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_codec(&codec, "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
Codec context structure.
Definition: vpx_codec.h:197
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_iface_name
const char * vpx_codec_iface_name(vpx_codec_iface_t *iface)
Return the name for a given interface.
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_codec_iter_t
const typedef void * vpx_codec_iter_t
Iterator.
Definition: vpx_codec.h:187
vpx_image
Image Descriptor.
Definition: vpx_image.h:71
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:144
vpx_decoder.h
Describes the decoder algorithm interface to applications.
vpx_codec_destroy
vpx_codec_err_t vpx_codec_destroy(vpx_codec_ctx_t *ctx)
Destroy a codec instance.