xref: /third_party/ffmpeg/libavcodec/bmpenc.c (revision cabdff1a)
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 "config.h"
24
25#include "libavutil/imgutils.h"
26#include "libavutil/avassert.h"
27#include "avcodec.h"
28#include "bytestream.h"
29#include "bmp.h"
30#include "codec_internal.h"
31#include "encode.h"
32
33static const uint32_t monoblack_pal[] = { 0x000000, 0xFFFFFF };
34static const uint32_t rgb565_masks[]  = { 0xF800, 0x07E0, 0x001F };
35static const uint32_t rgb444_masks[]  = { 0x0F00, 0x00F0, 0x000F };
36
37static av_cold int bmp_encode_init(AVCodecContext *avctx){
38    switch (avctx->pix_fmt) {
39    case AV_PIX_FMT_BGRA:
40        avctx->bits_per_coded_sample = 32;
41        break;
42    case AV_PIX_FMT_BGR24:
43        avctx->bits_per_coded_sample = 24;
44        break;
45    case AV_PIX_FMT_RGB555:
46    case AV_PIX_FMT_RGB565:
47    case AV_PIX_FMT_RGB444:
48        avctx->bits_per_coded_sample = 16;
49        break;
50    case AV_PIX_FMT_RGB8:
51    case AV_PIX_FMT_BGR8:
52    case AV_PIX_FMT_RGB4_BYTE:
53    case AV_PIX_FMT_BGR4_BYTE:
54    case AV_PIX_FMT_GRAY8:
55    case AV_PIX_FMT_PAL8:
56        avctx->bits_per_coded_sample = 8;
57        break;
58    case AV_PIX_FMT_MONOBLACK:
59        avctx->bits_per_coded_sample = 1;
60        break;
61    }
62
63    return 0;
64}
65
66static int bmp_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
67                            const AVFrame *pict, int *got_packet)
68{
69    const AVFrame * const p = pict;
70    int n_bytes_image, n_bytes_per_row, n_bytes, i, n, hsize, ret;
71    const uint32_t *pal = NULL;
72    uint32_t palette256[256];
73    int pad_bytes_per_row, pal_entries = 0, compression = BMP_RGB;
74    int bit_count = avctx->bits_per_coded_sample;
75    uint8_t *ptr, *buf;
76
77    switch (avctx->pix_fmt) {
78    case AV_PIX_FMT_RGB444:
79        compression = BMP_BITFIELDS;
80        pal = rgb444_masks; // abuse pal to hold color masks
81        pal_entries = 3;
82        break;
83    case AV_PIX_FMT_RGB565:
84        compression = BMP_BITFIELDS;
85        pal = rgb565_masks; // abuse pal to hold color masks
86        pal_entries = 3;
87        break;
88    case AV_PIX_FMT_RGB8:
89    case AV_PIX_FMT_BGR8:
90    case AV_PIX_FMT_RGB4_BYTE:
91    case AV_PIX_FMT_BGR4_BYTE:
92    case AV_PIX_FMT_GRAY8:
93        av_assert1(bit_count == 8);
94        avpriv_set_systematic_pal2(palette256, avctx->pix_fmt);
95        pal = palette256;
96        break;
97    case AV_PIX_FMT_PAL8:
98        pal = (uint32_t *)p->data[1];
99        break;
100    case AV_PIX_FMT_MONOBLACK:
101        pal = monoblack_pal;
102        break;
103    }
104    if (pal && !pal_entries) pal_entries = 1 << bit_count;
105    n_bytes_per_row = ((int64_t)avctx->width * (int64_t)bit_count + 7LL) >> 3LL;
106    pad_bytes_per_row = (4 - n_bytes_per_row) & 3;
107    n_bytes_image = avctx->height * (n_bytes_per_row + pad_bytes_per_row);
108
109    // STRUCTURE.field refer to the MSVC documentation for BITMAPFILEHEADER
110    // and related pages.
111#define SIZE_BITMAPFILEHEADER 14
112#define SIZE_BITMAPINFOHEADER 40
113    hsize = SIZE_BITMAPFILEHEADER + SIZE_BITMAPINFOHEADER + (pal_entries << 2);
114    n_bytes = n_bytes_image + hsize;
115    if ((ret = ff_get_encode_buffer(avctx, pkt, n_bytes, 0)) < 0)
116        return ret;
117    buf = pkt->data;
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 = pkt->data + hsize;
140    for(i = 0; i < avctx->height; i++) {
141        if (HAVE_BIGENDIAN && bit_count == 16) {
142            const uint16_t *src = (const uint16_t *) ptr;
143            for(n = 0; n < avctx->width; n++)
144                AV_WL16(buf + 2 * n, src[n]);
145        } else {
146            memcpy(buf, ptr, n_bytes_per_row);
147        }
148        buf += n_bytes_per_row;
149        memset(buf, 0, pad_bytes_per_row);
150        buf += pad_bytes_per_row;
151        ptr -= p->linesize[0]; // ... and go back
152    }
153
154    *got_packet = 1;
155    return 0;
156}
157
158const FFCodec ff_bmp_encoder = {
159    .p.name         = "bmp",
160    .p.long_name    = NULL_IF_CONFIG_SMALL("BMP (Windows and OS/2 bitmap)"),
161    .p.type         = AVMEDIA_TYPE_VIDEO,
162    .p.id           = AV_CODEC_ID_BMP,
163    .p.capabilities = AV_CODEC_CAP_DR1,
164    .init           = bmp_encode_init,
165    FF_CODEC_ENCODE_CB(bmp_encode_frame),
166    .p.pix_fmts     = (const enum AVPixelFormat[]){
167        AV_PIX_FMT_BGRA, AV_PIX_FMT_BGR24,
168        AV_PIX_FMT_RGB565, AV_PIX_FMT_RGB555, AV_PIX_FMT_RGB444,
169        AV_PIX_FMT_RGB8, AV_PIX_FMT_BGR8, AV_PIX_FMT_RGB4_BYTE, AV_PIX_FMT_BGR4_BYTE, AV_PIX_FMT_GRAY8, AV_PIX_FMT_PAL8,
170        AV_PIX_FMT_MONOBLACK,
171        AV_PIX_FMT_NONE
172    },
173    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
174};
175