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 Libav.
7 *
8 * Libav 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 * Libav 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 Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#include "libavutil/imgutils.h"
24#include "avcodec.h"
25#include "bytestream.h"
26#include "bmp.h"
27
28static const uint32_t monoblack_pal[] = { 0x000000, 0xFFFFFF };
29static const uint32_t rgb565_masks[]  = { 0xF800, 0x07E0, 0x001F };
30static const uint32_t rgb444_masks[]  = { 0x0F00, 0x00F0, 0x000F };
31
32static av_cold int bmp_encode_init(AVCodecContext *avctx){
33    BMPContext *s = avctx->priv_data;
34
35    avcodec_get_frame_defaults((AVFrame*)&s->picture);
36    avctx->coded_frame = (AVFrame*)&s->picture;
37
38    switch (avctx->pix_fmt) {
39    case PIX_FMT_BGR24:
40        avctx->bits_per_coded_sample = 24;
41        break;
42    case PIX_FMT_RGB555:
43    case PIX_FMT_RGB565:
44    case PIX_FMT_RGB444:
45        avctx->bits_per_coded_sample = 16;
46        break;
47    case PIX_FMT_RGB8:
48    case PIX_FMT_BGR8:
49    case PIX_FMT_RGB4_BYTE:
50    case PIX_FMT_BGR4_BYTE:
51    case PIX_FMT_GRAY8:
52    case PIX_FMT_PAL8:
53        avctx->bits_per_coded_sample = 8;
54        break;
55    case PIX_FMT_MONOBLACK:
56        avctx->bits_per_coded_sample = 1;
57        break;
58    default:
59        av_log(avctx, AV_LOG_INFO, "unsupported pixel format\n");
60        return -1;
61    }
62
63    return 0;
64}
65
66static int bmp_encode_frame(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
67    BMPContext *s = avctx->priv_data;
68    AVFrame *pict = data;
69    AVFrame * const p= (AVFrame*)&s->picture;
70    int n_bytes_image, n_bytes_per_row, n_bytes, i, n, hsize;
71    const uint32_t *pal = NULL;
72    int pad_bytes_per_row, pal_entries = 0, compression = BMP_RGB;
73    int bit_count = avctx->bits_per_coded_sample;
74    uint8_t *ptr;
75    unsigned char* buf0 = buf;
76    *p = *pict;
77    p->pict_type= AV_PICTURE_TYPE_I;
78    p->key_frame= 1;
79    switch (avctx->pix_fmt) {
80    case PIX_FMT_RGB444:
81        compression = BMP_BITFIELDS;
82        pal = rgb444_masks; // abuse pal to hold color masks
83        pal_entries = 3;
84        break;
85    case PIX_FMT_RGB565:
86        compression = BMP_BITFIELDS;
87        pal = rgb565_masks; // abuse pal to hold color masks
88        pal_entries = 3;
89        break;
90    case PIX_FMT_RGB8:
91    case PIX_FMT_BGR8:
92    case PIX_FMT_RGB4_BYTE:
93    case PIX_FMT_BGR4_BYTE:
94    case PIX_FMT_GRAY8:
95        ff_set_systematic_pal2((uint32_t*)p->data[1], avctx->pix_fmt);
96    case PIX_FMT_PAL8:
97        pal = (uint32_t *)p->data[1];
98        break;
99    case PIX_FMT_MONOBLACK:
100        pal = monoblack_pal;
101        break;
102    }
103    if (pal && !pal_entries) pal_entries = 1 << bit_count;
104    n_bytes_per_row = ((int64_t)avctx->width * (int64_t)bit_count + 7LL) >> 3LL;
105    pad_bytes_per_row = (4 - n_bytes_per_row) & 3;
106    n_bytes_image = avctx->height * (n_bytes_per_row + pad_bytes_per_row);
107
108    // STRUCTURE.field refer to the MSVC documentation for BITMAPFILEHEADER
109    // and related pages.
110#define SIZE_BITMAPFILEHEADER 14
111#define SIZE_BITMAPINFOHEADER 40
112    hsize = SIZE_BITMAPFILEHEADER + SIZE_BITMAPINFOHEADER + (pal_entries << 2);
113    n_bytes = n_bytes_image + hsize;
114    if(n_bytes>buf_size) {
115        av_log(avctx, AV_LOG_ERROR, "buf size too small (need %d, got %d)\n", n_bytes, buf_size);
116        return -1;
117    }
118    bytestream_put_byte(&buf, 'B');                   // BITMAPFILEHEADER.bfType
119    bytestream_put_byte(&buf, 'M');                   // do.
120    bytestream_put_le32(&buf, n_bytes);               // BITMAPFILEHEADER.bfSize
121    bytestream_put_le16(&buf, 0);                     // BITMAPFILEHEADER.bfReserved1
122    bytestream_put_le16(&buf, 0);                     // BITMAPFILEHEADER.bfReserved2
123    bytestream_put_le32(&buf, hsize);                 // BITMAPFILEHEADER.bfOffBits
124    bytestream_put_le32(&buf, SIZE_BITMAPINFOHEADER); // BITMAPINFOHEADER.biSize
125    bytestream_put_le32(&buf, avctx->width);          // BITMAPINFOHEADER.biWidth
126    bytestream_put_le32(&buf, avctx->height);         // BITMAPINFOHEADER.biHeight
127    bytestream_put_le16(&buf, 1);                     // BITMAPINFOHEADER.biPlanes
128    bytestream_put_le16(&buf, bit_count);             // BITMAPINFOHEADER.biBitCount
129    bytestream_put_le32(&buf, compression);           // BITMAPINFOHEADER.biCompression
130    bytestream_put_le32(&buf, n_bytes_image);         // BITMAPINFOHEADER.biSizeImage
131    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biXPelsPerMeter
132    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biYPelsPerMeter
133    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biClrUsed
134    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biClrImportant
135    for (i = 0; i < pal_entries; i++)
136        bytestream_put_le32(&buf, pal[i] & 0xFFFFFF);
137    // BMP files are bottom-to-top so we start from the end...
138    ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
139    buf = buf0 + hsize;
140    for(i = 0; i < avctx->height; i++) {
141        if (bit_count == 16) {
142            const uint16_t *src = (const uint16_t *) ptr;
143            uint16_t *dst = (uint16_t *) buf;
144            for(n = 0; n < avctx->width; n++)
145                AV_WL16(dst + n, src[n]);
146        } else {
147            memcpy(buf, ptr, n_bytes_per_row);
148        }
149        buf += n_bytes_per_row;
150        memset(buf, 0, pad_bytes_per_row);
151        buf += pad_bytes_per_row;
152        ptr -= p->linesize[0]; // ... and go back
153    }
154    return n_bytes;
155}
156
157AVCodec ff_bmp_encoder = {
158    .name           = "bmp",
159    .type           = AVMEDIA_TYPE_VIDEO,
160    .id             = CODEC_ID_BMP,
161    .priv_data_size = sizeof(BMPContext),
162    .init           = bmp_encode_init,
163    .encode         = bmp_encode_frame,
164    .pix_fmts = (const enum PixelFormat[]){
165        PIX_FMT_BGR24,
166        PIX_FMT_RGB555, PIX_FMT_RGB444, PIX_FMT_RGB565,
167        PIX_FMT_RGB8, PIX_FMT_BGR8, PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE, PIX_FMT_GRAY8, PIX_FMT_PAL8,
168        PIX_FMT_MONOBLACK,
169        PIX_FMT_NONE},
170    .long_name = NULL_IF_CONFIG_SMALL("BMP image"),
171};
172