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
59static const char *exec_name;
60
61void usage_exit() {
62  fprintf(stderr, "Usage: %s <width> <height> <infile> <outfile> <frame>\n",
63          exec_name);
64  exit(EXIT_FAILURE);
65}
66
67static 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
99int 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}
195