2 * BMP image format encoder
3 * Copyright (c) 2006, 2007 Michel Bardiaux
4 * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
6 * This file is part of FFmpeg.
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.
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.
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
23 #include "libavutil/imgutils.h"
25 #include "bytestream.h"
29 static const uint32_t monoblack_pal[] = { 0x000000, 0xFFFFFF };
30 static const uint32_t rgb565_masks[] = { 0xF800, 0x07E0, 0x001F };
32 static av_cold int bmp_encode_init(AVCodecContext *avctx){
33 BMPContext *s = avctx->priv_data;
35 avcodec_get_frame_defaults((AVFrame*)&s->picture);
36 avctx->coded_frame = (AVFrame*)&s->picture;
38 switch (avctx->pix_fmt) {
40 avctx->bits_per_coded_sample = 24;
43 avctx->bits_per_coded_sample = 16;
46 avctx->bits_per_coded_sample = 16;
50 case PIX_FMT_RGB4_BYTE:
51 case PIX_FMT_BGR4_BYTE:
54 avctx->bits_per_coded_sample = 8;
56 case PIX_FMT_MONOBLACK:
57 avctx->bits_per_coded_sample = 1;
60 av_log(avctx, AV_LOG_INFO, "unsupported pixel format\n");
67 static int bmp_encode_frame(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
68 BMPContext *s = avctx->priv_data;
70 AVFrame * const p= (AVFrame*)&s->picture;
71 int n_bytes_image, n_bytes_per_row, n_bytes, i, n, hsize;
72 const uint32_t *pal = NULL;
73 uint32_t palette256[256];
74 int pad_bytes_per_row, pal_entries = 0, compression = BMP_RGB;
75 int bit_count = avctx->bits_per_coded_sample;
77 unsigned char* buf0 = buf;
79 p->pict_type= AV_PICTURE_TYPE_I;
81 switch (avctx->pix_fmt) {
83 compression = BMP_BITFIELDS;
84 pal = rgb565_masks; // abuse pal to hold color masks
89 case PIX_FMT_RGB4_BYTE:
90 case PIX_FMT_BGR4_BYTE:
92 assert(bit_count == 8);
93 ff_set_systematic_pal2(palette256, avctx->pix_fmt);
97 pal = (uint32_t *)p->data[1];
99 case PIX_FMT_MONOBLACK:
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);
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);
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];
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]);
147 memcpy(buf, ptr, n_bytes_per_row);
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
157 AVCodec ff_bmp_encoder = {
159 .type = AVMEDIA_TYPE_VIDEO,
161 .priv_data_size = sizeof(BMPContext),
162 .init = bmp_encode_init,
163 .encode = bmp_encode_frame,
164 .pix_fmts = (const enum PixelFormat[]){
166 PIX_FMT_RGB555, PIX_FMT_RGB565,
167 PIX_FMT_RGB8, PIX_FMT_BGR8, PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE, PIX_FMT_GRAY8, PIX_FMT_PAL8,
170 .long_name = NULL_IF_CONFIG_SMALL("BMP image"),