/*
  * LOCO codec
  * Copyright (c) 2005 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

  * LOCO codec.
  */

 #include "avcodec.h"

 #include "get_bits.h"

 #include "golomb.h"

 #include "internal.h"

 #include "mathops.h"

 enum LOCO_MODE {
     LOCO_UNKN  =  0,
     LOCO_CYUY2 = -1,
     LOCO_CRGB  = -2,
     LOCO_CRGBA = -3,
     LOCO_CYV12 = -4,
     LOCO_YUY2  =  1,
     LOCO_UYVY  =  2,
     LOCO_RGB   =  3,
     LOCO_RGBA  =  4,
     LOCO_YV12  =  5,
 };

 typedef struct LOCOContext {

     AVCodecContext *avctx;
     int lossy;
     int mode;
 } LOCOContext;
 

 typedef struct RICEContext {

     GetBitContext gb;
     int save, run, run2; /* internal rice decoder state */
     int sum, count; /* sum and count for getting rice parameter */

     int lossy;

 } RICEContext;

 
 static int loco_get_rice_param(RICEContext *r)
 {
     int cnt = 0;
     int val = r->count;

     while (r->sum > val && cnt < 9) {

         val <<= 1;
         cnt++;
     }

     return cnt;
 }
 
 static inline void loco_update_rice_param(RICEContext *r, int val)
 {
     r->sum += val;
     r->count++;

     if (r->count == 16) {
         r->sum   >>= 1;

         r->count >>= 1;
     }
 }
 
 static inline int loco_get_rice(RICEContext *r)
 {
     int v;
     if (r->run > 0) { /* we have zero run */
         r->run--;

         loco_update_rice_param(r, 0);

         return 0;
     }

     v = get_ur_golomb_jpegls(&r->gb, loco_get_rice_param(r), INT_MAX, 0);

     loco_update_rice_param(r, (v + 1) >> 1);

     if (!v) {
         if (r->save >= 0) {

             r->run = get_ur_golomb_jpegls(&r->gb, 2, INT_MAX, 0);

             if (r->run > 1)

                 r->save += r->run + 1;
             else
                 r->save -= 3;

         } else

             r->run2++;

     } else {

         v = ((v >> 1) + r->lossy) ^ -(v & 1);

         if (r->run2 > 0) {
             if (r->run2 > 2)
                 r->save += r->run2;
             else
                 r->save -= 3;
             r->run2 = 0;
         }

     }

     return v;
 }
 
 /* LOCO main predictor - LOCO-I/JPEG-LS predictor */
 static inline int loco_predict(uint8_t* data, int stride, int step)
 {
     int a, b, c;

     a = data[-stride];
     b = data[-step];
     c = data[-stride - step];

     return mid_pred(a, a + b - c, b);

 }
 
 static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,

                              int stride, const uint8_t *buf, int buf_size, int step)

 {
     RICEContext rc;
     int val;
     int i, j;

     if(buf_size<=0)
         return -1;
 

     init_get_bits8(&rc.gb, buf, buf_size);

     rc.save  = 0;
     rc.run   = 0;
     rc.run2  = 0;

     rc.lossy = l->lossy;
 

     rc.sum   = 8;

     rc.count = 1;

     /* restore top left pixel */

     val     = loco_get_rice(&rc);

     data[0] = 128 + val;
     /* restore top line */
     for (i = 1; i < width; i++) {
         val = loco_get_rice(&rc);
         data[i * step] = data[i * step - step] + val;
     }
     data += stride;
     for (j = 1; j < height; j++) {
         /* restore left column */
         val = loco_get_rice(&rc);
         data[0] = data[-stride] + val;
         /* restore all other pixels */
         for (i = 1; i < width; i++) {
             val = loco_get_rice(&rc);
             data[i * step] = loco_predict(&data[i * step], stride, step) + val;
         }
         data += stride;
     }

     return (get_bits_count(&rc.gb) + 7) >> 3;

 }
 

 static int decode_frame(AVCodecContext *avctx,

                         void *data, int *got_frame,

                         AVPacket *avpkt)

 {
     LOCOContext * const l = avctx->priv_data;

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

     AVFrame * const p     = data;

     int decoded, ret;

     if ((ret = ff_get_buffer(avctx, p, 0)) < 0)

         return ret;

     p->key_frame = 1;
 

