Statistics
| Branch: | Revision:

ffmpeg / libavcodec / bmpenc.c @ 2912e87a

History | View | Annotate | Download (6.31 KB)

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

    
28
static const uint32_t monoblack_pal[] = { 0x000000, 0xFFFFFF };
29
static const uint32_t rgb565_masks[]  = { 0xF800, 0x07E0, 0x001F };
30

    
31
static av_cold int bmp_encode_init(AVCodecContext *avctx){
32
    BMPContext *s = avctx->priv_data;
33

    
34
    avcodec_get_frame_defaults((AVFrame*)&s->picture);
35
    avctx->coded_frame = (AVFrame*)&s->picture;
36

    
37
    switch (avctx->pix_fmt) {
38
    case PIX_FMT_BGR24:
39
        avctx->bits_per_coded_sample = 24;
40
        break;
41
    case PIX_FMT_RGB555:
42
        avctx->bits_per_coded_sample = 16;
43
        break;
44
    case PIX_FMT_RGB565:
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

    
66
static 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= FF_I_TYPE;
78
    p->key_frame= 1;
79
    switch (avctx->pix_fmt) {
80
    case PIX_FMT_RGB565:
81
        compression = BMP_BITFIELDS;
82
        pal = rgb565_masks; // abuse pal to hold color masks
83
        pal_entries = 3;
84
        break;
85
    case PIX_FMT_RGB8:
86
    case PIX_FMT_BGR8:
87
    case PIX_FMT_RGB4_BYTE:
88
    case PIX_FMT_BGR4_BYTE:
89
    case PIX_FMT_GRAY8:
90
        ff_set_systematic_pal2((uint32_t*)p->data[1], avctx->pix_fmt);
91
    case PIX_FMT_PAL8:
92
        pal = (uint32_t *)p->data[1];
93
        break;
94
    case PIX_FMT_MONOBLACK:
95
        pal = monoblack_pal;
96
        break;
97
    }
98
    if (pal && !pal_entries) pal_entries = 1 << bit_count;
99
    n_bytes_per_row = ((int64_t)avctx->width * (int64_t)bit_count + 7LL) >> 3LL;
100
    pad_bytes_per_row = (4 - n_bytes_per_row) & 3;
101
    n_bytes_image = avctx->height * (n_bytes_per_row + pad_bytes_per_row);
102

    
103
    // STRUCTURE.field refer to the MSVC documentation for BITMAPFILEHEADER
104
    // and related pages.
105
#define SIZE_BITMAPFILEHEADER 14
106
#define SIZE_BITMAPINFOHEADER 40
107
    hsize = SIZE_BITMAPFILEHEADER + SIZE_BITMAPINFOHEADER + (pal_entries << 2);
108
    n_bytes = n_bytes_image + hsize;
109
    if(n_bytes>buf_size) {
110
        av_log(avctx, AV_LOG_ERROR, "buf size too small (need %d, got %d)\n", n_bytes, buf_size);
111
        return -1;
112
    }
113
    bytestream_put_byte(&buf, 'B');                   // BITMAPFILEHEADER.bfType
114
    bytestream_put_byte(&buf, 'M');                   // do.
115
    bytestream_put_le32(&buf, n_bytes);               // BITMAPFILEHEADER.bfSize
116
    bytestream_put_le16(&buf, 0);                     // BITMAPFILEHEADER.bfReserved1
117
    bytestream_put_le16(&buf, 0);                     // BITMAPFILEHEADER.bfReserved2
118
    bytestream_put_le32(&buf, hsize);                 // BITMAPFILEHEADER.bfOffBits
119
    bytestream_put_le32(&buf, SIZE_BITMAPINFOHEADER); // BITMAPINFOHEADER.biSize
120
    bytestream_put_le32(&buf, avctx->width);          // BITMAPINFOHEADER.biWidth
121
    bytestream_put_le32(&buf, avctx->height);         // BITMAPINFOHEADER.biHeight
122
    bytestream_put_le16(&buf, 1);                     // BITMAPINFOHEADER.biPlanes
123
    bytestream_put_le16(&buf, bit_count);             // BITMAPINFOHEADER.biBitCount
124
    bytestream_put_le32(&buf, compression);           // BITMAPINFOHEADER.biCompression
125
    bytestream_put_le32(&buf, n_bytes_image);         // BITMAPINFOHEADER.biSizeImage
126
    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biXPelsPerMeter
127
    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biYPelsPerMeter
128
    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biClrUsed
129
    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biClrImportant
130
    for (i = 0; i < pal_entries; i++)
131
        bytestream_put_le32(&buf, pal[i] & 0xFFFFFF);
132
    // BMP files are bottom-to-top so we start from the end...
133
    ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
134
    buf = buf0 + hsize;
135
    for(i = 0; i < avctx->height; i++) {
136
        if (bit_count == 16) {
137
            const uint16_t *src = (const uint16_t *) ptr;
138
            uint16_t *dst = (uint16_t *) buf;
139
            for(n = 0; n < avctx->width; n++)
140
                AV_WL16(dst + n, src[n]);
141
        } else {
142
            memcpy(buf, ptr, n_bytes_per_row);
143
        }
144
        buf += n_bytes_per_row;
145
        memset(buf, 0, pad_bytes_per_row);
146
        buf += pad_bytes_per_row;
147
        ptr -= p->linesize[0]; // ... and go back
148
    }
149
    return n_bytes;
150
}
151

    
152
AVCodec ff_bmp_encoder = {
153
    "bmp",
154
    AVMEDIA_TYPE_VIDEO,
155
    CODEC_ID_BMP,
156
    sizeof(BMPContext),
157
    bmp_encode_init,
158
    bmp_encode_frame,
159
    NULL, //encode_end,
160
    .pix_fmts = (const enum PixelFormat[]){
161
        PIX_FMT_BGR24,
162
        PIX_FMT_RGB555, PIX_FMT_RGB565,
163
        PIX_FMT_RGB8, PIX_FMT_BGR8, PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE, PIX_FMT_GRAY8, PIX_FMT_PAL8,
164
        PIX_FMT_MONOBLACK,
165
        PIX_FMT_NONE},
166
    .long_name = NULL_IF_CONFIG_SMALL("BMP image"),
167
};