[FFmpeg-devel,v3,05/14] vvcdec: add reference management

---
 libavcodec/vvc/Makefile   |   3 +-
 libavcodec/vvc/vvc_refs.c | 526 ++++++++++++++++++++++++++++++++++++++
 libavcodec/vvc/vvc_refs.h |  47 ++++
 3 files changed, 575 insertions(+), 1 deletion(-)
 create mode 100644 libavcodec/vvc/vvc_refs.c
 create mode 100644 libavcodec/vvc/vvc_refs.h

Nuo Mi:
> ---
>  libavcodec/vvc/Makefile   |   3 +-
>  libavcodec/vvc/vvc_refs.c | 526 ++++++++++++++++++++++++++++++++++++++
>  libavcodec/vvc/vvc_refs.h |  47 ++++
>  3 files changed, 575 insertions(+), 1 deletion(-)
>  create mode 100644 libavcodec/vvc/vvc_refs.c
>  create mode 100644 libavcodec/vvc/vvc_refs.h
> 
> diff --git a/libavcodec/vvc/Makefile b/libavcodec/vvc/Makefile
> index 64c9ea9688..6eb181784b 100644
> --- a/libavcodec/vvc/Makefile
> +++ b/libavcodec/vvc/Makefile
> @@ -5,4 +5,5 @@ OBJS-$(CONFIG_VVC_DECODER)          +=  vvc/vvcdec.o            \
>                                          vvc/vvc_cabac.o         \
>                                          vvc/vvc_ctu.o           \
>                                          vvc/vvc_data.o          \
> -                                        vvc/vvc_ps.o
> +                                        vvc/vvc_ps.o            \
> +                                        vvc/vvc_refs.o
> diff --git a/libavcodec/vvc/vvc_refs.c b/libavcodec/vvc/vvc_refs.c
> new file mode 100644
> index 0000000000..010f1892ed
> --- /dev/null
> +++ b/libavcodec/vvc/vvc_refs.c
> @@ -0,0 +1,526 @@
> +/*
> + * VVC reference management
> + *
> + * Copyright (C) 2023 Nuo Mi
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#include <stdatomic.h>
> +
> +#include "libavutil/thread.h"
> +
> +#include "vvc_refs.h"
> +
> +#define VVC_FRAME_FLAG_OUTPUT    (1 << 0)
> +#define VVC_FRAME_FLAG_SHORT_REF (1 << 1)
> +#define VVC_FRAME_FLAG_LONG_REF  (1 << 2)
> +#define VVC_FRAME_FLAG_BUMPING   (1 << 3)
> +
> +typedef struct FrameProgress {
> +    atomic_int progress[VVC_PROGRESS_LAST];
> +    AVMutex lock;
> +} FrameProgress;
> +
> +void ff_vvc_unref_frame(VVCFrameContext *fc, VVCFrame *frame, int flags)
> +{
> +    /* frame->frame can be NULL if context init failed */
> +    if (!frame->frame || !frame->frame->buf[0])
> +        return;
> +
> +    frame->flags &= ~flags;
> +    if (!frame->flags) {
> +        ff_thread_release_ext_buffer(fc->avctx, &frame->tf);
> +
> +        av_buffer_unref(&frame->progress_buf);
> +
> +        av_buffer_unref(&frame->tab_dmvr_mvf_buf);
> +        frame->tab_dmvr_mvf = NULL;
> +
> +        av_buffer_unref(&frame->rpl_buf);
> +        av_buffer_unref(&frame->rpl_tab_buf);
> +        frame->rpl_tab    = NULL;
> +
> +        frame->collocated_ref = NULL;
> +    }
> +}
> +
> +const RefPicList *ff_vvc_get_ref_list(const VVCFrameContext *fc, const VVCFrame *ref, int x0, int y0)
> +{
> +    int x_cb         = x0 >> fc->ps.sps->ctb_log2_size_y;
> +    int y_cb         = y0 >> fc->ps.sps->ctb_log2_size_y;
> +    int pic_width_cb = fc->ps.pps->ctb_width;
> +    int ctb_addr_rs  = y_cb * pic_width_cb + x_cb;
> +
> +    return (const RefPicList *)ref->rpl_tab[ctb_addr_rs];
> +}
> +
> +void ff_vvc_clear_refs(VVCFrameContext *fc)
> +{
> +    int i;
> +    for (i = 0; i < FF_ARRAY_ELEMS(fc->DPB); i++)
> +        ff_vvc_unref_frame(fc, &fc->DPB[i],
> +            VVC_FRAME_FLAG_SHORT_REF | VVC_FRAME_FLAG_LONG_REF);
> +}
> +
> +static void free_progress(void *opaque, uint8_t *data)
