/*
  * Copyright (C) 2003 the ffmpeg project
  *
  * 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

  * id RoQ Video Decoder by Dr. Tim Ferguson
  * For more information about the id RoQ format, visit:

  *   http://www.csse.monash.edu.au/~timf/
  */
 

 #include "libavutil/avassert.h"

 #include "avcodec.h"
 #include "bytestream.h"
 #include "roqvideo.h"
 
 static void roqvideo_decode_frame(RoqContext *ri)
 {
     unsigned int chunk_id = 0, chunk_arg = 0;
     unsigned long chunk_size = 0;
     int i, j, k, nv1, nv2, vqflg = 0, vqflg_pos = -1;

     int vqid, xpos, ypos, xp, yp, x, y, mx, my;

     int frame_stats[2][4] = {{0},{0}};
     roq_qcell *qcell;

     int64_t chunk_start;

     while (bytestream2_get_bytes_left(&ri->gb) >= 8) {

         chunk_id   = bytestream2_get_le16(&ri->gb);

         chunk_size = bytestream2_get_le32(&ri->gb);

         chunk_arg  = bytestream2_get_le16(&ri->gb);

 
         if(chunk_id == RoQ_QUAD_VQ)
             break;
         if(chunk_id == RoQ_QUAD_CODEBOOK) {
             if((nv1 = chunk_arg >> 8) == 0)
                 nv1 = 256;
             if((nv2 = chunk_arg & 0xff) == 0 && nv1 * 6 < chunk_size)
                 nv2 = 256;
             for(i = 0; i < nv1; i++) {

                 ri->cb2x2[i].y[0] = bytestream2_get_byte(&ri->gb);
                 ri->cb2x2[i].y[1] = bytestream2_get_byte(&ri->gb);
                 ri->cb2x2[i].y[2] = bytestream2_get_byte(&ri->gb);
                 ri->cb2x2[i].y[3] = bytestream2_get_byte(&ri->gb);

                 ri->cb2x2[i].u    = bytestream2_get_byte(&ri->gb);
                 ri->cb2x2[i].v    = bytestream2_get_byte(&ri->gb);

             }
             for(i = 0; i < nv2; i++)
                 for(j = 0; j < 4; j++)

                     ri->cb4x4[i].idx[j] = bytestream2_get_byte(&ri->gb);

         }
     }
 

     chunk_start = bytestream2_tell(&ri->gb);
     xpos = ypos = 0;

 
     if (chunk_size > bytestream2_get_bytes_left(&ri->gb)) {

         av_log(ri->avctx, AV_LOG_ERROR, "Chunk does not fit in input buffer\n");

         chunk_size = bytestream2_get_bytes_left(&ri->gb);

     }

     while (bytestream2_tell(&ri->gb) < chunk_start + chunk_size) {

         for (yp = ypos; yp < ypos + 16; yp += 8)
             for (xp = xpos; xp < xpos + 16; xp += 8) {

                 if (bytestream2_tell(&ri->gb) >= chunk_start + chunk_size) {

                     av_log(ri->avctx, AV_LOG_ERROR, "Input buffer too small\n");
                     return;
                 }

                 if (vqflg_pos < 0) {

                     vqflg = bytestream2_get_le16(&ri->gb);

                     vqflg_pos = 7;
                 }
                 vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;
                 frame_stats[0][vqid]++;
                 vqflg_pos--;
 
                 switch(vqid) {
                 case RoQ_ID_MOT:
                     break;

                 case RoQ_ID_FCC: {
                     int byte = bytestream2_get_byte(&ri->gb);
                     mx = 8 - (byte >> 4) - ((signed char) (chunk_arg >> 8));
                     my = 8 - (byte & 0xf) - ((signed char) chunk_arg);

                     ff_apply_motion_8x8(ri, xp, yp, mx, my);
                     break;

                 }

                 case RoQ_ID_SLD:

                     qcell = ri->cb4x4 + bytestream2_get_byte(&ri->gb);

                     ff_apply_vector_4x4(ri, xp,     yp,     ri->cb2x2 + qcell->idx[0]);
                     ff_apply_vector_4x4(ri, xp + 4, yp,     ri->cb2x2 + qcell->idx[1]);
                     ff_apply_vector_4x4(ri, xp,     yp + 4, ri->cb2x2 + qcell->idx[2]);
                     ff_apply_vector_4x4(ri, xp + 4, yp + 4, ri->cb2x2 + qcell->idx[3]);

                     break;
                 case RoQ_ID_CCC:
                     for (k = 0; k < 4; k++) {
                         x = xp; y = yp;
                         if(k & 0x01) x += 4;
                         if(k & 0x02) y += 4;
 

                         if (bytestream2_tell(&ri->gb) >= chunk_start + chunk_size) {

                             av_log(ri->avctx, AV_LOG_ERROR, "Input buffer too small\n");
                             return;
                         }

