ref: c7f58bcc70f0d8fb7ff48c115f53f78165d26792
dir: /rate_hist.c/
/*
* Copyright (c) 2014 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.
*/
#include <assert.h>
#include <stdlib.h>
#include <limits.h>
#include <stdio.h>
#include <math.h>
#include "./rate_hist.h"
#define RATE_BINS 100
#define HIST_BAR_MAX 40
struct hist_bucket {
int low;
int high;
int count;
};
struct rate_hist {
int64_t *pts;
int *sz;
int samples;
int frames;
struct hist_bucket bucket[RATE_BINS];
int total;
};
struct rate_hist *init_rate_histogram(const vpx_codec_enc_cfg_t *cfg,
const vpx_rational_t *fps) {
int i;
struct rate_hist *hist = malloc(sizeof(*hist));
// Determine the number of samples in the buffer. Use the file's framerate
// to determine the number of frames in rc_buf_sz milliseconds, with an
// adjustment (5/4) to account for alt-refs
hist->samples = cfg->rc_buf_sz * 5 / 4 * fps->num / fps->den / 1000;
// prevent division by zero
if (hist->samples == 0)
hist->samples = 1;
hist->frames = 0;
hist->total = 0;
hist->pts = calloc(hist->samples, sizeof(*hist->pts));
hist->sz = calloc(hist->samples, sizeof(*hist->sz));
for (i = 0; i < RATE_BINS; i++) {
hist->bucket[i].low = INT_MAX;
hist->bucket[i].high = 0;
hist->bucket[i].count = 0;
}
return hist;
}
void destroy_rate_histogram(struct rate_hist *hist) {
if (hist) {
free(hist->pts);
free(hist->sz);
free(hist);
}
}
void update_rate_histogram(struct rate_hist *hist,
const vpx_codec_enc_cfg_t *cfg,
const vpx_codec_cx_pkt_t *pkt) {
int i;
int64_t then = 0;
int64_t avg_bitrate = 0;
int64_t sum_sz = 0;
const int64_t now = pkt->data.frame.pts * 1000 *
(uint64_t)cfg->g_timebase.num /
(uint64_t)cfg->g_timebase.den;
int idx = hist->frames++ % hist->samples;
hist->pts[idx] = now;
hist->sz[idx] = (int)pkt->data.frame.sz;
if (now < cfg->rc_buf_initial_sz)
return;
if (!cfg->rc_target_bitrate)
return;
then = now;
/* Sum the size over the past rc_buf_sz ms */
for (i = hist->frames; i > 0 && hist->frames - i < hist->samples; i--) {
const int i_idx = (i - 1) % hist->samples;
then = hist->pts[i_idx];
if (now - then > cfg->rc_buf_sz)
break;
sum_sz += hist->sz[i_idx];
}
if (now == then)
return;
avg_bitrate = sum_sz * 8 * 1000 / (now - then);
idx = (int)(avg_bitrate * (RATE_BINS / 2) / (cfg->rc_target_bitrate * 1000));
if (idx < 0)
idx = 0;
if (idx > RATE_BINS - 1)
idx = RATE_BINS - 1;
if (hist->bucket[idx].low > avg_bitrate)
hist->bucket[idx].low = (int)avg_bitrate;
if (hist->bucket[idx].high < avg_bitrate)
hist->bucket[idx].high = (int)avg_bitrate;
hist->bucket[idx].count++;
hist->total++;
}
static int merge_hist_buckets(struct hist_bucket *bucket,
int max_buckets, int *num_buckets) {
int small_bucket = 0, merge_bucket = INT_MAX, big_bucket = 0;
int buckets = *num_buckets;
int i;
/* Find the extrema for this list of buckets */
big_bucket = small_bucket = 0;
for (i = 0; i < buckets; i++) {
if (bucket[i].count < bucket[small_bucket].count)
small_bucket = i;
if (bucket[i].count > bucket[big_bucket].count)
big_bucket = i;
}
/* If we have too many buckets, merge the smallest with an adjacent
* bucket.
