xref: /aosp_15_r20/external/libaom/av1/encoder/lookahead.h (revision 77c1e3ccc04c968bd2bc212e87364f250e820521)
1 /*
2  * Copyright (c) 2016, Alliance for Open Media. All rights reserved.
3  *
4  * This source code is subject to the terms of the BSD 2 Clause License and
5  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
6  * was not distributed with this source code in the LICENSE file, you can
7  * obtain it at www.aomedia.org/license/software. If the Alliance for Open
8  * Media Patent License 1.0 was not distributed with this source code in the
9  * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
10  */
11 
12 /*!\file
13  * \brief Describes look ahead buffer operations.
14  */
15 #ifndef AOM_AV1_ENCODER_LOOKAHEAD_H_
16 #define AOM_AV1_ENCODER_LOOKAHEAD_H_
17 
18 #include <stdbool.h>
19 
20 #include "aom_scale/yv12config.h"
21 #include "aom/aom_integer.h"
22 
23 #ifdef __cplusplus
24 extern "C" {
25 #endif
26 
27 /*!\cond */
28 #define MAX_LAG_BUFFERS 48
29 #define MAX_LAP_BUFFERS 48
30 #define MAX_TOTAL_BUFFERS (MAX_LAG_BUFFERS + MAX_LAP_BUFFERS)
31 #define LAP_LAG_IN_FRAMES 17
32 
33 struct lookahead_entry {
34   YV12_BUFFER_CONFIG img;
35   int64_t ts_start;
36   int64_t ts_end;
37   int display_idx;
38   aom_enc_frame_flags_t flags;
39 };
40 
41 // The max of past frames we want to keep in the queue.
42 #define MAX_PRE_FRAMES 1
43 
44 enum { ENCODE_STAGE, LAP_STAGE, MAX_STAGES } UENUM1BYTE(COMPRESSOR_STAGE);
45 
46 struct read_ctx {
47   int sz;       /* Number of buffers currently in the queue */
48   int read_idx; /* Read index */
49   int pop_sz;   /* Size to check for pop condition */
50   int valid;    /* Is this ctx valid? */
51 };
52 
53 struct lookahead_ctx {
54   int max_sz;                            /* Absolute size of the queue */
55   int write_idx;                         /* Write index */
56   struct read_ctx read_ctxs[MAX_STAGES]; /* Read context */
57   struct lookahead_entry *buf;           /* Buffer list */
58   int push_frame_count; /* Number of frames that have been pushed in the queue*/
59   uint8_t
60       max_pre_frames; /* Maximum number of past frames allowed in the queue */
61 };
62 /*!\endcond */
63 
64 /**\brief Initializes the lookahead stage
65  *
66  * The lookahead stage is a queue of frame buffers on which some analysis
67  * may be done when buffers are enqueued.
68  */
69 struct lookahead_ctx *av1_lookahead_init(
70     unsigned int width, unsigned int height, unsigned int subsampling_x,
71     unsigned int subsampling_y, int use_highbitdepth, unsigned int depth,
72     const int border_in_pixels, int byte_alignment, int num_lap_buffers,
73     bool is_all_intra, bool alloc_pyramid);
74 
75 /**\brief Destroys the lookahead stage
76  */
77 void av1_lookahead_destroy(struct lookahead_ctx *ctx);
78 
79 /**\brief Check if lookahead buffer is full
80  */
81 int av1_lookahead_full(const struct lookahead_ctx *ctx);
82 
83 /**\brief Enqueue a source buffer
84  *
85  * This function will copy the source image into a new framebuffer with
86  * the expected stride/border.
87  *
88  * \param[in] ctx               Pointer to the lookahead context
89  * \param[in] src               Pointer to the image to enqueue
90  * \param[in] ts_start          Timestamp for the start of this frame
91  * \param[in] ts_end            Timestamp for the end of this frame
92  * \param[in] use_highbitdepth  Tell if HBD is used
93  * \param[in] alloc_pyramid     Whether to allocate a downsampling pyramid
94  *                              for each frame buffer
95  * \param[in] flags             Flags set on this frame
96  */
97 int av1_lookahead_push(struct lookahead_ctx *ctx, const YV12_BUFFER_CONFIG *src,
98                        int64_t ts_start, int64_t ts_end, int use_highbitdepth,
99                        bool alloc_pyramid, aom_enc_frame_flags_t flags);
100 
101 /**\brief Get the next source buffer to encode
102  *
103  * \param[in] ctx       Pointer to the lookahead context
104  * \param[in] drain     Flag indicating the buffer should be drained
105  *                      (return a buffer regardless of the current queue depth)
106  * \param[in] stage     Encoder stage
107  *
108  * \retval Return NULL, if drain set and queue is empty, or if drain not set and
109  * queue not of the configured depth.
110  */
111 struct lookahead_entry *av1_lookahead_pop(struct lookahead_ctx *ctx, int drain,
112                                           COMPRESSOR_STAGE stage);
113 
114 /**\brief Get a future source buffer to encode
115  *
116  * \param[in] ctx       Pointer to the lookahead context
117  * \param[in] index     Index of the frame to be returned, 0 == next frame
118  * \param[in] stage     Encoder stage
119  *
120  * \retval Return NULL, if no buffer exists at the specified index
121  */
122 struct lookahead_entry *av1_lookahead_peek(struct lookahead_ctx *ctx, int index,
123                                            COMPRESSOR_STAGE stage);
124 
125 /**\brief Get the number of frames currently in the lookahead queue
126  */
127 unsigned int av1_lookahead_depth(struct lookahead_ctx *ctx,
128                                  COMPRESSOR_STAGE stage);
129 
130 /**\brief Get pop_sz value
131  */
132 int av1_lookahead_pop_sz(struct lookahead_ctx *ctx, COMPRESSOR_STAGE stage);
133 
134 #ifdef __cplusplus
135 }  // extern "C"
136 #endif
137 
138 #endif  // AOM_AV1_ENCODER_LOOKAHEAD_H_
139