common/y4minput.h

/*
 * Copyright (c) 2021, Alliance for Open Media. All rights reserved
 *
 * This source code is subject to the terms of the BSD 3-Clause Clear License
 * and the Alliance for Open Media Patent License 1.0. If the BSD 3-Clause Clear
 * License was not distributed with this source code in the LICENSE file, you
 * can obtain it at aomedia.org/license/software-license/bsd-3-c-c/.  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
 * aomedia.org/license/patent-license/.
 *
 * Based on code from the OggTheora software codec source code,
 * Copyright (C) 2002-2010 The Xiph.Org Foundation and contributors.
 */

#ifndef AOM_COMMON_Y4MINPUT_H_
#define AOM_COMMON_Y4MINPUT_H_

#include <stdio.h>
#include "aom/aom_image.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef struct y4m_input y4m_input;

/*The function used to perform chroma conversion.*/
typedef void (*y4m_convert_func)(y4m_input *_y4m, unsigned char *_dst,
                                 unsigned char *_src);

struct y4m_input {
  int pic_w;
  int pic_h;
  int fps_n;
  int fps_d;
  int par_n;
  int par_d;
  char interlace;
  int src_c_dec_h;
  int src_c_dec_v;
  int dst_c_dec_h;
  int dst_c_dec_v;
  char chroma_type[16];
  /*The size of each converted frame buffer.*/
  size_t dst_buf_sz;
  /*The amount to read directly into the converted frame buffer.*/
  size_t dst_buf_read_sz;
  /*The size of the auxilliary buffer.*/
  size_t aux_buf_sz;
  /*The amount to read into the auxilliary buffer.*/
  size_t aux_buf_read_sz;
  y4m_convert_func convert;
  unsigned char *dst_buf;
  unsigned char *aux_buf;
  enum aom_img_fmt aom_fmt;
  int bps;
  unsigned int bit_depth;
  aom_color_range_t color_range;
};

/**
 * Open the input file, treating it as Y4M. |y4m_ctx| is filled in after
 * reading it. Note that |csp| should only be set for 420 input, and the input
 * chroma is shifted if necessary. The code does not support the conversion
 * from co-located to vertical. The |skip_buffer| indicates bytes that were
 * previously read from |file|, to do input-type detection; this buffer will
 * be read before the |file| is read. It is of size |num_skip|, which *must*
 * be 8 or less.
 *
 * Returns 0 on success, -1 on failure.
 */
int y4m_input_open(y4m_input *y4m_ctx, FILE *file, char *skip_buffer,
                   int num_skip, aom_chroma_sample_position_t csp,
                   int only_420);
void y4m_input_close(y4m_input *_y4m);
int y4m_input_fetch_frame(y4m_input *_y4m, FILE *_fin, aom_image_t *img);

#ifdef __cplusplus
}  // extern "C"
#endif

#endif  // AOM_COMMON_Y4MINPUT_H_