[FFmpeg-devel] [PATCH v6 2/9] avcodec/vaapi_encode: introduce a base layer for vaapi encode

Lynne dev at lynne.ee
Wed Mar 13 05:37:37 EET 2024


Feb 29, 2024, 06:35 by tong1.wu-at-intel.com at ffmpeg.org:

> From: Tong Wu <tong1.wu at intel.com>
>
> Since VAAPI and future D3D12VA implementation may share the same dpb
> logic and some other functions. A base layer encode context is introduced
> as vaapi context's base and extract the related funtions to a common
> file such as receive_packet, init, close, etc.
>
> Signed-off-by: Tong Wu <tong1.wu at intel.com>
> ---
>  libavcodec/Makefile             |   2 +-
>  libavcodec/hw_base_encode.c     | 644 ++++++++++++++++++++++
>  libavcodec/hw_base_encode.h     | 252 +++++++++
>  libavcodec/vaapi_encode.c       | 927 ++++++--------------------------
>  libavcodec/vaapi_encode.h       | 202 +------
>  libavcodec/vaapi_encode_av1.c   |  71 +--
>  libavcodec/vaapi_encode_h264.c  | 199 +++----
>  libavcodec/vaapi_encode_h265.c  | 161 +++---
>  libavcodec/vaapi_encode_mjpeg.c |  22 +-
>  libavcodec/vaapi_encode_mpeg2.c |  51 +-
>  libavcodec/vaapi_encode_vp8.c   |  26 +-
>  libavcodec/vaapi_encode_vp9.c   |  68 +--
>  12 files changed, 1400 insertions(+), 1225 deletions(-)
>  create mode 100644 libavcodec/hw_base_encode.c
>  create mode 100644 libavcodec/hw_base_encode.h
>
> +#define AVCODEC_HW_BASE_ENCODE_H
> +
> +#include "libavutil/hwcontext.h"
> +#include "libavutil/fifo.h"
> +
> +#include "avcodec.h"
> +
> +static inline const char *ff_hw_base_encode_get_pictype_name(const int type) {
> +    const char * const picture_type_name[] = { "IDR", "I", "P", "B" };
> +    return picture_type_name[type];
> +}
> +
> +enum {
> +    MAX_DPB_SIZE           = 16,
> +    MAX_PICTURE_REFERENCES = 2,
>

Only two max refs per picture?


> +    MAX_REORDER_DELAY      = 16,
> +    MAX_ASYNC_DEPTH        = 64,
> +    MAX_REFERENCE_LIST_NUM = 2,
> +};
>

Define these, don't enum them unnecessarily.


> +enum {
> +    PICTURE_TYPE_IDR = 0,
> +    PICTURE_TYPE_I   = 1,
> +    PICTURE_TYPE_P   = 2,
> +    PICTURE_TYPE_B   = 3,
> +};
> +
> +enum {
> +    // Codec supports controlling the subdivision of pictures into slices.
> +    FLAG_SLICE_CONTROL         = 1 << 0,
> +    // Codec only supports constant quality (no rate control).
> +    FLAG_CONSTANT_QUALITY_ONLY = 1 << 1,
> +    // Codec is intra-only.
> +    FLAG_INTRA_ONLY            = 1 << 2,
> +    // Codec supports B-pictures.
> +    FLAG_B_PICTURES            = 1 << 3,
> +    // Codec supports referencing B-pictures.
> +    FLAG_B_PICTURE_REFERENCES  = 1 << 4,
> +    // Codec supports non-IDR key pictures (that is, key pictures do
> +    // not necessarily empty the DPB).
> +    FLAG_NON_IDR_KEY_PICTURES  = 1 << 5,
> +    // Codec output packet without timestamp delay, which means the
> +    // output packet has same PTS and DTS.
> +    FLAG_TIMESTAMP_NO_DELAY    = 1 << 6,
>

This is a low-level API. Concepts such as delay don't exist
if you're the one setting up references.


