/*
  * VMware Screen Codec (VMnc) decoder
  * Copyright (c) 2006 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

  * VMware Screen Codec (VMnc) decoder
  * As Alex Beregszaszi discovered, this is effectively RFB data dump
  */
 
 #include <stdio.h>
 #include <stdlib.h>
 

 #include "libavutil/intreadwrite.h"

 #include "avcodec.h"
 

 enum EncTypes {
     MAGIC_WMVd = 0x574D5664,
     MAGIC_WMVe,
     MAGIC_WMVf,
     MAGIC_WMVg,
     MAGIC_WMVh,
     MAGIC_WMVi,
     MAGIC_WMVj
 };

 
 enum HexTile_Flags {
     HT_RAW =  1, // tile is raw
     HT_BKG =  2, // background color is present
     HT_FG  =  4, // foreground color is present
     HT_SUB =  8, // subrects are present
     HT_CLR = 16  // each subrect has own color
 };
 
 /*
  * Decoder context
  */
 typedef struct VmncContext {
     AVCodecContext *avctx;
     AVFrame pic;
 
     int bpp;
     int bpp2;
     int bigendian;
     uint8_t pal[768];
     int width, height;

 
     /* cursor data */
     int cur_w, cur_h;
     int cur_x, cur_y;
     int cur_hx, cur_hy;
     uint8_t* curbits, *curmask;
     uint8_t* screendta;

 } VmncContext;
 
 /* read pixel value from stream */

 static av_always_inline int vmnc_get_pixel(const uint8_t* buf, int bpp, int be) {

     switch(bpp * 2 + be) {
     case 2:
     case 3: return *buf;

     case 4: return AV_RL16(buf);
     case 5: return AV_RB16(buf);
     case 8: return AV_RL32(buf);
     case 9: return AV_RB32(buf);

     default: return 0;
     }
 }
 

 static void load_cursor(VmncContext *c, const uint8_t *src)

 {
     int i, j, p;
     const int bpp = c->bpp2;
     uint8_t  *dst8  = c->curbits;
     uint16_t *dst16 = (uint16_t*)c->curbits;
     uint32_t *dst32 = (uint32_t*)c->curbits;
 
     for(j = 0; j < c->cur_h; j++) {
         for(i = 0; i < c->cur_w; i++) {
             p = vmnc_get_pixel(src, bpp, c->bigendian);
             src += bpp;
             if(bpp == 1) *dst8++ = p;
             if(bpp == 2) *dst16++ = p;
             if(bpp == 4) *dst32++ = p;
         }
     }
     dst8 = c->curmask;
     dst16 = (uint16_t*)c->curmask;
     dst32 = (uint32_t*)c->curmask;
     for(j = 0; j < c->cur_h; j++) {
         for(i = 0; i < c->cur_w; i++) {
             p = vmnc_get_pixel(src, bpp, c->bigendian);
             src += bpp;
             if(bpp == 1) *dst8++ = p;
             if(bpp == 2) *dst16++ = p;
             if(bpp == 4) *dst32++ = p;
         }
     }
 }
 
 static void put_cursor(uint8_t *dst, int stride, VmncContext *c, int dx, int dy)
 {

     int i, j;

     int w, h, x, y;
     w = c->cur_w;
     if(c->width < c->cur_x + c->cur_w) w = c->width - c->cur_x;
     h = c->cur_h;
     if(c->height < c->cur_y + c->cur_h) h = c->height - c->cur_y;
     x = c->cur_x;
     y = c->cur_y;
     if(x < 0) {
         w += x;
         x = 0;
     }
     if(y < 0) {
         h += y;
         y = 0;
     }
 
     if((w < 1) || (h < 1)) return;
     dst += x * c->bpp2 + y * stride;
 