                         if (vqflg_pos < 0) {

                             vqflg = bytestream2_get_le16(&ri->gb);

                             vqflg_pos = 7;
                         }
                         vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;
                         frame_stats[1][vqid]++;
                         vqflg_pos--;
                         switch(vqid) {
                         case RoQ_ID_MOT:
                             break;

                         case RoQ_ID_FCC: {
                             int byte = bytestream2_get_byte(&ri->gb);
                             mx = 8 - (byte >> 4) - ((signed char) (chunk_arg >> 8));
                             my = 8 - (byte & 0xf) - ((signed char) chunk_arg);

                             ff_apply_motion_4x4(ri, x, y, mx, my);
                             break;

                         }

                         case RoQ_ID_SLD:

                             qcell = ri->cb4x4 + bytestream2_get_byte(&ri->gb);

                             ff_apply_vector_2x2(ri, x,     y,     ri->cb2x2 + qcell->idx[0]);
                             ff_apply_vector_2x2(ri, x + 2, y,     ri->cb2x2 + qcell->idx[1]);
                             ff_apply_vector_2x2(ri, x,     y + 2, ri->cb2x2 + qcell->idx[2]);
                             ff_apply_vector_2x2(ri, x + 2, y + 2, ri->cb2x2 + qcell->idx[3]);

                             break;
                         case RoQ_ID_CCC:

                             ff_apply_vector_2x2(ri, x,     y,     ri->cb2x2 + bytestream2_get_byte(&ri->gb));
                             ff_apply_vector_2x2(ri, x + 2, y,     ri->cb2x2 + bytestream2_get_byte(&ri->gb));
                             ff_apply_vector_2x2(ri, x,     y + 2, ri->cb2x2 + bytestream2_get_byte(&ri->gb));
                             ff_apply_vector_2x2(ri, x + 2, y + 2, ri->cb2x2 + bytestream2_get_byte(&ri->gb));

                             break;
                         }
                     }
                     break;
                 default:

                     av_assert2(0);

             }
         }
 
         xpos += 16;

         if (xpos >= ri->width) {
             xpos -= ri->width;

             ypos += 16;
         }

         if(ypos >= ri->height)

             break;
     }
 }
 
 

 static av_cold int roq_decode_init(AVCodecContext *avctx)

 {
     RoqContext *s = avctx->priv_data;
 
     s->avctx = avctx;

     if (avctx->width % 16 || avctx->height % 16) {
         av_log(avctx, AV_LOG_ERROR,
                "Dimensions must be a multiple of 16\n");
         return AVERROR_PATCHWELCOME;

     }
 

     s->width = avctx->width;
     s->height = avctx->height;

     avcodec_get_frame_defaults(&s->frames[0]);
     avcodec_get_frame_defaults(&s->frames[1]);

     s->last_frame    = &s->frames[0];
     s->current_frame = &s->frames[1];

     avctx->pix_fmt = AV_PIX_FMT_YUV444P;

 
     return 0;
 }
 
 static int roq_decode_frame(AVCodecContext *avctx,

                             void *data, int *got_frame,

                             AVPacket *avpkt)

 {

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

     RoqContext *s = avctx->priv_data;

     int copy= !s->current_frame->data[0];

     int ret;

     s->current_frame->reference = 3;

     if ((ret = avctx->reget_buffer(avctx, s->current_frame)) < 0) {

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

         return ret;

     }
 

     if(copy)
         av_picture_copy((AVPicture*)s->current_frame, (AVPicture*)s->last_frame,
                         avctx->pix_fmt, avctx->width, avctx->height);
 

     bytestream2_init(&s->gb, buf, buf_size);

     roqvideo_decode_frame(s);
 

     *got_frame      = 1;

     *(AVFrame*)data = *s->current_frame;
 
     /* shuffle frames */
     FFSWAP(AVFrame *, s->current_frame, s->last_frame);
 
     return buf_size;
 }
 

 static av_cold int roq_decode_end(AVCodecContext *avctx)

 {
     RoqContext *s = avctx->priv_data;
 
     /* release the last frame */
     if (s->last_frame->data[0])
         avctx->release_buffer(avctx, s->last_frame);

     if (s->current_frame->data[0])
         avctx->release_buffer(avctx, s->current_frame);

 
     return 0;
 }
 

 AVCodec ff_roq_decoder = {

     .name           = "roqvideo",
     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_ROQ,

     .priv_data_size = sizeof(RoqContext),
     .init           = roq_decode_init,
     .close          = roq_decode_end,
     .decode         = roq_decode_frame,
     .capabilities   = CODEC_CAP_DR1,

     .long_name      = NULL_IF_CONFIG_SMALL("id RoQ video"),

 };