1/*
2 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11// Decode With Drops Example
12// =========================
13//
14// This is an example utility which drops a series of frames, as specified
15// on the command line. This is useful for observing the error recovery
16// features of the codec.
17//
18// Usage
19// -----
20// This example adds a single argument to the `simple_decoder` example,
21// which specifies the range or pattern of frames to drop. The parameter is
22// parsed as follows:
23//
24// Dropping A Range Of Frames
25// --------------------------
26// To drop a range of frames, specify the starting frame and the ending
27// frame to drop, separated by a dash. The following command will drop
28// frames 5 through 10 (base 1).
29//
30//  $ ./decode_with_drops in.ivf out.i420 5-10
31//
32//
33// Dropping A Pattern Of Frames
34// ----------------------------
35// To drop a pattern of frames, specify the number of frames to drop and
36// the number of frames after which to repeat the pattern, separated by
37// a forward-slash. The following command will drop 3 of 7 frames.
38// Specifically, it will decode 4 frames, then drop 3 frames, and then
39// repeat.
40//
41//  $ ./decode_with_drops in.ivf out.i420 3/7
42//
43//
44// Extra Variables
45// ---------------
46// This example maintains the pattern passed on the command line in the
47// `n`, `m`, and `is_range` variables:
48//
49//
50// Making The Drop Decision
51// ------------------------
52// The example decides whether to drop the frame based on the current
53// frame number, immediately before decoding the frame.
54
55#include <stdio.h>
56#include <stdlib.h>
57#include <string.h>
58
59#include "vpx/vp8dx.h"
60#include "vpx/vpx_decoder.h"
61
62#include "./tools_common.h"
63#include "./video_reader.h"
64#include "./vpx_config.h"
65
66static const char *exec_name;
67
68void usage_exit() {
69  fprintf(stderr, "Usage: %s <infile> <outfile> <N-M|N/M>\n", exec_name);
70  exit(EXIT_FAILURE);
71}
72
73int main(int argc, char **argv) {
74  int frame_cnt = 0;
75  FILE *outfile = NULL;
76  vpx_codec_ctx_t codec;
77  const VpxInterface *decoder = NULL;
78  VpxVideoReader *reader = NULL;
79  const VpxVideoInfo *info = NULL;
80  int n = 0;
81  int m = 0;
82  int is_range = 0;
83  char *nptr = NULL;
84
85  exec_name = argv[0];
86
87  if (argc != 4)
88    die("Invalid number of arguments.");
89
90  reader = vpx_video_reader_open(argv[1]);
91  if (!reader)
92    die("Failed to open %s for reading.", argv[1]);
93
94  if (!(outfile = fopen(argv[2], "wb")))
95    die("Failed to open %s for writing.", argv[2]);
96
97  n = strtol(argv[3], &nptr, 0);
98  m = strtol(nptr + 1, NULL, 0);
99  is_range = (*nptr == '-');
100  if (!n || !m || (*nptr != '-' && *nptr != '/'))
101    die("Couldn't parse pattern %s.\n", argv[3]);
102
103  info = vpx_video_reader_get_info(reader);
104
105  decoder = get_vpx_decoder_by_fourcc(info->codec_fourcc);
106  if (!decoder)
107    die("Unknown input codec.");
108
109  printf("Using %s\n", vpx_codec_iface_name(decoder->codec_interface()));
110
111  if (vpx_codec_dec_init(&codec, decoder->codec_interface(), NULL, 0))
112    die_codec(&codec, "Failed to initialize decoder.");
113
114  while (vpx_video_reader_read_frame(reader)) {
115    vpx_codec_iter_t iter = NULL;
116    vpx_image_t *img = NULL;
117    size_t frame_size = 0;
118    int skip;
119    const unsigned char *frame = vpx_video_reader_get_frame(reader,
120                                                            &frame_size);
121    if (vpx_codec_decode(&codec, frame, (unsigned int)frame_size, NULL, 0))
122      die_codec(&codec, "Failed to decode frame.");
123
124    ++frame_cnt;
125
126    skip = (is_range && frame_cnt >= n && frame_cnt <= m) ||
127           (!is_range && m - (frame_cnt - 1) % m <= n);
128
129    if (!skip) {
130      putc('.', stdout);
131
132      while ((img = vpx_codec_get_frame(&codec, &iter)) != NULL)
133        vpx_img_write(img, outfile);
134    } else {
135      putc('X', stdout);
136    }
137
138    fflush(stdout);
139  }
140
141  printf("Processed %d frames.\n", frame_cnt);
142  if (vpx_codec_destroy(&codec))
143    die_codec(&codec, "Failed to destroy codec.");
144
145  printf("Play: ffplay -f rawvideo -pix_fmt yuv420p -s %dx%d %s\n",
146         info->frame_width, info->frame_height, argv[2]);
147
148  vpx_video_reader_close(reader);
149  fclose(outfile);
150
151  return EXIT_SUCCESS;
152}
153