> +};
> +
> +typedef struct HWBaseEncodePicture {
> +    struct HWBaseEncodePicture *next;
> +
> +    int64_t         display_order;
> +    int64_t         encode_order;
> +    int64_t         pts;
> +    int64_t         duration;
> +    int             force_idr;
> +
> +    void           *opaque;
> +    AVBufferRef    *opaque_ref;
> +
> +    int             type;
> +    int             b_depth;
> +    int             encode_issued;
> +    int             encode_complete;
> +
> +    AVFrame        *input_image;
> +    AVFrame        *recon_image;
> +
> +    void           *priv_data;
> +
> +    // Whether this picture is a reference picture.
> +    int             is_reference;
> +
> +    // The contents of the DPB after this picture has been decoded.
> +    // This will contain the picture itself if it is a reference picture,
> +    // but not if it isn't.
> +    int                     nb_dpb_pics;
> +    struct HWBaseEncodePicture *dpb[MAX_DPB_SIZE];
> +    // The reference pictures used in decoding this picture. If they are
> +    // used by later pictures they will also appear in the DPB. ref[0][] for
> +    // previous reference frames. ref[1][] for future reference frames.
> +    int                     nb_refs[MAX_REFERENCE_LIST_NUM];
> +    struct HWBaseEncodePicture *refs[MAX_REFERENCE_LIST_NUM][MAX_PICTURE_REFERENCES];
> +    // The previous reference picture in encode order.  Must be in at least
> +    // one of the reference list and DPB list.
> +    struct HWBaseEncodePicture *prev;
> +    // Reference count for other pictures referring to this one through
> +    // the above pointers, directly from incomplete pictures and indirectly
> +    // through completed pictures.
> +    int             ref_count[2];
> +    int             ref_removed[2];
> +} HWBaseEncodePicture;
> +
> +typedef struct HWEncodePictureOperation {
> +    // Alloc memory for the picture structure.
> +    HWBaseEncodePicture * (*alloc)(AVCodecContext *avctx, const AVFrame *frame);
> +    // Issue the picture structure, which will send the frame surface to HW Encode API.
> +    int (*issue)(AVCodecContext *avctx, const HWBaseEncodePicture *base_pic);
> +    // Get the output AVPacket.
> +    int (*output)(AVCodecContext *avctx, const HWBaseEncodePicture *base_pic, AVPacket *pkt);
> +    // Free the picture structure.
> +    int (*free)(AVCodecContext *avctx, HWBaseEncodePicture *base_pic);
> +}  HWEncodePictureOperation;
> +
> +typedef struct HWBaseEncodeContext {
> +    const AVClass *class;
> +
> +    // Hardware-specific hooks.
> +    const struct HWEncodePictureOperation *op;
> +
> +    // Global options.
> +
> +    // Number of I frames between IDR frames.
> +    int             idr_interval;
> +
> +    // Desired B frame reference depth.
> +    int             desired_b_depth;
> +
> +    // Explicitly set RC mode (otherwise attempt to pick from
> +    // available modes).
> +    int             explicit_rc_mode;
> +
> +    // Explicitly-set QP, for use with the "qp" options.
> +    // (Forces CQP mode when set, overriding everything else.)
> +    int             explicit_qp;
> +
> +    // The required size of surfaces.  This is probably the input
> +    // size (AVCodecContext.width|height) aligned up to whatever
> +    // block size is required by the codec.
> +    int             surface_width;
> +    int             surface_height;
> +
> +    // The block size for slice calculations.
> +    int             slice_block_width;
> +    int             slice_block_height;
> +
> +    // RC quality level - meaning depends on codec and RC mode.
> +    // In CQP mode this sets the fixed quantiser value.
> +    int             rc_quality;
> +
> +    AVBufferRef    *device_ref;
> +    AVHWDeviceContext *device;
> +
> +    // The hardware frame context containing the input frames.
> +    AVBufferRef    *input_frames_ref;
