/*

  * Delphine Software International CIN video decoder

  * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
  *
  * 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

  * Delphine Software International CIN video decoder

  */
 
 #include "avcodec.h"

 #include "bytestream.h"

 #include "internal.h"

 
 typedef enum CinVideoBitmapIndex {
     CIN_CUR_BMP = 0, /* current */
     CIN_PRE_BMP = 1, /* previous */
     CIN_INT_BMP = 2  /* intermediate */
 } CinVideoBitmapIndex;
 
 typedef struct CinVideoContext {
     AVCodecContext *avctx;

     AVFrame *frame;

     unsigned int bitmap_size;
     uint32_t palette[256];
     uint8_t *bitmap_table[3];
 } CinVideoContext;
 

 static av_cold void destroy_buffers(CinVideoContext *cin)
 {
     int i;
 
     for (i = 0; i < 3; ++i)
         av_freep(&cin->bitmap_table[i]);
 }
 
 static av_cold int allocate_buffers(CinVideoContext *cin)
 {
     int i;
 
     for (i = 0; i < 3; ++i) {
         cin->bitmap_table[i] = av_mallocz(cin->bitmap_size);
         if (!cin->bitmap_table[i]) {
             av_log(cin->avctx, AV_LOG_ERROR, "Can't allocate bitmap buffers.\n");
             destroy_buffers(cin);
             return AVERROR(ENOMEM);
         }
     }
 
     return 0;
 }

 static av_cold int cinvideo_decode_init(AVCodecContext *avctx)

 {

     CinVideoContext *cin = avctx->priv_data;

 
     cin->avctx = avctx;

     avctx->pix_fmt = AV_PIX_FMT_PAL8;

     cin->frame = av_frame_alloc();
     if (!cin->frame)
         return AVERROR(ENOMEM);

 
     cin->bitmap_size = avctx->width * avctx->height;

     if (allocate_buffers(cin))
         return AVERROR(ENOMEM);

 
     return 0;
 }
 

 static void cin_apply_delta_data(const unsigned char *src, unsigned char *dst,
                                  int size)

 {
     while (size--)
         *dst++ += *src++;
 }
 

 static int cin_decode_huffman(const unsigned char *src, int src_size,
                               unsigned char *dst, int dst_size)

 {
     int b, huff_code = 0;
     unsigned char huff_code_table[15];

     unsigned char *dst_cur       = dst;
     unsigned char *dst_end       = dst + dst_size;

     const unsigned char *src_end = src + src_size;
 

     memcpy(huff_code_table, src, 15);
     src += 15;

 
     while (src < src_end) {
         huff_code = *src++;
         if ((huff_code >> 4) == 15) {

             b          = huff_code << 4;
             huff_code  = *src++;

             *dst_cur++ = b | (huff_code >> 4);
         } else
             *dst_cur++ = huff_code_table[huff_code >> 4];
         if (dst_cur >= dst_end)
             break;
 
         huff_code &= 15;
         if (huff_code == 15) {
             *dst_cur++ = *src++;
         } else
             *dst_cur++ = huff_code_table[huff_code];
         if (dst_cur >= dst_end)
             break;
     }
 
     return dst_cur - dst;
 }
 

 static int cin_decode_lzss(const unsigned char *src, int src_size,
                            unsigned char *dst, int dst_size)

 {
     uint16_t cmd;
     int i, sz, offset, code;

     unsigned char *dst_end       = dst + dst_size, *dst_start = dst;

     const unsigned char *src_end = src + src_size;
 
     while (src < src_end && dst < dst_end) {
         code = *src++;
         for (i = 0; i < 8 && src < src_end && dst < dst_end; ++i) {
             if (code & (1 << i)) {
                 *dst++ = *src++;
             } else {

                 cmd    = AV_RL16(src);
                 src   += 2;

                 offset = cmd >> 4;

                 if ((int)(dst - dst_start) < offset + 1)

                     return AVERROR_INVALIDDATA;

                 sz = (cmd & 0xF) + 2;

                 /* don't use memcpy/memmove here as the decoding routine
                  * (ab)uses buffer overlappings to repeat bytes in the
                  * destination */

                 sz = FFMIN(sz, dst_end - dst);
                 while (sz--) {
                     *dst = *(dst - offset - 1);
                     ++dst;
                 }
             }
         }
     }

     return 0;

 }
 

 static int cin_decode_rle(const unsigned char *src, int src_size,

                            unsigned char *dst, int dst_size)

 {
     int len, code;

     unsigned char *dst_end       = dst + dst_size;

     const unsigned char *src_end = src + src_size;
 

     while (src + 1 < src_end && dst < dst_end) {

         code = *src++;
         if (code & 0x80) {
             len = code - 0x7F;
             memset(dst, *src++, FFMIN(len, dst_end - dst));
         } else {
             len = code + 1;

             if (len > src_end-src) {

                 av_log(NULL, AV_LOG_ERROR, "RLE overread\n");

                 return AVERROR_INVALIDDATA;
             }

             memcpy(dst, src, FFMIN3(len, dst_end - dst, src_end - src));

             src += len;
         }
         dst += len;
     }

     return 0;

