/*
  * VC3/DNxHD decoder.

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

  * Copyright (c) 2011 MirriAd Ltd
  *
  * 10 bit support added by MirriAd Ltd, Joseph Artsimovich <joseph@mirriad.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 "libavutil/imgutils.h"

 #include "avcodec.h"

 #include "get_bits.h"

 #include "dnxhddata.h"
 #include "dsputil.h"

 #include "internal.h"

 #include "thread.h"

 typedef struct DNXHDContext {

     AVCodecContext *avctx;
     AVFrame picture;
     GetBitContext gb;

     int64_t 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, int16_t, blocks)[8][64];

     ScanTable scantable;

     const CIDEntry *cid_table;

     int bit_depth; // 8, 10 or 0 if not initialized at all.

     void (*decode_dct_block)(struct DNXHDContext *ctx, int16_t *block,

                              int n, int qscale);

     int last_qscale;
     int luma_scale[64];
     int chroma_scale[64];

 } DNXHDContext;
 
 #define DNXHD_VLC_BITS 9

 #define DNXHD_DC_VLC_BITS 7

 static void dnxhd_decode_dct_block_8(DNXHDContext *ctx, int16_t *block, int n, int qscale);
 static void dnxhd_decode_dct_block_10(DNXHDContext *ctx, int16_t *block, int n, int qscale);

 static av_cold int dnxhd_decode_init(AVCodecContext *avctx)

 {
     DNXHDContext *ctx = avctx->priv_data;
 
     ctx->avctx = avctx;
     avctx->coded_frame = &ctx->picture;

     avcodec_get_frame_defaults(&ctx->picture);

     ctx->picture.type = AV_PICTURE_TYPE_I;

     ctx->picture.key_frame = 1;

     ctx->cid = -1;

     return 0;
 }
 

 static int dnxhd_init_vlc(DNXHDContext *ctx, uint32_t cid)

 {

     if (cid != ctx->cid) {

         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;
         }

         if (ff_dnxhd_cid_table[index].bit_depth != ctx->bit_depth) {
             av_log(ctx->avctx, AV_LOG_ERROR, "bit depth mismatches %d %d\n", ff_dnxhd_cid_table[index].bit_depth, ctx->bit_depth);
             return AVERROR_INVALIDDATA;
         }

         ctx->cid_table = &ff_dnxhd_cid_table[index];

         ff_free_vlc(&ctx->ac_vlc);
         ff_free_vlc(&ctx->dc_vlc);
         ff_free_vlc(&ctx->run_vlc);

         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->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);

         ctx->cid = cid;

     }
     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, cid;

 
     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);
 

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

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

         ctx->avctx->pix_fmt = AV_PIX_FMT_YUV422P10;

         ctx->avctx->bits_per_raw_sample = 10;
         if (ctx->bit_depth != 10) {

             ff_dsputil_init(&ctx->dsp, ctx->avctx);

             ctx->bit_depth = 10;

             ctx->decode_dct_block = dnxhd_decode_dct_block_10;

         }
     } else {

         ctx->avctx->pix_fmt = AV_PIX_FMT_YUV422P;

         ctx->avctx->bits_per_raw_sample = 8;
         if (ctx->bit_depth != 8) {

             ff_dsputil_init(&ctx->dsp, ctx->avctx);

             ctx->bit_depth = 8;

             ctx->decode_dct_block = dnxhd_decode_dct_block_8;

         }

     }
 

     cid = AV_RB32(buf + 0x28);
     av_dlog(ctx->avctx, "compression id %d\n", cid);

     if (dnxhd_init_vlc(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];
 

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

 
     if ((ctx->height+15)>>4 == ctx->mb_height && ctx->picture.interlaced_frame)
         ctx->height <<= 1;
 
     if (ctx->mb_height > 68 ||
         (ctx->mb_height<<ctx->picture.interlaced_frame) > (ctx->height+15)>>4) {
         av_log(ctx->avctx, AV_LOG_ERROR, "mb height too big: %d\n", ctx->mb_height);

         return -1;
     }
 
     for (i = 0; i < ctx->mb_height; i++) {
         ctx->mb_scan_index[i] = AV_RB32(buf + 0x170 + (i<<2));

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

         if (buf_size < ctx->mb_scan_index[i] + 0x280LL) {

             av_log(ctx->avctx, AV_LOG_ERROR, "invalid mb scan index\n");
             return -1;
         }
     }
 
     return 0;
 }
 

 static av_always_inline void dnxhd_decode_dct_block(DNXHDContext *ctx,

                                                     int16_t *block, int n,

                                                     int qscale,
                                                     int index_bits,
                                                     int level_bias,
                                                     int level_shift)

 {

     int i, j, index1, index2, len, flags;

     int level, component, sign;

     const int *scale;

     const uint8_t *weight_matrix;

     const uint8_t *ac_level = ctx->cid_table->ac_level;

     const uint8_t *ac_flags = ctx->cid_table->ac_flags;

     const int eob_index     = ctx->cid_table->eob_index;

     OPEN_READER(bs, &ctx->gb);

 
     if (n&2) {
         component = 1 + (n&1);

         scale = ctx->chroma_scale;

         weight_matrix = ctx->cid_table->chroma_weight;

     } else {
         component = 0;

         scale = ctx->luma_scale;

         weight_matrix = ctx->cid_table->luma_weight;

