1/*
2 * BMP image format encoder
3 * Copyright (c) 2006, 2007 Michel Bardiaux
4 * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#include "avcodec.h"
24#include "bytestream.h"
25#include "bmp.h"
26
27static const uint32_t monoblack_pal[] = { 0x000000, 0xFFFFFF };
28static const uint32_t rgb565_masks[]  = { 0xF800, 0x07E0, 0x001F };
29
30static av_cold int bmp_encode_init(AVCodecContext *avctx){
31    BMPContext *s = avctx->priv_data;
32
33    avcodec_get_frame_defaults((AVFrame*)&s->picture);
34    avctx->coded_frame = (AVFrame*)&s->picture;
35
36    return 0;
37}
38
39static int bmp_encode_frame(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
40    BMPContext *s = avctx->priv_data;
41    AVFrame *pict = data;
42    AVFrame * const p= (AVFrame*)&s->picture;
43    int n_bytes_image, n_bytes_per_row, n_bytes, i, n, hsize;
44    const uint32_t *pal = NULL;
45    int pad_bytes_per_row, bit_count, pal_entries = 0, compression = BMP_RGB;
46    uint8_t *ptr;
47    unsigned char* buf0 = buf;
48    *p = *pict;
49    p->pict_type= FF_I_TYPE;
50    p->key_frame= 1;
51    switch (avctx->pix_fmt) {
52    case PIX_FMT_BGR24:
53        bit_count = 24;
54        break;
55    case PIX_FMT_RGB555:
56        bit_count = 16;
57        break;
58    case PIX_FMT_RGB565:
59        bit_count = 16;
60        compression = BMP_BITFIELDS;
61        pal = rgb565_masks; // abuse pal to hold color masks
62        pal_entries = 3;
63        break;
64    case PIX_FMT_RGB8:
65    case PIX_FMT_BGR8:
66    case PIX_FMT_RGB4_BYTE:
67    case PIX_FMT_BGR4_BYTE:
68    case PIX_FMT_GRAY8:
69    case PIX_FMT_PAL8:
70        bit_count = 8;
71        pal = (uint32_t *)p->data[1];
72        break;
73    case PIX_FMT_MONOBLACK:
74        bit_count = 1;
75        pal = monoblack_pal;
76        break;
77    default:
78        return -1;
79    }
80    if (pal && !pal_entries) pal_entries = 1 << bit_count;
81    n_bytes_per_row = ((int64_t)avctx->width * (int64_t)bit_count + 7LL) >> 3LL;
82    pad_bytes_per_row = (4 - n_bytes_per_row) & 3;
83    n_bytes_image = avctx->height * (n_bytes_per_row + pad_bytes_per_row);
84
85    // STRUCTURE.field refer to the MSVC documentation for BITMAPFILEHEADER
86    // and related pages.
87#define SIZE_BITMAPFILEHEADER 14
88#define SIZE_BITMAPINFOHEADER 40
89    hsize = SIZE_BITMAPFILEHEADER + SIZE_BITMAPINFOHEADER + (pal_entries << 2);
90    n_bytes = n_bytes_image + hsize;
91    if(n_bytes>buf_size) {
92        av_log(avctx, AV_LOG_ERROR, "buf size too small (need %d, got %d)\n", n_bytes, buf_size);
93        return -1;
94    }
95    bytestream_put_byte(&buf, 'B');                   // BITMAPFILEHEADER.bfType
96    bytestream_put_byte(&buf, 'M');                   // do.
97    bytestream_put_le32(&buf, n_bytes);               // BITMAPFILEHEADER.bfSize
98    bytestream_put_le16(&buf, 0);                     // BITMAPFILEHEADER.bfReserved1
99    bytestream_put_le16(&buf, 0);                     // BITMAPFILEHEADER.bfReserved2
100    bytestream_put_le32(&buf, hsize);                 // BITMAPFILEHEADER.bfOffBits
101    bytestream_put_le32(&buf, SIZE_BITMAPINFOHEADER); // BITMAPINFOHEADER.biSize
102    bytestream_put_le32(&buf, avctx->width);          // BITMAPINFOHEADER.biWidth
103    bytestream_put_le32(&buf, avctx->height);         // BITMAPINFOHEADER.biHeight
104    bytestream_put_le16(&buf, 1);                     // BITMAPINFOHEADER.biPlanes
105    bytestream_put_le16(&buf, bit_count);             // BITMAPINFOHEADER.biBitCount
106    bytestream_put_le32(&buf, compression);           // BITMAPINFOHEADER.biCompression
107    bytestream_put_le32(&buf, n_bytes_image);         // BITMAPINFOHEADER.biSizeImage
108    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biXPelsPerMeter
109    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biYPelsPerMeter
110    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biClrUsed
111    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biClrImportant
112    for (i = 0; i < pal_entries; i++)
113        bytestream_put_le32(&buf, pal[i] & 0xFFFFFF);
114    // BMP files are bottom-to-top so we start from the end...
115    ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
116    buf = buf0 + hsize;
117    for(i = 0; i < avctx->height; i++) {
118        if (bit_count == 16) {
119            const uint16_t *src = (const uint16_t *) ptr;
120            uint16_t *dst = (uint16_t *) buf;
121            for(n = 0; n < avctx->width; n++)
122                AV_WL16(dst + n, src[n]);
123        } else {
124            memcpy(buf, ptr, n_bytes_per_row);
125        }
126        buf += n_bytes_per_row;
127        memset(buf, 0, pad_bytes_per_row);
128        buf += pad_bytes_per_row;
129        ptr -= p->linesize[0]; // ... and go back
130    }
131    return n_bytes;
132}
133
134AVCodec bmp_encoder = {
135    "bmp",
136    AVMEDIA_TYPE_VIDEO,
137    CODEC_ID_BMP,
138    sizeof(BMPContext),
139    bmp_encode_init,
140    bmp_encode_frame,
141    NULL, //encode_end,
142    .pix_fmts = (const enum PixelFormat[]){
143        PIX_FMT_BGR24,
144        PIX_FMT_RGB555, PIX_FMT_RGB565,
145        PIX_FMT_RGB8, PIX_FMT_BGR8, PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE, PIX_FMT_GRAY8, PIX_FMT_PAL8,
146        PIX_FMT_MONOBLACK,
147        PIX_FMT_NONE},
148    .long_name = NULL_IF_CONFIG_SMALL("BMP image"),
149};
150