/*

  * BMP image format decoder

  * Copyright (c) 2005 Mans Rullgard
  *

  * 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 "bmp.h"

 #include "internal.h"

 #include "msrledec.h"

 static av_cold int bmp_decode_init(AVCodecContext *avctx)
 {

     BMPContext *s = avctx->priv_data;
 

     avcodec_get_frame_defaults(&s->picture);
     avctx->coded_frame = &s->picture;

 
     return 0;
 }
 

 static int bmp_decode_frame(AVCodecContext *avctx,

                             void *data, int *got_frame,

                             AVPacket *avpkt)

 {

     const uint8_t *buf = avpkt->data;

     int buf_size       = avpkt->size;
     BMPContext *s      = avctx->priv_data;
     AVFrame *picture   = data;
     AVFrame *p         = &s->picture;

     unsigned int fsize, hsize;
     int width, height;
     unsigned int depth;

     BiCompression comp;

     unsigned int ihsize;

     int i, j, n, linesize, ret;

     uint32_t rgb[3] = {0};

     uint32_t alpha = 0;

     uint8_t *ptr;
     int dsize;

     const uint8_t *buf0 = buf;

     GetByteContext gb;

     if (buf_size < 14) {

         av_log(avctx, AV_LOG_ERROR, "buf size too small (%d)\n", buf_size);

         return AVERROR_INVALIDDATA;

     }
 

     if (bytestream_get_byte(&buf) != 'B' ||
         bytestream_get_byte(&buf) != 'M') {

         av_log(avctx, AV_LOG_ERROR, "bad magic number\n");

         return AVERROR_INVALIDDATA;

     }
 

     fsize = bytestream_get_le32(&buf);

     if (buf_size < fsize) {

         av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d), trying to decode anyway\n",

                buf_size, fsize);

         fsize = buf_size;

     }
 

     buf += 2; /* reserved1 */
     buf += 2; /* reserved2 */

     hsize  = bytestream_get_le32(&buf); /* header size */
     ihsize = bytestream_get_le32(&buf); /* more header size */
     if (ihsize + 14 > hsize) {

         av_log(avctx, AV_LOG_ERROR, "invalid header size %d\n", hsize);

         return AVERROR_INVALIDDATA;

     }
 

     /* sometimes file size is set to some headers size, set a real size in that case */

     if (fsize == 14 || fsize == ihsize + 14)

         fsize = buf_size - 2;
 

     if (fsize <= hsize) {

         av_log(avctx, AV_LOG_ERROR, "declared file size is less than header size (%d < %d)\n",
                fsize, hsize);

         return AVERROR_INVALIDDATA;

     }
 

     switch (ihsize) {

     case  40: // windib
     case  56: // windib v3

     case  64: // OS/2 v2
     case 108: // windib v4
     case 124: // windib v5

         width  = bytestream_get_le32(&buf);

         height = bytestream_get_le32(&buf);

         break;
     case  12: // OS/2 v1

         width  = bytestream_get_le16(&buf);
         height = bytestream_get_le16(&buf);

         break;
     default:

         av_log(avctx, AV_LOG_ERROR, "unsupported BMP file, patch welcome\n");

         return AVERROR_PATCHWELCOME;

     }

     /* planes */
     if (bytestream_get_le16(&buf) != 1) {

         av_log(avctx, AV_LOG_ERROR, "invalid BMP header\n");

         return AVERROR_INVALIDDATA;

     }
 

     depth = bytestream_get_le16(&buf);

     if (ihsize >= 40)

         comp = bytestream_get_le32(&buf);

     else
         comp = BMP_RGB;
 

     if (comp != BMP_RGB && comp != BMP_BITFIELDS && comp != BMP_RLE4 &&
         comp != BMP_RLE8) {

         av_log(avctx, AV_LOG_ERROR, "BMP coding %d not supported\n", comp);

         return AVERROR_INVALIDDATA;

     }
 

     if (comp == BMP_BITFIELDS) {

         buf += 20;
         rgb[0] = bytestream_get_le32(&buf);
         rgb[1] = bytestream_get_le32(&buf);
         rgb[2] = bytestream_get_le32(&buf);

         alpha = bytestream_get_le32(&buf);

