WebM Codec SDK

decode_with_drops
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
66 static const char *exec_name;
67
68 void usage_exit(void) {
69 fprintf(stderr, "Usage: %s <infile> <outfile> <N-M|N/M>\n", exec_name);
70 exit(EXIT_FAILURE);
71}
72
73 int 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) die("Invalid number of arguments.");
88
89 reader = vpx_video_reader_open(argv[1]);
90 if (!reader) die("Failed to open %s for reading.", argv[1]);
91
92 if (!(outfile = fopen(argv[2], "wb")))
93 die("Failed to open %s for writing.", argv[2]);
94
95 n = (int)strtol(argv[3], &nptr, 0);
96 m = (int)strtol(nptr + 1, NULL, 0);
97 is_range = (*nptr == '-');
98 if (!n || !m || (*nptr != '-' && *nptr != '/'))
99 die("Couldn't parse pattern %s.\n", argv[3]);
100
101 info = vpx_video_reader_get_info(reader);
102
103 decoder = get_vpx_decoder_by_fourcc(info->codec_fourcc);
104 if (!decoder) die("Unknown input codec.");
105
106 printf("Using %s\n", vpx_codec_iface_name(decoder->codec_interface()));
107
108 if (vpx_codec_dec_init(&codec, decoder->codec_interface(), NULL, 0))
109 die("Failed to initialize decoder.");
110
111 while (vpx_video_reader_read_frame(reader)) {
112 vpx_codec_iter_t iter = NULL;
113 vpx_image_t *img = NULL;
114 size_t frame_size = 0;
115 int skip;
116 const unsigned char *frame =
117 vpx_video_reader_get_frame(reader, &frame_size);
118 if (vpx_codec_decode(&codec, frame, (unsigned int)frame_size, NULL, 0))
119 die_codec(&codec, "Failed to decode frame.");
120
121 ++frame_cnt;
122
123 skip = (is_range && frame_cnt >= n && frame_cnt <= m) ||
124 (!is_range && m - (frame_cnt - 1) % m <= n);
125
126 if (!skip) {
127 putc('.', stdout);
128
129 while ((img = vpx_codec_get_frame(&codec, &iter)) != NULL)
130 vpx_img_write(img, outfile);
131 } else {
132 putc('X', stdout);
133 }
134
135 fflush(stdout);
136 }
137
138 printf("Processed %d frames.\n", frame_cnt);
139 if (vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec.");
140
141 printf("Play: ffplay -f rawvideo -pix_fmt yuv420p -s %dx%d %s\n",
142 info->frame_width, info->frame_height, argv[2]);
143
144 vpx_video_reader_close(reader);
145 fclose(outfile);
146
147 return EXIT_SUCCESS;
148}
vpx_codec_ctx_t
struct vpx_codec_ctx vpx_codec_ctx_t
Codec context structure.
vpx_codec_destroy
vpx_codec_err_t vpx_codec_destroy(vpx_codec_ctx_t *ctx)
Destroy a codec instance.
vpx_codec_iter_t
const void * vpx_codec_iter_t
Iterator.
Definition vpx_codec.h:190
vpx_codec_iface_name
const char * vpx_codec_iface_name(vpx_codec_iface_t *iface)
Return the name for a given interface.
vpx_codec_decode
vpx_codec_err_t vpx_codec_decode(vpx_codec_ctx_t *ctx, const uint8_t *data, unsigned int data_sz, void *user_priv, long deadline)
Decode data.
vpx_codec_dec_init
#define vpx_codec_dec_init(ctx, iface, cfg, flags)
Convenience macro for vpx_codec_dec_init_ver().
Definition vpx_decoder.h:143
vpx_codec_get_frame
vpx_image_t * vpx_codec_get_frame(vpx_codec_ctx_t *ctx, vpx_codec_iter_t *iter)
Decoded frames iterator.
vp8dx.h
Provides definitions for using VP8 or VP9 within the vpx Decoder interface.
vpx_decoder.h
Describes the decoder algorithm interface to applications.
vpx_image_t
struct vpx_image vpx_image_t
Image Descriptor.