| AOMedia AV1 Codec

Functions
lookahead.h File Reference

Describes look ahead buffer operations. More...

`#include <stdbool.h>`
`#include "aom_scale/yv12config.h"`
`#include "aom/aom_integer.h"`

Go to the source code of this file.

## Functions
struct lookahead_ctx * | av1_lookahead_init (unsigned int width, unsigned int height, unsigned int subsampling_x, unsigned int subsampling_y, int use_highbitdepth, unsigned int depth, const int border_in_pixels, int byte_alignment, int num_lap_buffers, bool is_all_intra, bool alloc_pyramid)
| Initializes the lookahead stage.
void | av1_lookahead_destroy (struct lookahead_ctx *ctx)
| Destroys the lookahead stage.
int | av1_lookahead_full (const struct lookahead_ctx *ctx)
| Check if lookahead buffer is full.
int | av1_lookahead_push (struct lookahead_ctx *ctx, const YV12_BUFFER_CONFIG *src, int64_t ts_start, int64_t ts_end, int use_highbitdepth, bool alloc_pyramid, aom_enc_frame_flags_t flags)
| Enqueue a source buffer.
struct lookahead_entry * | av1_lookahead_pop (struct lookahead_ctx *ctx, int drain, COMPRESSOR_STAGE stage)
| Get the next source buffer to encode.
struct lookahead_entry * | av1_lookahead_peek (struct lookahead_ctx *ctx, int index, COMPRESSOR_STAGE stage)
| Get a future source buffer to encode.
unsigned int | av1_lookahead_depth (struct lookahead_ctx *ctx, COMPRESSOR_STAGE stage)
| Get the number of frames currently in the lookahead queue.
int | av1_lookahead_pop_sz (struct lookahead_ctx *ctx, COMPRESSOR_STAGE stage)
| Get pop_sz value.

## Detailed Description

Describes look ahead buffer operations.

## Function Documentation

## ◆ av1_lookahead_init()

struct lookahead_ctx * av1_lookahead_init | ( | unsigned int | width,
|  | unsigned int | height,
|  | unsigned int | subsampling_x,
|  | unsigned int | subsampling_y,
|  | int | use_highbitdepth,
|  | unsigned int | depth,
|  | const int | border_in_pixels,
|  | int | byte_alignment,
|  | int | num_lap_buffers,
|  | bool | is_all_intra,
|  | bool | alloc_pyramid )

Initializes the lookahead stage.

The lookahead stage is a queue of frame buffers on which some analysis may be done when buffers are enqueued.

## ◆ av1_lookahead_push()

int av1_lookahead_push | ( | struct lookahead_ctx * | ctx,
|  | const YV12_BUFFER_CONFIG * | src,
|  | int64_t | ts_start,
|  | int64_t | ts_end,
|  | int | use_highbitdepth,
|  | bool | alloc_pyramid,
|  | aom_enc_frame_flags_t | flags )

Enqueue a source buffer.

This function will copy the source image into a new framebuffer with the expected stride/border.

Parameters

  [in] | ctx | Pointer to the lookahead context
  [in] | src | Pointer to the image to enqueue
  [in] | ts_start | Timestamp for the start of this frame
  [in] | ts_end | Timestamp for the end of this frame
  [in] | use_highbitdepth | Tell if HBD is used
  [in] | alloc_pyramid | Whether to allocate a downsampling pyramid for each frame buffer
  [in] | flags | Flags set on this frame

Referenced by av1_receive_raw_frame().

## ◆ av1_lookahead_pop()

struct lookahead_entry * av1_lookahead_pop | ( | struct lookahead_ctx * | ctx,
|  | int | drain,
|  | COMPRESSOR_STAGE | stage )

Get the next source buffer to encode.

Parameters

  [in] | ctx | Pointer to the lookahead context
  [in] | drain | Flag indicating the buffer should be drained (return a buffer regardless of the current queue depth)
  [in] | stage | Encoder stage

Return values

  Return | NULL, if drain set and queue is empty, or if drain not set and queue not of the configured depth.

## ◆ av1_lookahead_peek()

struct lookahead_entry * av1_lookahead_peek | ( | struct lookahead_ctx * | ctx,
|  | int | index,
|  | COMPRESSOR_STAGE | stage )

Get a future source buffer to encode.

Parameters

  [in] | ctx | Pointer to the lookahead context
  [in] | index | Index of the frame to be returned, 0 == next frame
  [in] | stage | Encoder stage

Return values

  Return | NULL, if no buffer exists at the specified index

Referenced by av1_encode_strategy(), and tf_setup_filtering_buffer().