     }
 

     avctx->width  = width;
     avctx->height = height > 0 ? height : -height;

     avctx->pix_fmt = AV_PIX_FMT_NONE;

     switch (depth) {

     case 32:

         if (comp == BMP_BITFIELDS) {

             if (rgb[0] == 0xFF000000 && rgb[1] == 0x00FF0000 && rgb[2] == 0x0000FF00)

                 avctx->pix_fmt = alpha ? AV_PIX_FMT_ABGR : AV_PIX_FMT_0BGR;

             else if (rgb[0] == 0x00FF0000 && rgb[1] == 0x0000FF00 && rgb[2] == 0x000000FF)

                 avctx->pix_fmt = alpha ? AV_PIX_FMT_BGRA : AV_PIX_FMT_BGR0;

             else if (rgb[0] == 0x0000FF00 && rgb[1] == 0x00FF0000 && rgb[2] == 0xFF000000)

                 avctx->pix_fmt = alpha ? AV_PIX_FMT_ARGB : AV_PIX_FMT_0RGB;

             else if (rgb[0] == 0x000000FF && rgb[1] == 0x0000FF00 && rgb[2] == 0x00FF0000)

                 avctx->pix_fmt = alpha ? AV_PIX_FMT_RGBA : AV_PIX_FMT_RGB0;

             else {
                 av_log(avctx, AV_LOG_ERROR, "Unknown bitfields %0X %0X %0X\n", rgb[0], rgb[1], rgb[2]);
                 return AVERROR(EINVAL);

             }
         } else {

             avctx->pix_fmt = AV_PIX_FMT_BGRA;

         }
         break;
     case 24:

         avctx->pix_fmt = AV_PIX_FMT_BGR24;

         break;
     case 16:

         if (comp == BMP_RGB)

             avctx->pix_fmt = AV_PIX_FMT_RGB555;

         else if (comp == BMP_BITFIELDS) {
             if (rgb[0] == 0xF800 && rgb[1] == 0x07E0 && rgb[2] == 0x001F)

                avctx->pix_fmt = AV_PIX_FMT_RGB565;

             else if (rgb[0] == 0x7C00 && rgb[1] == 0x03E0 && rgb[2] == 0x001F)

                avctx->pix_fmt = AV_PIX_FMT_RGB555;

             else if (rgb[0] == 0x0F00 && rgb[1] == 0x00F0 && rgb[2] == 0x000F)

                avctx->pix_fmt = AV_PIX_FMT_RGB444;

             else {
                av_log(avctx, AV_LOG_ERROR, "Unknown bitfields %0X %0X %0X\n", rgb[0], rgb[1], rgb[2]);
                return AVERROR(EINVAL);
             }
         }

         break;
     case 8:

         if (hsize - ihsize - 14 > 0)

             avctx->pix_fmt = AV_PIX_FMT_PAL8;

         else

             avctx->pix_fmt = AV_PIX_FMT_GRAY8;

         break;

     case 1:

     case 4:

         if (hsize - ihsize - 14 > 0) {

             avctx->pix_fmt = AV_PIX_FMT_PAL8;

         } else {

             av_log(avctx, AV_LOG_ERROR, "Unknown palette for %d-colour BMP\n", 1<<depth);

             return AVERROR_INVALIDDATA;

         }
         break;

     default:
         av_log(avctx, AV_LOG_ERROR, "depth %d not supported\n", depth);

         return AVERROR_INVALIDDATA;

     }
 

     if (avctx->pix_fmt == AV_PIX_FMT_NONE) {

         av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n");

         return AVERROR_INVALIDDATA;

     }
 

     if (p->data[0])

         avctx->release_buffer(avctx, p);
 

     p->reference = 0;

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

         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

         return ret;

     }

     p->pict_type = AV_PICTURE_TYPE_I;

     p->key_frame = 1;
 

     buf   = buf0 + hsize;

     dsize = buf_size - hsize;
 

     /* Line size in file multiple of 4 */

     n = ((avctx->width * depth + 31) / 8) & ~3;

     if (n * avctx->height > dsize && comp != BMP_RLE4 && comp != BMP_RLE8) {

         av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
                dsize, n * avctx->height);

         return AVERROR_INVALIDDATA;

     }
 

     // RLE may skip decoding some picture areas, so blank picture before decoding

     if (comp == BMP_RLE4 || comp == BMP_RLE8)

         memset(p->data[0], 0, avctx->height * p->linesize[0]);
 

     if (height > 0) {
         ptr      = p->data[0] + (avctx->height - 1) * p->linesize[0];

         linesize = -p->linesize[0];
     } else {

         ptr      = p->data[0];

         linesize = p->linesize[0];
     }
 

     if (avctx->pix_fmt == AV_PIX_FMT_PAL8) {

         int colors = 1 << depth;

 
         memset(p->data[1], 0, 1024);
 

         if (ihsize >= 36) {

             int t;
             buf = buf0 + 46;

             t   = bytestream_get_le32(&buf);
             if (t < 0 || t > (1 << depth)) {

                 av_log(avctx, AV_LOG_ERROR, "Incorrect number of colors - %X for bitdepth %d\n", t, depth);

