diff options
Diffstat (limited to 'media/libvpx/libvpx/rate_hist.c')
| -rw-r--r-- | media/libvpx/libvpx/rate_hist.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/media/libvpx/libvpx/rate_hist.c b/media/libvpx/libvpx/rate_hist.c new file mode 100644 index 0000000000..947950d481 --- /dev/null +++ b/media/libvpx/libvpx/rate_hist.c @@ -0,0 +1,292 @@ +/* + * 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 = calloc(1, sizeof(*hist)); + + if (hist == NULL || cfg == NULL || fps == NULL || fps->num == 0 || + fps->den == 0) { + destroy_rate_histogram(hist); + return NULL; + } + + // 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; + + if (hist == NULL || cfg == NULL || pkt == NULL) return; + + 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; + int i; + + assert(bucket != NULL); + assert(num_buckets != NULL); + + buckets = *num_buckets; + + /* 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) { + int width1, width2; + int i; + + if (!buckets) return; + assert(bucket != NULL); + assert(buckets > 0); + + switch ((int)(log(bucket[buckets - 1].high) / log(10)) + 1) { + case 1: + case 2: + width1 = 4; + width2 = 2; + break; + case 3: + width1 = 5; + width2 = 3; + break; + case 4: + width1 = 6; + width2 = 4; + break; + case 5: + width1 = 7; + width2 = 5; + break; + case 6: + width1 = 8; + width2 = 6; + break; + case 7: + width1 = 9; + width2 = 7; + break; + default: + width1 = 12; + width2 = 10; + 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, "%*d %*s: ", width1, bucket[i].low, width2, ""); + else + fprintf(stderr, "%*d-%*d: ", width1, bucket[i].low, width2, + 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; + + if (hist == NULL || cfg == NULL) return; + + 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); +} |