// Copyright 2011 Google Inc. All Rights Reserved.

//

// Use of this source code is governed by a BSD-style license

// that can be found in the COPYING file in the root of the source

// tree. An additional intellectual property rights grant can be found

// in the file PATENTS. All contributing project authors may

// be found in the AUTHORS file in the root of the source tree.

// -----------------------------------------------------------------------------

//

// Everything about WebPDecBuffer

//

// Author: Skal (pascal.massimino@gmail.com)

#include <assert.h>

#include <stdlib.h>

#include <string.h>

#include "src/dec/vp8i_dec.h"

#include "src/dec/webpi_dec.h"

#include "src/utils/rescaler_utils.h"

#include "src/utils/utils.h"

#include "src/webp/decode.h"

#include "src/webp/types.h"

WEBP_ASSUME_UNSAFE_INDEXABLE_ABI

//------------------------------------------------------------------------------

// WebPDecBuffer

// Number of bytes per pixel for the different color-spaces.

static const uint8_t kModeBpp[MODE_LAST] = {3, 4, 3, 4, 4, 2, 2,  //

                                            4, 4, 4, 2,  // pre-multiplied modes

                                            1, 1};

// Convert to an integer to handle both the unsigned/signed enum cases

// without the need for casting to remove type limit warnings.

int IsValidColorspace(int webp_csp_mode) {

  return (webp_csp_mode >= MODE_RGB && webp_csp_mode < MODE_LAST);

}

// strictly speaking, the very last (or first, if flipped) row

// doesn't require padding.

#define MIN_BUFFER_SIZE(WIDTH, HEIGHT, STRIDE) \

  ((uint64_t)(STRIDE) * ((HEIGHT) - 1) + (WIDTH))

static VP8StatusCode CheckDecBuffer(const WebPDecBuffer* const buffer) {

  int ok = 1;

  const WEBP_CSP_MODE mode = buffer->colorspace;

  const int width = buffer->width;

  const int height = buffer->height;

  if (!IsValidColorspace(mode)) {

    ok = 0;

  } else if (!WebPIsRGBMode(mode)) {  // YUV checks

    const WebPYUVABuffer* const buf = &buffer->u.YUVA;

    const int uv_width = (width + 1) / 2;

    const int uv_height = (height + 1) / 2;

    const int y_stride = abs(buf->y_stride);

    const int u_stride = abs(buf->u_stride);

    const int v_stride = abs(buf->v_stride);

    const int a_stride = abs(buf->a_stride);

    const uint64_t y_size = MIN_BUFFER_SIZE(width, height, y_stride);

    const uint64_t u_size = MIN_BUFFER_SIZE(uv_width, uv_height, u_stride);

    const uint64_t v_size = MIN_BUFFER_SIZE(uv_width, uv_height, v_stride);

    const uint64_t a_size = MIN_BUFFER_SIZE(width, height, a_stride);

    ok &= (y_size <= buf->y_size);

    ok &= (u_size <= buf->u_size);

    ok &= (v_size <= buf->v_size);

    ok &= (y_stride >= width);

    ok &= (u_stride >= uv_width);

    ok &= (v_stride >= uv_width);

    ok &= (buf->y != NULL);

    ok &= (buf->u != NULL);

    ok &= (buf->v != NULL);

    if (mode == MODE_YUVA) {

      ok &= (a_stride >= width);

      ok &= (a_size <= buf->a_size);

      ok &= (buf->a != NULL);

    }

  } else {  // RGB checks

    const WebPRGBABuffer* const buf = &buffer->u.RGBA;

    const int stride = abs(buf->stride);

    const uint64_t size =

        MIN_BUFFER_SIZE((uint64_t)width * kModeBpp[mode], height, stride);

    ok &= (size <= buf->size);

    ok &= (stride >= width * kModeBpp[mode]);

    ok &= (buf->rgba != NULL);

  }

  return ok ? VP8_STATUS_OK : VP8_STATUS_INVALID_PARAM;

}

#undef MIN_BUFFER_SIZE

static VP8StatusCode AllocateBuffer(WebPDecBuffer* const buffer) {

  const int w = buffer->width;

  const int h = buffer->height;

  const WEBP_CSP_MODE mode = buffer->colorspace;

  if (w <= 0 || h <= 0 || !IsValidColorspace(mode)) {

    return VP8_STATUS_INVALID_PARAM;

  }

  if (buffer->is_external_memory <= 0 && buffer->private_memory == NULL) {

    uint8_t* output;

    int uv_stride = 0, a_stride = 0;

    uint64_t uv_size = 0, a_size = 0, total_size;

    // We need memory and it hasn't been allocated yet.

