/*

  * HEVC video decoder

  *
  * Copyright (C) 2012 - 2013 Guillaume Martres
  * Copyright (C) 2012 - 2013 Gildas Cocherel
  *
  * 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 "libavutil/pixdesc.h"
 
 #include "internal.h"
 #include "thread.h"

 #include "hevc.h"

 
 void ff_hevc_unref_frame(HEVCContext *s, HEVCFrame *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_buffer(s->avctx, &frame->tf);
 
         av_buffer_unref(&frame->tab_mvf_buf);
         frame->tab_mvf = NULL;
 
         av_buffer_unref(&frame->rpl_buf);
         av_buffer_unref(&frame->rpl_tab_buf);
         frame->rpl_tab    = NULL;
         frame->refPicList = NULL;
 
         frame->collocated_ref = NULL;
     }
 }
 

 RefPicList *ff_hevc_get_ref_list(HEVCContext *s, HEVCFrame *ref, int x0, int y0)

 {
     if (x0 < 0 || y0 < 0) {
         return s->ref->refPicList;
     } else {
         int x_cb         = x0 >> s->sps->log2_ctb_size;
         int y_cb         = y0 >> s->sps->log2_ctb_size;

         int pic_width_cb = (s->sps->width + (1 << s->sps->log2_ctb_size) - 1) >>
                            s->sps->log2_ctb_size;

         int ctb_addr_ts  = s->pps->ctb_addr_rs_to_ts[y_cb * pic_width_cb + x_cb];

         return (RefPicList *)ref->rpl_tab[ctb_addr_ts];

     }
 }
 
 void ff_hevc_clear_refs(HEVCContext *s)
 {
     int i;
     for (i = 0; i < FF_ARRAY_ELEMS(s->DPB); i++)
         ff_hevc_unref_frame(s, &s->DPB[i],

                             HEVC_FRAME_FLAG_SHORT_REF |
                             HEVC_FRAME_FLAG_LONG_REF);

 }
 
 void ff_hevc_flush_dpb(HEVCContext *s)
 {
     int i;
     for (i = 0; i < FF_ARRAY_ELEMS(s->DPB); i++)
         ff_hevc_unref_frame(s, &s->DPB[i], ~0);
 }
 
 static HEVCFrame *alloc_frame(HEVCContext *s)
 {
     int i, j, ret;
     for (i = 0; i < FF_ARRAY_ELEMS(s->DPB); i++) {
         HEVCFrame *frame = &s->DPB[i];
         if (frame->frame->buf[0])
             continue;
 

         ret = ff_thread_get_buffer(s->avctx, &frame->tf,
                                    AV_GET_BUFFER_FLAG_REF);

         if (ret < 0)
             return NULL;
 
         frame->rpl_buf = av_buffer_allocz(s->nb_nals * sizeof(RefPicListTab));
         if (!frame->rpl_buf)
             goto fail;
 
         frame->tab_mvf_buf = av_buffer_pool_get(s->tab_mvf_pool);
         if (!frame->tab_mvf_buf)
             goto fail;

         frame->tab_mvf = (MvField *)frame->tab_mvf_buf->data;

 
         frame->rpl_tab_buf = av_buffer_pool_get(s->rpl_tab_pool);
         if (!frame->rpl_tab_buf)
             goto fail;

         frame->rpl_tab   = (RefPicListTab **)frame->rpl_tab_buf->data;

         frame->ctb_count = s->sps->ctb_width * s->sps->ctb_height;
         for (j = 0; j < frame->ctb_count; j++)

             frame->rpl_tab[j] = (RefPicListTab *)frame->rpl_buf->data;

         frame->frame->top_field_first  = s->picture_struct == AV_PICTURE_STRUCTURE_TOP_FIELD;
         frame->frame->interlaced_frame = (s->picture_struct == AV_PICTURE_STRUCTURE_TOP_FIELD) || (s->picture_struct == AV_PICTURE_STRUCTURE_BOTTOM_FIELD);

         return frame;
 fail:
         ff_hevc_unref_frame(s, frame, ~0);
         return NULL;
     }
     av_log(s->avctx, AV_LOG_ERROR, "Error allocating frame, DPB full.\n");
     return NULL;
 }
 
 int ff_hevc_set_new_ref(HEVCContext *s, AVFrame **frame, int poc)
 {
     HEVCFrame *ref;
     int i;
 
