/*
  * ClearVideo decoder

  * Copyright (c) 2012-2018 Konstantin Shishkov

  *
  * 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
  */
 
 /**
  * @file
  * ClearVideo decoder
  */
 
 #include "avcodec.h"

 #include "bytestream.h"
 #include "get_bits.h"

 #include "idctdsp.h"
 #include "internal.h"

 #include "mathops.h"
 #include "clearvideodata.h"
 
 typedef struct LevelCodes {
     uint16_t    mv_esc;
     uint16_t    bias_esc;
     VLC         flags_cb;
     VLC         mv_cb;
     VLC         bias_cb;
 } LevelCodes;
 
 typedef struct MV {
     int16_t x, y;
 } MV;
 
 static const MV zero_mv = { 0 };
 
 typedef struct MVInfo {
     int mb_w;
     int mb_h;
     int mb_size;
     int mb_stride;
     int top;
     MV  *mv;
 } MVInfo;
 
 typedef struct TileInfo {
     uint16_t        flags;
     int16_t         bias;
     MV              mv;
     struct TileInfo *child[4];
 } TileInfo;

 
 typedef struct CLVContext {
     AVCodecContext *avctx;
     IDCTDSPContext idsp;
     AVFrame        *pic;

     AVFrame        *prev;

     GetBitContext  gb;
     int            mb_width, mb_height;

     int            pmb_width, pmb_height;
     MVInfo         mvi;
     int            tile_size;
     int            tile_shift;

     VLC            dc_vlc, ac_vlc;

     LevelCodes     ylev[4], ulev[3], vlev[3];

     int            luma_dc_quant, chroma_dc_quant, ac_quant;
     DECLARE_ALIGNED(16, int16_t, block)[64];
     int            top_dc[3], left_dc[4];
 } CLVContext;
 
 static inline int decode_block(CLVContext *ctx, int16_t *blk, int has_ac,
                                int ac_quant)
 {
     GetBitContext *gb = &ctx->gb;
     int idx = 1, last = 0, val, skip;
 
     memset(blk, 0, sizeof(*blk) * 64);
     blk[0] = get_vlc2(gb, ctx->dc_vlc.table, 9, 3);
     if (blk[0] < 0)
         return AVERROR_INVALIDDATA;
     blk[0] -= 63;
 
     if (!has_ac)
         return 0;
 
     while (idx < 64 && !last) {
         val = get_vlc2(gb, ctx->ac_vlc.table, 9, 2);
         if (val < 0)
             return AVERROR_INVALIDDATA;
         if (val != 0x1BFF) {
             last =  val >> 12;
             skip = (val >> 4) & 0xFF;
             val &= 0xF;
             if (get_bits1(gb))
                 val = -val;
         } else {
             last = get_bits1(gb);
             skip = get_bits(gb, 6);
             val  = get_sbits(gb, 8);
         }
         if (val) {
             int aval = FFABS(val), sign = val < 0;
             val = ac_quant * (2 * aval + 1);
             if (!(ac_quant & 1))
                 val--;
             if (sign)
                 val = -val;
         }
         idx += skip;
         if (idx >= 64)
             return AVERROR_INVALIDDATA;
         blk[ff_zigzag_direct[idx++]] = val;
     }
 
     return (idx <= 64 && last) ? 0 : -1;
 }
 
 #define DCT_TEMPLATE(blk, step, bias, shift, dshift, OP)                \

     const int t0 = OP(2841 * blk[1 * step] +  565 * blk[7 * step]);     \
     const int t1 = OP( 565 * blk[1 * step] - 2841 * blk[7 * step]);     \
     const int t2 = OP(1609 * blk[5 * step] + 2408 * blk[3 * step]);     \
     const int t3 = OP(2408 * blk[5 * step] - 1609 * blk[3 * step]);     \
     const int t4 = OP(1108 * blk[2 * step] - 2676 * blk[6 * step]);     \
     const int t5 = OP(2676 * blk[2 * step] + 1108 * blk[6 * step]);     \

     const int t6 = ((blk[0 * step] + blk[4 * step]) * (1 << dshift)) + bias;  \
     const int t7 = ((blk[0 * step] - blk[4 * step]) * (1 << dshift)) + bias;  \