> +{
> +    ff_mutex_destroy(&((FrameProgress*)data)->lock);
> +    av_free(data);
> +}
> +
> +static AVBufferRef *alloc_progress(void)
> +{
> +    int ret;
> +    AVBufferRef *buf;
> +    FrameProgress *p = av_mallocz(sizeof(FrameProgress));
> +
> +    if (!p)
> +        return NULL;
> +
> +    ret = ff_mutex_init(&p->lock, NULL);
> +    if (ret) {
> +        av_free(p);
> +        return NULL;
> +    }
> +    buf = av_buffer_create((void*)p, sizeof(*p), free_progress, NULL, 0);
> +    if (!buf)
> +        free_progress(NULL, (void*)p);
> +    return buf;
> +}
> +
> +static VVCFrame *alloc_frame(VVCContext *s, VVCFrameContext *fc)
> +{
> +    const VVCPPS *pps = fc->ps.pps;
> +    int i, j, ret;
> +    for (i = 0; i < FF_ARRAY_ELEMS(fc->DPB); i++) {
> +        VVCFrame *frame = &fc->DPB[i];
> +        if (frame->frame->buf[0])
> +            continue;
> +
> +        ret = ff_thread_get_ext_buffer(fc->avctx, &frame->tf,
> +                                   AV_GET_BUFFER_FLAG_REF);
> +        if (ret < 0)
> +            return NULL;
> +
> +        frame->rpl_buf = av_buffer_allocz(s->current_frame.nb_units * sizeof(RefPicListTab));
> +        if (!frame->rpl_buf)
> +            goto fail;
> +
> +        frame->tab_dmvr_mvf_buf = av_buffer_pool_get(fc->tab_dmvr_mvf_pool);
> +        if (!frame->tab_dmvr_mvf_buf)
> +            goto fail;
> +        frame->tab_dmvr_mvf = (MvField *)frame->tab_dmvr_mvf_buf->data;
> +        //fixme: remove this
> +        memset(frame->tab_dmvr_mvf, 0, frame->tab_dmvr_mvf_buf->size);

This stuff here would benefit a lot from the (not yet merged) RefStruct
pool API. There is even a flag to zero pool entries automatically so you
don't have to.

> +
> +        frame->rpl_tab_buf = av_buffer_pool_get(fc->rpl_tab_pool);
> +        if (!frame->rpl_tab_buf)
> +            goto fail;
> +        frame->rpl_tab   = (RefPicListTab **)frame->rpl_tab_buf->data;
> +        frame->ctb_count = pps->ctb_width * pps->ctb_height;
> +        for (j = 0; j < frame->ctb_count; j++)
> +            frame->rpl_tab[j] = (RefPicListTab *)frame->rpl_buf->data;
> +
> +
> +        frame->progress_buf = alloc_progress();
> +        if (!frame->progress_buf)
> +            goto fail;
> +
> +        return frame;
> +fail:
> +        ff_vvc_unref_frame(fc, frame, ~0);
> +        return NULL;
> +    }
> +    av_log(s->avctx, AV_LOG_ERROR, "Error allocating frame, DPB full.\n");
> +    return NULL;
> +}
> +
> +int ff_vvc_set_new_ref(VVCContext *s, VVCFrameContext *fc, AVFrame **frame)
> +{
> +    const VVCPH *ph= &fc->ps.ph;
> +    const int poc = ph->poc;
> +    VVCFrame *ref;
> +    int i;
> +
> +    /* check that this POC doesn't already exist */
> +    for (i = 0; i < FF_ARRAY_ELEMS(fc->DPB); i++) {
> +        VVCFrame *frame = &fc->DPB[i];
> +
> +        if (frame->frame->buf[0] && frame->sequence == s->seq_decode &&
> +            frame->poc == poc) {
> +            av_log(s->avctx, AV_LOG_ERROR, "Duplicate POC in a sequence: %d.\n",
> +                   poc);
> +            return AVERROR_INVALIDDATA;
> +        }
> +    }
> +
> +    ref = alloc_frame(s, fc);
> +    if (!ref)
> +        return AVERROR(ENOMEM);
> +
> +    *frame = ref->frame;
> +    fc->ref = ref;
> +
> +    if (s->no_output_before_recovery_flag && (IS_RASL(s) || !GDR_IS_RECOVERED(s)))
> +        ref->flags = 0;
> +    else if (ph->r->ph_pic_output_flag)
