vpx/vp9/encoder/vp9_lookahead.c

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/*
* Copyright (c) 2011 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 "./vpx_config.h"
#include "vp9/common/vp9_common.h"
#include "vp9/encoder/vp9_encoder.h"
#include "vp9/encoder/vp9_extend.h"
#include "vp9/encoder/vp9_lookahead.h"
// The max of past frames we want to keep in the queue.
#define MAX_PRE_FRAMES 1
struct lookahead_ctx {
unsigned int max_sz; /* Absolute size of the queue */
unsigned int sz; /* Number of buffers currently in the queue */
unsigned int read_idx; /* Read index */
unsigned int write_idx; /* Write index */
struct lookahead_entry *buf; /* Buffer list */
};
/* Return the buffer at the given absolute index and increment the index */
static struct lookahead_entry *pop(struct lookahead_ctx *ctx,
unsigned int *idx) {
unsigned int index = *idx;
struct lookahead_entry *buf = ctx->buf + index;
assert(index < ctx->max_sz);
if (++index >= ctx->max_sz)
index -= ctx->max_sz;
*idx = index;
return buf;
}
void vp9_lookahead_destroy(struct lookahead_ctx *ctx) {
if (ctx) {
if (ctx->buf) {
unsigned int i;
for (i = 0; i < ctx->max_sz; i++)
vp9_free_frame_buffer(&ctx->buf[i].img);
free(ctx->buf);
}
free(ctx);
}
}
struct lookahead_ctx *vp9_lookahead_init(unsigned int width,
unsigned int height,
unsigned int subsampling_x,
unsigned int subsampling_y,
unsigned int depth) {
struct lookahead_ctx *ctx = NULL;
// Clamp the lookahead queue depth
depth = clamp(depth, 1, MAX_LAG_BUFFERS);
// Allocate memory to keep previous source frames available.
depth += MAX_PRE_FRAMES;
// Allocate the lookahead structures
ctx = calloc(1, sizeof(*ctx));
if (ctx) {
unsigned int i;
ctx->max_sz = depth;
ctx->buf = calloc(depth, sizeof(*ctx->buf));
if (!ctx->buf)
goto bail;
for (i = 0; i < depth; i++)
if (vp9_alloc_frame_buffer(&ctx->buf[i].img,
width, height, subsampling_x, subsampling_y,
VP9_ENC_BORDER_IN_PIXELS))
goto bail;
}
return ctx;
bail:
vp9_lookahead_destroy(ctx);
return NULL;
}
#define USE_PARTIAL_COPY 0
int vp9_lookahead_push(struct lookahead_ctx *ctx, YV12_BUFFER_CONFIG *src,
int64_t ts_start, int64_t ts_end, unsigned int flags) {
struct lookahead_entry *buf;
#if USE_PARTIAL_COPY
int row, col, active_end;
int mb_rows = (src->y_height + 15) >> 4;
int mb_cols = (src->y_width + 15) >> 4;
#endif
if (ctx->sz + 1 + MAX_PRE_FRAMES > ctx->max_sz)
return 1;
ctx->sz++;
buf = pop(ctx, &ctx->write_idx);
#if USE_PARTIAL_COPY
// TODO(jkoleszar): This is disabled for now, as
// vp9_copy_and_extend_frame_with_rect is not subsampling/alpha aware.
// Only do this partial copy if the following conditions are all met:
// 1. Lookahead queue has has size of 1.
// 2. Active map is provided.
// 3. This is not a key frame, golden nor altref frame.
if (ctx->max_sz == 1 && active_map && !flags) {
for (row = 0; row < mb_rows; ++row) {
col = 0;
while (1) {
// Find the first active macroblock in this row.
for (; col < mb_cols; ++col) {
if (active_map[col])
break;
}
// No more active macroblock in this row.
if (col == mb_cols)
break;
// Find the end of active region in this row.
active_end = col;
for (; active_end < mb_cols; ++active_end) {
if (!active_map[active_end])
break;
}
// Only copy this active region.
vp9_copy_and_extend_frame_with_rect(src, &buf->img,
row << 4,
col << 4, 16,
(active_end - col) << 4);
// Start again from the end of this active region.
col = active_end;
}
active_map += mb_cols;
}
} else {
vp9_copy_and_extend_frame(src, &buf->img);
}
#else
// Partial copy not implemented yet
vp9_copy_and_extend_frame(src, &buf->img);
#endif
buf->ts_start = ts_start;
buf->ts_end = ts_end;
buf->flags = flags;
return 0;
}
struct lookahead_entry *vp9_lookahead_pop(struct lookahead_ctx *ctx,
int drain) {
struct lookahead_entry *buf = NULL;
if (ctx->sz && (drain || ctx->sz == ctx->max_sz - MAX_PRE_FRAMES)) {
buf = pop(ctx, &ctx->read_idx);
ctx->sz--;
}
return buf;
}
struct lookahead_entry *vp9_lookahead_peek(struct lookahead_ctx *ctx,
int index) {
struct lookahead_entry *buf = NULL;
if (index >= 0) {
// Forward peek
if (index < (int)ctx->sz) {
index += ctx->read_idx;
if (index >= (int)ctx->max_sz)
index -= ctx->max_sz;
buf = ctx->buf + index;
}
} else if (index < 0) {
// Backward peek
if (-index <= MAX_PRE_FRAMES) {
index += ctx->read_idx;
if (index < 0)
index += ctx->max_sz;
buf = ctx->buf + index;
}
}
return buf;
}
unsigned int vp9_lookahead_depth(struct lookahead_ctx *ctx) {
return ctx->sz;
}