     const int t8 = t0 + t2;                                             \
     const int t9 = t0 - t2;                                             \

     const int tA = (int)(181U * (t9 + (t1 - t3)) + 0x80) >> 8;          \
     const int tB = (int)(181U * (t9 - (t1 - t3)) + 0x80) >> 8;          \

     const int tC = t1 + t3;                                             \
                                                                         \
     blk[0 * step] = (t6 + t5 + t8) >> shift;                            \
     blk[1 * step] = (t7 + t4 + tA) >> shift;                            \
     blk[2 * step] = (t7 - t4 + tB) >> shift;                            \
     blk[3 * step] = (t6 - t5 + tC) >> shift;                            \
     blk[4 * step] = (t6 - t5 - tC) >> shift;                            \
     blk[5 * step] = (t7 - t4 - tB) >> shift;                            \
     blk[6 * step] = (t7 + t4 - tA) >> shift;                            \
     blk[7 * step] = (t6 + t5 - t8) >> shift;                            \
 
 #define ROP(x) x
 #define COP(x) (((x) + 4) >> 3)
 
 static void clv_dct(int16_t *block)
 {
     int i;
     int16_t *ptr;
 
     ptr = block;
     for (i = 0; i < 8; i++) {
         DCT_TEMPLATE(ptr, 1, 0x80, 8, 11, ROP);
         ptr += 8;
     }
 
     ptr = block;
     for (i = 0; i < 8; i++) {
         DCT_TEMPLATE(ptr, 8, 0x2000, 14, 8, COP);
         ptr++;
     }
 }
 
 static int decode_mb(CLVContext *c, int x, int y)
 {

     int i, has_ac[6], off;

 
     for (i = 0; i < 6; i++)
         has_ac[i] = get_bits1(&c->gb);
 
     off = x * 16 + y * 16 * c->pic->linesize[0];
     for (i = 0; i < 4; i++) {
         if (decode_block(c, c->block, has_ac[i], c->ac_quant) < 0)
             return AVERROR_INVALIDDATA;
         if (!x && !(i & 1)) {
             c->block[0] += c->top_dc[0];
             c->top_dc[0] = c->block[0];
         } else {
             c->block[0] += c->left_dc[(i & 2) >> 1];
         }
         c->left_dc[(i & 2) >> 1] = c->block[0];
         c->block[0]             *= c->luma_dc_quant;
         clv_dct(c->block);
         if (i == 2)
             off += c->pic->linesize[0] * 8;

         c->idsp.put_pixels_clamped(c->block,
                                    c->pic->data[0] + off + (i & 1) * 8,

                                    c->pic->linesize[0]);
     }
 
     off = x * 8 + y * 8 * c->pic->linesize[1];
     for (i = 1; i < 3; i++) {
         if (decode_block(c, c->block, has_ac[i + 3], c->ac_quant) < 0)
             return AVERROR_INVALIDDATA;
         if (!x) {
             c->block[0] += c->top_dc[i];
             c->top_dc[i] = c->block[0];
         } else {
             c->block[0] += c->left_dc[i + 1];
         }
         c->left_dc[i + 1] = c->block[0];
         c->block[0]      *= c->chroma_dc_quant;
         clv_dct(c->block);
         c->idsp.put_pixels_clamped(c->block, c->pic->data[i] + off,
                                    c->pic->linesize[i]);
     }
 
     return 0;
 }
 

 static int copy_block(AVCodecContext *avctx, AVFrame *dst, AVFrame *src,
                       int plane, int x, int y, int dx, int dy, int size)
 {
     int shift = plane > 0;
     int sx = x + dx;
     int sy = y + dy;
     int sstride, dstride, soff, doff;
     uint8_t *sbuf, *dbuf;
     int i;
 
     if (x < 0 || sx < 0 || y < 0 || sy < 0 ||
         x + size > avctx->coded_width >> shift ||
         y + size > avctx->coded_height >> shift ||
         sx + size > avctx->coded_width >> shift ||
         sy + size > avctx->coded_height >> shift)
         return AVERROR_INVALIDDATA;
 
     sstride = src->linesize[plane];
     dstride = dst->linesize[plane];
     soff    = sx + sy * sstride;
     sbuf    = src->data[plane];
     doff    = x + y * dstride;
     dbuf    = dst->data[plane];
 
