/*
  * PC Paintbrush PCX (.pcx) image decoder
  * Copyright (c) 2007, 2008 Ivo van Poorten
  *
  * This decoder does not support CGA palettes. I am unable to find samples
  * and Netpbm cannot generate them.
  *
  * 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
  */
 

 #include "libavutil/imgutils.h"

 #include "avcodec.h"
 #include "bytestream.h"

 #include "get_bits.h"

 #include "internal.h"

 #define PCX_HEADER_SIZE 128
 

 static void pcx_rle_decode(GetByteContext *gb,
                            uint8_t *dst,
                            unsigned int bytes_per_scanline,
                            int compressed)

 {

     unsigned int i = 0;
     unsigned char run, value;
 

     if (compressed) {

         while (i < bytes_per_scanline && bytestream2_get_bytes_left(gb)>0) {

             run   = 1;

             value = bytestream2_get_byte(gb);

             if (value >= 0xc0 && bytestream2_get_bytes_left(gb)>0) {

                 run   = value & 0x3f;

                 value = bytestream2_get_byte(gb);

             }

             while (i < bytes_per_scanline && run--)

                 dst[i++] = value;

         }

     } else {

         bytestream2_get_buffer(gb, dst, bytes_per_scanline);

     }
 }
 

 static void pcx_palette(GetByteContext *gb, uint32_t *dst, int pallen)
 {
     int i;

     pallen = FFMIN(pallen, bytestream2_get_bytes_left(gb) / 3);

     for (i = 0; i < pallen; i++)

         *dst++ = 0xFF000000 | bytestream2_get_be24u(gb);

     if (pallen < 256)

         memset(dst, 0, (256 - pallen) * sizeof(*dst));

 }
 

 static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,

                             AVPacket *avpkt)
 {

     GetByteContext gb;

     AVFrame * const p  = data;

     int compressed, xmin, ymin, xmax, ymax;

     int ret;

     unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
                  bytes_per_scanline;

     uint8_t *ptr, *scanline;
 

     if (avpkt->size < PCX_HEADER_SIZE) {

         av_log(avctx, AV_LOG_ERROR, "Packet too small\n");

         return AVERROR_INVALIDDATA;

     }

 
     bytestream2_init(&gb, avpkt->data, avpkt->size);

     if (bytestream2_get_byteu(&gb) != 0x0a || bytestream2_get_byteu(&gb) > 5) {

         av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");

         return AVERROR_INVALIDDATA;

     }
 

     compressed                     = bytestream2_get_byteu(&gb);
     bits_per_pixel                 = bytestream2_get_byteu(&gb);
     xmin                           = bytestream2_get_le16u(&gb);
     ymin                           = bytestream2_get_le16u(&gb);
     xmax                           = bytestream2_get_le16u(&gb);
     ymax                           = bytestream2_get_le16u(&gb);

     avctx->sample_aspect_ratio.num = bytestream2_get_le16u(&gb);
     avctx->sample_aspect_ratio.den = bytestream2_get_le16u(&gb);

 
     if (xmax < xmin || ymax < ymin) {
         av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");

         return AVERROR_INVALIDDATA;

     }
 
     w = xmax - xmin + 1;
     h = ymax - ymin + 1;
 

     bytestream2_skipu(&gb, 49);

     nplanes            = bytestream2_get_byteu(&gb);
     bytes_per_line     = bytestream2_get_le16u(&gb);

     bytes_per_scanline = nplanes * bytes_per_line;
 

     if (bytes_per_scanline < (w * bits_per_pixel * nplanes + 7) / 8 ||
         (!compressed && bytes_per_scanline > bytestream2_get_bytes_left(&gb) / h)) {

         av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");

         return AVERROR_INVALIDDATA;