     if(c->bpp2 == 1) {
         uint8_t* cd = c->curbits, *msk = c->curmask;
         for(j = 0; j < h; j++) {
             for(i = 0; i < w; i++)
                 dst[i] = (dst[i] & cd[i]) ^ msk[i];
             msk += c->cur_w;
             cd += c->cur_w;
             dst += stride;
         }
     } else if(c->bpp2 == 2) {
         uint16_t* cd = (uint16_t*)c->curbits, *msk = (uint16_t*)c->curmask;
         uint16_t* dst2;
         for(j = 0; j < h; j++) {
             dst2 = (uint16_t*)dst;
             for(i = 0; i < w; i++)
                 dst2[i] = (dst2[i] & cd[i]) ^ msk[i];
             msk += c->cur_w;
             cd += c->cur_w;
             dst += stride;
         }
     } else if(c->bpp2 == 4) {
         uint32_t* cd = (uint32_t*)c->curbits, *msk = (uint32_t*)c->curmask;
         uint32_t* dst2;
         for(j = 0; j < h; j++) {
             dst2 = (uint32_t*)dst;
             for(i = 0; i < w; i++)
                 dst2[i] = (dst2[i] & cd[i]) ^ msk[i];
             msk += c->cur_w;
             cd += c->cur_w;
             dst += stride;
         }
     }
 }
 

 /* fill rectangle with given color */

 static av_always_inline void paint_rect(uint8_t *dst, int dx, int dy, int w, int h, int color, int bpp, int stride)

 {
     int i, j;
     dst += dx * bpp + dy * stride;
     if(bpp == 1){
         for(j = 0; j < h; j++) {
             memset(dst, color, w);
             dst += stride;
         }
     }else if(bpp == 2){
         uint16_t* dst2;
         for(j = 0; j < h; j++) {
             dst2 = (uint16_t*)dst;
             for(i = 0; i < w; i++) {
                 *dst2++ = color;
             }
             dst += stride;
         }
     }else if(bpp == 4){
         uint32_t* dst2;
         for(j = 0; j < h; j++) {
             dst2 = (uint32_t*)dst;
             for(i = 0; i < w; i++) {
                 dst2[i] = color;
             }
             dst += stride;
         }
     }
 }
 

 static av_always_inline void paint_raw(uint8_t *dst, int w, int h, const uint8_t* src, int bpp, int be, int stride)

 {
     int i, j, p;
     for(j = 0; j < h; j++) {
         for(i = 0; i < w; i++) {
             p = vmnc_get_pixel(src, bpp, be);
             src += bpp;

             switch(bpp){
             case 1:
                 dst[i] = p;
                 break;
             case 2:
                 ((uint16_t*)dst)[i] = p;
                 break;
             case 4:
                 ((uint32_t*)dst)[i] = p;
                 break;
             }

         }
         dst += stride;
     }
 }
 

 static int decode_hextile(VmncContext *c, uint8_t* dst, const uint8_t* src, int ssize, int w, int h, int stride)

 {
     int i, j, k;
     int bg = 0, fg = 0, rects, color, flags, xy, wh;
     const int bpp = c->bpp2;
     uint8_t *dst2;
     int bw = 16, bh = 16;

     const uint8_t *ssrc=src;

 
     for(j = 0; j < h; j += 16) {
         dst2 = dst;
         bw = 16;
         if(j + 16 > h) bh = h - j;
         for(i = 0; i < w; i += 16, dst2 += 16 * bpp) {

             if(src - ssrc >= ssize) {
                 av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
                 return -1;
             }

             if(i + 16 > w) bw = w - i;
             flags = *src++;
             if(flags & HT_RAW) {

                 if(src - ssrc > ssize - bw * bh * bpp) {
                     av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
                     return -1;
                 }

                 paint_raw(dst2, bw, bh, src, bpp, c->bigendian, stride);

                 src += bw * bh * bpp;

             } else {
                 if(flags & HT_BKG) {
                     bg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;
                 }
                 if(flags & HT_FG) {
                     fg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;
                 }
                 rects = 0;
                 if(flags & HT_SUB)
                     rects = *src++;

                 color = !!(flags & HT_CLR);

 
                 paint_rect(dst2, 0, 0, bw, bh, bg, bpp, stride);
 

                 if(src - ssrc > ssize - rects * (color * bpp + 2)) {
                     av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
                     return -1;
                 }

                 for(k = 0; k < rects; k++) {
                     if(color) {
                         fg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;
                     }
                     xy = *src++;
                     wh = *src++;
                     paint_rect(dst2, xy >> 4, xy & 0xF, (wh>>4)+1, (wh & 0xF)+1, fg, bpp, stride);
                 }
             }
         }
         dst += stride * 16;
     }
     return src - ssrc;
 }
 