     for (i = 0; i < size; i++) {
         uint8_t *dptr = &dbuf[doff];
         uint8_t *sptr = &sbuf[soff];
 
         memcpy(dptr, sptr, size);
         doff += dstride;
         soff += sstride;
     }
 
     return 0;
 }
 
 static int copyadd_block(AVCodecContext *avctx, AVFrame *dst, AVFrame *src,
                          int plane, int x, int y, int dx, int dy, int size, int bias)
 {
     int shift = plane > 0;
     int sx = x + dx;
     int sy = y + dy;
     int sstride   = src->linesize[plane];
     int dstride   = dst->linesize[plane];
     int soff      = sx + sy * sstride;
     uint8_t *sbuf = src->data[plane];
     int doff      = x + y * dstride;
     uint8_t *dbuf = dst->data[plane];
     int i, j;
 
     if (x < 0 || sx < 0 || y < 0 || sy < 0 ||
         x + size > avctx->coded_width >> shift ||
         y + size > avctx->coded_height >> shift ||
         sx + size > avctx->coded_width >> shift ||
         sy + size > avctx->coded_height >> shift)
         return AVERROR_INVALIDDATA;
 
     for (j = 0; j < size; j++) {
         uint8_t *dptr = &dbuf[doff];
         uint8_t *sptr = &sbuf[soff];
 
         for (i = 0; i < size; i++) {
             int val = sptr[i] + bias;
 
             dptr[i] = av_clip_uint8(val);
         }
 
         doff += dstride;
         soff += sstride;
     }
 
     return 0;
 }
 
 static MV mvi_predict(MVInfo *mvi, int mb_x, int mb_y, MV diff)
 {
     MV res, pred_mv;

     int left_mv, right_mv, top_mv, bot_mv;

 
     if (mvi->top) {
         if (mb_x > 0) {
             pred_mv = mvi->mv[mvi->mb_stride + mb_x - 1];
         } else {
             pred_mv = zero_mv;
         }
     } else if ((mb_x == 0) || (mb_x == mvi->mb_w - 1)) {
         pred_mv = mvi->mv[mb_x];
     } else {
         MV A = mvi->mv[mvi->mb_stride + mb_x - 1];
         MV B = mvi->mv[                 mb_x    ];
         MV C = mvi->mv[                 mb_x + 1];
         pred_mv.x = mid_pred(A.x, B.x, C.x);
         pred_mv.y = mid_pred(A.y, B.y, C.y);
     }
 
     res = pred_mv;
 

     left_mv = -((mb_x * mvi->mb_size));
     right_mv = ((mvi->mb_w - mb_x - 1) * mvi->mb_size);

     if (res.x < left_mv) {
         res.x = left_mv;
     }
     if (res.x > right_mv) {
         res.x = right_mv;
     }

     top_mv = -((mb_y * mvi->mb_size));
     bot_mv = ((mvi->mb_h - mb_y - 1) * mvi->mb_size);

     if (res.y < top_mv) {
         res.y = top_mv;
     }
     if (res.y > bot_mv) {
         res.y = bot_mv;
     }
 
     mvi->mv[mvi->mb_stride + mb_x].x = res.x + diff.x;
     mvi->mv[mvi->mb_stride + mb_x].y = res.y + diff.y;
 
     return res;
 }
 
 static void mvi_reset(MVInfo *mvi, int mb_w, int mb_h, int mb_size)
 {
     mvi->top       = 1;
     mvi->mb_w      = mb_w;
     mvi->mb_h      = mb_h;
     mvi->mb_size   = mb_size;
     mvi->mb_stride = mb_w;
     memset(mvi->mv, 0, sizeof(MV) * mvi->mb_stride * 2);
 }
 
 static void mvi_update_row(MVInfo *mvi)
 {
     int i;
 
     mvi->top = 0;
     for (i = 0 ; i < mvi->mb_stride; i++) {
         mvi->mv[i] = mvi->mv[mvi->mb_stride + i];
     }
 }
 
 static TileInfo* decode_tile_info(GetBitContext *gb, LevelCodes *lc, int level)
 {
     TileInfo *ti;
     int i, flags = 0;
     int16_t bias = 0;
     MV mv = { 0 };
 
