(supported_formats); i++) {
         if (ctx->sw_format == supported_formats[i])
             break;
     }
     if (i == FF_ARRAY_ELEMS(supported_formats)) {
         av_log(ctx, AV_LOG_ERROR, "Pixel format '%s' is not supported\n",
                av_get_pix_fmt_name(ctx->sw_format));
         return AVERROR(ENOSYS);
     }
 
     av_pix_fmt_get_chroma_sub_sample(ctx->sw_format, &priv->shift_width, &priv->shift_height);
 
     if (!ctx->pool) {
         int size;
 
         switch (ctx->sw_format) {
         case AV_PIX_FMT_NV12:
         case AV_PIX_FMT_YUV420P:
             size = ctx->width * ctx->height * 3 / 2;
             break;
         case AV_PIX_FMT_YUV444P:
             size = ctx->width * ctx->height * 3;
             break;
         }
 
         ctx->internal->pool_internal = av_buffer_pool_init2(size, ctx, cuda_pool_alloc, NULL);
         if (!ctx->internal->pool_internal)
             return AVERROR(ENOMEM);
     }
 
     return 0;
 }
 
 static int cuda_get_buffer(AVHWFramesContext *ctx, AVFrame *frame)
 {
     frame->buf[0] = av_buffer_pool_get(ctx->pool);
     if (!frame->buf[0])
         return AVERROR(ENOMEM);
 
     switch (ctx->sw_format) {
     case AV_PIX_FMT_NV12:
         frame->data[0]     = frame->buf[0]->data;
         frame->data[1]     = frame->data[0] + ctx->width * ctx->height;
         frame->linesize[0] = ctx->width;
         frame->linesize[1] = ctx->width;
         break;
     case AV_PIX_FMT_YUV420P:
         frame->data[0]     = frame->buf[0]->data;
         frame->data[2]     = frame->data[0] + ctx->width * ctx->height;
         frame->data[1]     = frame->data[2] + ctx->width * ctx->height / 4;
         frame->linesize[0] = ctx->width;
         frame->linesize[1] = ctx->width / 2;
         frame->linesize[2] = ctx->width / 2;
         break;
     case AV_PIX_FMT_YUV444P:
         frame->data[0]     = frame->buf[0]->data;
         frame->data[1]     = frame->data[0] + ctx->width * ctx->height;
         frame->data[2]     = frame->data[1] + ctx->width * ctx->height;
         frame->linesize[0] = ctx->width;
         frame->linesize[1] = ctx->width;
         frame->linesize[2] = ctx->width;
         break;
     default:
         av_frame_unref(frame);
         return AVERROR_BUG;
     }
 
     frame->format = AV_PIX_FMT_CUDA;
     frame->width  = ctx->width;
     frame->height = ctx->height;
 
     return 0;
 }
 
 static int cuda_transfer_get_formats(AVHWFramesContext *ctx,
                                      enum AVHWFrameTransferDirection dir,
                                      enum AVPixelFormat **formats)
 {
     enum AVPixelFormat *fmts;
 
     fmts = av_malloc_array(2, sizeof(*fmts));
     if (!fmts)
         return AVERROR(ENOMEM);
 
     fmts[0] = ctx->sw_format;
     fmts[1] = AV_PIX_FMT_NONE;
 
     *formats = fmts;
 
     return 0;
 }
 
 static int cuda_transfer_data_from(AVHWFramesContext *ctx, AVFrame *dst,
                                    const AVFrame *src)
 {
     CUDAFramesContext           *priv = ctx->internal->priv;
     AVCUDADeviceContext *device_hwctx = ctx->device_ctx->hwctx;
 
     CUcontext dummy;
     CUresult err;
     int i;
 
     err = cuCtxPushCurrent(device_hwctx->cuda_ctx);
     if (err != CUDA_SUCCESS)
         return AVERROR_UNKNOWN;
 
     for (i = 0; i < FF_ARRAY_ELEMS(src->data) && src->data[i]; i++) {
         CUDA_MEMCPY2D cpy = {
             .srcMemoryType = CU_MEMORYTYPE_DEVICE,
             .dstMemoryType = CU_MEMORYTYPE_HOST,
             .srcDevice     = (CUdeviceptr)src->data[i],
             .dstHost       = dst->data[i],
             .srcPitch      = src->linesize[i],
             .dstPitch      = dst->linesize[i],
             .WidthInBytes  = FFMIN(src->linesize[i], dst->linesize[i]),
             .Height        = src->height >> (i ? priv->shift_height : 0),
         };
 