 }
 
 static int cinvideo_decode_frame(AVCodecContext *avctx,

                                  void *data, int *got_frame,

                                  AVPacket *avpkt)

 {

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

     CinVideoContext *cin = avctx->priv_data;

     int i, y, palette_type, palette_colors_count,
         bitmap_frame_type, bitmap_frame_size, res = 0;

     palette_type         = buf[0];
     palette_colors_count = AV_RL16(buf + 1);
     bitmap_frame_type    = buf[3];
     buf                 += 4;

 
     bitmap_frame_size = buf_size - 4;
 
     /* handle palette */

     if (bitmap_frame_size < palette_colors_count * (3 + (palette_type != 0)))
         return AVERROR_INVALIDDATA;

     if (palette_type == 0) {

         if (palette_colors_count > 256)
             return AVERROR_INVALIDDATA;

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

             cin->palette[i]    = 0xFFU << 24 | bytestream_get_le24(&buf);

             bitmap_frame_size -= 3;
         }
     } else {
         for (i = 0; i < palette_colors_count; ++i) {

             cin->palette[buf[0]] = 0xFFU << 24 | AV_RL24(buf + 1);

             buf                 += 4;
             bitmap_frame_size   -= 4;

         }
     }
 

     /* note: the decoding routines below assumes that
      * surface.width = surface.pitch */

     switch (bitmap_frame_type) {
     case 9:
         cin_decode_rle(buf, bitmap_frame_size,

                        cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);

         break;
     case 34:
         cin_decode_rle(buf, bitmap_frame_size,

                        cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);

         cin_apply_delta_data(cin->bitmap_table[CIN_PRE_BMP],

                              cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);

         break;
     case 35:

         bitmap_frame_size = cin_decode_huffman(buf, bitmap_frame_size,

                            cin->bitmap_table[CIN_INT_BMP], cin->bitmap_size);

         cin_decode_rle(cin->bitmap_table[CIN_INT_BMP], bitmap_frame_size,

                        cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);

         break;
     case 36:
         bitmap_frame_size = cin_decode_huffman(buf, bitmap_frame_size,

                                                cin->bitmap_table[CIN_INT_BMP],
                                                cin->bitmap_size);

         cin_decode_rle(cin->bitmap_table[CIN_INT_BMP], bitmap_frame_size,

                        cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);

         cin_apply_delta_data(cin->bitmap_table[CIN_PRE_BMP],

                              cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);

         break;
     case 37:
         cin_decode_huffman(buf, bitmap_frame_size,

                            cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);

         break;
     case 38:

         res = cin_decode_lzss(buf, bitmap_frame_size,
                               cin->bitmap_table[CIN_CUR_BMP],
                               cin->bitmap_size);
         if (res < 0)
             return res;

         break;
     case 39:

         res = cin_decode_lzss(buf, bitmap_frame_size,
                               cin->bitmap_table[CIN_CUR_BMP],
                               cin->bitmap_size);
         if (res < 0)
             return res;

         cin_apply_delta_data(cin->bitmap_table[CIN_PRE_BMP],

                              cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);

         break;
     }
 

     if ((res = ff_reget_buffer(avctx, cin->frame)) < 0)

         return res;

     memcpy(cin->frame->data[1], cin->palette, sizeof(cin->palette));
     cin->frame->palette_has_changed = 1;

     for (y = 0; y < cin->avctx->height; ++y)

         memcpy(cin->frame->data[0] + (cin->avctx->height - 1 - y) * cin->frame->linesize[0],

                cin->bitmap_table[CIN_CUR_BMP] + y * cin->avctx->width,
                cin->avctx->width);

     FFSWAP(uint8_t *, cin->bitmap_table[CIN_CUR_BMP],
                       cin->bitmap_table[CIN_PRE_BMP]);

     if ((res = av_frame_ref(data, cin->frame)) < 0)

         return res;
 

     *got_frame = 1;

 
     return buf_size;
 }
 

 static av_cold int cinvideo_decode_end(AVCodecContext *avctx)

 {

     CinVideoContext *cin = avctx->priv_data;

     av_frame_free(&cin->frame);

     destroy_buffers(cin);

 
     return 0;
 }
 

 AVCodec ff_dsicinvideo_decoder = {

     .name           = "dsicinvideo",

     .long_name      = NULL_IF_CONFIG_SMALL("Delphine Software International CIN video"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_DSICINVIDEO,

     .priv_data_size = sizeof(CinVideoContext),
     .init           = cinvideo_decode_init,
     .close          = cinvideo_decode_end,
     .decode         = cinvideo_decode_frame,
     .capabilities   = CODEC_CAP_DR1,

 };