/*

 * Copyright (c) 2019, Alliance for Open Media. All rights reserved.

 *

 * This source code is subject to the terms of the BSD 2 Clause License and

 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License

 * was not distributed with this source code in the LICENSE file, you can

 * obtain it at www.aomedia.org/license/software. If the Alliance for Open

 * Media Patent License 1.0 was not distributed with this source code in the

 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.

 */

/*

 * See build_av1_dec_fuzzer.sh for building instructions.

 */

#include <stddef.h>

#include <stdint.h>

#include <stdio.h>

#include <stdlib.h>

#include <algorithm>

#include <memory>

#include "config/aom_config.h"

#include "aom/aom_decoder.h"

#include "aom/aomdx.h"

#include "aom_ports/mem_ops.h"

#define IVF_FRAME_HDR_SZ (4 + 8) /* 4 byte size + 8 byte timestamp */

#define IVF_FILE_HDR_SZ 32

extern "C" void usage_exit(void) { exit(EXIT_FAILURE); }

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {

  if (size <= IVF_FILE_HDR_SZ) {

    return 0;

  }

  // Abusing the four unused bytes at the end of the IVF file header as a source

  // of random bits.

  unsigned int tile_mode = (data[IVF_FILE_HDR_SZ - 1] & 2) != 0;

  unsigned int ext_tile_debug = (data[IVF_FILE_HDR_SZ - 1] & 4) != 0;

  unsigned int is_annexb = (data[IVF_FILE_HDR_SZ - 1] & 8) != 0;

  int output_all_layers = (data[IVF_FILE_HDR_SZ - 1] & 0x10) != 0;

  int operating_point = data[IVF_FILE_HDR_SZ - 2] & 0x1F;

  aom_codec_iface_t *codec_interface = aom_codec_av1_dx();

  aom_codec_ctx_t codec;

  // Set thread count in the range [1, 64].

  const unsigned int threads = (data[IVF_FILE_HDR_SZ] & 0x3f) + 1;

  aom_codec_dec_cfg_t cfg = { threads, 0, 0, !FORCE_HIGHBITDEPTH_DECODING };

  if (aom_codec_dec_init(&codec, codec_interface, &cfg, 0)) {

    return 0;

  }

  AOM_CODEC_CONTROL_TYPECHECKED(&codec, AV1_SET_TILE_MODE, tile_mode);

  AOM_CODEC_CONTROL_TYPECHECKED(&codec, AV1D_EXT_TILE_DEBUG, ext_tile_debug);

  AOM_CODEC_CONTROL_TYPECHECKED(&codec, AV1D_SET_IS_ANNEXB, is_annexb);

  AOM_CODEC_CONTROL_TYPECHECKED(&codec, AV1D_SET_OUTPUT_ALL_LAYERS,

                                output_all_layers);

  AOM_CODEC_CONTROL_TYPECHECKED(&codec, AV1D_SET_OPERATING_POINT,

                                operating_point);

  data += IVF_FILE_HDR_SZ;

  size -= IVF_FILE_HDR_SZ;

  while (size > IVF_FRAME_HDR_SZ) {

    size_t frame_size = mem_get_le32(data);

    size -= IVF_FRAME_HDR_SZ;

    data += IVF_FRAME_HDR_SZ;

    frame_size = std::min(size, frame_size);

    aom_codec_stream_info_t stream_info;

    stream_info.is_annexb = is_annexb;

    aom_codec_err_t err =

        aom_codec_peek_stream_info(codec_interface, data, size, &stream_info);

    static_cast<void>(err);

    err = aom_codec_decode(&codec, data, frame_size, nullptr);

    static_cast<void>(err);

    aom_codec_iter_t iter = nullptr;

    aom_image_t *img = nullptr;

    while ((img = aom_codec_get_frame(&codec, &iter)) != nullptr) {

    }

    data += frame_size;

    size -= frame_size;

  }

  aom_codec_destroy(&codec);

  return 0;

}