 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)

 {

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

     VmncContext * const c = avctx->priv_data;

     uint8_t *outptr;

     const uint8_t *src = buf;

     int dx, dy, w, h, depth, enc, chunks, res, size_left;

 
     c->pic.reference = 1;
     c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
     if(avctx->reget_buffer(avctx, &c->pic) < 0){
         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
         return -1;
     }
 

     c->pic.key_frame = 0;

     c->pic.pict_type = AV_PICTURE_TYPE_P;

     //restore screen after cursor
     if(c->screendta) {
         int i;
         w = c->cur_w;
         if(c->width < c->cur_x + w) w = c->width - c->cur_x;
         h = c->cur_h;
         if(c->height < c->cur_y + h) h = c->height - c->cur_y;
         dx = c->cur_x;
         if(dx < 0) {
             w += dx;
             dx = 0;
         }
         dy = c->cur_y;
         if(dy < 0) {
             h += dy;
             dy = 0;
         }
         if((w > 0) && (h > 0)) {
             outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];
             for(i = 0; i < h; i++) {
                 memcpy(outptr, c->screendta + i * c->cur_w * c->bpp2, w * c->bpp2);
                 outptr += c->pic.linesize[0];
             }
         }
     }

     src += 2;

     chunks = AV_RB16(src); src += 2;

     while(chunks--) {

         dx = AV_RB16(src); src += 2;
         dy = AV_RB16(src); src += 2;
         w  = AV_RB16(src); src += 2;
         h  = AV_RB16(src); src += 2;
         enc = AV_RB32(src); src += 4;

         outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];

         size_left = buf_size - (src - buf);

         switch(enc) {

         case MAGIC_WMVd: // cursor

             if(size_left < 2 + w * h * c->bpp2 * 2) {
                 av_log(avctx, AV_LOG_ERROR, "Premature end of data! (need %i got %i)\n", 2 + w * h * c->bpp2 * 2, size_left);
                 return -1;
             }

             src += 2;

             c->cur_w = w;
             c->cur_h = h;
             c->cur_hx = dx;
             c->cur_hy = dy;
             if((c->cur_hx > c->cur_w) || (c->cur_hy > c->cur_h)) {
                 av_log(avctx, AV_LOG_ERROR, "Cursor hot spot is not in image: %ix%i of %ix%i cursor size\n", c->cur_hx, c->cur_hy, c->cur_w, c->cur_h);
                 c->cur_hx = c->cur_hy = 0;
             }
             c->curbits = av_realloc(c->curbits, c->cur_w * c->cur_h * c->bpp2);
             c->curmask = av_realloc(c->curmask, c->cur_w * c->cur_h * c->bpp2);
             c->screendta = av_realloc(c->screendta, c->cur_w * c->cur_h * c->bpp2);
             load_cursor(c, src);
             src += w * h * c->bpp2 * 2;

             break;
         case MAGIC_WMVe: // unknown
             src += 2;
             break;

         case MAGIC_WMVf: // update cursor position
             c->cur_x = dx - c->cur_hx;
             c->cur_y = dy - c->cur_hy;

             break;

         case MAGIC_WMVg: // unknown
             src += 10;
             break;
         case MAGIC_WMVh: // unknown
             src += 4;
             break;

         case MAGIC_WMVi: // ServerInitialization struct
             c->pic.key_frame = 1;

             c->pic.pict_type = AV_PICTURE_TYPE_I;

             depth = *src++;
             if(depth != c->bpp) {
                 av_log(avctx, AV_LOG_INFO, "Depth mismatch. Container %i bpp, Frame data: %i bpp\n", c->bpp, depth);
             }
             src++;
             c->bigendian = *src++;
             if(c->bigendian & (~1)) {
                 av_log(avctx, AV_LOG_INFO, "Invalid header: bigendian flag = %i\n", c->bigendian);
                 return -1;
             }
             //skip the rest of pixel format data
             src += 13;
             break;

