1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
/*
* Copyright (c) 2016, 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.
*/
// 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
// -----------------
// For decoders, you only have to include `aom_decoder.h` and then any
// header files for the specific codecs you use. In this case, we're using
// aom.
//
// Initializing The Codec
// ----------------------
// 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
// beyond the scope of this example, but the main gist is to open the input file
// and parse just enough of it to determine if it's a AVx file and which AVx
// codec is contained within the file.
// Note the NULL pointer passed to aom_codec_dec_init(). We do that in this
// example because we want the algorithm to determine the stream configuration
// (width/height) and allocate memory automatically.
//
// Decoding A Frame
// ----------------
// Once the frame has been read into memory, it is decoded using the
// `aom_codec_decode` function. The call takes a pointer to the data
// (`frame`) and the length of the data (`frame_size`). No application data
// is associated with the frame in this example, so the `user_priv`
// parameter is NULL. The `deadline` parameter is left at zero for this
// example. This parameter is generally only used when doing adaptive post
// processing.
//
// Codecs may produce a variable number of output frames for every call to
// `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
// 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
// -------
// The `aom_codec_destroy` call frees any memory allocated by the codec.
//
// 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
// few exceptions, aom_codec functions return an enumerated error status,
// with the value `0` indicating success.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "aom/aom_decoder.h"
#include "../tools_common.h"
#include "../video_reader.h"
#include "./aom_config.h"
static const char *exec_name;
void usage_exit(void) {
fprintf(stderr, "Usage: %s <infile> <outfile>\n", exec_name);
exit(EXIT_FAILURE);
}
int main(int argc, char **argv) {
int frame_cnt = 0;
FILE *outfile = NULL;
aom_codec_ctx_t codec;
AvxVideoReader *reader = NULL;
const AvxInterface *decoder = NULL;
const AvxVideoInfo *info = NULL;
exec_name = argv[0];
if (argc != 3) die("Invalid number of arguments.");
reader = aom_video_reader_open(argv[1]);
if (!reader) die("Failed to open %s for reading.", argv[1]);
if (!(outfile = fopen(argv[2], "wb")))
die("Failed to open %s for writing.", argv[2]);
info = aom_video_reader_get_info(reader);
decoder = get_aom_decoder_by_fourcc(info->codec_fourcc);
if (!decoder) die("Unknown input codec.");
printf("Using %s\n", aom_codec_iface_name(decoder->codec_interface()));
if (aom_codec_dec_init(&codec, decoder->codec_interface(), NULL, 0))
die_codec(&codec, "Failed to initialize decoder.");
while (aom_video_reader_read_frame(reader)) {
aom_codec_iter_t iter = NULL;
aom_image_t *img = NULL;
size_t frame_size = 0;
const unsigned char *frame =
aom_video_reader_get_frame(reader, &frame_size);
if (aom_codec_decode(&codec, frame, (unsigned int)frame_size, NULL, 0))
die_codec(&codec, "Failed to decode frame.");
while ((img = aom_codec_get_frame(&codec, &iter)) != NULL) {
aom_img_write(img, outfile);
++frame_cnt;
}
}
printf("Processed %d frames.\n", frame_cnt);
if (aom_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec");
printf("Play: ffplay -f rawvideo -pix_fmt yuv420p -s %dx%d %s\n",
info->frame_width, info->frame_height, argv[2]);
aom_video_reader_close(reader);
fclose(outfile);
return EXIT_SUCCESS;
}
|
