2 * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
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.
12 // VP8 Set Reference Frame
13 // =======================
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.
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.
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:
32 // This example maintains the frame number passed on the command line
33 // in the `update_frame_num` variable.
39 // The reference frame is updated on the frame specified on the command
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.
53 #define VPX_CODEC_DISABLE_COMPAT 1
54 #include "vpx/vp8cx.h"
55 #include "vpx/vpx_encoder.h"
57 #include "./tools_common.h"
58 #include "./video_writer.h"
60 static const char *exec_name;
63 fprintf(stderr, "Usage: %s <width> <height> <infile> <outfile> <frame>\n",
68 static void encode_frame(vpx_codec_ctx_t *codec,
71 VpxVideoWriter *writer) {
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,
76 if (res != VPX_CODEC_OK)
77 die_codec(codec, "Failed to encode frame");
79 while ((pkt = vpx_codec_get_cx_data(codec, &iter)) != NULL) {
80 if (pkt->kind == VPX_CODEC_CX_FRAME_PKT) {
81 const int keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY) != 0;
82 if (!vpx_video_writer_write_frame(writer,
85 pkt->data.frame.pts)) {
86 die_codec(codec, "Failed to write compressed frame");
89 printf(keyframe ? "K" : ".");
95 int main(int argc, char **argv) {
97 vpx_codec_ctx_t codec = {0};
98 vpx_codec_enc_cfg_t cfg = {0};
102 VpxVideoInfo info = {0};
103 VpxVideoWriter *writer = NULL;
104 const VpxInterface *encoder = NULL;
105 int update_frame_num = 0;
106 const int fps = 30; // TODO(dkovalev) add command line argument
107 const int bitrate = 200; // kbit/s TODO(dkovalev) add command line argument
112 die("Invalid number of arguments");
114 // TODO(dkovalev): add vp9 support and rename the file accordingly
115 encoder = get_vpx_encoder_by_name("vp8");
117 die("Unsupported codec.");
119 update_frame_num = atoi(argv[5]);
120 if (!update_frame_num)
121 die("Couldn't parse frame number '%s'\n", argv[5]);
123 info.codec_fourcc = encoder->fourcc;
124 info.frame_width = strtol(argv[1], NULL, 0);
125 info.frame_height = strtol(argv[2], NULL, 0);
126 info.time_base.numerator = 1;
127 info.time_base.denominator = fps;
129 if (info.frame_width <= 0 ||
130 info.frame_height <= 0 ||
131 (info.frame_width % 2) != 0 ||
132 (info.frame_height % 2) != 0) {
133 die("Invalid frame size: %dx%d", info.frame_width, info.frame_height);
136 if (!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, info.frame_width,
137 info.frame_height, 1)) {
138 die("Failed to allocate image.");
141 printf("Using %s\n", vpx_codec_iface_name(encoder->codec_interface()));
143 res = vpx_codec_enc_config_default(encoder->codec_interface(), &cfg, 0);
145 die_codec(&codec, "Failed to get default codec config.");
147 cfg.g_w = info.frame_width;
148 cfg.g_h = info.frame_height;
149 cfg.g_timebase.num = info.time_base.numerator;
150 cfg.g_timebase.den = info.time_base.denominator;
151 cfg.rc_target_bitrate = bitrate;
153 writer = vpx_video_writer_open(argv[4], kContainerIVF, &info);
155 die("Failed to open %s for writing.", argv[4]);
157 if (!(infile = fopen(argv[3], "rb")))
158 die("Failed to open %s for reading.", argv[3]);
160 if (vpx_codec_enc_init(&codec, encoder->codec_interface(), &cfg, 0))
161 die_codec(&codec, "Failed to initialize encoder");
163 while (vpx_img_read(&raw, infile)) {
164 if (frame_count + 1 == update_frame_num) {
166 ref.frame_type = VP8_LAST_FRAME;
168 if (vpx_codec_control(&codec, VP8_SET_REFERENCE, &ref))
169 die_codec(&codec, "Failed to set reference frame");
172 encode_frame(&codec, &raw, frame_count++, writer);
174 encode_frame(&codec, NULL, -1, writer);
178 printf("Processed %d frames.\n", frame_count);
181 if (vpx_codec_destroy(&codec))
182 die_codec(&codec, "Failed to destroy codec.");
184 vpx_video_writer_close(writer);