1 /*
2  *  Copyright (c) 2011 The WebM project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 #include <assert.h>
11 #include <stdlib.h>
12 
13 #include "./vpx_config.h"
14 
15 #include "vp9/common/vp9_common.h"
16 
17 #include "vp9/encoder/vp9_encoder.h"
18 #include "vp9/encoder/vp9_extend.h"
19 #include "vp9/encoder/vp9_lookahead.h"
20 
21 /* Return the buffer at the given absolute index and increment the index */
pop(struct lookahead_ctx * ctx,unsigned int * idx)22 static struct lookahead_entry *pop(struct lookahead_ctx *ctx,
23                                    unsigned int *idx) {
24   unsigned int index = *idx;
25   struct lookahead_entry *buf = ctx->buf + index;
26 
27   assert(index < ctx->max_sz);
28   if (++index >= ctx->max_sz)
29     index -= ctx->max_sz;
30   *idx = index;
31   return buf;
32 }
33 
34 
vp9_lookahead_destroy(struct lookahead_ctx * ctx)35 void vp9_lookahead_destroy(struct lookahead_ctx *ctx) {
36   if (ctx) {
37     if (ctx->buf) {
38       unsigned int i;
39 
40       for (i = 0; i < ctx->max_sz; i++)
41         vp9_free_frame_buffer(&ctx->buf[i].img);
42       free(ctx->buf);
43     }
44     free(ctx);
45   }
46 }
47 
48 
vp9_lookahead_init(unsigned int width,unsigned int height,unsigned int subsampling_x,unsigned int subsampling_y,unsigned int depth)49 struct lookahead_ctx *vp9_lookahead_init(unsigned int width,
50                                          unsigned int height,
51                                          unsigned int subsampling_x,
52                                          unsigned int subsampling_y,
53                                          unsigned int depth) {
54   struct lookahead_ctx *ctx = NULL;
55 
56   // Clamp the lookahead queue depth
57   depth = clamp(depth, 1, MAX_LAG_BUFFERS);
58 
59   // Allocate memory to keep previous source frames available.
60   depth += MAX_PRE_FRAMES;
61 
62   // Allocate the lookahead structures
63   ctx = calloc(1, sizeof(*ctx));
64   if (ctx) {
65     unsigned int i;
66     ctx->max_sz = depth;
67     ctx->buf = calloc(depth, sizeof(*ctx->buf));
68     if (!ctx->buf)
69       goto bail;
70     for (i = 0; i < depth; i++)
71       if (vp9_alloc_frame_buffer(&ctx->buf[i].img,
72                                  width, height, subsampling_x, subsampling_y,
73                                  VP9_ENC_BORDER_IN_PIXELS))
74         goto bail;
75   }
76   return ctx;
77  bail:
78   vp9_lookahead_destroy(ctx);
79   return NULL;
80 }
81 
82 #define USE_PARTIAL_COPY 0
83 
vp9_lookahead_push(struct lookahead_ctx * ctx,YV12_BUFFER_CONFIG * src,int64_t ts_start,int64_t ts_end,unsigned int flags)84 int vp9_lookahead_push(struct lookahead_ctx *ctx, YV12_BUFFER_CONFIG   *src,
85                        int64_t ts_start, int64_t ts_end, unsigned int flags) {
86   struct lookahead_entry *buf;
87 #if USE_PARTIAL_COPY
88   int row, col, active_end;
89   int mb_rows = (src->y_height + 15) >> 4;
90   int mb_cols = (src->y_width + 15) >> 4;
91 #endif
92 
93   if (ctx->sz + 1  + MAX_PRE_FRAMES > ctx->max_sz)
94     return 1;
95   ctx->sz++;
96   buf = pop(ctx, &ctx->write_idx);
97 
98 #if USE_PARTIAL_COPY
99   // TODO(jkoleszar): This is disabled for now, as
100   // vp9_copy_and_extend_frame_with_rect is not subsampling/alpha aware.
101 
102   // Only do this partial copy if the following conditions are all met:
103   // 1. Lookahead queue has has size of 1.
104   // 2. Active map is provided.
105   // 3. This is not a key frame, golden nor altref frame.
106   if (ctx->max_sz == 1 && active_map && !flags) {
107     for (row = 0; row < mb_rows; ++row) {
108       col = 0;
109 
110       while (1) {
111         // Find the first active macroblock in this row.
112         for (; col < mb_cols; ++col) {
113           if (active_map[col])
114             break;
115         }
116 
117         // No more active macroblock in this row.
118         if (col == mb_cols)
119           break;
120 
121         // Find the end of active region in this row.
122         active_end = col;
123 
124         for (; active_end < mb_cols; ++active_end) {
125           if (!active_map[active_end])
126             break;
127         }
128 
129         // Only copy this active region.
130         vp9_copy_and_extend_frame_with_rect(src, &buf->img,
131                                             row << 4,
132                                             col << 4, 16,
133                                             (active_end - col) << 4);
134 
135         // Start again from the end of this active region.
136         col = active_end;
137       }
138 
139       active_map += mb_cols;
140     }
141   } else {
142     vp9_copy_and_extend_frame(src, &buf->img);
143   }
144 #else
145   // Partial copy not implemented yet
146   vp9_copy_and_extend_frame(src, &buf->img);
147 #endif
148 
149   buf->ts_start = ts_start;
150   buf->ts_end = ts_end;
151   buf->flags = flags;
152   return 0;
153 }
154 
155 
vp9_lookahead_pop(struct lookahead_ctx * ctx,int drain)156 struct lookahead_entry *vp9_lookahead_pop(struct lookahead_ctx *ctx,
157                                           int drain) {
158   struct lookahead_entry *buf = NULL;
159 
160   if (ctx->sz && (drain || ctx->sz == ctx->max_sz - MAX_PRE_FRAMES)) {
161     buf = pop(ctx, &ctx->read_idx);
162     ctx->sz--;
163   }
164   return buf;
165 }
166 
167 
vp9_lookahead_peek(struct lookahead_ctx * ctx,int index)168 struct lookahead_entry *vp9_lookahead_peek(struct lookahead_ctx *ctx,
169                                            int index) {
170   struct lookahead_entry *buf = NULL;
171 
172   if (index >= 0) {
173     // Forward peek
174     if (index < (int)ctx->sz) {
175       index += ctx->read_idx;
176       if (index >= (int)ctx->max_sz)
177         index -= ctx->max_sz;
178       buf = ctx->buf + index;
179     }
180   } else if (index < 0) {
181     // Backward peek
182     if (-index <= MAX_PRE_FRAMES) {
183       index += ctx->read_idx;
184       if (index < 0)
185         index += ctx->max_sz;
186       buf = ctx->buf + index;
187     }
188   }
189 
190   return buf;
191 }
192 
vp9_lookahead_depth(struct lookahead_ctx * ctx)193 unsigned int vp9_lookahead_depth(struct lookahead_ctx *ctx) {
194   return ctx->sz;
195 }
196