WebM Codec SDK

- Main Page
- Related Pages
- Modules
- Data Structures
- Files

vp8cx_set_ref
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
12 // VP8 Set Reference Frame
13 // =======================
14 //
15 // This is an example demonstrating how to overwrite the VP8 encoder's
16 // internal reference frame. In the sample we set the last frame to the
17 // current frame. If this is done at a cut scene it will avoid a keyframe.
18 // This technique could be used to bounce between two cameras.
19 //
20 // Note that the decoder would also have to set the reference frame to the
21 // same value on the same frame, or the video will become corrupt.
22 //
23 // Usage
24 // -----
25 // This example adds a single argument to the `simple_encoder` example,
26 // which specifies the frame number to update the reference frame on.
27 // The parameter is parsed as follows:
28 //
29 //
30 // Extra Variables
31 // ---------------
32 // This example maintains the frame number passed on the command line
33 // in the `update_frame_num` variable.
34 //
35 //
36 // Configuration
37 // -------------
38 //
39 // The reference frame is updated on the frame specified on the command
40 // line.
41 //
42 // Observing The Effects
43 // ---------------------
44 // Use the `simple_encoder` example to encode a sample with a cut scene.
45 // Determine the frame number of the cut scene by looking for a generated
46 // key-frame (indicated by a 'K'). Supply that frame number as an argument
47 // to this example, and observe that no key-frame is generated.
48
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.h>
52
53 #include "vpx/vp8cx.h"
54 #include "vpx/vpx_encoder.h"
55
56 #include "../tools_common.h"
57 #include "../video_writer.h"
58
59 static const char *exec_name;
60
61 void usage_exit() {
62 fprintf(stderr, "Usage: %s <width> <height> <infile> <outfile> <frame>\n",
63 exec_name);
64 exit(EXIT_FAILURE);
65 }
66
67 static int encode_frame(vpx_codec_ctx_t *codec,
68 vpx_image_t *img,
69 int frame_index,
70 VpxVideoWriter *writer) {
71 int got_pkts = 0;
72 vpx_codec_iter_t iter = NULL;
73 const vpx_codec_cx_pkt_t *pkt = NULL;
74 const vpx_codec_err_t res = vpx_codec_encode(codec, img, frame_index, 1, 0,
75 VPX_DL_GOOD_QUALITY);
76 if (res != VPX_CODEC_OK)
77 die_codec(codec, "Failed to encode frame");
78
79 while ((pkt = vpx_codec_get_cx_data(codec, &iter)) != NULL) {
80 got_pkts = 1;
81
82 if (pkt->kind == VPX_CODEC_CX_FRAME_PKT) {
83 const int keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY) != 0;
84 if (!vpx_video_writer_write_frame(writer,
85 pkt->data.frame.buf,
86 pkt->data.frame.sz,
87 pkt->data.frame.pts)) {
88 die_codec(codec, "Failed to write compressed frame");
89 }
90
91 printf(keyframe ? "K" : ".");
92 fflush(stdout);
93 }
94 }
95
96 return got_pkts;
97 }
98
99 int main(int argc, char **argv) {
100 FILE *infile = NULL;
101 vpx_codec_ctx_t codec = {0};
102 vpx_codec_enc_cfg_t cfg = {0};
103 int frame_count = 0;
104 vpx_image_t raw;
105 vpx_codec_err_t res;
106 VpxVideoInfo info = {0};
107 VpxVideoWriter *writer = NULL;
108 const VpxInterface *encoder = NULL;
109 int update_frame_num = 0;
110 const int fps = 30; // TODO(dkovalev) add command line argument
111 const int bitrate = 200; // kbit/s TODO(dkovalev) add command line argument
112
113 exec_name = argv[0];
114
115 if (argc != 6)
116 die("Invalid number of arguments");
117
118 // TODO(dkovalev): add vp9 support and rename the file accordingly
119 encoder = get_vpx_encoder_by_name("vp8");
120 if (!encoder)
121 die("Unsupported codec.");
122
123 update_frame_num = atoi(argv[5]);
124 if (!update_frame_num)
125 die("Couldn't parse frame number '%s'\n", argv[5]);
126
127 info.codec_fourcc = encoder->fourcc;
128 info.frame_width = strtol(argv[1], NULL, 0);
129 info.frame_height = strtol(argv[2], NULL, 0);
130 info.time_base.numerator = 1;
131 info.time_base.denominator = fps;
132
133 if (info.frame_width <= 0 ||
134 info.frame_height <= 0 ||
135 (info.frame_width % 2) != 0 ||
136 (info.frame_height % 2) != 0) {
137 die("Invalid frame size: %dx%d", info.frame_width, info.frame_height);
138 }
139
140 if (!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, info.frame_width,
141 info.frame_height, 1)) {
142 die("Failed to allocate image.");
143 }
144
145 printf("Using %s\n", vpx_codec_iface_name(encoder->codec_interface()));
146
147 res = vpx_codec_enc_config_default(encoder->codec_interface(), &cfg, 0);
148 if (res)
149 die_codec(&codec, "Failed to get default codec config.");
150
151 cfg.g_w = info.frame_width;
152 cfg.g_h = info.frame_height;
153 cfg.g_timebase.num = info.time_base.numerator;
154 cfg.g_timebase.den = info.time_base.denominator;
155 cfg.rc_target_bitrate = bitrate;
156
157 writer = vpx_video_writer_open(argv[4], kContainerIVF, &info);
158 if (!writer)
159 die("Failed to open %s for writing.", argv[4]);
160
161 if (!(infile = fopen(argv[3], "rb")))
162 die("Failed to open %s for reading.", argv[3]);
163
164 if (vpx_codec_enc_init(&codec, encoder->codec_interface(), &cfg, 0))
165 die_codec(&codec, "Failed to initialize encoder");
166
167 // Encode frames.
