/*
  * PNM image format
  * Copyright (c) 2002, 2003 Fabrice Bellard
  *
  * 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 "avcodec.h"
 #include "bytestream.h"

 #include "put_bits.h"

 #include "pnm.h"
 
 
 static int pnm_decode_frame(AVCodecContext *avctx, void *data,
                             int *data_size, AVPacket *avpkt)
 {
     const uint8_t *buf   = avpkt->data;
     int buf_size         = avpkt->size;
     PNMContext * const s = avctx->priv_data;
     AVFrame *picture     = data;
     AVFrame * const p    = (AVFrame*)&s->picture;

     int i, j, n, linesize, h, upgrade = 0, is_mono = 0;

     unsigned char *ptr;

     int components, sample_len;

 
     s->bytestream_start =
     s->bytestream       = buf;
     s->bytestream_end   = buf + buf_size;
 
     if (ff_pnm_decode_header(avctx, s) < 0)
         return -1;
 
     if (p->data[0])
         avctx->release_buffer(avctx, p);
 
     p->reference = 0;
     if (avctx->get_buffer(avctx, p) < 0) {
         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
         return -1;
     }

     p->pict_type = AV_PICTURE_TYPE_I;

     p->key_frame = 1;
 
     switch (avctx->pix_fmt) {
     default:
         return -1;
     case PIX_FMT_RGB48BE:
         n = avctx->width * 6;

         components=3;
         sample_len=16;

         goto do_read;
     case PIX_FMT_RGB24:
         n = avctx->width * 3;

         components=3;
         sample_len=8;

         goto do_read;
     case PIX_FMT_GRAY8:
         n = avctx->width;

         components=1;
         sample_len=8;

         if (s->maxval < 255)
             upgrade = 1;
         goto do_read;
     case PIX_FMT_GRAY16BE:
     case PIX_FMT_GRAY16LE:
         n = avctx->width * 2;

         components=1;
         sample_len=16;

         if (s->maxval < 65535)
             upgrade = 2;
         goto do_read;
     case PIX_FMT_MONOWHITE:
     case PIX_FMT_MONOBLACK:
         n = (avctx->width + 7) >> 3;

         components=1;
         sample_len=1;

         is_mono = 1;

     do_read:
         ptr      = p->data[0];
         linesize = p->linesize[0];
         if (s->bytestream + n * avctx->height > s->bytestream_end)
             return -1;

         if(s->type < 4){
             for (i=0; i<avctx->height; i++) {
                 PutBitContext pb;
                 init_put_bits(&pb, ptr, linesize);
                 for(j=0; j<avctx->width * components; j++){
                     unsigned int c=0;
                     int v=0;
                     while(s->bytestream < s->bytestream_end && (*s->bytestream < '0' || *s->bytestream > '9' ))
                         s->bytestream++;
                     if(s->bytestream >= s->bytestream_end)
                         return -1;

                     if (is_mono) {
                         /* read a single digit */
                         v = (*s->bytestream++) - '0';
                     } else {

                         /* read a sequence of digits */
                         do {
                             v = 10*v + c;
                             c = (*s->bytestream++) - '0';
                         } while (c <= 9);

                     }

                     put_bits(&pb, sample_len, (((1<<sample_len)-1)*v + (s->maxval>>1))/s->maxval);
                 }
                 flush_put_bits(&pb);
                 ptr+= linesize;
             }
         }else{

         for (i = 0; i < avctx->height; i++) {
             if (!upgrade)
                 memcpy(ptr, s->bytestream, n);
             else if (upgrade == 1) {
                 unsigned int j, f = (255 * 128 + s->maxval / 2) / s->maxval;
                 for (j = 0; j < n; j++)
                     ptr[j] = (s->bytestream[j] * f + 64) >> 7;
             } else if (upgrade == 2) {
                 unsigned int j, v, f = (65535 * 32768 + s->maxval / 2) / s->maxval;
                 for (j = 0; j < n / 2; j++) {

                     v = av_be2ne16(((uint16_t *)s->bytestream)[j]);

                     ((uint16_t *)ptr)[j] = (v * f + 16384) >> 15;
                 }
             }
             s->bytestream += n;
             ptr           += linesize;
         }