> +        ref->flags = VVC_FRAME_FLAG_OUTPUT;
> +
> +    if (!ph->r->ph_non_ref_pic_flag)
> +        ref->flags |= VVC_FRAME_FLAG_SHORT_REF;
> +
> +    ref->poc      = poc;
> +    ref->sequence = s->seq_decode;
> +    ref->frame->crop_left   = fc->ps.pps->r->pps_conf_win_left_offset;
> +    ref->frame->crop_right  = fc->ps.pps->r->pps_conf_win_right_offset;
> +    ref->frame->crop_top    = fc->ps.pps->r->pps_conf_win_top_offset;
> +    ref->frame->crop_bottom = fc->ps.pps->r->pps_conf_win_bottom_offset;
> +
> +    return 0;
> +}
> +
> +int ff_vvc_output_frame(VVCContext *s, VVCFrameContext *fc, AVFrame *out, const int no_output_of_prior_pics_flag, int flush)
> +{
> +    const VVCSPS *sps = fc->ps.sps;
> +    do {
> +        int nb_output = 0;
> +        int min_poc   = INT_MAX;
> +        int i, min_idx, ret;
> +
> +        if (no_output_of_prior_pics_flag) {
> +            for (i = 0; i < FF_ARRAY_ELEMS(fc->DPB); i++) {
> +                VVCFrame *frame = &fc->DPB[i];
> +                if (!(frame->flags & VVC_FRAME_FLAG_BUMPING) && frame->poc != fc->ps.ph.poc &&
> +                        frame->sequence == s->seq_output) {
> +                    ff_vvc_unref_frame(fc, frame, VVC_FRAME_FLAG_OUTPUT);
> +                }
> +            }
> +        }
> +
> +        for (i = 0; i < FF_ARRAY_ELEMS(fc->DPB); i++) {
> +            VVCFrame *frame = &fc->DPB[i];
> +            if ((frame->flags & VVC_FRAME_FLAG_OUTPUT) &&
> +                frame->sequence == s->seq_output) {
> +                nb_output++;
> +                if (frame->poc < min_poc || nb_output == 1) {
> +                    min_poc = frame->poc;
> +                    min_idx = i;
> +                }
> +            }
> +        }
> +
> +        /* wait for more frames before output */
> +        if (!flush && s->seq_output == s->seq_decode && sps &&
> +            nb_output <= sps->r->sps_dpb_params.dpb_max_dec_pic_buffering_minus1[sps->r->sps_max_sublayers_minus1] + 1)
> +            return 0;
> +
> +        if (nb_output) {
> +            VVCFrame *frame = &fc->DPB[min_idx];
> +
> +            ret = av_frame_ref(out, frame->frame);
> +            if (frame->flags & VVC_FRAME_FLAG_BUMPING)
> +                ff_vvc_unref_frame(fc, frame, VVC_FRAME_FLAG_OUTPUT | VVC_FRAME_FLAG_BUMPING);
> +            else
> +                ff_vvc_unref_frame(fc, frame, VVC_FRAME_FLAG_OUTPUT);
> +            if (ret < 0)
> +                return ret;
> +
> +            av_log(s->avctx, AV_LOG_DEBUG,
> +                   "Output frame with POC %d.\n", frame->poc);
> +            return 1;
> +        }
> +
> +        if (s->seq_output != s->seq_decode)
> +            s->seq_output = (s->seq_output + 1) & 0xff;
> +        else
> +            break;
> +    } while (1);
> +    return 0;
> +}
> +
> +void ff_vvc_bump_frame(VVCContext *s, VVCFrameContext *fc)
> +{
> +    const VVCSPS *sps = fc->ps.sps;
> +    const int poc = fc->ps.ph.poc;
> +    int dpb = 0;
> +    int min_poc = INT_MAX;
> +    int i;
> +
> +    for (i = 0; i < FF_ARRAY_ELEMS(fc->DPB); i++) {
> +        VVCFrame *frame = &fc->DPB[i];
> +        if ((frame->flags) &&
> +            frame->sequence == s->seq_output &&
> +            frame->poc != poc) {
> +            dpb++;
> +        }
> +    }
> +
> +    if (sps && dpb >= sps->r->sps_dpb_params.dpb_max_dec_pic_buffering_minus1[sps->r->sps_max_sublayers_minus1] + 1) {
