/*
  * VC3/DNxHD decoder.

  * Copyright (c) 2007 SmartJog S.A., Baptiste Coudurier <baptiste dot coudurier at smartjog dot com>

  *
  * 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
  */
 
 //#define TRACE
 //#define DEBUG
 
 #include "avcodec.h"
 #include "bitstream.h"
 #include "dnxhddata.h"
 #include "dsputil.h"
 
 typedef struct {
     AVCodecContext *avctx;
     AVFrame picture;
     GetBitContext gb;
     int cid;                            ///< compression id
     unsigned int width, height;
     unsigned int mb_width, mb_height;
     uint32_t mb_scan_index[68];         /* max for 1080p */
     int cur_field;                      ///< current interlaced field
     VLC ac_vlc, dc_vlc, run_vlc;
     int last_dc[3];
     DSPContext dsp;
     DECLARE_ALIGNED_16(DCTELEM, blocks[8][64]);
     DECLARE_ALIGNED_8(ScanTable, scantable);
     const CIDEntry *cid_table;
 } DNXHDContext;
 
 #define DNXHD_VLC_BITS 9

 #define DNXHD_DC_VLC_BITS 7

 static av_cold int dnxhd_decode_init(AVCodecContext *avctx)

 {
     DNXHDContext *ctx = avctx->priv_data;
 
     ctx->avctx = avctx;
     dsputil_init(&ctx->dsp, avctx);
     avctx->coded_frame = &ctx->picture;
     ctx->picture.type = FF_I_TYPE;
     return 0;
 }
 
 static int dnxhd_init_vlc(DNXHDContext *ctx, int cid)
 {
     if (!ctx->cid_table) {
         int index;
 

         if ((index = ff_dnxhd_get_cid_table(cid)) < 0) {

             av_log(ctx->avctx, AV_LOG_ERROR, "unsupported cid %d\n", cid);
             return -1;
         }

         ctx->cid_table = &ff_dnxhd_cid_table[index];

         init_vlc(&ctx->ac_vlc, DNXHD_VLC_BITS, 257,

                  ctx->cid_table->ac_bits, 1, 1,
                  ctx->cid_table->ac_codes, 2, 2, 0);

         init_vlc(&ctx->dc_vlc, DNXHD_DC_VLC_BITS, ctx->cid_table->bit_depth+4,

                  ctx->cid_table->dc_bits, 1, 1,
                  ctx->cid_table->dc_codes, 1, 1, 0);

         init_vlc(&ctx->run_vlc, DNXHD_VLC_BITS, 62,

                  ctx->cid_table->run_bits, 1, 1,
                  ctx->cid_table->run_codes, 2, 2, 0);

 
         ff_init_scantable(ctx->dsp.idct_permutation, &ctx->scantable, ff_zigzag_direct);
     }
     return 0;
 }
 

 static int dnxhd_decode_header(DNXHDContext *ctx, const uint8_t *buf, int buf_size, int first_field)

 {
     static const uint8_t header_prefix[] = { 0x00, 0x00, 0x02, 0x80, 0x01 };
     int i;
 
     if (buf_size < 0x280)
         return -1;
 
     if (memcmp(buf, header_prefix, 5)) {
         av_log(ctx->avctx, AV_LOG_ERROR, "error in header\n");
         return -1;
     }

     if (buf[5] & 2) { /* interlaced */
         ctx->cur_field = buf[5] & 1;

         ctx->picture.interlaced_frame = 1;

         ctx->picture.top_field_first = first_field ^ ctx->cur_field;

         av_log(ctx->avctx, AV_LOG_DEBUG, "interlaced %d, cur field %d\n", buf[5] & 3, ctx->cur_field);

     }
 
     ctx->height = AV_RB16(buf + 0x18);
     ctx->width  = AV_RB16(buf + 0x1a);
 

     dprintf(ctx->avctx, "width %d, heigth %d\n", ctx->width, ctx->height);

     if (buf[0x21] & 0x40) {

         av_log(ctx->avctx, AV_LOG_ERROR, "10 bit per component\n");
         return -1;
     }
 
     ctx->cid = AV_RB32(buf + 0x28);

     dprintf(ctx->avctx, "compression id %d\n", ctx->cid);

 
     if (dnxhd_init_vlc(ctx, ctx->cid) < 0)
         return -1;
 

     if (buf_size < ctx->cid_table->coding_unit_size) {

         av_log(ctx->avctx, AV_LOG_ERROR, "incorrect frame size\n");
         return -1;
     }
 
     ctx->mb_width = ctx->width>>4;
     ctx->mb_height = buf[0x16d];
 