         }

         break;
     case PIX_FMT_YUV420P:
         {
             unsigned char *ptr1, *ptr2;
 
             n        = avctx->width;
             ptr      = p->data[0];
             linesize = p->linesize[0];
             if (s->bytestream + n * avctx->height * 3 / 2 > s->bytestream_end)
                 return -1;
             for (i = 0; i < avctx->height; i++) {
                 memcpy(ptr, s->bytestream, n);
                 s->bytestream += n;
                 ptr           += linesize;
             }
             ptr1 = p->data[1];
             ptr2 = p->data[2];
             n >>= 1;
             h = avctx->height >> 1;
             for (i = 0; i < h; i++) {
                 memcpy(ptr1, s->bytestream, n);
                 s->bytestream += n;
                 memcpy(ptr2, s->bytestream, n);
                 s->bytestream += n;
                 ptr1 += p->linesize[1];
                 ptr2 += p->linesize[2];
             }
         }
         break;
     case PIX_FMT_RGB32:
         ptr      = p->data[0];
         linesize = p->linesize[0];
         if (s->bytestream + avctx->width * avctx->height * 4 > s->bytestream_end)
             return -1;
         for (i = 0; i < avctx->height; i++) {
             int j, r, g, b, a;
 
             for (j = 0; j < avctx->width; j++) {
                 r = *s->bytestream++;
                 g = *s->bytestream++;
                 b = *s->bytestream++;
                 a = *s->bytestream++;
                 ((uint32_t *)ptr)[j] = (a << 24) | (r << 16) | (g << 8) | b;
             }
             ptr += linesize;
         }
         break;
     }
     *picture   = *(AVFrame*)&s->picture;
     *data_size = sizeof(AVPicture);
 
     return s->bytestream - s->bytestream_start;
 }
 
 
 #if CONFIG_PGM_DECODER

 AVCodec ff_pgm_decoder = {

     "pgm",

     AVMEDIA_TYPE_VIDEO,

     CODEC_ID_PGM,
     sizeof(PNMContext),
     ff_pnm_init,
     NULL,
     ff_pnm_end,
     pnm_decode_frame,
     CODEC_CAP_DR1,
     .pix_fmts  = (const enum PixelFormat[]){PIX_FMT_GRAY8, PIX_FMT_GRAY16BE, PIX_FMT_NONE},
     .long_name = NULL_IF_CONFIG_SMALL("PGM (Portable GrayMap) image"),
 };
 #endif
 
 #if CONFIG_PGMYUV_DECODER

 AVCodec ff_pgmyuv_decoder = {

     "pgmyuv",

     AVMEDIA_TYPE_VIDEO,

     CODEC_ID_PGMYUV,
     sizeof(PNMContext),
     ff_pnm_init,
     NULL,
     ff_pnm_end,
     pnm_decode_frame,
     CODEC_CAP_DR1,
     .pix_fmts  = (const enum PixelFormat[]){PIX_FMT_YUV420P, PIX_FMT_NONE},
     .long_name = NULL_IF_CONFIG_SMALL("PGMYUV (Portable GrayMap YUV) image"),
 };
 #endif
 
 #if CONFIG_PPM_DECODER

 AVCodec ff_ppm_decoder = {

     "ppm",

     AVMEDIA_TYPE_VIDEO,

     CODEC_ID_PPM,
     sizeof(PNMContext),
     ff_pnm_init,
     NULL,
     ff_pnm_end,
     pnm_decode_frame,
     CODEC_CAP_DR1,
     .pix_fmts  = (const enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGB48BE, PIX_FMT_NONE},
     .long_name = NULL_IF_CONFIG_SMALL("PPM (Portable PixelMap) image"),
 };
 #endif
 
 #if CONFIG_PBM_DECODER

 AVCodec ff_pbm_decoder = {

     "pbm",

     AVMEDIA_TYPE_VIDEO,

     CODEC_ID_PBM,
     sizeof(PNMContext),
     ff_pnm_init,
     NULL,
     ff_pnm_end,
     pnm_decode_frame,
     CODEC_CAP_DR1,
     .pix_fmts  = (const enum PixelFormat[]){PIX_FMT_MONOWHITE, PIX_FMT_NONE},
     .long_name = NULL_IF_CONFIG_SMALL("PBM (Portable BitMap) image"),
 };
 #endif
 
 #if CONFIG_PAM_DECODER

 AVCodec ff_pam_decoder = {

     "pam",

     AVMEDIA_TYPE_VIDEO,

     CODEC_ID_PAM,
     sizeof(PNMContext),
     ff_pnm_init,
     NULL,
     ff_pnm_end,
     pnm_decode_frame,
     CODEC_CAP_DR1,
     .pix_fmts  = (const enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGB32, PIX_FMT_GRAY8, PIX_FMT_MONOWHITE, PIX_FMT_NONE},
     .long_name = NULL_IF_CONFIG_SMALL("PAM (Portable AnyMap) image"),
 };
 #endif