> +    AVHWFramesContext *input_frames;
> +
> +    // The hardware frame context containing the reconstructed frames.
> +    AVBufferRef    *recon_frames_ref;
> +    AVHWFramesContext *recon_frames;
> +
> +    // Current encoding window, in display (input) order.
> +    HWBaseEncodePicture *pic_start, *pic_end;
> +    // The next picture to use as the previous reference picture in
> +    // encoding order. Order from small to large in encoding order.
> +    HWBaseEncodePicture *next_prev[MAX_PICTURE_REFERENCES];
> +    int                  nb_next_prev;
> +
> +    // Next input order index (display order).
> +    int64_t         input_order;
> +    // Number of frames that output is behind input.
> +    int64_t         output_delay;
> +    // Next encode order index.
> +    int64_t         encode_order;
> +    // Number of frames decode output will need to be delayed.
> +    int64_t         decode_delay;
> +    // Next output order index (in encode order).
> +    int64_t         output_order;
> +
> +    // Timestamp handling.
> +    int64_t         first_pts;
> +    int64_t         dts_pts_diff;
> +    int64_t         ts_ring[MAX_REORDER_DELAY * 3 +
> +                            MAX_ASYNC_DEPTH];
> +
> +    // Frame type decision.
> +    int gop_size;
> +    int closed_gop;
> +    int gop_per_idr;
> +    int p_per_i;
> +    int max_b_depth;
> +    int b_per_p;
> +    int force_idr;
> +    int idr_counter;
> +    int gop_counter;
> +    int end_of_stream;
> +    int p_to_gpb;
> +
> +    // Whether the driver supports ROI at all.
> +    int             roi_allowed;
> +
> +    // The encoder does not support cropping information, so warn about
> +    // it the first time we encounter any nonzero crop fields.
> +    int             crop_warned;
> +    // If the driver does not support ROI then warn the first time we
> +    // encounter a frame with ROI side data.
> +    int             roi_warned;
> +
> +    AVFrame         *frame;
> +
> +    // Whether the HW supports sync buffer function.
> +    // If supported, encode_fifo/async_depth will be used together.
> +    // Used for output buffer synchronization.
> +    int             async_encode;
> +
> +    // Store buffered pic
> +    AVFifo          *encode_fifo;
> +    // Max number of frame buffered in encoder.
> +    int             async_depth;
> +
> +    /** Tail data of a pic, now only used for av1 repeat frame header. */
> +    AVPacket        *tail_pkt;
> +} HWBaseEncodeContext;
> +
> +int ff_hw_base_encode_receive_packet(AVCodecContext *avctx, AVPacket *pkt);
> +
> +int ff_hw_base_encode_init(AVCodecContext *avctx);
> +
> +int ff_hw_base_encode_close(AVCodecContext *avctx);
> +
> +#define HW_BASE_ENCODE_COMMON_OPTIONS \
> +    { "idr_interval", \
> +      "Distance (in I-frames) between IDR frames", \
> +      OFFSET(common.base.idr_interval), AV_OPT_TYPE_INT, \
>

Call them keyframes. Don't hardcode MPEGese.


> +      { .i64 = 0 }, 0, INT_MAX, FLAGS }, \
> +    { "b_depth", \
> +      "Maximum B-frame reference depth", \
> +      OFFSET(common.base.desired_b_depth), AV_OPT_TYPE_INT, \
> +      { .i64 = 1 }, 1, INT_MAX, FLAGS }, \
> +    { "async_depth", "Maximum processing parallelism. " \
> +      "Increase this to improve single channel performance.", \
> +      OFFSET(common.base.async_depth), AV_OPT_TYPE_INT, \
> +      { .i64 = 2 }, 1, MAX_ASYNC_DEPTH, FLAGS }
> +
> +#endif /* AVCODEC_HW_BASE_ENCODE_H */
>

No namespacing of any structs or functions.
Split this into multiple commits rather than converting VAAPI in the same commit.

This looks like a copy of VAAPI's logic, with all specific limitations
to VAAPI, but able to be wrapped on top of D3D12. I'd like to see something
more generic.
This doesn't look like it would be that useful for Vulkan as-is.


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