/*
  * BMP image format encoder
  * Copyright (c) 2006, 2007 Michel Bardiaux

  * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>

  *
  * 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 "libavutil/imgutils.h"

 #include "libavutil/avassert.h"

 #include "avcodec.h"
 #include "bytestream.h"
 #include "bmp.h"

 #include "internal.h"

 static const uint32_t monoblack_pal[] = { 0x000000, 0xFFFFFF };
 static const uint32_t rgb565_masks[]  = { 0xF800, 0x07E0, 0x001F };

 static const uint32_t rgb444_masks[]  = { 0x0F00, 0x00F0, 0x000F };

 static av_cold int bmp_encode_init(AVCodecContext *avctx){

     switch (avctx->pix_fmt) {

     case AV_PIX_FMT_BGRA:

         avctx->bits_per_coded_sample = 32;
         break;

     case AV_PIX_FMT_BGR24:

         avctx->bits_per_coded_sample = 24;
         break;

     case AV_PIX_FMT_RGB555:
     case AV_PIX_FMT_RGB565:
     case AV_PIX_FMT_RGB444:

         avctx->bits_per_coded_sample = 16;
         break;

     case AV_PIX_FMT_RGB8:
     case AV_PIX_FMT_BGR8:
     case AV_PIX_FMT_RGB4_BYTE:
     case AV_PIX_FMT_BGR4_BYTE:
     case AV_PIX_FMT_GRAY8:
     case AV_PIX_FMT_PAL8:

         avctx->bits_per_coded_sample = 8;
         break;

     case AV_PIX_FMT_MONOBLACK:

         avctx->bits_per_coded_sample = 1;
         break;
     default:
         av_log(avctx, AV_LOG_INFO, "unsupported pixel format\n");

         return AVERROR(EINVAL);

     }
 

     avctx->coded_frame = av_frame_alloc();
     if (!avctx->coded_frame)
         return AVERROR(ENOMEM);
 

     return 0;
 }
 

 static int bmp_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                             const AVFrame *pict, int *got_packet)
 {

     const AVFrame * const p = pict;

     int n_bytes_image, n_bytes_per_row, n_bytes, i, n, hsize, ret;

     const uint32_t *pal = NULL;

     uint32_t palette256[256];

     int pad_bytes_per_row, pal_entries = 0, compression = BMP_RGB;
     int bit_count = avctx->bits_per_coded_sample;

     uint8_t *ptr, *buf;

     avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
     avctx->coded_frame->key_frame = 1;

     switch (avctx->pix_fmt) {

     case AV_PIX_FMT_RGB444:

         compression = BMP_BITFIELDS;
         pal = rgb444_masks; // abuse pal to hold color masks
         pal_entries = 3;
         break;

     case AV_PIX_FMT_RGB565:

         compression = BMP_BITFIELDS;
         pal = rgb565_masks; // abuse pal to hold color masks
         pal_entries = 3;
         break;

     case AV_PIX_FMT_RGB8:
     case AV_PIX_FMT_BGR8:
     case AV_PIX_FMT_RGB4_BYTE:
     case AV_PIX_FMT_BGR4_BYTE:
     case AV_PIX_FMT_GRAY8:

         av_assert1(bit_count == 8);

         avpriv_set_systematic_pal2(palette256, avctx->pix_fmt);

         pal = palette256;
         break;

     case AV_PIX_FMT_PAL8:

         pal = (uint32_t *)p->data[1];
         break;

     case AV_PIX_FMT_MONOBLACK:

         pal = monoblack_pal;
         break;
     }
     if (pal && !pal_entries) pal_entries = 1 << bit_count;
     n_bytes_per_row = ((int64_t)avctx->width * (int64_t)bit_count + 7LL) >> 3LL;
     pad_bytes_per_row = (4 - n_bytes_per_row) & 3;
     n_bytes_image = avctx->height * (n_bytes_per_row + pad_bytes_per_row);