     }
 

     switch ((nplanes << 8) + bits_per_pixel) {
     case 0x0308:
         avctx->pix_fmt = AV_PIX_FMT_RGB24;
         break;
     case 0x0108:
     case 0x0104:
     case 0x0102:
     case 0x0101:
     case 0x0401:
     case 0x0301:
     case 0x0201:
         avctx->pix_fmt = AV_PIX_FMT_PAL8;
         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
         return AVERROR_INVALIDDATA;

     }
 

     bytestream2_skipu(&gb, 60);

     if ((ret = ff_set_dimensions(avctx, w, h)) < 0)

         return ret;

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

         return ret;

     p->pict_type = AV_PICTURE_TYPE_I;

 
     ptr    = p->data[0];
     stride = p->linesize[0];
 

     scanline = av_malloc(bytes_per_scanline + AV_INPUT_BUFFER_PADDING_SIZE);

     if (!scanline)
         return AVERROR(ENOMEM);

     if (nplanes == 3 && bits_per_pixel == 8) {

         for (y = 0; y < h; y++) {

             pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);

             for (x = 0; x < w; x++) {
                 ptr[3 * x]     = scanline[x];
                 ptr[3 * x + 1] = scanline[x + bytes_per_line];
                 ptr[3 * x + 2] = scanline[x + (bytes_per_line << 1)];

             }
 
             ptr += stride;
         }
     } else if (nplanes == 1 && bits_per_pixel == 8) {

         int palstart = avpkt->size - 769;

         if (avpkt->size < 769) {

             av_log(avctx, AV_LOG_ERROR, "File is too short\n");

             ret = avctx->err_recognition & AV_EF_EXPLODE ?

                   AVERROR_INVALIDDATA : avpkt->size;

             goto end;
         }
 

         for (y = 0; y < h; y++, ptr += stride) {

             pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);

             memcpy(ptr, scanline, w);
         }
 

         if (bytestream2_tell(&gb) != palstart) {

             av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");

             bytestream2_seek(&gb, palstart, SEEK_SET);

         }

         if (bytestream2_get_byte(&gb) != 12) {

             av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");

             ret = avctx->err_recognition & AV_EF_EXPLODE ?

                   AVERROR_INVALIDDATA : avpkt->size;

             goto end;

         }
     } else if (nplanes == 1) {   /* all packed formats, max. 16 colors */
         GetBitContext s;
 

         for (y = 0; y < h; y++) {

             init_get_bits8(&s, scanline, bytes_per_scanline);

             pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);

             for (x = 0; x < w; x++)

                 ptr[x] = get_bits(&s, bits_per_pixel);
             ptr += stride;
         }
     } else {    /* planar, 4, 8 or 16 colors */
         int i;
 

         for (y = 0; y < h; y++) {

             pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);

             for (x = 0; x < w; x++) {
                 int m = 0x80 >> (x & 7), v = 0;
                 for (i = nplanes - 1; i >= 0; i--) {

                     v <<= 1;

                     v  += !!(scanline[i * bytes_per_line + (x >> 3)] & m);

                 }
                 ptr[x] = v;
             }
             ptr += stride;
         }
     }
 

     ret = bytestream2_tell(&gb);

     if (nplanes == 1 && bits_per_pixel == 8) {

         pcx_palette(&gb, (uint32_t *)p->data[1], 256);

         ret += 256 * 3;

     } else if (bits_per_pixel * nplanes == 1) {
         AV_WN32A(p->data[1]  , 0xFF000000);
         AV_WN32A(p->data[1]+4, 0xFFFFFFFF);

     } else if (bits_per_pixel < 8) {

         bytestream2_seek(&gb, 16, SEEK_SET);

         pcx_palette(&gb, (uint32_t *)p->data[1], 16);

     }
 

     *got_frame = 1;

 end:
     av_free(scanline);
     return ret;

 }
 

 AVCodec ff_pcx_decoder = {

     .name         = "pcx",

     .long_name    = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),

     .type         = AVMEDIA_TYPE_VIDEO,
     .id           = AV_CODEC_ID_PCX,
     .decode       = pcx_decode_frame,

     .capabilities = AV_CODEC_CAP_DR1,

 };