         err = cuMemcpy2D(&cpy);
         if (err != CUDA_SUCCESS) {
             av_log(ctx, AV_LOG_ERROR, "Error transferring the data from the CUDA frame\n");
             return AVERROR_UNKNOWN;
         }
     }
 
     cuCtxPopCurrent(&dummy);
 
     return 0;
 }
 
 static int cuda_transfer_data_to(AVHWFramesContext *ctx, AVFrame *dst,
                                  const AVFrame *src)
 {
     CUDAFramesContext           *priv = ctx->internal->priv;
     AVCUDADeviceContext *device_hwctx = ctx->device_ctx->hwctx;
 
     CUcontext dummy;
     CUresult err;
     int i;
 
     err = cuCtxPushCurrent(device_hwctx->cuda_ctx);
     if (err != CUDA_SUCCESS)
         return AVERROR_UNKNOWN;
 
     for (i = 0; i < FF_ARRAY_ELEMS(src->data) && src->data[i]; i++) {
         CUDA_MEMCPY2D cpy = {
             .srcMemoryType = CU_MEMORYTYPE_HOST,
             .dstMemoryType = CU_MEMORYTYPE_DEVICE,
             .srcHost       = src->data[i],
             .dstDevice     = (CUdeviceptr)dst->data[i],
             .srcPitch      = src->linesize[i],
             .dstPitch      = dst->linesize[i],
             .WidthInBytes  = FFMIN(src->linesize[i], dst->linesize[i]),
             .Height        = src->height >> (i ? priv->shift_height : 0),
         };
 
         err = cuMemcpy2D(&cpy);
         if (err != CUDA_SUCCESS) {
             av_log(ctx, AV_LOG_ERROR, "Error transferring the data from the CUDA frame\n");
             return AVERROR_UNKNOWN;
         }
     }
 
     cuCtxPopCurrent(&dummy);
 
     return 0;
 }
 

 static void cuda_device_free(AVHWDeviceContext *ctx)
 {
     AVCUDADeviceContext *hwctx = ctx->hwctx;
     cuCtxDestroy(hwctx->cuda_ctx);
 }
 
 static int cuda_device_create(AVHWDeviceContext *ctx, const char *device,
                               AVDictionary *opts, int flags)
 {
     AVCUDADeviceContext *hwctx = ctx->hwctx;
     CUdevice cu_device;
     CUcontext dummy;
     CUresult err;
     int device_idx = 0;
 
     if (device)
         device_idx = strtol(device, NULL, 0);
 
     err = cuInit(0);
     if (err != CUDA_SUCCESS) {
         av_log(ctx, AV_LOG_ERROR, "Could not initialize the CUDA driver API\n");
         return AVERROR_UNKNOWN;
     }
 
     err = cuDeviceGet(&cu_device, device_idx);
     if (err != CUDA_SUCCESS) {
         av_log(ctx, AV_LOG_ERROR, "Could not get the device number %d\n", device_idx);
         return AVERROR_UNKNOWN;
     }
 
     err = cuCtxCreate(&hwctx->cuda_ctx, 0, cu_device);
     if (err != CUDA_SUCCESS) {
         av_log(ctx, AV_LOG_ERROR, "Error creating a CUDA context\n");
         return AVERROR_UNKNOWN;
     }
 
     cuCtxPopCurrent(&dummy);
 
     ctx->free = cuda_device_free;
 
     return 0;
 }
 

 const HWContextType ff_hwcontext_type_cuda = {
     .type                 = AV_HWDEVICE_TYPE_CUDA,
     .name                 = "CUDA",
 
     .device_hwctx_size    = sizeof(AVCUDADeviceContext),
     .frames_priv_size     = sizeof(CUDAFramesContext),
 

     .device_create        = cuda_device_create,

     .frames_init          = cuda_frames_init,
     .frames_get_buffer    = cuda_get_buffer,
     .transfer_get_formats = cuda_transfer_get_formats,
     .transfer_data_to     = cuda_transfer_data_to,
     .transfer_data_from   = cuda_transfer_data_from,
 
     .pix_fmts             = (const enum AVPixelFormat[]){ AV_PIX_FMT_CUDA, AV_PIX_FMT_NONE },
 };