/*

  * Intel Indeo 2 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

  * Intel Indeo 2 decoder.
  */

 #define ALT_BITSTREAM_READER_LE

 #include "avcodec.h"

 #include "get_bits.h"

 #include "indeo2data.h"

 #include "libavutil/common.h"

 
 typedef struct Ir2Context{
     AVCodecContext *avctx;
     AVFrame picture;
     GetBitContext gb;
     int decode_delta;
 } Ir2Context;
 
 #define CODE_VLC_BITS 14
 static VLC ir2_vlc;
 
 /* Indeo 2 codes are in range 0x01..0x7F and 0x81..0x90 */
 static inline int ir2_get_code(GetBitContext *gb)
 {

     return get_vlc2(gb, ir2_vlc.table, CODE_VLC_BITS, 1) + 1;

 }
 

 static int ir2_decode_plane(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,

                              const uint8_t *table)
 {
     int i;
     int j;
     int out = 0;
     int c;
     int t;

     if(width&1)
         return -1;
 

     /* first line contain absolute values, other lines contain deltas */
     while (out < width){
         c = ir2_get_code(&ctx->gb);

         if(c >= 0x80) { /* we have a run */
             c -= 0x7F;

             if(out + c*2 > width)
                 return -1;

             for (i = 0; i < c * 2; i++)
                 dst[out++] = 0x80;
         } else { /* copy two values from table */
             dst[out++] = table[c * 2];
             dst[out++] = table[(c * 2) + 1];
         }
     }
     dst += stride;

     for (j = 1; j < height; j++){
         out = 0;
         while (out < width){
             c = ir2_get_code(&ctx->gb);

             if(c >= 0x80) { /* we have a skip */
                 c -= 0x7F;

                 if(out + c*2 > width)
                     return -1;

                 for (i = 0; i < c * 2; i++) {
                     dst[out] = dst[out - stride];
                     out++;
                 }
             } else { /* add two deltas from table */
                 t = dst[out - stride] + (table[c * 2] - 128);

                 t= av_clip_uint8(t);

                 dst[out] = t;
                 out++;
                 t = dst[out - stride] + (table[(c * 2) + 1] - 128);

                 t= av_clip_uint8(t);

                 dst[out] = t;
                 out++;
             }
         }
         dst += stride;
     }

     return 0;

 }
 

 static int ir2_decode_plane_inter(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,

                              const uint8_t *table)
 {
     int j;
     int out = 0;
     int c;
     int t;

 
     if(width&1)
         return -1;
 

     for (j = 0; j < height; j++){
         out = 0;
         while (out < width){
             c = ir2_get_code(&ctx->gb);

             if(c >= 0x80) { /* we have a skip */
                 c -= 0x7F;

                 out += c * 2;
             } else { /* add two deltas from table */

                 t = dst[out] + (((table[c * 2] - 128)*3) >> 2);

                 t= av_clip_uint8(t);

                 dst[out] = t;
                 out++;

                 t = dst[out] + (((table[(c * 2) + 1] - 128)*3) >> 2);

                 t= av_clip_uint8(t);

                 dst[out] = t;
                 out++;
             }
         }
         dst += stride;
     }

     return 0;

 }
 

 static int ir2_decode_frame(AVCodecContext *avctx,

                         void *data, int *data_size,

                         AVPacket *avpkt)

 {

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

     Ir2Context * const s = avctx->priv_data;
     AVFrame *picture = data;
     AVFrame * const p= (AVFrame*)&s->picture;
     int start;
 
     p->reference = 1;
     p->buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
     if (avctx->reget_buffer(avctx, p)) {
         av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
         return -1;
     }
 

     start = 48; /* hardcoded for now */
 
     if (start >= buf_size) {
         av_log(s->avctx, AV_LOG_ERROR, "input buffer size too small (%d)\n", buf_size);
         return AVERROR_INVALIDDATA;
     }
 

     s->decode_delta = buf[18];

     /* decide whether frame uses deltas or not */

 #ifndef ALT_BITSTREAM_READER_LE

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

         buf[i] = av_reverse[buf[i]];

 #endif

     init_get_bits(&s->gb, buf + start, (buf_size - start) * 8);

 
     if (s->decode_delta) { /* intraframe */
         ir2_decode_plane(s, avctx->width, avctx->height,
                          s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
         /* swapped U and V */
         ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
                          s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
         ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
                          s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
     } else { /* interframe */
         ir2_decode_plane_inter(s, avctx->width, avctx->height,
                          s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
         /* swapped U and V */
         ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
                          s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
         ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
                          s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
     }
 
     *picture= *(AVFrame*)&s->picture;
     *data_size = sizeof(AVPicture);
 
     return buf_size;
 }
 

 static av_cold int ir2_decode_init(AVCodecContext *avctx){

     Ir2Context * const ic = avctx->priv_data;

     static VLC_TYPE vlc_tables[1 << CODE_VLC_BITS][2];

     avcodec_get_frame_defaults(&ic->picture);

     ic->avctx = avctx;
 
     avctx->pix_fmt= PIX_FMT_YUV410P;

     ir2_vlc.table = vlc_tables;
     ir2_vlc.table_allocated = 1 << CODE_VLC_BITS;

 #ifdef ALT_BITSTREAM_READER_LE

         init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
                  &ir2_codes[0][1], 4, 2,

                  &ir2_codes[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);

 #else

         init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
                  &ir2_codes[0][1], 4, 2,

                  &ir2_codes[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC);

 #endif

     return 0;
 }
 

 static av_cold int ir2_decode_end(AVCodecContext *avctx){
     Ir2Context * const ic = avctx->priv_data;
     AVFrame *pic = &ic->picture;
 
     if (pic->data[0])
         avctx->release_buffer(avctx, pic);
 
     return 0;
 }
 

 AVCodec ff_indeo2_decoder = {

     "indeo2",

     AVMEDIA_TYPE_VIDEO,

     CODEC_ID_INDEO2,
     sizeof(Ir2Context),
     ir2_decode_init,
     NULL,

     ir2_decode_end,

     ir2_decode_frame,
     CODEC_CAP_DR1,

     .long_name = NULL_IF_CONFIG_SMALL("Intel Indeo 2"),

 };