     if (ctx->mb_height > 68) {
         av_log(ctx->avctx, AV_LOG_ERROR, "mb height too big\n");
         return -1;
     }
 

     dprintf(ctx->avctx, "mb width %d, mb height %d\n", ctx->mb_width, ctx->mb_height);

     for (i = 0; i < ctx->mb_height; i++) {
         ctx->mb_scan_index[i] = AV_RB32(buf + 0x170 + (i<<2));

         dprintf(ctx->avctx, "mb scan index %d\n", ctx->mb_scan_index[i]);

         if (buf_size < ctx->mb_scan_index[i] + 0x280) {
             av_log(ctx->avctx, AV_LOG_ERROR, "invalid mb scan index\n");
             return -1;
         }
     }
 
     return 0;
 }
 
 static int dnxhd_decode_dc(DNXHDContext *ctx)
 {
     int len;
 
     len = get_vlc2(&ctx->gb, ctx->dc_vlc.table, DNXHD_DC_VLC_BITS, 1);
     return len ? get_xbits(&ctx->gb, len) : 0;
 }
 
 static void dnxhd_decode_dct_block(DNXHDContext *ctx, DCTELEM *block, int n, int qscale)
 {
     int i, j, index, index2;
     int level, component, sign;
     const uint8_t *weigth_matrix;
 
     if (n&2) {
         component = 1 + (n&1);

         weigth_matrix = ctx->cid_table->chroma_weight;

     } else {
         component = 0;

         weigth_matrix = ctx->cid_table->luma_weight;

     }
 
     ctx->last_dc[component] += dnxhd_decode_dc(ctx);
     block[0] = ctx->last_dc[component];
     //av_log(ctx->avctx, AV_LOG_DEBUG, "dc %d\n", block[0]);
     for (i = 1; ; i++) {
         index = get_vlc2(&ctx->gb, ctx->ac_vlc.table, DNXHD_VLC_BITS, 2);
         //av_log(ctx->avctx, AV_LOG_DEBUG, "index %d\n", index);

         level = ctx->cid_table->ac_level[index];

         if (!level) { /* EOB */
             //av_log(ctx->avctx, AV_LOG_DEBUG, "EOB\n");
             return;
         }
         sign = get_sbits(&ctx->gb, 1);
 

         if (ctx->cid_table->ac_index_flag[index]) {
             level += get_bits(&ctx->gb, ctx->cid_table->index_bits)<<6;

         }
 

         if (ctx->cid_table->ac_run_flag[index]) {

             index2 = get_vlc2(&ctx->gb, ctx->run_vlc.table, DNXHD_VLC_BITS, 2);

             i += ctx->cid_table->run[index2];

         }
 

         if (i > 63) {
             av_log(ctx->avctx, AV_LOG_ERROR, "ac tex damaged %d, %d\n", n, i);
             return;
         }
 

         j = ctx->scantable.permutated[i];
         //av_log(ctx->avctx, AV_LOG_DEBUG, "j %d\n", j);
         //av_log(ctx->avctx, AV_LOG_DEBUG, "level %d, weigth %d\n", level, weigth_matrix[i]);
         level = (2*level+1) * qscale * weigth_matrix[i];

         if (ctx->cid_table->bit_depth == 10) {
             if (weigth_matrix[i] != 8)
                 level += 8;
             level >>= 4;
         } else {
             if (weigth_matrix[i] != 32)
                 level += 32;
             level >>= 6;
         }

         //av_log(NULL, AV_LOG_DEBUG, "i %d, j %d, end level %d\n", i, j, level);

         block[j] = (level^sign) - sign;

     }
 }
 
 static int dnxhd_decode_macroblock(DNXHDContext *ctx, int x, int y)
 {
     int dct_linesize_luma   = ctx->picture.linesize[0];
     int dct_linesize_chroma = ctx->picture.linesize[1];
     uint8_t *dest_y, *dest_u, *dest_v;
     int dct_offset;
     int qscale, i;
 
     qscale = get_bits(&ctx->gb, 11);
     skip_bits1(&ctx->gb);
     //av_log(ctx->avctx, AV_LOG_DEBUG, "qscale %d\n", qscale);
 
     for (i = 0; i < 8; i++) {

         ctx->dsp.clear_block(ctx->blocks[i]);

         dnxhd_decode_dct_block(ctx, ctx->blocks[i], i, qscale);
     }

 
     if (ctx->picture.interlaced_frame) {
         dct_linesize_luma   <<= 1;
         dct_linesize_chroma <<= 1;
     }
 