     if (lc[level].flags_cb.table) {
         flags = get_vlc2(gb, lc[level].flags_cb.table, lc[level].flags_cb.bits, 2);
     }
 
     if (lc[level].mv_cb.table) {
         uint16_t mv_code = get_vlc2(gb, lc[level].mv_cb.table, lc[level].mv_cb.bits, 3);
 
         if (mv_code != lc[level].mv_esc) {
             mv.x = (int8_t)(mv_code & 0xff);
             mv.y = (int8_t)(mv_code >> 8);
         } else {
             mv.x = get_sbits(gb, 8);
             mv.y = get_sbits(gb, 8);
         }
     }
 
     if (lc[level].bias_cb.table) {
         uint16_t bias_val = get_vlc2(gb, lc[level].bias_cb.table, lc[level].bias_cb.bits, 2);
 
         if (bias_val != lc[level].bias_esc) {
             bias = (int16_t)(bias_val);
         } else {
             bias = get_sbits(gb, 16);
         }
     }
 
     ti = av_calloc(1, sizeof(*ti));
     if (!ti)
         return NULL;
 
     ti->flags = flags;
     ti->mv = mv;
     ti->bias = bias;
 
     if (ti->flags) {
         for (i = 0; i < 4; i++) {
             if (ti->flags & (1 << i)) {
                 TileInfo *subti = decode_tile_info(gb, lc, level + 1);
                 ti->child[i] = subti;
             }
         }
     }
 
     return ti;
 }
 
 static int tile_do_block(AVCodecContext *avctx, AVFrame *dst, AVFrame *src,
                          int plane, int x, int y, int dx, int dy, int size, int bias)
 {
     int ret;
 
     if (!bias) {
         ret = copy_block(avctx, dst, src, plane, x, y, dx, dy, size);
     } else {
         ret = copyadd_block(avctx, dst, src, plane, x, y, dx, dy, size, bias);
     }
 
     return ret;
 }
 
 static int restore_tree(AVCodecContext *avctx, AVFrame *dst, AVFrame *src,
                         int plane, int x, int y, int size,
                         TileInfo *tile, MV root_mv)
 {
     int ret;
     MV mv;
 
     mv.x = root_mv.x + tile->mv.x;
     mv.y = root_mv.y + tile->mv.y;
 
     if (!tile->flags) {
         ret = tile_do_block(avctx, dst, src, plane, x, y, mv.x, mv.y, size, tile->bias);
     } else {
         int i, hsize = size >> 1;
 
         for (i = 0; i < 4; i++) {
             int xoff = (i & 2) == 0 ? 0 : hsize;
             int yoff = (i & 1) == 0 ? 0 : hsize;
 
             if (tile->child[i]) {
                 ret = restore_tree(avctx, dst, src, plane, x + xoff, y + yoff, hsize, tile->child[i], root_mv);
                 av_freep(&tile->child[i]);
             } else {
                 ret = tile_do_block(avctx, dst, src, plane, x + xoff, y + yoff, mv.x, mv.y, hsize, tile->bias);
             }
         }
     }
 
     return ret;
 }
 
 static void extend_edges(AVFrame *buf, int tile_size)
 {
     int comp, i, j;
 
     for (comp = 0; comp < 3; comp++) {
         int shift = comp > 0;
         int w = buf->width  >> shift;
         int h = buf->height >> shift;
         int size = comp == 0 ? tile_size : tile_size >> 1;
         int stride = buf->linesize[comp];
         uint8_t *framebuf = buf->data[comp];
 
         int right  = size - (w & (size - 1));
         int bottom = size - (h & (size - 1));
 
         if ((right == size) && (bottom == size)) {
             return;
         }
         if (right != size) {
             int off = w;
             for (j = 0; j < h; j++) {
                 for (i = 0; i < right; i++) {
                     framebuf[off + i] = 0x80;
                 }
                 off += stride;
             }
         }
         if (bottom != size) {
             int off = h * stride;
             for (j = 0; j < bottom; j++) {
                 for (i = 0; i < stride; i++) {
                     framebuf[off + i] = 0x80;
                 }
                 off += stride;
             }
         }
     }
 }
 

