1/*
2 * BMP image format encoder
3 * Copyright (c) 2006, 2007 Michel Bardiaux
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#include "avcodec.h"
23#include "bytestream.h"
24#include "bmp.h"
25
26static av_cold int bmp_encode_init(AVCodecContext *avctx){
27    BMPContext *s = avctx->priv_data;
28
29    avcodec_get_frame_defaults((AVFrame*)&s->picture);
30    avctx->coded_frame = (AVFrame*)&s->picture;
31
32    return 0;
33}
34
35static int bmp_encode_frame(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
36    BMPContext *s = avctx->priv_data;
37    AVFrame *pict = data;
38    AVFrame * const p= (AVFrame*)&s->picture;
39    int n_bytes_image, n_bytes_per_row, n_bytes, i, n, hsize;
40    uint8_t *ptr;
41    unsigned char* buf0 = buf;
42    *p = *pict;
43    p->pict_type= FF_I_TYPE;
44    p->key_frame= 1;
45    n_bytes_per_row = (avctx->width*3 + 3) & ~3;
46    n_bytes_image = avctx->height*n_bytes_per_row;
47
48    // STRUCTURE.field refer to the MSVC documentation for BITMAPFILEHEADER
49    // and related pages.
50#define SIZE_BITMAPFILEHEADER 14
51#define SIZE_BITMAPINFOHEADER 40
52    hsize = SIZE_BITMAPFILEHEADER + SIZE_BITMAPINFOHEADER;
53    n_bytes = n_bytes_image + hsize;
54    if(n_bytes>buf_size) {
55        av_log(avctx, AV_LOG_ERROR, "buf size too small (need %d, got %d)\n", n_bytes, buf_size);
56        return -1;
57    }
58    bytestream_put_byte(&buf, 'B');                   // BITMAPFILEHEADER.bfType
59    bytestream_put_byte(&buf, 'M');                   // do.
60    bytestream_put_le32(&buf, n_bytes);               // BITMAPFILEHEADER.bfSize
61    bytestream_put_le16(&buf, 0);                     // BITMAPFILEHEADER.bfReserved1
62    bytestream_put_le16(&buf, 0);                     // BITMAPFILEHEADER.bfReserved2
63    bytestream_put_le32(&buf, hsize);                 // BITMAPFILEHEADER.bfOffBits
64    bytestream_put_le32(&buf, SIZE_BITMAPINFOHEADER); // BITMAPINFOHEADER.biSize
65    bytestream_put_le32(&buf, avctx->width);          // BITMAPINFOHEADER.biWidth
66    bytestream_put_le32(&buf, avctx->height);         // BITMAPINFOHEADER.biHeight
67    bytestream_put_le16(&buf, 1);                     // BITMAPINFOHEADER.biPlanes
68    bytestream_put_le16(&buf, 24);                    // BITMAPINFOHEADER.biBitCount
69    bytestream_put_le32(&buf, BMP_RGB);               // BITMAPINFOHEADER.biCompression
70    bytestream_put_le32(&buf, n_bytes_image);         // BITMAPINFOHEADER.biSizeImage
71    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biXPelsPerMeter
72    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biYPelsPerMeter
73    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biClrUsed
74    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biClrImportant
75    // BMP files are bottom-to-top so we start from the end...
76    ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
77    buf = buf0 + hsize;
78    for(i = 0; i < avctx->height; i++) {
79        n = 3*avctx->width;
80        memcpy(buf, ptr, n);
81        buf += n;
82        memset(buf, 0, n_bytes_per_row-n);
83        buf += n_bytes_per_row-n;
84        ptr -= p->linesize[0]; // ... and go back
85    }
86    return n_bytes;
87}
88
89AVCodec bmp_encoder = {
90    "bmp",
91    CODEC_TYPE_VIDEO,
92    CODEC_ID_BMP,
93    sizeof(BMPContext),
94    bmp_encode_init,
95    bmp_encode_frame,
96    NULL, //encode_end,
97    .pix_fmts= (enum PixelFormat[]){PIX_FMT_BGR24, PIX_FMT_NONE},
98    .long_name = NULL_IF_CONFIG_SMALL("BMP image"),
99};
100