> +        for (i = 0; i < FF_ARRAY_ELEMS(fc->DPB); i++) {
> +            VVCFrame *frame = &fc->DPB[i];
> +            if ((frame->flags) &&
> +                frame->sequence == s->seq_output &&
> +                frame->poc != poc) {
> +                if (frame->flags == VVC_FRAME_FLAG_OUTPUT && frame->poc < min_poc) {
> +                    min_poc = frame->poc;
> +                }
> +            }
> +        }
> +
> +        for (i = 0; i < FF_ARRAY_ELEMS(fc->DPB); i++) {
> +            VVCFrame *frame = &fc->DPB[i];
> +            if (frame->flags & VVC_FRAME_FLAG_OUTPUT &&
> +                frame->sequence == s->seq_output &&
> +                frame->poc <= min_poc) {
> +                frame->flags |= VVC_FRAME_FLAG_BUMPING;
> +            }
> +        }
> +
> +        dpb--;
> +    }
> +}
> +
> +static VVCFrame *find_ref_idx(VVCContext *s, VVCFrameContext *fc, int poc, uint8_t use_msb)
> +{
> +    int mask = use_msb ? ~0 : fc->ps.sps->max_pic_order_cnt_lsb - 1;
> +    int i;
> +
> +    for (i = 0; i < FF_ARRAY_ELEMS(fc->DPB); i++) {
> +        VVCFrame *ref = &fc->DPB[i];
> +        if (ref->frame->buf[0] && ref->sequence == s->seq_decode) {
> +            if ((ref->poc & mask) == poc)
> +                return ref;
> +        }
> +    }
> +    return NULL;
> +}
> +
> +static void mark_ref(VVCFrame *frame, int flag)
> +{
> +    frame->flags &= ~(VVC_FRAME_FLAG_LONG_REF | VVC_FRAME_FLAG_SHORT_REF);
> +    frame->flags |= flag;
> +}
> +
> +static VVCFrame *generate_missing_ref(VVCContext *s, VVCFrameContext *fc, int poc)
> +{
> +    const VVCSPS *sps = fc->ps.sps;
> +    VVCFrame *frame;
> +    int i, y;
> +
> +    frame = alloc_frame(s, fc);
> +    if (!frame)
> +        return NULL;
> +
> +    if (!s->avctx->hwaccel) {
> +        if (!sps->pixel_shift) {
> +            for (i = 0; frame->frame->buf[i]; i++)
> +                memset(frame->frame->buf[i]->data, 1 << (sps->bit_depth - 1),
> +                       frame->frame->buf[i]->size);
> +        } else {
> +            for (i = 0; frame->frame->data[i]; i++)
> +                for (y = 0; y < (sps->height >> sps->vshift[i]); y++) {
> +                    uint8_t *dst = frame->frame->data[i] + y * frame->frame->linesize[i];
> +                    AV_WN16(dst, 1 << (sps->bit_depth - 1));
> +                    av_memcpy_backptr(dst + 2, 2, 2*(sps->width >> sps->hshift[i]) - 2);
> +                }
> +        }
> +    }
> +
> +    frame->poc      = poc;
> +    frame->sequence = s->seq_decode;
> +    frame->flags    = 0;
> +
> +    ff_vvc_report_frame_finished(frame);
> +
> +    return frame;
> +}
> +
> +/* add a reference with the given poc to the list and mark it as used in DPB */
> +static int add_candidate_ref(VVCContext *s, VVCFrameContext *fc, RefPicList *list,
> +                             int poc, int ref_flag, uint8_t use_msb)
> +{
> +    VVCFrame *ref = find_ref_idx(s, fc, poc, use_msb);
> +
> +    if (ref == fc->ref || list->nb_refs >= VVC_MAX_REF_ENTRIES)
> +        return AVERROR_INVALIDDATA;
> +
> +    if (!ref) {
> +        ref = generate_missing_ref(s, fc, poc);
> +        if (!ref)
> +            return AVERROR(ENOMEM);
> +    }
> +
> +    list->list[list->nb_refs] = poc;
> +    list->ref[list->nb_refs]  = ref;
> +    list->isLongTerm[list->nb_refs] = ref_flag & VVC_FRAME_FLAG_LONG_REF;
> +    list->nb_refs++;
> +
> +    mark_ref(ref, ref_flag);
> +    return 0;
> +}
> +