    // => initialize output buffer, now that dimensions are known.

    int stride;

    uint64_t size;

    if ((uint64_t)w * kModeBpp[mode] >= (1ull << 31)) {

      return VP8_STATUS_INVALID_PARAM;

    }

    stride = w * kModeBpp[mode];

    size = (uint64_t)stride * h;

    if (!WebPIsRGBMode(mode)) {

      uv_stride = (w + 1) / 2;

      uv_size = (uint64_t)uv_stride * ((h + 1) / 2);

      if (mode == MODE_YUVA) {

        a_stride = w;

        a_size = (uint64_t)a_stride * h;

      }

    }

    total_size = size + 2 * uv_size + a_size;

    output = (uint8_t*)WebPSafeMalloc(total_size, sizeof(*output));

    if (output == NULL) {

      return VP8_STATUS_OUT_OF_MEMORY;

    }

    buffer->private_memory = output;

    if (!WebPIsRGBMode(mode)) {  // YUVA initialization

      WebPYUVABuffer* const buf = &buffer->u.YUVA;

      buf->y = output;

      buf->y_stride = stride;

      buf->y_size = (size_t)size;

      buf->u = output + size;

      buf->u_stride = uv_stride;

      buf->u_size = (size_t)uv_size;

      buf->v = output + size + uv_size;

      buf->v_stride = uv_stride;

      buf->v_size = (size_t)uv_size;

      if (mode == MODE_YUVA) {

        buf->a = output + size + 2 * uv_size;

      }

      buf->a_size = (size_t)a_size;

      buf->a_stride = a_stride;

    } else {  // RGBA initialization

      WebPRGBABuffer* const buf = &buffer->u.RGBA;

      buf->rgba = output;

      buf->stride = stride;

      buf->size = (size_t)size;

    }

  }

  return CheckDecBuffer(buffer);

}

VP8StatusCode WebPFlipBuffer(WebPDecBuffer* const buffer) {

  if (buffer == NULL) {

    return VP8_STATUS_INVALID_PARAM;

  }

  if (WebPIsRGBMode(buffer->colorspace)) {

    WebPRGBABuffer* const buf = &buffer->u.RGBA;

    buf->rgba += (int64_t)(buffer->height - 1) * buf->stride;

    buf->stride = -buf->stride;

  } else {

    WebPYUVABuffer* const buf = &buffer->u.YUVA;

    const int64_t H = buffer->height;

    buf->y += (H - 1) * buf->y_stride;

    buf->y_stride = -buf->y_stride;

    buf->u += ((H - 1) >> 1) * buf->u_stride;

    buf->u_stride = -buf->u_stride;

    buf->v += ((H - 1) >> 1) * buf->v_stride;

    buf->v_stride = -buf->v_stride;

    if (buf->a != NULL) {

      buf->a += (H - 1) * buf->a_stride;

      buf->a_stride = -buf->a_stride;

    }

  }

  return VP8_STATUS_OK;

}

VP8StatusCode WebPAllocateDecBuffer(int width, int height,

                                    const WebPDecoderOptions* const options,

                                    WebPDecBuffer* const buffer) {

  VP8StatusCode status;

  if (buffer == NULL || width <= 0 || height <= 0) {

    return VP8_STATUS_INVALID_PARAM;

  }

  if (options != NULL) {  // First, apply options if there is any.

    if (options->use_cropping) {

      const int cw = options->crop_width;

      const int ch = options->crop_height;

      const int x = options->crop_left & ~1;

      const int y = options->crop_top & ~1;

      if (!WebPCheckCropDimensions(width, height, x, y, cw, ch)) {

        return VP8_STATUS_INVALID_PARAM;  // out of frame boundary.