     }
 

     UPDATE_CACHE(bs, &ctx->gb);
     GET_VLC(len, bs, &ctx->gb, ctx->dc_vlc.table, DNXHD_DC_VLC_BITS, 1);
     if (len) {
         level = GET_CACHE(bs, &ctx->gb);
         LAST_SKIP_BITS(bs, &ctx->gb, len);
         sign  = ~level >> 31;
         level = (NEG_USR32(sign ^ level, len) ^ sign) - sign;
         ctx->last_dc[component] += level;
     }

     block[0] = ctx->last_dc[component];

     i = 0;

     UPDATE_CACHE(bs, &ctx->gb);
     GET_VLC(index1, bs, &ctx->gb, ctx->ac_vlc.table,
             DNXHD_VLC_BITS, 2);
 

     while (index1 != eob_index) {
         level = ac_level[index1];

         flags = ac_flags[index1];

         sign = SHOW_SBITS(bs, &ctx->gb, 1);
         SKIP_BITS(bs, &ctx->gb, 1);
 

         if (flags & 1) {

             level += SHOW_UBITS(bs, &ctx->gb, index_bits) << 7;

             SKIP_BITS(bs, &ctx->gb, index_bits);

         }
 

         if (flags & 2) {

             UPDATE_CACHE(bs, &ctx->gb);
             GET_VLC(index2, bs, &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);

             break;

         }
 

         j = ctx->scantable.permutated[i];

         level *= scale[i];

         if (level_bias < 32 || weight_matrix[i] != level_bias)

             level += level_bias;
         level >>= level_shift;
 

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

 
         UPDATE_CACHE(bs, &ctx->gb);
         GET_VLC(index1, bs, &ctx->gb, ctx->ac_vlc.table,
                 DNXHD_VLC_BITS, 2);

     }

 
     CLOSE_READER(bs, &ctx->gb);
 }
 

 static void dnxhd_decode_dct_block_8(DNXHDContext *ctx, int16_t *block,

                                      int n, int qscale)
 {
     dnxhd_decode_dct_block(ctx, block, n, qscale, 4, 32, 6);
 }
 

 static void dnxhd_decode_dct_block_10(DNXHDContext *ctx, int16_t *block,

                                       int n, int qscale)
 {
     dnxhd_decode_dct_block(ctx, block, n, qscale, 6, 8, 4);

 }
 
 static int dnxhd_decode_macroblock(DNXHDContext *ctx, int x, int y)
 {

     int shift1 = ctx->bit_depth == 10;

     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_y_offset, dct_x_offset;

     int qscale, i;
 
     qscale = get_bits(&ctx->gb, 11);
     skip_bits1(&ctx->gb);
 

     if (qscale != ctx->last_qscale) {
         for (i = 0; i < 64; i++) {
             ctx->luma_scale[i]   = qscale * ctx->cid_table->luma_weight[i];
             ctx->chroma_scale[i] = qscale * ctx->cid_table->chroma_weight[i];
         }
         ctx->last_qscale = qscale;
     }
 

     for (i = 0; i < 8; i++) {

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

         ctx->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 + shift1));
     dest_u = ctx->picture.data[1] + ((y * dct_linesize_chroma) << 4) + (x << (3 + shift1));
     dest_v = ctx->picture.data[2] + ((y * dct_linesize_chroma) << 4) + (x << (3 + shift1));

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

     dct_y_offset = dct_linesize_luma << 3;
     dct_x_offset = 8 << shift1;
     ctx->dsp.idct_put(dest_y,                               dct_linesize_luma, ctx->blocks[0]);
     ctx->dsp.idct_put(dest_y + dct_x_offset,                dct_linesize_luma, ctx->blocks[1]);
     ctx->dsp.idct_put(dest_y + dct_y_offset,                dct_linesize_luma, ctx->blocks[4]);
     ctx->dsp.idct_put(dest_y + dct_y_offset + dct_x_offset, dct_linesize_luma, ctx->blocks[5]);

 
     if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {

         dct_y_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_y_offset, dct_linesize_chroma, ctx->blocks[6]);
         ctx->dsp.idct_put(dest_v + dct_y_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->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 *got_frame,

                               AVPacket *avpkt)

 {

     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;

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

     int first_field = 1;

     int ret;

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

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

         return -1;
 

     if ((avctx->width || avctx->height) &&
         (ctx->width != avctx->width || ctx->height != avctx->height)) {
         av_log(avctx, AV_LOG_WARNING, "frame size changed: %dx%d -> %dx%d\n",
                avctx->width, avctx->height, ctx->width, ctx->height);
         first_field = 1;
     }
 

     if (av_image_check_size(ctx->width, ctx->height, 0, avctx))

         return -1;
     avcodec_set_dimensions(avctx, ctx->width, ctx->height);
 

     if (first_field) {

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

             ff_thread_release_buffer(avctx, &ctx->picture);
         if ((ret = ff_thread_get_buffer(avctx, &ctx->picture)) < 0) {

             av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

             return ret;

         }

     }

 
     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;

     *got_frame = 1;

     return avpkt->size;

 }
 

 static av_cold int dnxhd_decode_close(AVCodecContext *avctx)

 {
     DNXHDContext *ctx = avctx->priv_data;
 

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

         ff_thread_release_buffer(avctx, &ctx->picture);

     ff_free_vlc(&ctx->ac_vlc);
     ff_free_vlc(&ctx->dc_vlc);
     ff_free_vlc(&ctx->run_vlc);

     return 0;
 }
 

 AVCodec ff_dnxhd_decoder = {

     .name           = "dnxhd",
     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_DNXHD,

     .priv_data_size = sizeof(DNXHDContext),
     .init           = dnxhd_decode_init,
     .close          = dnxhd_decode_close,
     .decode         = dnxhd_decode_frame,

     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS,

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

 };