     dest_y = ctx->picture.data[0] + ((y * dct_linesize_luma)   << 4) + (x << 4);
     dest_u = ctx->picture.data[1] + ((y * dct_linesize_chroma) << 4) + (x << 3);
     dest_v = ctx->picture.data[2] + ((y * dct_linesize_chroma) << 4) + (x << 3);
 

     if (ctx->cur_field) {
         dest_y += ctx->picture.linesize[0];
         dest_u += ctx->picture.linesize[1];
         dest_v += ctx->picture.linesize[2];
     }
 

     dct_offset = dct_linesize_luma << 3;
     ctx->dsp.idct_put(dest_y,                  dct_linesize_luma, ctx->blocks[0]);
     ctx->dsp.idct_put(dest_y + 8,              dct_linesize_luma, ctx->blocks[1]);
     ctx->dsp.idct_put(dest_y + dct_offset,     dct_linesize_luma, ctx->blocks[4]);
     ctx->dsp.idct_put(dest_y + dct_offset + 8, dct_linesize_luma, ctx->blocks[5]);
 
     if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {
         dct_offset = dct_linesize_chroma << 3;
         ctx->dsp.idct_put(dest_u,              dct_linesize_chroma, ctx->blocks[2]);
         ctx->dsp.idct_put(dest_v,              dct_linesize_chroma, ctx->blocks[3]);
         ctx->dsp.idct_put(dest_u + dct_offset, dct_linesize_chroma, ctx->blocks[6]);
         ctx->dsp.idct_put(dest_v + dct_offset, dct_linesize_chroma, ctx->blocks[7]);
     }
 
     return 0;
 }
 

 static int dnxhd_decode_macroblocks(DNXHDContext *ctx, const uint8_t *buf, int buf_size)

 {
     int x, y;
     for (y = 0; y < ctx->mb_height; y++) {

         ctx->last_dc[0] =
         ctx->last_dc[1] =

         ctx->last_dc[2] = 1<<(ctx->cid_table->bit_depth+2); // for levels +2^(bitdepth-1)

         init_get_bits(&ctx->gb, buf + ctx->mb_scan_index[y], (buf_size - ctx->mb_scan_index[y]) << 3);
         for (x = 0; x < ctx->mb_width; x++) {
             //START_TIMER;
             dnxhd_decode_macroblock(ctx, x, y);
             //STOP_TIMER("decode macroblock");
         }
     }
     return 0;
 }
 
 static int dnxhd_decode_frame(AVCodecContext *avctx, void *data, int *data_size,

                               const uint8_t *buf, int buf_size)

 {
     DNXHDContext *ctx = avctx->priv_data;
     AVFrame *picture = data;

     int first_field = 1;

     dprintf(avctx, "frame size %d\n", buf_size);

  decode_coding_unit:
     if (dnxhd_decode_header(ctx, buf, buf_size, first_field) < 0)

         return -1;
 
     avctx->pix_fmt = PIX_FMT_YUV422P;
     if (avcodec_check_dimensions(avctx, ctx->width, ctx->height))
         return -1;
     avcodec_set_dimensions(avctx, ctx->width, ctx->height);
 

     if (first_field) {

         if (ctx->picture.data[0])
             avctx->release_buffer(avctx, &ctx->picture);
         if (avctx->get_buffer(avctx, &ctx->picture) < 0) {
             av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
             return -1;
         }

     }

 
     dnxhd_decode_macroblocks(ctx, buf + 0x280, buf_size - 0x280);
 

     if (first_field && ctx->picture.interlaced_frame) {
         buf      += ctx->cid_table->coding_unit_size;
         buf_size -= ctx->cid_table->coding_unit_size;
         first_field = 0;
         goto decode_coding_unit;
     }
 

     *picture = ctx->picture;
     *data_size = sizeof(AVPicture);

     return buf_size;

 }
 

 static av_cold int dnxhd_decode_close(AVCodecContext *avctx)

 {
     DNXHDContext *ctx = avctx->priv_data;
 

     if (ctx->picture.data[0])

         avctx->release_buffer(avctx, &ctx->picture);
     free_vlc(&ctx->ac_vlc);
     free_vlc(&ctx->dc_vlc);
     free_vlc(&ctx->run_vlc);
     return 0;
 }
 
 AVCodec dnxhd_decoder = {
     "dnxhd",
     CODEC_TYPE_VIDEO,
     CODEC_ID_DNXHD,
     sizeof(DNXHDContext),
     dnxhd_decode_init,
     NULL,
     dnxhd_decode_close,
     dnxhd_decode_frame,
     CODEC_CAP_DR1,

     .long_name = NULL_IF_CONFIG_SMALL("VC3/DNxHD"),

 };