         case MAGIC_WMVj: // unknown
             src += 2;
             break;

         case 0x00000000: // raw rectangle data
             if((dx + w > c->width) || (dy + h > c->height)) {
                 av_log(avctx, AV_LOG_ERROR, "Incorrect frame size: %ix%i+%ix%i of %ix%i\n", w, h, dx, dy, c->width, c->height);
                 return -1;
             }

             if(size_left < w * h * c->bpp2) {
                 av_log(avctx, AV_LOG_ERROR, "Premature end of data! (need %i got %i)\n", w * h * c->bpp2, size_left);
                 return -1;
             }

             paint_raw(outptr, w, h, src, c->bpp2, c->bigendian, c->pic.linesize[0]);
             src += w * h * c->bpp2;
             break;
         case 0x00000005: // HexTile encoded rectangle
             if((dx + w > c->width) || (dy + h > c->height)) {
                 av_log(avctx, AV_LOG_ERROR, "Incorrect frame size: %ix%i+%ix%i of %ix%i\n", w, h, dx, dy, c->width, c->height);
                 return -1;

             }

             res = decode_hextile(c, outptr, src, size_left, w, h, c->pic.linesize[0]);

             if(res < 0)
                 return -1;
             src += res;
             break;
         default:
             av_log(avctx, AV_LOG_ERROR, "Unsupported block type 0x%08X\n", enc);
             chunks = 0; // leave chunks decoding loop

         }
     }

     if(c->screendta){
         int i;
         //save screen data before painting cursor
         w = c->cur_w;
         if(c->width < c->cur_x + w) w = c->width - c->cur_x;
         h = c->cur_h;
         if(c->height < c->cur_y + h) h = c->height - c->cur_y;
         dx = c->cur_x;
         if(dx < 0) {
             w += dx;
             dx = 0;
         }
         dy = c->cur_y;
         if(dy < 0) {
             h += dy;
             dy = 0;
         }
         if((w > 0) && (h > 0)) {
             outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];
             for(i = 0; i < h; i++) {
                 memcpy(c->screendta + i * c->cur_w * c->bpp2, outptr, w * c->bpp2);
                 outptr += c->pic.linesize[0];
             }
             outptr = c->pic.data[0];
             put_cursor(outptr, c->pic.linesize[0], c, c->cur_x, c->cur_y);
         }
     }

     *data_size = sizeof(AVFrame);
     *(AVFrame*)data = c->pic;
 
     /* always report that the buffer was completely consumed */
     return buf_size;
 }
 
 
 
 /*
  *
  * Init VMnc decoder
  *
  */

 static av_cold int decode_init(AVCodecContext *avctx)

 {

     VmncContext * const c = avctx->priv_data;

 
     c->avctx = avctx;
 
     c->width = avctx->width;
     c->height = avctx->height;
 

     c->bpp = avctx->bits_per_coded_sample;

     c->bpp2 = c->bpp/8;

     avcodec_get_frame_defaults(&c->pic);

 
     switch(c->bpp){
     case 8:
         avctx->pix_fmt = PIX_FMT_PAL8;
         break;
     case 16:
         avctx->pix_fmt = PIX_FMT_RGB555;
         break;
     case 32:
         avctx->pix_fmt = PIX_FMT_RGB32;
         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "Unsupported bitdepth %i\n", c->bpp);
     }
 
     return 0;
 }
 
 
 
 /*
  *
  * Uninit VMnc decoder
  *
  */

 static av_cold int decode_end(AVCodecContext *avctx)

 {

     VmncContext * const c = avctx->priv_data;

 
     if (c->pic.data[0])
         avctx->release_buffer(avctx, &c->pic);
 

     av_free(c->curbits);
     av_free(c->curmask);
     av_free(c->screendta);

     return 0;
 }
 

 AVCodec ff_vmnc_decoder = {

     "vmnc",

     AVMEDIA_TYPE_VIDEO,

     CODEC_ID_VMNC,
     sizeof(VmncContext),
     decode_init,
     NULL,
     decode_end,

     decode_frame,

     CODEC_CAP_DR1,

     .long_name = NULL_IF_CONFIG_SMALL("VMware Screen Codec / VMware Video"),

 };