     /* check that this POC doesn't already exist */
     for (i = 0; i < FF_ARRAY_ELEMS(s->DPB); i++) {
         HEVCFrame *frame = &s->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);
     if (!ref)
         return AVERROR(ENOMEM);
 

     *frame = ref->frame;
     s->ref = ref;

     ref->poc      = poc;
     ref->flags    = HEVC_FRAME_FLAG_OUTPUT | HEVC_FRAME_FLAG_SHORT_REF;
     ref->sequence = s->seq_decode;
     ref->window   = s->sps->output_window;

 
     return 0;
 }
 
 int ff_hevc_output_frame(HEVCContext *s, AVFrame *out, int flush)
 {
     do {

         int nb_output = 0;
         int min_poc   = INT_MAX;

         int i, min_idx, ret;

         for (i = 0; i < FF_ARRAY_ELEMS(s->DPB); i++) {
             HEVCFrame *frame = &s->DPB[i];
             if ((frame->flags & HEVC_FRAME_FLAG_OUTPUT) &&
                 frame->sequence == s->seq_output) {
                 nb_output++;
                 if (frame->poc < min_poc) {
                     min_poc = frame->poc;
                     min_idx = i;
                 }
             }
         }
 
         /* wait for more frames before output */
         if (!flush && s->seq_output == s->seq_decode && s->sps &&

             nb_output <= s->sps->temporal_layer[s->sps->max_sub_layers - 1].num_reorder_pics)

             return 0;
 
         if (nb_output) {
             HEVCFrame *frame = &s->DPB[min_idx];
             AVFrame *dst = out;
             AVFrame *src = frame->frame;
             const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(src->format);
             int pixel_shift = !!(desc->comp[0].depth_minus1 > 7);
 
             ret = av_frame_ref(out, src);
             ff_hevc_unref_frame(s, frame, HEVC_FRAME_FLAG_OUTPUT);
             if (ret < 0)
                 return ret;
 

             for (i = 0; i < 3; i++) {
                 int hshift = (i > 0) ? desc->log2_chroma_w : 0;
                 int vshift = (i > 0) ? desc->log2_chroma_h : 0;

                 int off = ((frame->window.left_offset >> hshift) << pixel_shift) +

                           (frame->window.top_offset   >> vshift) * dst->linesize[i];
                 dst->data[i] += off;

             }

             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;
 }
 
 static int init_slice_rpl(HEVCContext *s)
 {
     HEVCFrame *frame = s->ref;

     int ctb_count    = frame->ctb_count;
     int ctb_addr_ts  = s->pps->ctb_addr_rs_to_ts[s->sh.slice_segment_addr];

     int i;
 
     if (s->slice_idx >= frame->rpl_buf->size / sizeof(RefPicListTab))
         return AVERROR_INVALIDDATA;
 
     for (i = ctb_addr_ts; i < ctb_count; i++)

         frame->rpl_tab[i] = (RefPicListTab *)frame->rpl_buf->data + s->slice_idx;

     frame->refPicList = (RefPicList *)frame->rpl_tab[ctb_addr_ts];

 
     return 0;
 }
 
 int ff_hevc_slice_rpl(HEVCContext *s)
 {
     SliceHeader *sh = &s->sh;
 

     uint8_t nb_list = sh->slice_type == B_SLICE ? 2 : 1;

     uint8_t list_idx;
     int i, j, ret;
 
     ret = init_slice_rpl(s);
     if (ret < 0)
         return ret;
 
     if (!(s->rps[ST_CURR_BEF].nb_refs + s->rps[ST_CURR_AFT].nb_refs +
           s->rps[LT_CURR].nb_refs)) {
         av_log(s->avctx, AV_LOG_ERROR, "Zero refs in the frame RPS.\n");
         return AVERROR_INVALIDDATA;
     }
 
     for (list_idx = 0; list_idx < nb_list; list_idx++) {
         RefPicList  rpl_tmp = { { 0 } };
         RefPicList *rpl     = &s->ref->refPicList[list_idx];
 
         /* The order of the elements is
          * ST_CURR_BEF - ST_CURR_AFT - LT_CURR for the L0 and

          * ST_CURR_AFT - ST_CURR_BEF - LT_CURR for the L1 */

         int cand_lists[3] = { list_idx ? ST_CURR_AFT : ST_CURR_BEF,
                               list_idx ? ST_CURR_BEF : ST_CURR_AFT,
                               LT_CURR };
 
