ref: 1aac02247f3814acc4f2a0126be4f7acde2e4ad3
dir: /examples/twopass_encoder.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.
*/
// Two Pass Encoder
// ================
//
// This is an example of a two pass encoder loop. It takes an input file in
// YV12 format, passes it through the encoder twice, and writes the compressed
// frames to disk in IVF format. It builds upon the simple_encoder example.
//
// Twopass Variables
// -----------------
// Twopass mode needs to track the current pass number and the buffer of
// statistics packets.
//
// Updating The Configuration
// ---------------------------------
// In two pass mode, the configuration has to be updated on each pass. The
// statistics buffer is passed on the last pass.
//
// Encoding A Frame
// ----------------
// Encoding a frame in two pass mode is identical to the simple encoder
// example. To increase the quality while sacrificing encoding speed,
// VPX_DL_BEST_QUALITY can be used in place of VPX_DL_GOOD_QUALITY.
//
// Processing Statistics Packets
// -----------------------------
// Each packet of type `VPX_CODEC_CX_FRAME_PKT` contains the encoded data
// for this frame. We write a IVF frame header, followed by the raw data.
//
//
// Pass Progress Reporting
// -----------------------------
// It's sometimes helpful to see when each pass completes.
//
//
// Clean-up
// -----------------------------
// Destruction of the encoder instance must be done on each pass. The
// raw image should be destroyed at the end as usual.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "vpx/vpx_encoder.h"
#include "../tools_common.h"
#include "../video_writer.h"
static const char *exec_name;
void usage_exit(void) {
fprintf(stderr, "Usage: %s <codec> <width> <height> <infile> <outfile>\n",
exec_name);
exit(EXIT_FAILURE);
}
static int get_frame_stats(vpx_codec_ctx_t *ctx,
const vpx_image_t *img,
vpx_codec_pts_t pts,
unsigned int duration,
vpx_enc_frame_flags_t flags,
unsigned int deadline,
vpx_fixed_buf_t *stats) {
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(ctx, img, pts, duration, flags,
deadline);
if (res != VPX_CODEC_OK)
die_codec(ctx, "Failed to get frame stats.");
while ((pkt = vpx_codec_get_cx_data(ctx, &iter)) != NULL) {
got_pkts = 1;
if (pkt->kind == VPX_CODEC_STATS_PKT) {
const uint8_t *const pkt_buf = pkt->data.twopass_stats.buf;
const size_t pkt_size = pkt->data.twopass_stats.sz;
stats->buf = realloc(stats->buf, stats->sz + pkt_size);
memcpy((uint8_t *)stats->buf + stats->sz, pkt_buf, pkt_size);
stats->sz += pkt_size;
}
}
return got_pkts;
}
static int encode_frame(vpx_codec_ctx_t *ctx,
const vpx_image_t *img,
vpx_codec_pts_t pts,
unsigned int duration,
vpx_enc_frame_flags_t flags,
unsigned int deadline,
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(ctx, img, pts, duration, flags,
deadline);
if (res != VPX_CODEC_OK)
die_codec(ctx, "Failed to encode frame.");
while ((pkt = vpx_codec_get_cx_data(ctx, &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(ctx, "Failed to write compressed frame.");
printf(keyframe ? "K" : ".");
fflush(stdout);
}
}
return got_pkts;
}
static vpx_fixed_buf_t pass0(vpx_image_t *raw,
FILE *infile,
const VpxInterface *encoder,
const vpx_codec_enc_cfg_t *cfg) {
vpx_codec_ctx_t codec;
int frame_count = 0;
vpx_fixed_buf_t stats = {NULL, 0};
if (vpx_codec_enc_init(&codec, encoder->codec_interface(), cfg, 0))
die_codec(&codec, "Failed to initialize encoder");
// Calculate frame statistics.
while (vpx_img_read(raw, infile)) {
++frame_count;
get_frame_stats(&codec, raw, frame_count, 1, 0, VPX_DL_GOOD_QUALITY,
&stats);
}
// Flush encoder.
while (get_frame_stats(&codec, NULL, frame_count, 1, 0,
VPX_DL_GOOD_QUALITY, &stats)) {}
printf("Pass 0 complete. Processed %d frames.\n", frame_count);
if (vpx_codec_destroy(&codec))
die_codec(&codec, "Failed to destroy codec.");
return stats;
}
static void pass1(vpx_image_t *raw,
FILE *infile,
const char *outfile_name,
const VpxInterface *encoder,
const vpx_codec_enc_cfg_t *cfg) {
VpxVideoInfo info = {
encoder->fourcc,
cfg->g_w,
cfg->g_h,
{cfg->g_timebase.num, cfg->g_timebase.den}
};
VpxVideoWriter *writer = NULL;
vpx_codec_ctx_t codec;
int frame_count = 0;
writer = vpx_video_writer_open(outfile_name, kContainerIVF, &info);
if (!writer)
die("Failed to open %s for writing", outfile_name);
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)) {
++frame_count;
encode_frame(&codec, raw, frame_count, 1, 0, VPX_DL_GOOD_QUALITY, writer);
}
// Flush encoder.
while (encode_frame(&codec, NULL, -1, 1, 0, VPX_DL_GOOD_QUALITY, writer)) {}
printf("\n");
if (vpx_codec_destroy(&codec))
die_codec(&codec, "Failed to destroy codec.");
vpx_video_writer_close(writer);
printf("Pass 1 complete. Processed %d frames.\n", frame_count);
}
int main(int argc, char **argv) {
FILE *infile = NULL;
int w, h;
vpx_codec_ctx_t codec;
vpx_codec_enc_cfg_t cfg;
vpx_image_t raw;
vpx_codec_err_t res;
vpx_fixed_buf_t stats;
const VpxInterface *encoder = NULL;
const int fps = 30; // TODO(dkovalev) add command line argument
const int bitrate = 200; // kbit/s TODO(dkovalev) add command line argument
const char *const codec_arg = argv[1];
const char *const width_arg = argv[2];
const char *const height_arg = argv[3];
const char *const infile_arg = argv[4];
const char *const outfile_arg = argv[5];
exec_name = argv[0];
if (argc != 6)
die("Invalid number of arguments.");
encoder = get_vpx_encoder_by_name(codec_arg);
if (!encoder)
die("Unsupported codec.");
w = strtol(width_arg, NULL, 0);
h = strtol(height_arg, NULL, 0);
if (w <= 0 || h <= 0 || (w % 2) != 0 || (h % 2) != 0)
die("Invalid frame size: %dx%d", w, h);
if (!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, w, h, 1))
die("Failed to allocate image", w, h);
printf("Using %s\n", vpx_codec_iface_name(encoder->codec_interface()));
// Configuration
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 = w;
cfg.g_h = h;
cfg.g_timebase.num = 1;
cfg.g_timebase.den = fps;
cfg.rc_target_bitrate = bitrate;
if (!(infile = fopen(infile_arg, "rb")))
die("Failed to open %s for reading", infile_arg);
// Pass 0
cfg.g_pass = VPX_RC_FIRST_PASS;
stats = pass0(&raw, infile, encoder, &cfg);
// Pass 1
rewind(infile);
cfg.g_pass = VPX_RC_LAST_PASS;
cfg.rc_twopass_stats_in = stats;
pass1(&raw, infile, outfile_arg, encoder, &cfg);
free(stats.buf);
vpx_img_free(&raw);
fclose(infile);
return EXIT_SUCCESS;
}