*/
while (buckets > max_buckets) {
int last_bucket = buckets - 1;
/* merge the small bucket with an adjacent one. */
if (small_bucket == 0)
merge_bucket = 1;
else if (small_bucket == last_bucket)
merge_bucket = last_bucket - 1;
else if (bucket[small_bucket - 1].count < bucket[small_bucket + 1].count)
merge_bucket = small_bucket - 1;
else
merge_bucket = small_bucket + 1;
assert(abs(merge_bucket - small_bucket) <= 1);
assert(small_bucket < buckets);
assert(big_bucket < buckets);
assert(merge_bucket < buckets);
if (merge_bucket < small_bucket) {
bucket[merge_bucket].high = bucket[small_bucket].high;
bucket[merge_bucket].count += bucket[small_bucket].count;
} else {
bucket[small_bucket].high = bucket[merge_bucket].high;
bucket[small_bucket].count += bucket[merge_bucket].count;
merge_bucket = small_bucket;
}
assert(bucket[merge_bucket].low != bucket[merge_bucket].high);
buckets--;
/* Remove the merge_bucket from the list, and find the new small
* and big buckets while we're at it
*/
big_bucket = small_bucket = 0;
for (i = 0; i < buckets; i++) {
if (i > merge_bucket)
bucket[i] = bucket[i + 1];
if (bucket[i].count < bucket[small_bucket].count)
small_bucket = i;
if (bucket[i].count > bucket[big_bucket].count)
big_bucket = i;
}
}
*num_buckets = buckets;
return bucket[big_bucket].count;
}
static void show_histogram(const struct hist_bucket *bucket,
int buckets, int total, int scale) {
const char *pat1, *pat2;
int i;
switch ((int)(log(bucket[buckets - 1].high) / log(10)) + 1) {
case 1:
case 2:
pat1 = "%4d %2s: ";
pat2 = "%4d-%2d: ";
break;
case 3:
pat1 = "%5d %3s: ";
pat2 = "%5d-%3d: ";
break;
case 4:
pat1 = "%6d %4s: ";
pat2 = "%6d-%4d: ";
break;
case 5:
pat1 = "%7d %5s: ";
pat2 = "%7d-%5d: ";
break;
case 6:
pat1 = "%8d %6s: ";
pat2 = "%8d-%6d: ";
break;
case 7:
pat1 = "%9d %7s: ";
pat2 = "%9d-%7d: ";
break;
default:
pat1 = "%12d %10s: ";
pat2 = "%12d-%10d: ";
break;
}
for (i = 0; i < buckets; i++) {
int len;
int j;
float pct;
pct = (float)(100.0 * bucket[i].count / total);
len = HIST_BAR_MAX * bucket[i].count / scale;
if (len < 1)
len = 1;
assert(len <= HIST_BAR_MAX);
if (bucket[i].low == bucket[i].high)
fprintf(stderr, pat1, bucket[i].low, "");
else
fprintf(stderr, pat2, bucket[i].low, bucket[i].high);
for (j = 0; j < HIST_BAR_MAX; j++)
fprintf(stderr, j < len ? "=" : " ");
fprintf(stderr, "\t%5d (%6.2f%%)\n", bucket[i].count, pct);
}
}
void show_q_histogram(const int counts[64], int max_buckets) {
struct hist_bucket bucket[64];
int buckets = 0;
int total = 0;
int scale;
int i;
for (i = 0; i < 64; i++) {
if (counts[i]) {
bucket[buckets].low = bucket[buckets].high = i;
bucket[buckets].count = counts[i];
buckets++;
total += counts[i];
}
}
fprintf(stderr, "\nQuantizer Selection:\n");
scale = merge_hist_buckets(bucket, max_buckets, &buckets);
show_histogram(bucket, buckets, total, scale);
}
void show_rate_histogram(struct rate_hist *hist,
const vpx_codec_enc_cfg_t *cfg, int max_buckets) {
int i, scale;
int buckets = 0;
for (i = 0; i < RATE_BINS; i++) {
if (hist->bucket[i].low == INT_MAX)
continue;
hist->bucket[buckets++] = hist->bucket[i];
}
fprintf(stderr, "\nRate (over %dms window):\n", cfg->rc_buf_sz);
scale = merge_hist_buckets(hist->bucket, max_buckets, &buckets);
show_histogram(hist->bucket, buckets, hist->total, scale);
}