         /* concatenate the candidate lists for the current frame */
         while (rpl_tmp.nb_refs < sh->nb_refs[list_idx]) {
             for (i = 0; i < FF_ARRAY_ELEMS(cand_lists); i++) {
                 RefPicList *rps = &s->rps[cand_lists[i]];

                 for (j = 0; j < rps->nb_refs && rpl_tmp.nb_refs < MAX_REFS; j++) {

                     rpl_tmp.list[rpl_tmp.nb_refs]       = rps->list[j];
                     rpl_tmp.ref[rpl_tmp.nb_refs]        = rps->ref[j];

                     rpl_tmp.isLongTerm[rpl_tmp.nb_refs] = i == 2;

                     rpl_tmp.nb_refs++;
                 }
             }
         }
 
         /* reorder the references if necessary */
         if (sh->rpl_modification_flag[list_idx]) {
             for (i = 0; i < sh->nb_refs[list_idx]; i++) {
                 int idx = sh->list_entry_lx[list_idx][i];
 
                 if (idx >= rpl_tmp.nb_refs) {
                     av_log(s->avctx, AV_LOG_ERROR, "Invalid reference index.\n");
                     return AVERROR_INVALIDDATA;
                 }
 
                 rpl->list[i]       = rpl_tmp.list[idx];
                 rpl->ref[i]        = rpl_tmp.ref[idx];
                 rpl->isLongTerm[i] = rpl_tmp.isLongTerm[idx];
                 rpl->nb_refs++;
             }
         } else {
             memcpy(rpl, &rpl_tmp, sizeof(*rpl));
             rpl->nb_refs = FFMIN(rpl->nb_refs, sh->nb_refs[list_idx]);
         }
 
         if (sh->collocated_list == list_idx &&
             sh->collocated_ref_idx < rpl->nb_refs)
             s->ref->collocated_ref = rpl->ref[sh->collocated_ref_idx];
     }
 
     return 0;
 }
 
 static HEVCFrame *find_ref_idx(HEVCContext *s, int poc)
 {
     int i;
     int LtMask = (1 << s->sps->log2_max_poc_lsb) - 1;
 
     for (i = 0; i < FF_ARRAY_ELEMS(s->DPB); i++) {
         HEVCFrame *ref = &s->DPB[i];
         if (ref->frame->buf[0] && (ref->sequence == s->seq_decode)) {
             if ((ref->poc & LtMask) == poc)

                 return ref;
         }

     }
 
     for (i = 0; i < FF_ARRAY_ELEMS(s->DPB); i++) {
         HEVCFrame *ref = &s->DPB[i];

         if (ref->frame->buf[0] && ref->sequence == s->seq_decode) {

             if (ref->poc == poc || (ref->poc & LtMask) == poc)

                 return ref;
         }

     }
 
     av_log(s->avctx, AV_LOG_ERROR,
            "Could not find ref with POC %d\n", poc);
     return NULL;
 }
 
 static void mark_ref(HEVCFrame *frame, int flag)
 {
     frame->flags &= ~(HEVC_FRAME_FLAG_LONG_REF | HEVC_FRAME_FLAG_SHORT_REF);
     frame->flags |= flag;
 }
 
 static HEVCFrame *generate_missing_ref(HEVCContext *s, int poc)
 {
     HEVCFrame *frame;
     int i, x, y;
 
     frame = alloc_frame(s);
     if (!frame)
         return NULL;
 
     if (!s->sps->pixel_shift) {
         for (i = 0; frame->frame->buf[i]; i++)

             memset(frame->frame->buf[i]->data, 1 << (s->sps->bit_depth - 1),
                    frame->frame->buf[i]->size);

     } else {
         for (i = 0; frame->frame->data[i]; i++)

             for (y = 0; y < (s->sps->height >> s->sps->vshift[i]); y++)
                 for (x = 0; x < (s->sps->width >> s->sps->hshift[i]); x++) {