> +static int init_slice_rpl(const VVCFrameContext *fc, SliceContext *sc)
> +{
> +    VVCFrame *frame = fc->ref;
> +    const VVCSH *sh = &sc->sh;
> +
> +    if (sc->slice_idx >= frame->rpl_buf->size / sizeof(RefPicListTab))
> +        return AVERROR_INVALIDDATA;
> +
> +    for (int i = 0; i < sh->num_ctus_in_curr_slice; i++) {
> +        const int rs = sh->ctb_addr_in_curr_slice[i];
> +        frame->rpl_tab[rs] = (RefPicListTab *)frame->rpl_buf->data + sc->slice_idx;
> +    }
> +
> +    sc->rpl = (RefPicList *)frame->rpl_tab[sh->ctb_addr_in_curr_slice[0]];
> +
> +    return 0;
> +}
> +
> +static int delta_poc_st(const H266RefPicListStruct *rpls,
> +    const int lx, const int i, const VVCSPS *sps)
> +{
> +    int abs_delta_poc_st = rpls->abs_delta_poc_st[i];
> +    if (!((sps->r->sps_weighted_pred_flag ||
> +        sps->r->sps_weighted_bipred_flag) && i != 0))
> +        abs_delta_poc_st++;
> +    return (1 - 2 * rpls->strp_entry_sign_flag[i]) * abs_delta_poc_st;
> +}
> +
> +static int poc_lt(int *prev_delta_poc_msb, const int poc, const H266RefPicLists *ref_lists,
> +    const int lx, const int j, const int max_poc_lsb)
> +{
> +    const H266RefPicListStruct *rpls = ref_lists->rpl_ref_list + lx;
> +    int lt_poc =  rpls->ltrp_in_header_flag ? ref_lists->poc_lsb_lt[lx][j] : rpls->rpls_poc_lsb_lt[j];
> +
> +    if (ref_lists->delta_poc_msb_cycle_present_flag[lx][j]) {
> +        const uint32_t delta = ref_lists->delta_poc_msb_cycle_lt[lx][j] + *prev_delta_poc_msb;
> +        lt_poc += poc - delta * max_poc_lsb - (poc & (max_poc_lsb - 1));
> +        *prev_delta_poc_msb = delta;
> +    }
> +    return lt_poc;
> +}
> +
> +int ff_vvc_slice_rpl(VVCContext *s, VVCFrameContext *fc, SliceContext *sc)
> +{
> +    const VVCSPS *sps                = fc->ps.sps;
> +    const H266RawPPS *pps            = fc->ps.pps->r;
> +    const VVCPH *ph                  = &fc->ps.ph;
> +    const H266RawSliceHeader *rsh    = sc->sh.r;
> +    const int max_poc_lsb            = sps->max_pic_order_cnt_lsb;
> +    const H266RefPicLists *ref_lists =
> +        pps->pps_rpl_info_in_ph_flag ?  &ph->r->ph_ref_pic_lists : &rsh->sh_ref_pic_lists;
> +    int ret = 0;
> +
> +    ret = init_slice_rpl(fc, sc);
> +    if (ret < 0)
> +        return ret;
> +
> +    for (int lx = L0; lx <= L1; lx++) {
> +        const H266RefPicListStruct *rpls = ref_lists->rpl_ref_list + lx;
> +        RefPicList *rpl = sc->rpl + lx;
> +        int poc_base = ph->poc;
> +        int prev_delta_poc_msb = 0;
> +
> +        rpl->nb_refs = 0;
> +        for (int i = 0, j = 0; i < rpls->num_ref_entries; i++) {
> +            int poc;
> +            if (!rpls->inter_layer_ref_pic_flag[i]) {
> +                int use_msb = 1;
> +                int ref_flag;
> +                if (rpls->st_ref_pic_flag[i]) {
> +                    poc = poc_base + delta_poc_st(rpls, lx, i, sps);
> +                    poc_base = poc;
> +                    ref_flag = VVC_FRAME_FLAG_SHORT_REF;
> +                } else {
> +                    use_msb = ref_lists->delta_poc_msb_cycle_present_flag[lx][j];
> +                    poc = poc_lt(&prev_delta_poc_msb, ph->poc, ref_lists, lx, j, max_poc_lsb);
> +                    ref_flag = VVC_FRAME_FLAG_LONG_REF;
> +                    j++;
> +                }
> +                ret = add_candidate_ref(s, fc, rpl, poc, ref_flag, use_msb);
> +                if (ret < 0)
> +                    goto fail;