             } else if (t) {

                 colors = t;
             }
         }

         buf = buf0 + 14 + ihsize; //palette location

         // OS/2 bitmap, 3 bytes per palette entry
         if ((hsize-ihsize-14) < (colors << 2)) {

             if ((hsize-ihsize-14) < colors * 3) {
                 av_log(avctx, AV_LOG_ERROR, "palette doesnt fit in packet\n");
                 return AVERROR_INVALIDDATA;
             }

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

                 ((uint32_t*)p->data[1])[i] = (0xFFU<<24) | bytestream_get_le24(&buf);

         } else {
             for (i = 0; i < colors; i++)

                 ((uint32_t*)p->data[1])[i] = 0xFFU << 24 | bytestream_get_le32(&buf);

         }
         buf = buf0 + hsize;
     }

     if (comp == BMP_RLE4 || comp == BMP_RLE8) {
         if (height < 0) {
             p->data[0]    +=  p->linesize[0] * (avctx->height - 1);

             p->linesize[0] = -p->linesize[0];
         }

         bytestream2_init(&gb, buf, dsize);
         ff_msrle_decode(avctx, (AVPicture*)p, depth, &gb);

         if (height < 0) {
             p->data[0]    +=  p->linesize[0] * (avctx->height - 1);

             p->linesize[0] = -p->linesize[0];
         }

     } else {
         switch (depth) {

         case 1:

             for (i = 0; i < avctx->height; i++) {

                 int j;

                 for (j = 0; j < n; j++) {

                     ptr[j*8+0] =  buf[j] >> 7;
                     ptr[j*8+1] = (buf[j] >> 6) & 1;
                     ptr[j*8+2] = (buf[j] >> 5) & 1;
                     ptr[j*8+3] = (buf[j] >> 4) & 1;
                     ptr[j*8+4] = (buf[j] >> 3) & 1;
                     ptr[j*8+5] = (buf[j] >> 2) & 1;
                     ptr[j*8+6] = (buf[j] >> 1) & 1;
                     ptr[j*8+7] =  buf[j]       & 1;
                 }
                 buf += n;
                 ptr += linesize;
             }
             break;

         case 8:
         case 24:

         case 32:

             for (i = 0; i < avctx->height; i++) {

                 memcpy(ptr, buf, n);
                 buf += n;
                 ptr += linesize;

             }

             break;
         case 4:

             for (i = 0; i < avctx->height; i++) {

                 int j;

                 for (j = 0; j < n; j++) {

                     ptr[j*2+0] = (buf[j] >> 4) & 0xF;
                     ptr[j*2+1] = buf[j] & 0xF;
                 }
                 buf += n;
                 ptr += linesize;
             }
             break;
         case 16:

             for (i = 0; i < avctx->height; i++) {

                 const uint16_t *src = (const uint16_t *) buf;

                 uint16_t *dst       = (uint16_t *) ptr;

                 for (j = 0; j < avctx->width; j++)

                     *dst++ = av_le2ne16(*src++);

                 buf += n;
                 ptr += linesize;

             }

             break;
         default:
             av_log(avctx, AV_LOG_ERROR, "BMP decoder is broken\n");

             return AVERROR_INVALIDDATA;

         }

     }

 
     *picture = s->picture;

     *got_frame = 1;

 
     return buf_size;
 }
 

 static av_cold int bmp_decode_end(AVCodecContext *avctx)

 {
     BMPContext* c = avctx->priv_data;
 
     if (c->picture.data[0])
         avctx->release_buffer(avctx, &c->picture);
 
     return 0;
 }
 

 AVCodec ff_bmp_decoder = {

     .name           = "bmp",
     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_BMP,

     .priv_data_size = sizeof(BMPContext),
     .init           = bmp_decode_init,
     .close          = bmp_decode_end,
     .decode         = bmp_decode_frame,
     .capabilities   = CODEC_CAP_DR1,

     .long_name      = NULL_IF_CONFIG_SMALL("BMP (Windows and OS/2 bitmap)"),

 };