 static int clv_decode_frame(AVCodecContext *avctx, void *data,
                             int *got_frame, AVPacket *avpkt)
 {
     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;
     CLVContext *c = avctx->priv_data;
     GetByteContext gb;
     uint32_t frame_type;

     int i, j, ret;

     int mb_ret = 0;

 
     bytestream2_init(&gb, buf, buf_size);

     if (avctx->codec_tag == MKTAG('C', 'L', 'V', '1')) {

         int skip = bytestream2_get_byte(&gb);
         bytestream2_skip(&gb, (skip + 1) * 8);
     }
 
     frame_type = bytestream2_get_byte(&gb);
 

     if ((frame_type & 0x7f) == 0x30) {
         if ((ret = ff_reget_buffer(avctx, c->pic)) < 0)
             return ret;
 
         c->pic->key_frame = 0;
         c->pic->pict_type = AV_PICTURE_TYPE_P;
     } else if (frame_type & 0x2) {

         if (buf_size < c->mb_width * c->mb_height) {
             av_log(avctx, AV_LOG_ERROR, "Packet too small\n");
             return AVERROR_INVALIDDATA;
         }
 

         if ((ret = ff_reget_buffer(avctx, c->pic)) < 0)
             return ret;
 

         c->pic->key_frame = 1;
         c->pic->pict_type = AV_PICTURE_TYPE_I;

         bytestream2_get_be32(&gb); // frame size;
         c->ac_quant        = bytestream2_get_byte(&gb);
         c->luma_dc_quant   = 32;
         c->chroma_dc_quant = 32;
 
         if ((ret = init_get_bits8(&c->gb, buf + bytestream2_tell(&gb),

                                   buf_size - bytestream2_tell(&gb))) < 0)

             return ret;
 
         for (i = 0; i < 3; i++)
             c->top_dc[i] = 32;
         for (i = 0; i < 4; i++)
             c->left_dc[i] = 32;
 
         for (j = 0; j < c->mb_height; j++) {
             for (i = 0; i < c->mb_width; i++) {

                 ret = decode_mb(c, i, j);
                 if (ret < 0)
                     mb_ret = ret;

             }
         }

         extend_edges(c->pic, c->tile_size);
     } else {
         int plane;

         if (c->pmb_width * c->pmb_height > 8LL*(buf_size - bytestream2_tell(&gb)))
             return AVERROR_INVALIDDATA;
 

         if ((ret = ff_reget_buffer(avctx, c->pic)) < 0)

             return ret;

         ret = av_frame_copy(c->pic, c->prev);
         if (ret < 0)
             return ret;
 
         if ((ret = init_get_bits8(&c->gb, buf + bytestream2_tell(&gb),
                                   buf_size - bytestream2_tell(&gb))) < 0)
             return ret;
 
         mvi_reset(&c->mvi, c->pmb_width, c->pmb_height, 1 << c->tile_shift);
 
         for (j = 0; j < c->pmb_height; j++) {
             for (i = 0; i < c->pmb_width; i++) {

                 if (get_bits_left(&c->gb) <= 0)
                     return AVERROR_INVALIDDATA;

                 if (get_bits1(&c->gb)) {
                     MV mv = mvi_predict(&c->mvi, i, j, zero_mv);
 
                     for (plane = 0; plane < 3; plane++) {
                         int16_t x = plane == 0 ? i << c->tile_shift : i << (c->tile_shift - 1);
                         int16_t y = plane == 0 ? j << c->tile_shift : j << (c->tile_shift - 1);
                         int16_t size = plane == 0 ? 1 << c->tile_shift : 1 << (c->tile_shift - 1);
                         int16_t mx = plane == 0 ? mv.x : mv.x / 2;
                         int16_t my = plane == 0 ? mv.y : mv.y / 2;
 
