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.
11 // VP8 Set Reference Frame
12 // =======================
14 // This is an example demonstrating how to overwrite the VP8 encoder's
15 // internal reference frame. In the sample we set the last frame to the
16 // current frame. If this is done at a cut scene it will avoid a keyframe.
17 // This technique could be used to bounce between two cameras.
19 // Note that the decoder would also have to set the reference frame to the
20 // same value on the same frame, or the video will become corrupt.
24 // This example adds a single argument to the `simple_encoder` example,
25 // which specifies the frame number to update the reference frame on.
26 // The parameter is parsed as follows:
31 // This example maintains the frame number passed on the command line
32 // in the `update_frame_num` variable.
38 // The reference frame is updated on the frame specified on the command
41 // Observing The Effects
42 // ---------------------
43 // Use the `simple_encoder` example to encode a sample with a cut scene.
44 // Determine the frame number of the cut scene by looking for a generated
45 // key-frame (indicated by a 'K'). Supply that frame number as an argument
46 // to this example, and observe that no key-frame is generated.
52 #include "vpx/vp8cx.h"
53 #include "vpx/vpx_encoder.h"
55 #include "../tools_common.h"
56 #include "../video_writer.h"
58 static const char *exec_name;
60 void usage_exit(void) {
61 fprintf(stderr, "Usage: %s <width> <height> <infile> <outfile> <frame>\n",
66 static int encode_frame(vpx_codec_ctx_t *codec, vpx_image_t *img,
67 int frame_index, VpxVideoWriter *writer) {
69 vpx_codec_iter_t iter = NULL;
70 const vpx_codec_cx_pkt_t *pkt = NULL;
71 const vpx_codec_err_t res =
72 vpx_codec_encode(codec, img, frame_index, 1, 0, VPX_DL_GOOD_QUALITY);
73 if (res != VPX_CODEC_OK) die_codec(codec, "Failed to encode frame");
75 while ((pkt = vpx_codec_get_cx_data(codec, &iter)) != NULL) {
78 if (pkt->kind == VPX_CODEC_CX_FRAME_PKT) {
79 const int keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY) != 0;
80 if (!vpx_video_writer_write_frame(writer, pkt->data.frame.buf,
82 pkt->data.frame.pts)) {
83 die_codec(codec, "Failed to write compressed frame");
86 printf(keyframe ? "K" : ".");
94 int main(int argc, char **argv) {
96 vpx_codec_ctx_t codec = { 0 };
97 vpx_codec_enc_cfg_t cfg = { 0 };
101 VpxVideoInfo info = { 0 };
102 VpxVideoWriter *writer = NULL;
103 const VpxInterface *encoder = NULL;
104 int update_frame_num = 0;
105 const int fps = 30; // TODO(dkovalev) add command line argument
106 const int bitrate = 200; // kbit/s TODO(dkovalev) add command line argument
110 if (argc != 6) die("Invalid number of arguments");
112 // TODO(dkovalev): add vp9 support and rename the file accordingly
113 encoder = get_vpx_encoder_by_name("vp8");
114 if (!encoder) die("Unsupported codec.");
116 update_frame_num = atoi(argv[5]);
117 if (!update_frame_num) die("Couldn't parse frame number '%s'\n", argv[5]);
119 info.codec_fourcc = encoder->fourcc;
120 info.frame_width = strtol(argv[1], NULL, 0);
121 info.frame_height = strtol(argv[2], NULL, 0);
122 info.time_base.numerator = 1;
123 info.time_base.denominator = fps;
125 if (info.frame_width <= 0 || info.frame_height <= 0 ||
126 (info.frame_width % 2) != 0 || (info.frame_height % 2) != 0) {
127 die("Invalid frame size: %dx%d", info.frame_width, info.frame_height);
130 if (!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, info.frame_width,
131 info.frame_height, 1)) {
132 die("Failed to allocate image.");
135 printf("Using %s\n", vpx_codec_iface_name(encoder->codec_interface()));
137 res = vpx_codec_enc_config_default(encoder->codec_interface(), &cfg, 0);
138 if (res) die_codec(&codec, "Failed to get default codec config.");
140 cfg.g_w = info.frame_width;
141 cfg.g_h = info.frame_height;
142 cfg.g_timebase.num = info.time_base.numerator;
143 cfg.g_timebase.den = info.time_base.denominator;
144 cfg.rc_target_bitrate = bitrate;
146 writer = vpx_video_writer_open(argv[4], kContainerIVF, &info);
147 if (!writer) die("Failed to open %s for writing.", argv[4]);
149 if (!(infile = fopen(argv[3], "rb")))
150 die("Failed to open %s for reading.", argv[3]);
152 if (vpx_codec_enc_init(&codec, encoder->codec_interface(), &cfg, 0))
153 die_codec(&codec, "Failed to initialize encoder");
156 while (vpx_img_read(&raw, infile)) {
157 if (frame_count + 1 == update_frame_num) {
159 ref.frame_type = VP8_LAST_FRAME;
161 if (vpx_codec_control(&codec, VP8_SET_REFERENCE, &ref))
162 die_codec(&codec, "Failed to set reference frame");
165 encode_frame(&codec, &raw, frame_count++, writer);
169 while (encode_frame(&codec, NULL, -1, writer)) {
174 printf("Processed %d frames.\n", frame_count);
177 if (vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec.");
179 vpx_video_writer_close(writer);