      }

      width = cw;

      height = ch;

    }

    if (options->use_scaling) {

#if !defined(WEBP_REDUCE_SIZE)

      int scaled_width = options->scaled_width;

      int scaled_height = options->scaled_height;

      if (!WebPRescalerGetScaledDimensions(width, height, &scaled_width,

                                           &scaled_height)) {

        return VP8_STATUS_INVALID_PARAM;

      }

      width = scaled_width;

      height = scaled_height;

#else

      return VP8_STATUS_INVALID_PARAM;  // rescaling not supported

#endif

    }

  }

  buffer->width = width;

  buffer->height = height;

  // Then, allocate buffer for real.

  status = AllocateBuffer(buffer);

  if (status != VP8_STATUS_OK) return status;

  // Use the stride trick if vertical flip is needed.

  if (options != NULL && options->flip) {

    status = WebPFlipBuffer(buffer);

  }

  return status;

}

//------------------------------------------------------------------------------

// constructors / destructors

int WebPInitDecBufferInternal(WebPDecBuffer* buffer, int version) {

  if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_DECODER_ABI_VERSION)) {

    return 0;  // version mismatch

  }

  if (buffer == NULL) return 0;

  WEBP_UNSAFE_MEMSET(buffer, 0, sizeof(*buffer));

  return 1;

}

void WebPFreeDecBuffer(WebPDecBuffer* buffer) {

  if (buffer != NULL) {

    if (buffer->is_external_memory <= 0) {

      WebPSafeFree(buffer->private_memory);

    }

    buffer->private_memory = NULL;

  }

}

void WebPCopyDecBuffer(const WebPDecBuffer* const src,

                       WebPDecBuffer* const dst) {

  if (src != NULL && dst != NULL) {

    *dst = *src;

    if (src->private_memory != NULL) {

      dst->is_external_memory = 1;  // dst buffer doesn't own the memory.

      dst->private_memory = NULL;

    }

  }

}

// Copy and transfer ownership from src to dst (beware of parameter order!)

void WebPGrabDecBuffer(WebPDecBuffer* const src, WebPDecBuffer* const dst) {

  if (src != NULL && dst != NULL) {

    *dst = *src;

    if (src->private_memory != NULL) {

      src->is_external_memory = 1;  // src relinquishes ownership

      src->private_memory = NULL;

    }

  }

}

VP8StatusCode WebPCopyDecBufferPixels(const WebPDecBuffer* const src_buf,

                                      WebPDecBuffer* const dst_buf) {

  assert(src_buf != NULL && dst_buf != NULL);

  assert(src_buf->colorspace == dst_buf->colorspace);

  dst_buf->width = src_buf->width;

  dst_buf->height = src_buf->height;

  if (CheckDecBuffer(dst_buf) != VP8_STATUS_OK) {

    return VP8_STATUS_INVALID_PARAM;

  }

  if (WebPIsRGBMode(src_buf->colorspace)) {

    const WebPRGBABuffer* const src = &src_buf->u.RGBA;

    const WebPRGBABuffer* const dst = &dst_buf->u.RGBA;

    WebPCopyPlane(src->rgba, src->stride, dst->rgba, dst->stride,

                  src_buf->width * kModeBpp[src_buf->colorspace],

                  src_buf->height);

  } else {

    const WebPYUVABuffer* const src = &src_buf->u.YUVA;

    const WebPYUVABuffer* const dst = &dst_buf->u.YUVA;

    WebPCopyPlane(src->y, src->y_stride, dst->y, dst->y_stride, src_buf->width,

                  src_buf->height);

    WebPCopyPlane(src->u, src->u_stride, dst->u, dst->u_stride,

                  (src_buf->width + 1) / 2, (src_buf->height + 1) / 2);

    WebPCopyPlane(src->v, src->v_stride, dst->v, dst->v_stride,

                  (src_buf->width + 1) / 2, (src_buf->height + 1) / 2);

    if (WebPIsAlphaMode(src_buf->colorspace)) {

      WebPCopyPlane(src->a, src->a_stride, dst->a, dst->a_stride,

                    src_buf->width, src_buf->height);

    }

  }

  return VP8_STATUS_OK;

}

int WebPAvoidSlowMemory(const WebPDecBuffer* const output,

                        const WebPBitstreamFeatures* const features) {

  assert(output != NULL);

  return (output->is_external_memory >= 2) &&

         WebPIsPremultipliedMode(output->colorspace) &&

         (features != NULL && features->has_alpha);

}

//------------------------------------------------------------------------------