                         ret = copy_block(avctx, c->pic, c->prev, plane, x, y, mx, my, size);
                         if (ret < 0)
                             mb_ret = ret;
                     }
                 } else {
                     int x = i << c->tile_shift;
                     int y = j << c->tile_shift;
                     int size = 1 << c->tile_shift;
                     TileInfo *tile;
                     MV mv, cmv;
 
                     tile = decode_tile_info(&c->gb, c->ylev, 0);
                     if (!tile)
                         return AVERROR(ENOMEM);
                     mv = mvi_predict(&c->mvi, i, j, tile->mv);
                     ret = restore_tree(avctx, c->pic, c->prev, 0, x, y, size, tile, mv);
                     if (ret < 0)
                         mb_ret = ret;
                     x = i << (c->tile_shift - 1);
                     y = j << (c->tile_shift - 1);
                     size = 1 << (c->tile_shift - 1);
                     cmv.x = mv.x + tile->mv.x;
                     cmv.y = mv.y + tile->mv.y;
                     cmv.x /= 2;
                     cmv.y /= 2;
                     av_freep(&tile);
                     tile = decode_tile_info(&c->gb, c->ulev, 0);
                     if (!tile)
                         return AVERROR(ENOMEM);
                     ret = restore_tree(avctx, c->pic, c->prev, 1, x, y, size, tile, cmv);
                     if (ret < 0)
                         mb_ret = ret;
                     av_freep(&tile);
                     tile = decode_tile_info(&c->gb, c->vlev, 0);
                     if (!tile)
                         return AVERROR(ENOMEM);
                     ret = restore_tree(avctx, c->pic, c->prev, 2, x, y, size, tile, cmv);
                     if (ret < 0)
                         mb_ret = ret;
                     av_freep(&tile);
                 }
             }
             mvi_update_row(&c->mvi);
         }
         extend_edges(c->pic, c->tile_size);
 
         c->pic->key_frame = 0;
         c->pic->pict_type = AV_PICTURE_TYPE_P;

     }

     if ((ret = av_frame_ref(data, c->pic)) < 0)
         return ret;
 
     FFSWAP(AVFrame *, c->pic, c->prev);
 
     *got_frame = 1;
 

     return mb_ret < 0 ? mb_ret : buf_size;

 }
 
 static av_cold int clv_decode_init(AVCodecContext *avctx)
 {

     CLVContext *const c = avctx->priv_data;

     int ret, w, h;
 
     if (avctx->extradata_size == 110) {
         c->tile_size = AV_RL32(&avctx->extradata[94]);
     } else if (avctx->extradata_size == 150) {
         c->tile_size = AV_RB32(&avctx->extradata[134]);

     } else if (!avctx->extradata_size) {
         c->tile_size = 16;

     } else {
         av_log(avctx, AV_LOG_ERROR, "Unsupported extradata size: %d\n", avctx->extradata_size);
         return AVERROR_INVALIDDATA;
     }
 
     c->tile_shift = av_log2(c->tile_size);

     if (1U << c->tile_shift != c->tile_size) {

         av_log(avctx, AV_LOG_ERROR, "Tile size: %d, is not power of 2.\n", c->tile_size);
         return AVERROR_INVALIDDATA;
     }

 
     avctx->pix_fmt = AV_PIX_FMT_YUV420P;

     w = avctx->width;
     h = avctx->height;
     ret = ff_set_dimensions(avctx, FFALIGN(w, 1 << c->tile_shift), FFALIGN(h, 1 << c->tile_shift));
     if (ret < 0)
         return ret;
     avctx->width  = w;
     avctx->height = h;

     c->avctx           = avctx;
     c->mb_width        = FFALIGN(avctx->width,  16) >> 4;
     c->mb_height       = FFALIGN(avctx->height, 16) >> 4;

     c->pmb_width       = (w + c->tile_size - 1) >> c->tile_shift;
     c->pmb_height      = (h + c->tile_size - 1) >> c->tile_shift;

     c->pic             = av_frame_alloc();

     c->prev            = av_frame_alloc();
     c->mvi.mv          = av_calloc(c->pmb_width * 2, sizeof(*c->mvi.mv));
     if (!c->pic || !c->prev || !c->mvi.mv)

         return AVERROR(ENOMEM);
 
     ff_idctdsp_init(&c->idsp, avctx);
     ret = init_vlc(&c->dc_vlc, 9, NUM_DC_CODES,
                    clv_dc_bits,  1, 1,
                    clv_dc_codes, 1, 1, 0);
     if (ret) {
         av_log(avctx, AV_LOG_ERROR, "Error initialising DC VLC\n");
         return ret;
     }
     ret = ff_init_vlc_sparse(&c->ac_vlc, 9, NUM_AC_CODES,
                              clv_ac_bits,  1, 1,
                              clv_ac_codes, 1, 1,
                              clv_ac_syms,  2, 2, 0);
     if (ret) {
         av_log(avctx, AV_LOG_ERROR, "Error initialising AC VLC\n");
         return ret;
     }
 