168 while (vpx_img_read(&raw, infile)) {
169 if (frame_count + 1 == update_frame_num) {
170 vpx_ref_frame_t ref;
171 ref.frame_type = VP8_LAST_FRAME;
172 ref.img = raw;
173 if (vpx_codec_control(&codec, VP8_SET_REFERENCE, &ref))
174 die_codec(&codec, "Failed to set reference frame");
175 }
176
177 encode_frame(&codec, &raw, frame_count++, writer);
178 }
179
180 // Flush encoder.
181 while (encode_frame(&codec, NULL, -1, writer)) {}
182
183 printf("\n");
184 fclose(infile);
185 printf("Processed %d frames.\n", frame_count);
186
187 vpx_img_free(&raw);
188 if (vpx_codec_destroy(&codec))
189 die_codec(&codec, "Failed to destroy codec.");
190
191 vpx_video_writer_close(writer);
192
193 return EXIT_SUCCESS;
194 }
vpx_image
Image Descriptor.
Definition: vpx_image.h:82
vpx_encoder.h
Describes the encoder algorithm interface to applications.
vpx_codec_iface_name
const char * vpx_codec_iface_name(vpx_codec_iface_t *iface)
Return the name for a given interface.
vpx_codec_enc_cfg::g_timebase
struct vpx_rational g_timebase
Stream timebase units.
Definition: vpx_encoder.h:394
vpx_rational::den
int den
Definition: vpx_encoder.h:258
vpx_codec_encode
vpx_codec_err_t vpx_codec_encode(vpx_codec_ctx_t *ctx, const vpx_image_t *img, vpx_codec_pts_t pts, unsigned long duration, vpx_enc_frame_flags_t flags, unsigned long deadline)
Encode a frame.
vpx_codec_enc_cfg
Encoder configuration structure.
Definition: vpx_encoder.h:311
vpx_codec_cx_pkt
Encoder output packet.
Definition: vpx_encoder.h:192
vpx_codec_cx_pkt::frame
struct vpx_codec_cx_pkt::@1::@2 frame
vpx_img_alloc
vpx_image_t * vpx_img_alloc(vpx_image_t *img, vpx_img_fmt_t fmt, unsigned int d_w, unsigned int d_h, unsigned int align)
Open a descriptor, allocating storage for the underlying image.
VPX_IMG_FMT_I420
Definition: vpx_image.h:56
vpx_codec_enc_cfg::g_w
unsigned int g_w
Width of the frame.
Definition: vpx_encoder.h:354
vpx_codec_enc_cfg::g_h
unsigned int g_h
Height of the frame.
Definition: vpx_encoder.h:364
vpx_codec_cx_pkt::kind
enum vpx_codec_cx_pkt_kind kind
Definition: vpx_encoder.h:193
VPX_CODEC_OK
Operation completed without error.
Definition: vpx_codec.h:91
vpx_img_free
void vpx_img_free(vpx_image_t *img)
Close an image descriptor.
vpx_codec_enc_cfg::rc_target_bitrate
unsigned int rc_target_bitrate
Target data rate.
Definition: vpx_encoder.h:522
vpx_rational::num
int num
Definition: vpx_encoder.h:257
VPX_DL_GOOD_QUALITY
#define VPX_DL_GOOD_QUALITY
Definition: vpx_encoder.h:894
vpx_ref_frame::img
vpx_image_t img
Definition: vp8.h:107
vp8cx.h
Provides definitions for using VP8 or VP9 encoder algorithm within the vpx Codec Interface.
vpx_codec_enc_init
#define vpx_codec_enc_init(ctx, iface, cfg, flags)
Convenience macro for vpx_codec_enc_init_ver()
Definition: vpx_encoder.h:793
vpx_codec_err_t
vpx_codec_err_t
Algorithm return codes.
Definition: vpx_codec.h:89
vpx_codec_get_cx_data
const vpx_codec_cx_pkt_t * vpx_codec_get_cx_data(vpx_codec_ctx_t *ctx, vpx_codec_iter_t *iter)
Encoded data iterator.
vpx_codec_cx_pkt::data
union vpx_codec_cx_pkt::@1 data
vpx_codec_enc_config_default
vpx_codec_err_t vpx_codec_enc_config_default(vpx_codec_iface_t *iface, vpx_codec_enc_cfg_t *cfg, unsigned int reserved)
Get a default configuration.
vpx_ref_frame
reference frame data struct
Definition: vp8.h:105
vpx_ref_frame::frame_type
vpx_ref_frame_type_t frame_type
Definition: vp8.h:106
vpx_codec_control
#define vpx_codec_control(ctx, id, data)
vpx_codec_control wrapper macro
Definition: vpx_codec.h:407
vpx_codec_destroy
vpx_codec_err_t vpx_codec_destroy(vpx_codec_ctx_t *ctx)
Destroy a codec instance.
VPX_FRAME_IS_KEY
#define VPX_FRAME_IS_KEY
Definition: vpx_encoder.h:127
vpx_codec_iter_t
const void * vpx_codec_iter_t
Iterator.
Definition: vpx_codec.h:188
VPX_CODEC_CX_FRAME_PKT
Definition: vpx_encoder.h:173
VP8_SET_REFERENCE
Definition: vp8.h:45
vpx_codec_ctx
Codec context structure.
Definition: vpx_codec.h:199