/* *  Copyright (c) 2010 The WebM project authors. All Rights Reserved. * *  Use of this source code is governed by a BSD-style license *  that can be found in the LICENSE file in the root of the source *  tree. An additional intellectual property rights grant can be found *  in the file PATENTS.  All contributing project authors may *  be found in the AUTHORS file in the root of the source tree. */ // VP8 Set Reference Frame// =======================//// This is an example demonstrating how to overwrite the VP8 encoder's// internal reference frame. In the sample we set the last frame to the// current frame. If this is done at a cut scene it will avoid a keyframe.// This technique could be used to bounce between two cameras.//// Note that the decoder would also have to set the reference frame to the// same value on the same frame, or the video will become corrupt.//// Usage// -----// This example adds a single argument to the `simple_encoder` example,// which specifies the frame number to update the reference frame on.// The parameter is parsed as follows:////// Extra Variables// ---------------// This example maintains the frame number passed on the command line// in the `update_frame_num` variable.////// Configuration// -------------//// The reference frame is updated on the frame specified on the command// line.//// Observing The Effects// ---------------------// Use the `simple_encoder` example to encode a sample with a cut scene.// Determine the frame number of the cut scene by looking for a generated// key-frame (indicated by a 'K'). Supply that frame number as an argument// to this example, and observe that no key-frame is generated. #include <stdio.h>#include <stdlib.h>#include <string.h> #include "vpx/vp8cx.h"#include "vpx/vpx_encoder.h"#include "vp8/common/common.h" #include "../tools_common.h"#include "../video_writer.h" static const char *exec_name; void usage_exit(void) {  fprintf(stderr, "Usage: %s <width> <height> <infile> <outfile> <frame>\n",          exec_name);  exit(EXIT_FAILURE);} static int encode_frame(vpx_codec_ctx_t *codec, vpx_image_t *img,                        int frame_index, VpxVideoWriter *writer) {  int got_pkts = 0;  vpx_codec_iter_t iter = NULL;  const vpx_codec_cx_pkt_t *pkt = NULL;  const vpx_codec_err_t res =      vpx_codec_encode(codec, img, frame_index, 1, 0, VPX_DL_GOOD_QUALITY);  if (res != VPX_CODEC_OK) die_codec(codec, "Failed to encode frame");   while ((pkt = vpx_codec_get_cx_data(codec, &iter)) != NULL) {    got_pkts = 1;     if (pkt->kind == VPX_CODEC_CX_FRAME_PKT) {      const int keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY) != 0;      if (!vpx_video_writer_write_frame(writer, pkt->data.frame.buf,                                        pkt->data.frame.sz,                                        pkt->data.frame.pts)) {        die_codec(codec, "Failed to write compressed frame");      }       printf(keyframe ? "K" : ".");      fflush(stdout);    }  }   return got_pkts;} int main(int argc, char **argv) {  FILE *infile = NULL;  vpx_codec_ctx_t codec;  vpx_codec_enc_cfg_t cfg;  int frame_count = 0;  vpx_image_t raw;  vpx_codec_err_t res;  VpxVideoInfo info;  VpxVideoWriter *writer = NULL;  const VpxInterface *encoder = NULL;  int update_frame_num = 0;  const int fps = 30;       // TODO(dkovalev) add command line argument  const int bitrate = 200;  // kbit/s TODO(dkovalev) add command line argument   vp8_zero(codec);  vp8_zero(cfg);  vp8_zero(info);   exec_name = argv[0];   if (argc != 6) die("Invalid number of arguments");   // TODO(dkovalev): add vp9 support and rename the file accordingly  encoder = get_vpx_encoder_by_name("vp8");  if (!encoder) die("Unsupported codec.");   update_frame_num = atoi(argv[5]);  if (!update_frame_num) die("Couldn't parse frame number '%s'\n", argv[5]);   info.codec_fourcc = encoder->fourcc;  info.frame_width = (int)strtol(argv[1], NULL, 0);  info.frame_height = (int)strtol(argv[2], NULL, 0);  info.time_base.numerator = 1;  info.time_base.denominator = fps;   if (info.frame_width <= 0 || info.frame_height <= 0 ||      (info.frame_width % 2) != 0 || (info.frame_height % 2) != 0) {    die("Invalid frame size: %dx%d", info.frame_width, info.frame_height);  }   if (!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, info.frame_width,                     info.frame_height, 1)) {    die("Failed to allocate image.");  }   printf("Using %s\n", vpx_codec_iface_name(encoder->codec_interface()));   res = vpx_codec_enc_config_default(encoder->codec_interface(), &cfg, 0);  if (res) die_codec(&codec, "Failed to get default codec config.");   cfg.g_w = info.frame_width;  cfg.g_h = info.frame_height;  cfg.g_timebase.num = info.time_base.numerator;  cfg.g_timebase.den = info.time_base.denominator;  cfg.rc_target_bitrate = bitrate;   writer = vpx_video_writer_open(argv[4], kContainerIVF, &info);  if (!writer) die("Failed to open %s for writing.", argv[4]);   if (!(infile = fopen(argv[3], "rb")))    die("Failed to open %s for reading.", argv[3]);   if (vpx_codec_enc_init(&codec, encoder->codec_interface(), &cfg, 0))    die("Failed to initialize encoder");   // Encode frames.  while (vpx_img_read(&raw, infile)) {    if (frame_count + 1 == update_frame_num) {      vpx_ref_frame_t ref;      ref.frame_type = VP8_LAST_FRAME;      ref.img = raw;      if (vpx_codec_control(&codec, VP8_SET_REFERENCE, &ref))        die_codec(&codec, "Failed to set reference frame");    }     encode_frame(&codec, &raw, frame_count++, writer);  }   // Flush encoder.  while (encode_frame(&codec, NULL, -1, writer)) {  }   printf("\n");  fclose(infile);  printf("Processed %d frames.\n", frame_count);   vpx_img_free(&raw);  if (vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec.");   vpx_video_writer_close(writer);   return EXIT_SUCCESS;}