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-rw-r--r--media/libvpx/vp8/encoder/lookahead.c231
1 files changed, 231 insertions, 0 deletions
diff --git a/media/libvpx/vp8/encoder/lookahead.c b/media/libvpx/vp8/encoder/lookahead.c
new file mode 100644
index 000000000..662338574
--- /dev/null
+++ b/media/libvpx/vp8/encoder/lookahead.c
@@ -0,0 +1,231 @@
+/*
+ * 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 "lookahead.h"
+#include "vp8/common/extend.h"
+
+#define MAX_LAG_BUFFERS (CONFIG_REALTIME_ONLY? 1 : 25)
+
+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
+vp8_lookahead_destroy(struct lookahead_ctx *ctx)
+{
+ if(ctx)
+ {
+ if(ctx->buf)
+ {
+ unsigned int i;
+
+ for(i = 0; i < ctx->max_sz; i++)
+ vp8_yv12_de_alloc_frame_buffer(&ctx->buf[i].img);
+ free(ctx->buf);
+ }
+ free(ctx);
+ }
+}
+
+
+struct lookahead_ctx*
+vp8_lookahead_init(unsigned int width,
+ unsigned int height,
+ unsigned int depth)
+{
+ struct lookahead_ctx *ctx = NULL;
+ unsigned int i;
+
+ /* Clamp the lookahead queue depth */
+ if(depth < 1)
+ depth = 1;
+ else if(depth > MAX_LAG_BUFFERS)
+ depth = MAX_LAG_BUFFERS;
+
+ /* Keep last frame in lookahead buffer by increasing depth by 1.*/
+ depth += 1;
+
+ /* Align the buffer dimensions */
+ width = (width + 15) & ~15;
+ height = (height + 15) & ~15;
+
+ /* Allocate the lookahead structures */
+ ctx = calloc(1, sizeof(*ctx));
+ if(ctx)
+ {
+ ctx->max_sz = depth;
+ ctx->buf = calloc(depth, sizeof(*ctx->buf));
+ if(!ctx->buf)
+ goto bail;
+ for(i=0; i<depth; i++)
+ if (vp8_yv12_alloc_frame_buffer(&ctx->buf[i].img,
+ width, height, VP8BORDERINPIXELS))
+ goto bail;
+ }
+ return ctx;
+bail:
+ vp8_lookahead_destroy(ctx);
+ return NULL;
+}
+
+
+int
+vp8_lookahead_push(struct lookahead_ctx *ctx,
+ YV12_BUFFER_CONFIG *src,
+ int64_t ts_start,
+ int64_t ts_end,
+ unsigned int flags,
+ unsigned char *active_map)
+{
+ struct lookahead_entry* buf;
+ int row, col, active_end;
+ int mb_rows = (src->y_height + 15) >> 4;
+ int mb_cols = (src->y_width + 15) >> 4;
+
+ if(ctx->sz + 2 > ctx->max_sz)
+ return 1;
+ ctx->sz++;
+ buf = pop(ctx, &ctx->write_idx);
+
+ /* 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. */
+ vp8_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
+ {
+ vp8_copy_and_extend_frame(src, &buf->img);
+ }
+ buf->ts_start = ts_start;
+ buf->ts_end = ts_end;
+ buf->flags = flags;
+ return 0;
+}
+
+
+struct lookahead_entry*
+vp8_lookahead_pop(struct lookahead_ctx *ctx,
+ int drain)
+{
+ struct lookahead_entry* buf = NULL;
+
+ assert(ctx != NULL);
+ if(ctx->sz && (drain || ctx->sz == ctx->max_sz - 1))
+ {
+ buf = pop(ctx, &ctx->read_idx);
+ ctx->sz--;
+ }
+ return buf;
+}
+
+
+struct lookahead_entry*
+vp8_lookahead_peek(struct lookahead_ctx *ctx,
+ unsigned int index,
+ int direction)
+{
+ struct lookahead_entry* buf = NULL;
+
+ if (direction == PEEK_FORWARD)
+ {
+ assert(index < ctx->max_sz - 1);
+ if(index < ctx->sz)
+ {
+ index += ctx->read_idx;
+ if(index >= ctx->max_sz)
+ index -= ctx->max_sz;
+ buf = ctx->buf + index;
+ }
+ }
+ else if (direction == PEEK_BACKWARD)
+ {
+ assert(index == 1);
+
+ if(ctx->read_idx == 0)
+ index = ctx->max_sz - 1;
+ else
+ index = ctx->read_idx - index;
+ buf = ctx->buf + index;
+ }
+
+ return buf;
+}
+
+
+unsigned int
+vp8_lookahead_depth(struct lookahead_ctx *ctx)
+{
+ return ctx->sz;
+}