 
     // STRUCTURE.field refer to the MSVC documentation for BITMAPFILEHEADER
     // and related pages.
 #define SIZE_BITMAPFILEHEADER 14
 #define SIZE_BITMAPINFOHEADER 40

     hsize = SIZE_BITMAPFILEHEADER + SIZE_BITMAPINFOHEADER + (pal_entries << 2);

     n_bytes = n_bytes_image + hsize;

     if ((ret = ff_alloc_packet2(avctx, pkt, n_bytes)) < 0)

         return ret;
     buf = pkt->data;

     bytestream_put_byte(&buf, 'B');                   // BITMAPFILEHEADER.bfType
     bytestream_put_byte(&buf, 'M');                   // do.
     bytestream_put_le32(&buf, n_bytes);               // BITMAPFILEHEADER.bfSize
     bytestream_put_le16(&buf, 0);                     // BITMAPFILEHEADER.bfReserved1
     bytestream_put_le16(&buf, 0);                     // BITMAPFILEHEADER.bfReserved2
     bytestream_put_le32(&buf, hsize);                 // BITMAPFILEHEADER.bfOffBits
     bytestream_put_le32(&buf, SIZE_BITMAPINFOHEADER); // BITMAPINFOHEADER.biSize
     bytestream_put_le32(&buf, avctx->width);          // BITMAPINFOHEADER.biWidth
     bytestream_put_le32(&buf, avctx->height);         // BITMAPINFOHEADER.biHeight
     bytestream_put_le16(&buf, 1);                     // BITMAPINFOHEADER.biPlanes

     bytestream_put_le16(&buf, bit_count);             // BITMAPINFOHEADER.biBitCount
     bytestream_put_le32(&buf, compression);           // BITMAPINFOHEADER.biCompression

     bytestream_put_le32(&buf, n_bytes_image);         // BITMAPINFOHEADER.biSizeImage
     bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biXPelsPerMeter
     bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biYPelsPerMeter
     bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biClrUsed
     bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biClrImportant

     for (i = 0; i < pal_entries; i++)
         bytestream_put_le32(&buf, pal[i] & 0xFFFFFF);

     // BMP files are bottom-to-top so we start from the end...
     ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];

     buf = pkt->data + hsize;

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

         if (bit_count == 16) {
             const uint16_t *src = (const uint16_t *) ptr;
             uint16_t *dst = (uint16_t *) buf;
             for(n = 0; n < avctx->width; n++)
                 AV_WL16(dst + n, src[n]);
         } else {
             memcpy(buf, ptr, n_bytes_per_row);
         }
         buf += n_bytes_per_row;
         memset(buf, 0, pad_bytes_per_row);
         buf += pad_bytes_per_row;

         ptr -= p->linesize[0]; // ... and go back
     }

 
     pkt->flags |= AV_PKT_FLAG_KEY;
     *got_packet = 1;
     return 0;

 }
 

 static av_cold int bmp_encode_close(AVCodecContext *avctx)
 {
     av_frame_free(&avctx->coded_frame);
     return 0;
 }
 

 AVCodec ff_bmp_encoder = {

     .name           = "bmp",

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

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_BMP,

     .init           = bmp_encode_init,

     .encode2        = bmp_encode_frame,

     .close          = bmp_encode_close,

     .pix_fmts       = (const enum AVPixelFormat[]){

         AV_PIX_FMT_BGRA, AV_PIX_FMT_BGR24,
         AV_PIX_FMT_RGB565, AV_PIX_FMT_RGB555, AV_PIX_FMT_RGB444,

         AV_PIX_FMT_RGB8, AV_PIX_FMT_BGR8, AV_PIX_FMT_RGB4_BYTE, AV_PIX_FMT_BGR4_BYTE, AV_PIX_FMT_GRAY8, AV_PIX_FMT_PAL8,
         AV_PIX_FMT_MONOBLACK,
         AV_PIX_FMT_NONE

     },

 };