simple_decoder.c 5.37 KB
Newer Older
1
/*
Yaowu Xu's avatar
Yaowu Xu committed
2
 * Copyright (c) 2016, Alliance for Open Media. All rights reserved
3
 *
Yaowu Xu's avatar
Yaowu Xu committed
4 5 6 7 8 9
 * 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.
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
 */

// Simple Decoder
// ==============
//
// This is an example of a simple decoder loop. It takes an input file
// containing the compressed data (in IVF format), passes it through the
// decoder, and writes the decompressed frames to disk. Other decoder
// examples build upon this one.
//
// The details of the IVF format have been elided from this example for
// simplicity of presentation, as IVF files will not generally be used by
// your application. In general, an IVF file consists of a file header,
// followed by a variable number of frames. Each frame consists of a frame
// header followed by a variable length payload. The length of the payload
// is specified in the first four bytes of the frame header. The payload is
// the raw compressed data.
//
// Standard Includes
// -----------------
Yaowu Xu's avatar
Yaowu Xu committed
30
// For decoders, you only have to include `aom_decoder.h` and then any
31
// header files for the specific codecs you use. In this case, we're using
Yaowu Xu's avatar
Yaowu Xu committed
32
// aom.
33 34 35
//
// Initializing The Codec
// ----------------------
Yaowu Xu's avatar
Yaowu Xu committed
36 37 38
// The libaom decoder is initialized by the call to aom_codec_dec_init().
// Determining the codec interface to use is handled by AvxVideoReader and the
// functions prefixed with aom_video_reader_. Discussion of those functions is
39
// beyond the scope of this example, but the main gist is to open the input file
Yaowu Xu's avatar
Yaowu Xu committed
40
// and parse just enough of it to determine if it's a AVx file and which AVx
41
// codec is contained within the file.
Yaowu Xu's avatar
Yaowu Xu committed
42
// Note the NULL pointer passed to aom_codec_dec_init(). We do that in this
43 44
// example because we want the algorithm to determine the stream configuration
// (width/height) and allocate memory automatically.
45 46 47 48
//
// Decoding A Frame
// ----------------
// Once the frame has been read into memory, it is decoded using the
Yaowu Xu's avatar
Yaowu Xu committed
49
// `aom_codec_decode` function. The call takes a pointer to the data
50
// (`frame`) and the length of the data (`frame_size`). No application data
51
// is associated with the frame in this example, so the `user_priv`
Sean DuBois's avatar
Sean DuBois committed
52
// parameter is NULL.
53 54
//
// Codecs may produce a variable number of output frames for every call to
Yaowu Xu's avatar
Yaowu Xu committed
55 56 57 58
// `aom_codec_decode`. These frames are retrieved by the
// `aom_codec_get_frame` iterator function. The iterator variable `iter` is
// initialized to NULL each time `aom_codec_decode` is called.
// `aom_codec_get_frame` is called in a loop, returning a pointer to a
59 60 61 62 63 64 65 66 67
// decoded image or NULL to indicate the end of list.
//
// Processing The Decoded Data
// ---------------------------
// In this example, we simply write the encoded data to disk. It is
// important to honor the image's `stride` values.
//
// Cleanup
// -------
Yaowu Xu's avatar
Yaowu Xu committed
68
// The `aom_codec_destroy` call frees any memory allocated by the codec.
69 70 71 72 73
//
// Error Handling
// --------------
// This example does not special case any error return codes. If there was
// an error, a descriptive message is printed and the program exits. With
Yaowu Xu's avatar
Yaowu Xu committed
74
// few exceptions, aom_codec functions return an enumerated error status,
75 76 77 78 79
// with the value `0` indicating success.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
80

Yaowu Xu's avatar
Yaowu Xu committed
81
#include "aom/aom_decoder.h"
82

Tom Finegan's avatar
Tom Finegan committed
83 84
#include "../tools_common.h"
#include "../video_reader.h"
Yaowu Xu's avatar
Yaowu Xu committed
85
#include "./aom_config.h"
86

87
static const char *exec_name;
88

89
void usage_exit(void) {
90 91
  fprintf(stderr, "Usage: %s <infile> <outfile>\n", exec_name);
  exit(EXIT_FAILURE);
92 93
}

94
int main(int argc, char **argv) {
95 96
  int frame_cnt = 0;
  FILE *outfile = NULL;
Yaowu Xu's avatar
Yaowu Xu committed
97 98 99 100
  aom_codec_ctx_t codec;
  AvxVideoReader *reader = NULL;
  const AvxInterface *decoder = NULL;
  const AvxVideoInfo *info = NULL;
101

102
  exec_name = argv[0];
103

clang-format's avatar
clang-format committed
104
  if (argc != 3) die("Invalid number of arguments.");
105

Yaowu Xu's avatar
Yaowu Xu committed
106
  reader = aom_video_reader_open(argv[1]);
clang-format's avatar
clang-format committed
107
  if (!reader) die("Failed to open %s for reading.", argv[1]);
108

109
  if (!(outfile = fopen(argv[2], "wb")))
110
    die("Failed to open %s for writing.", argv[2]);
111

Yaowu Xu's avatar
Yaowu Xu committed
112
  info = aom_video_reader_get_info(reader);
113

Yaowu Xu's avatar
Yaowu Xu committed
114
  decoder = get_aom_decoder_by_fourcc(info->codec_fourcc);
clang-format's avatar
clang-format committed
115
  if (!decoder) die("Unknown input codec.");
116

Yaowu Xu's avatar
Yaowu Xu committed
117
  printf("Using %s\n", aom_codec_iface_name(decoder->codec_interface()));
118

Yaowu Xu's avatar
Yaowu Xu committed
119
  if (aom_codec_dec_init(&codec, decoder->codec_interface(), NULL, 0))
120
    die_codec(&codec, "Failed to initialize decoder.");
121

Yaowu Xu's avatar
Yaowu Xu committed
122 123 124
  while (aom_video_reader_read_frame(reader)) {
    aom_codec_iter_t iter = NULL;
    aom_image_t *img = NULL;
125
    size_t frame_size = 0;
clang-format's avatar
clang-format committed
126
    const unsigned char *frame =
Yaowu Xu's avatar
Yaowu Xu committed
127
        aom_video_reader_get_frame(reader, &frame_size);
Sean DuBois's avatar
Sean DuBois committed
128
    if (aom_codec_decode(&codec, frame, (unsigned int)frame_size, NULL))
129
      die_codec(&codec, "Failed to decode frame.");
130

Yaowu Xu's avatar
Yaowu Xu committed
131 132
    while ((img = aom_codec_get_frame(&codec, &iter)) != NULL) {
      aom_img_write(img, outfile);
133
      ++frame_cnt;
134
    }
135 136 137
  }

  printf("Processed %d frames.\n", frame_cnt);
Yaowu Xu's avatar
Yaowu Xu committed
138
  if (aom_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec");
139 140

  printf("Play: ffplay -f rawvideo -pix_fmt yuv420p -s %dx%d %s\n",
141
         info->frame_width, info->frame_height, argv[2]);
142

Yaowu Xu's avatar
Yaowu Xu committed
143
  aom_video_reader_close(reader);
144 145

  fclose(outfile);
146

147
  return EXIT_SUCCESS;
148
}