 #define ADVANCE_BY_DECODED do { \

     if (decoded < 0 || decoded >= buf_size) goto buf_too_small; \

     buf += decoded; buf_size -= decoded; \
 } while(0)

     switch(l->mode) {
     case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
         decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
                                     p->linesize[0], buf, buf_size, 1);

         ADVANCE_BY_DECODED;

         decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
                                     p->linesize[1], buf, buf_size, 1);

         ADVANCE_BY_DECODED;

         decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
                                     p->linesize[2], buf, buf_size, 1);
         break;
     case LOCO_CYV12: case LOCO_YV12:
         decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
                                     p->linesize[0], buf, buf_size, 1);

         ADVANCE_BY_DECODED;

         decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
                                     p->linesize[2], buf, buf_size, 1);

         ADVANCE_BY_DECODED;

         decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
                                     p->linesize[1], buf, buf_size, 1);

         break;
     case LOCO_CRGB: case LOCO_RGB:

         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
                                     -p->linesize[0], buf, buf_size, 3);

         ADVANCE_BY_DECODED;

         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 1, avctx->width, avctx->height,
                                     -p->linesize[0], buf, buf_size, 3);

         ADVANCE_BY_DECODED;

         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 2, avctx->width, avctx->height,
                                     -p->linesize[0], buf, buf_size, 3);

         break;

     case LOCO_CRGBA:

     case LOCO_RGBA:

         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
                                     -p->linesize[0], buf, buf_size, 4);

         ADVANCE_BY_DECODED;

         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 1, avctx->width, avctx->height,
                                     -p->linesize[0], buf, buf_size, 4);

         ADVANCE_BY_DECODED;

         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 2, avctx->width, avctx->height,
                                     -p->linesize[0], buf, buf_size, 4);

         ADVANCE_BY_DECODED;

         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 3, avctx->width, avctx->height,
                                     -p->linesize[0], buf, buf_size, 4);

         break;

     default:
         av_assert0(0);

     }
 

     if (decoded < 0 || decoded > buf_size)
         goto buf_too_small;
     buf_size -= decoded;
 

     *got_frame      = 1;

     return avpkt->size - buf_size;

 buf_too_small:
     av_log(avctx, AV_LOG_ERROR, "Input data too small.\n");
     return AVERROR(EINVAL);

 }
 

 static av_cold int decode_init(AVCodecContext *avctx)
 {

     LOCOContext * const l = avctx->priv_data;
     int version;
 
     l->avctx = avctx;
     if (avctx->extradata_size < 12) {
         av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
                avctx->extradata_size);

         return AVERROR_INVALIDDATA;

     }

     version = AV_RL32(avctx->extradata);

     switch (version) {

     case 1:
         l->lossy = 0;
         break;
     case 2:

         l->lossy = AV_RL32(avctx->extradata + 8);

         break;
     default:

         l->lossy = AV_RL32(avctx->extradata + 8);

         avpriv_request_sample(avctx, "LOCO codec version %i", version);

     }

     l->mode = AV_RL32(avctx->extradata + 4);

     switch (l->mode) {
     case LOCO_CYUY2:
     case LOCO_YUY2:
     case LOCO_UYVY:

         avctx->pix_fmt = AV_PIX_FMT_YUV422P;

         break;

     case LOCO_CRGB:
     case LOCO_RGB:

         avctx->pix_fmt = AV_PIX_FMT_BGR24;

         break;

     case LOCO_CYV12:
     case LOCO_YV12:

         avctx->pix_fmt = AV_PIX_FMT_YUV420P;

         break;

     case LOCO_CRGBA:
     case LOCO_RGBA:

         avctx->pix_fmt = AV_PIX_FMT_BGRA;

         break;
     default:
         av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);

         return AVERROR_INVALIDDATA;

     }

     if (avctx->debug & FF_DEBUG_PICT_INFO)

         av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);

     return 0;
 }
 

 AVCodec ff_loco_decoder = {

     .name           = "loco",

     .long_name      = NULL_IF_CONFIG_SMALL("LOCO"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_LOCO,

     .priv_data_size = sizeof(LOCOContext),
     .init           = decode_init,
     .decode         = decode_frame,
     .capabilities   = CODEC_CAP_DR1,

 };