     ret = init_vlc(&c->ylev[0].flags_cb, 9, FF_ARRAY_ELEMS(clv_flagsy_0_bits),
                    clv_flagsy_0_bits,  1, 1,
                    clv_flagsy_0_codes, 2, 2, 0);
     if (ret)
         return ret;
 
     ret = init_vlc(&c->ylev[1].flags_cb, 9, FF_ARRAY_ELEMS(clv_flagsy_1_bits),
                    clv_flagsy_1_bits,  1, 1,
                    clv_flagsy_1_codes, 2, 2, 0);
     if (ret)
         return ret;
 
     ret = init_vlc(&c->ylev[2].flags_cb, 9, FF_ARRAY_ELEMS(clv_flagsy_2_bits),
                    clv_flagsy_2_bits,  1, 1,
                    clv_flagsy_2_codes, 2, 2, 0);
     if (ret)
         return ret;
 
     ret = init_vlc(&c->ulev[0].flags_cb, 9, FF_ARRAY_ELEMS(clv_flagsu_0_bits),
                    clv_flagsu_0_bits,  1, 1,
                    clv_flagsu_0_codes, 2, 2, 0);
     if (ret)
         return ret;
 
     ret = init_vlc(&c->ulev[1].flags_cb, 9, FF_ARRAY_ELEMS(clv_flagsu_1_bits),
                    clv_flagsu_1_bits,  1, 1,
                    clv_flagsu_1_codes, 2, 2, 0);
     if (ret)
         return ret;
 
     ret = init_vlc(&c->vlev[0].flags_cb, 9, FF_ARRAY_ELEMS(clv_flagsv_0_bits),
                    clv_flagsv_0_bits,  1, 1,
                    clv_flagsv_0_codes, 2, 2, 0);
     if (ret)
         return ret;
 
     ret = init_vlc(&c->vlev[1].flags_cb, 9, FF_ARRAY_ELEMS(clv_flagsv_1_bits),
                    clv_flagsv_1_bits,  1, 1,
                    clv_flagsv_1_codes, 2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->ylev[0].mv_cb, 9, FF_ARRAY_ELEMS(clv_mvy_0_bits),
                              clv_mvy_0_bits,  1, 1,
                              clv_mvy_0_codes, 2, 2,
                              clv_mvy_0_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->ylev[1].mv_cb, 9, FF_ARRAY_ELEMS(clv_mvy_1_bits),
                              clv_mvy_1_bits,  1, 1,
                              clv_mvy_1_codes, 2, 2,
                              clv_mvy_1_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->ylev[2].mv_cb, 9, FF_ARRAY_ELEMS(clv_mvy_2_bits),
                              clv_mvy_2_bits,  1, 1,
                              clv_mvy_2_codes, 2, 2,
                              clv_mvy_2_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->ylev[3].mv_cb, 9, FF_ARRAY_ELEMS(clv_mvy_3_bits),
                              clv_mvy_3_bits,  1, 1,
                              clv_mvy_3_codes, 2, 2,
                              clv_mvy_3_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->ulev[1].mv_cb, 9, FF_ARRAY_ELEMS(clv_mvu_1_bits),
                              clv_mvu_1_bits,  1, 1,
                              clv_mvu_1_codes, 2, 2,
                              clv_mvu_1_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->ulev[2].mv_cb, 9, FF_ARRAY_ELEMS(clv_mvu_2_bits),
                              clv_mvu_2_bits,  1, 1,
                              clv_mvu_2_codes, 2, 2,
                              clv_mvu_2_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->vlev[1].mv_cb, 9, FF_ARRAY_ELEMS(clv_mvv_1_bits),
                              clv_mvv_1_bits,  1, 1,
                              clv_mvv_1_codes, 2, 2,
                              clv_mvv_1_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->vlev[2].mv_cb, 9, FF_ARRAY_ELEMS(clv_mvv_2_bits),
                              clv_mvv_2_bits,  1, 1,
                              clv_mvv_2_codes, 2, 2,
                              clv_mvv_2_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->ylev[1].bias_cb, 9, FF_ARRAY_ELEMS(clv_biasy_1_bits),
                              clv_biasy_1_bits,  1, 1,
                              clv_biasy_1_codes, 2, 2,
                              clv_biasy_1_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->ylev[2].bias_cb, 9, FF_ARRAY_ELEMS(clv_biasy_2_bits),
                              clv_biasy_2_bits,  1, 1,
                              clv_biasy_2_codes, 2, 2,
                              clv_biasy_2_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->ylev[3].bias_cb, 9, FF_ARRAY_ELEMS(clv_biasy_3_bits),
                              clv_biasy_3_bits,  1, 1,
                              clv_biasy_3_codes, 2, 2,
                              clv_biasy_3_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->ulev[1].bias_cb, 9, FF_ARRAY_ELEMS(clv_biasu_1_bits),
                              clv_biasu_1_bits,  1, 1,
                              clv_biasu_1_codes, 2, 2,
                              clv_biasu_1_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->ulev[2].bias_cb, 9, FF_ARRAY_ELEMS(clv_biasu_2_bits),
                              clv_biasu_2_bits,  1, 1,
                              clv_biasu_2_codes, 2, 2,
                              clv_biasu_2_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->vlev[1].bias_cb, 9, FF_ARRAY_ELEMS(clv_biasv_1_bits),
                              clv_biasv_1_bits,  1, 1,
                              clv_biasv_1_codes, 2, 2,
                              clv_biasv_1_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     ret = ff_init_vlc_sparse(&c->vlev[2].bias_cb, 9, FF_ARRAY_ELEMS(clv_biasv_2_bits),
                              clv_biasv_2_bits,  1, 1,
                              clv_biasv_2_codes, 2, 2,
                              clv_biasv_2_syms,  2, 2, 0);
     if (ret)
         return ret;
 