> +            } else {
> +                avpriv_request_sample(fc->avctx, "Inter layer ref");
> +                ret = AVERROR_PATCHWELCOME;
> +                goto fail;
> +            }
> +        }
> +        if ((!rsh->sh_collocated_from_l0_flag) == lx &&
> +            rsh->sh_collocated_ref_idx < rpl->nb_refs)
> +            fc->ref->collocated_ref = rpl->ref[rsh->sh_collocated_ref_idx];
> +    }
> +fail:
> +    return ret;
> +}
> +
> +int ff_vvc_frame_rpl(VVCContext *s, VVCFrameContext *fc, SliceContext *sc)
> +{
> +    int i, ret = 0;
> +
> +    /* clear the reference flags on all frames except the current one */
> +    for (i = 0; i < FF_ARRAY_ELEMS(fc->DPB); i++) {
> +        VVCFrame *frame = &fc->DPB[i];
> +
> +        if (frame == fc->ref)
> +            continue;
> +
> +        mark_ref(frame, 0);
> +    }
> +
> +    if ((ret = ff_vvc_slice_rpl(s, fc, sc)) < 0)
> +        goto fail;
> +
> +fail:
> +    /* release any frames that are now unused */
> +    for (i = 0; i < FF_ARRAY_ELEMS(fc->DPB); i++)
> +        ff_vvc_unref_frame(fc, &fc->DPB[i], 0);
> +    return ret;
> +}
> +
> +void ff_vvc_report_frame_finished(VVCFrame *frame)
> +{
> +    ff_vvc_report_progress(frame, VVC_PROGRESS_MV, INT_MAX);
> +    ff_vvc_report_progress(frame, VVC_PROGRESS_PIXEL, INT_MAX);
> +}
> +
> +void ff_vvc_report_progress(VVCFrame *frame, const VVCProgress vp, const int y)
> +{
> +    FrameProgress *p = (FrameProgress*)frame->progress_buf->data;
> +
> +    ff_mutex_lock(&p->lock);
> +
> +    av_assert0(p->progress[vp] < y || p->progress[vp] == INT_MAX);
> +    p->progress[vp] = y;
> +
> +    ff_mutex_unlock(&p->lock);
> +}
> +
> +int ff_vvc_check_progress(VVCFrame *frame, const VVCProgress vp, const int y)
> +{
> +    int ready ;
> +    FrameProgress *p = (FrameProgress*)frame->progress_buf->data;
> +
> +    ff_mutex_lock(&p->lock);
> +
> +    ready = p->progress[vp] > y + 1;
> +
> +    ff_mutex_unlock(&p->lock);
> +    return ready;
> +}
> diff --git a/libavcodec/vvc/vvc_refs.h b/libavcodec/vvc/vvc_refs.h
> new file mode 100644
> index 0000000000..1bba2ca34a
> --- /dev/null
> +++ b/libavcodec/vvc/vvc_refs.h
> @@ -0,0 +1,47 @@
> +/*
> + * VVC reference management
> + *
> + * Copyright (C) 2023 Nuo Mi
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#ifndef AVCODEC_VVC_REFS_H
> +#define AVCODEC_VVC_REFS_H
> +
> +#include "vvcdec.h"
> +
> +int ff_vvc_output_frame(VVCContext *s, VVCFrameContext *fc, AVFrame *out, int no_output_of_prior_pics_flag, int flush);
> +void ff_vvc_bump_frame(VVCContext *s, VVCFrameContext *fc);
> +int ff_vvc_set_new_ref(VVCContext *s, VVCFrameContext *fc, AVFrame **frame);
> +const RefPicList *ff_vvc_get_ref_list(const VVCFrameContext *fc, const VVCFrame *ref, int x0, int y0);
> +int ff_vvc_frame_rpl(VVCContext *s, VVCFrameContext *fc, SliceContext *sc);
> +int ff_vvc_slice_rpl(VVCContext *s, VVCFrameContext *fc, SliceContext *sc);
> +void ff_vvc_unref_frame(VVCFrameContext *fc, VVCFrame *frame, int flags);
> +void ff_vvc_clear_refs(VVCFrameContext *fc);
> +
> +typedef enum VVCProgress{
> +    VVC_PROGRESS_MV,
> +    VVC_PROGRESS_PIXEL,
> +    VVC_PROGRESS_LAST,
> +} VVCProgress;
> +
> +void ff_vvc_report_frame_finished(VVCFrame *frame);
> +void ff_vvc_report_progress(VVCFrame *frame, VVCProgress vp, int y);
> +int ff_vvc_check_progress(VVCFrame *frame, VVCProgress vp, int y);
> +
> +#endif // AVCODEC_VVC_REFS_H