                     AV_WN16(frame->frame->data[i] + y * frame->frame->linesize[i] + 2 * x,
                             1 << (s->sps->bit_depth - 1));
                 }
     }
 
     frame->poc      = poc;
     frame->sequence = s->seq_decode;
     frame->flags    = 0;
 

     if (s->threads_type == FF_THREAD_FRAME)
         ff_thread_report_progress(&frame->tf, INT_MAX, 0);

 
     return frame;
 }
 
 /* add a reference with the given poc to the list and mark it as used in DPB */
 static int add_candidate_ref(HEVCContext *s, RefPicList *list,
                              int poc, int ref_flag)
 {
     HEVCFrame *ref = find_ref_idx(s, poc);
 
     if (ref == s->ref)
         return AVERROR_INVALIDDATA;
 
     if (!ref) {
         ref = generate_missing_ref(s, poc);
         if (!ref)
             return AVERROR(ENOMEM);
     }
 
     list->list[list->nb_refs] = ref->poc;
     list->ref[list->nb_refs]  = ref;
     list->nb_refs++;
 
     mark_ref(ref, ref_flag);
     return 0;
 }
 
 int ff_hevc_frame_rps(HEVCContext *s)
 {
     const ShortTermRPS *short_rps = s->sh.short_term_rps;
     const LongTermRPS  *long_rps  = &s->sh.long_term_rps;
     RefPicList               *rps = s->rps;
     int i, ret;
 

     if (!short_rps) {
         rps[0].nb_refs = rps[1].nb_refs = 0;

         return 0;

     }

 
     /* clear the reference flags on all frames except the current one */
     for (i = 0; i < FF_ARRAY_ELEMS(s->DPB); i++) {
         HEVCFrame *frame = &s->DPB[i];
 
         if (frame == s->ref)
             continue;
 
         mark_ref(frame, 0);
     }
 
     for (i = 0; i < NB_RPS_TYPE; i++)
         rps[i].nb_refs = 0;
 
     /* add the short refs */
     for (i = 0; i < short_rps->num_delta_pocs; i++) {
         int poc = s->poc + short_rps->delta_poc[i];
         int list;
 
         if (!short_rps->used[i])
             list = ST_FOLL;
         else if (i < short_rps->num_negative_pics)
             list = ST_CURR_BEF;
         else
             list = ST_CURR_AFT;
 
         ret = add_candidate_ref(s, &rps[list], poc, HEVC_FRAME_FLAG_SHORT_REF);
         if (ret < 0)
             return ret;
     }
 
     /* add the long refs */
     for (i = 0; i < long_rps->nb_refs; i++) {
         int poc  = long_rps->poc[i];
         int list = long_rps->used[i] ? LT_CURR : LT_FOLL;
 
         ret = add_candidate_ref(s, &rps[list], poc, HEVC_FRAME_FLAG_LONG_REF);
         if (ret < 0)
             return ret;
     }
 
     /* release any frames that are now unused */
     for (i = 0; i < FF_ARRAY_ELEMS(s->DPB); i++)
         ff_hevc_unref_frame(s, &s->DPB[i], 0);
 
     return 0;
 }
 
 int ff_hevc_compute_poc(HEVCContext *s, int poc_lsb)
 {
     int max_poc_lsb  = 1 << s->sps->log2_max_poc_lsb;
     int prev_poc_lsb = s->pocTid0 % max_poc_lsb;
     int prev_poc_msb = s->pocTid0 - prev_poc_lsb;
     int poc_msb;
 

     if (poc_lsb < prev_poc_lsb && prev_poc_lsb - poc_lsb >= max_poc_lsb / 2)

         poc_msb = prev_poc_msb + max_poc_lsb;

     else if (poc_lsb > prev_poc_lsb && poc_lsb - prev_poc_lsb > max_poc_lsb / 2)

         poc_msb = prev_poc_msb - max_poc_lsb;
     else
         poc_msb = prev_poc_msb;
 
     // For BLA picture types, POCmsb is set to 0.

     if (s->nal_unit_type == NAL_BLA_W_LP   ||

         s->nal_unit_type == NAL_BLA_W_RADL ||
         s->nal_unit_type == NAL_BLA_N_LP)
         poc_msb = 0;
 
     return poc_msb + poc_lsb;
 }
 
 int ff_hevc_frame_nb_refs(HEVCContext *s)
 {
     int ret = 0;
     int i;
     const ShortTermRPS *rps = s->sh.short_term_rps;
     LongTermRPS *long_rps   = &s->sh.long_term_rps;
 
     if (rps) {
         for (i = 0; i < rps->num_negative_pics; i++)
             ret += !!rps->used[i];
         for (; i < rps->num_delta_pocs; i++)
             ret += !!rps->used[i];
     }
 
     if (long_rps) {
         for (i = 0; i < long_rps->nb_refs; i++)
             ret += !!long_rps->used[i];
     }
     return ret;
 }