     c->ylev[0].mv_esc = 0x0909;
     c->ylev[1].mv_esc = 0x0A0A;
     c->ylev[2].mv_esc = 0x1010;
     c->ylev[3].mv_esc = 0x1313;
     c->ulev[1].mv_esc = 0x0808;
     c->ulev[2].mv_esc = 0x0B0B;
     c->vlev[1].mv_esc = 0x0808;
     c->vlev[2].mv_esc = 0x0B0B;
 
     c->ylev[1].bias_esc = 0x100;
     c->ylev[2].bias_esc = 0x100;
     c->ylev[3].bias_esc = 0x100;
     c->ulev[1].bias_esc = 0x100;
     c->ulev[2].bias_esc = 0x100;
     c->vlev[1].bias_esc = 0x100;
     c->vlev[2].bias_esc = 0x100;
 

     return 0;
 }
 
 static av_cold int clv_decode_end(AVCodecContext *avctx)
 {

     CLVContext *const c = avctx->priv_data;

     int i;

     av_frame_free(&c->prev);

     av_frame_free(&c->pic);
 

     av_freep(&c->mvi.mv);
 

     ff_free_vlc(&c->dc_vlc);
     ff_free_vlc(&c->ac_vlc);

     for (i = 0; i < 4; i++) {
         ff_free_vlc(&c->ylev[i].mv_cb);
         ff_free_vlc(&c->ylev[i].flags_cb);
         ff_free_vlc(&c->ylev[i].bias_cb);
     }
     for (i = 0; i < 3; i++) {
         ff_free_vlc(&c->ulev[i].mv_cb);
         ff_free_vlc(&c->ulev[i].flags_cb);
         ff_free_vlc(&c->ulev[i].bias_cb);
         ff_free_vlc(&c->vlev[i].mv_cb);
         ff_free_vlc(&c->vlev[i].flags_cb);
         ff_free_vlc(&c->vlev[i].bias_cb);
     }

 
     return 0;
 }
 
 AVCodec ff_clearvideo_decoder = {
     .name           = "clearvideo",

     .long_name      = NULL_IF_CONFIG_SMALL("Iterated Systems ClearVideo"),

     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_CLEARVIDEO,
     .priv_data_size = sizeof(CLVContext),
     .init           = clv_decode_init,
     .close          = clv_decode_end,
     .decode         = clv_decode_frame,

     .capabilities   = AV_CODEC_CAP_DR1,

     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,

 };