/*
  * Quicktime Planar RGB (8BPS) Video Decoder
  * Copyright (C) 2003 Roberto Togni
  *

  * 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 libavcodec/8bps.c

  * QT 8BPS Video Decoder by Roberto Togni

  * For more information about the 8BPS format, visit:
  *   http://www.pcisys.net/~melanson/codecs/
  *
  * Supports: PAL8 (RGB 8bpp, paletted)

  *         : BGR24 (RGB 24bpp) (can also output it as RGB32)
  *         : RGB32 (RGB 32bpp, 4th plane is probably alpha and it's ignored)

  *
  */
 
 #include <stdio.h>
 #include <stdlib.h>
 

 #include "libavutil/intreadwrite.h"

 #include "avcodec.h"
 
 

 static const enum PixelFormat pixfmt_rgb24[] = {PIX_FMT_BGR24, PIX_FMT_RGB32, PIX_FMT_NONE};

 
 /*
  * Decoder context
  */
 typedef struct EightBpsContext {
 

         AVCodecContext *avctx;
         AVFrame pic;

         unsigned char planes;
         unsigned char planemap[4];

 } EightBpsContext;
 
 
 /*
  *
  * Decode a frame
  *
  */

 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)

 {

         EightBpsContext * const c = avctx->priv_data;

         const unsigned char *encoded = buf;

         unsigned char *pixptr, *pixptr_end;
         unsigned int height = avctx->height; // Real image height
         unsigned int dlen, p, row;

         const unsigned char *lp, *dp;

         unsigned char count;
         unsigned int px_inc;
         unsigned int planes = c->planes;
         unsigned char *planemap = c->planemap;
 
         if(c->pic.data[0])
                 avctx->release_buffer(avctx, &c->pic);
 
         c->pic.reference = 0;
         c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
         if(avctx->get_buffer(avctx, &c->pic) < 0){
                 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
                 return -1;
         }
 
         /* Set data pointer after line lengths */
         dp = encoded + planes * (height << 1);
 
         /* Ignore alpha plane, don't know what to do with it */
         if (planes == 4)
                 planes--;
 

         px_inc = planes + (avctx->pix_fmt == PIX_FMT_RGB32);

 
         for (p = 0; p < planes; p++) {
                 /* Lines length pointer for this plane */
                 lp = encoded + p * (height << 1);
 
                 /* Decode a plane */
                 for(row = 0; row < height; row++) {
                         pixptr = c->pic.data[0] + row * c->pic.linesize[0] + planemap[p];
                         pixptr_end = pixptr + c->pic.linesize[0];

                         dlen = be2me_16(*(const unsigned short *)(lp+row*2));

                         /* Decode a row of this plane */
                         while(dlen > 0) {
                                 if(dp + 1 >= buf+buf_size) return -1;
                                 if ((count = *dp++) <= 127) {
                                         count++;
                                         dlen -= count + 1;
                                         if (pixptr + count * px_inc > pixptr_end)
                                             break;
                                         if(dp + count > buf+buf_size) return -1;
                                         while(count--) {
                                                 *pixptr = *dp++;
                                                 pixptr += px_inc;
                                         }
                                 } else {
                                         count = 257 - count;
                                         if (pixptr + count * px_inc > pixptr_end)
                                             break;
                                         while(count--) {
                                                 *pixptr = *dp;
                                                 pixptr += px_inc;
                                         }
                                         dp++;
                                         dlen -= 2;
                                 }
                         }
                 }
         }
 
         if (avctx->palctrl) {
                 memcpy (c->pic.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
                 if (avctx->palctrl->palette_changed) {
                         c->pic.palette_has_changed = 1;
                         avctx->palctrl->palette_changed = 0;
                 } else
                         c->pic.palette_has_changed = 0;
         }
 
         *data_size = sizeof(AVFrame);
         *(AVFrame*)data = c->pic;
 
         /* always report that the buffer was completely consumed */
         return buf_size;

 }
 
 
 /*
  *
  * Init 8BPS decoder
  *
  */

 static av_cold int decode_init(AVCodecContext *avctx)

 {

         EightBpsContext * const c = avctx->priv_data;

         c->avctx = avctx;

         c->pic.data[0] = NULL;

     if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {

         return 1;
     }
 

         switch (avctx->bits_per_coded_sample) {

                 case 8:
                         avctx->pix_fmt = PIX_FMT_PAL8;
                         c->planes = 1;
                         c->planemap[0] = 0; // 1st plane is palette indexes
                         if (avctx->palctrl == NULL) {
                                 av_log(avctx, AV_LOG_ERROR, "Error: PAL8 format but no palette from demuxer.\n");
                                 return -1;
                         }
                         break;
                 case 24:
                         avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);
                         c->planes = 3;
                         c->planemap[0] = 2; // 1st plane is red
                         c->planemap[1] = 1; // 2nd plane is green
                         c->planemap[2] = 0; // 3rd plane is blue
                         break;
                 case 32:

                         avctx->pix_fmt = PIX_FMT_RGB32;

                         c->planes = 4;

 #ifdef WORDS_BIGENDIAN

                         c->planemap[0] = 1; // 1st plane is red
                         c->planemap[1] = 2; // 2nd plane is green
                         c->planemap[2] = 3; // 3rd plane is blue
                         c->planemap[3] = 0; // 4th plane is alpha???

 #else

                         c->planemap[0] = 2; // 1st plane is red
                         c->planemap[1] = 1; // 2nd plane is green
                         c->planemap[2] = 0; // 3rd plane is blue
                         c->planemap[3] = 3; // 4th plane is alpha???

 #endif

                         break;
                 default:

                         av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n", avctx->bits_per_coded_sample);

                         return -1;
         }

 
   return 0;
 }
 
 
 
 
 /*
  *
  * Uninit 8BPS decoder
  *
  */

 static av_cold int decode_end(AVCodecContext *avctx)

 {

         EightBpsContext * const c = avctx->priv_data;

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

         return 0;

 }
 
 
 
 AVCodec eightbps_decoder = {

         "8bps",
         CODEC_TYPE_VIDEO,
         CODEC_ID_8BPS,
         sizeof(EightBpsContext),
         decode_init,
         NULL,
         decode_end,
         decode_frame,
         CODEC_CAP_DR1,

         .long_name = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),

 };