ref: 4130e691bb911d58134fca85297ab279a6bae6a2
dir: /examples/vp8cx_set_ref.c/
/*
* 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 "./tools_common.h"
#include "./video_writer.h"
static const char *exec_name;
void usage_exit() {
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 = {0};
vpx_codec_enc_cfg_t cfg = {0};
int frame_count = 0;
vpx_image_t raw;
vpx_codec_err_t res;
VpxVideoInfo info = {0};
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
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 = strtol(argv[1], NULL, 0);
info.frame_height = 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_codec(&codec, "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;
}