bmpenc.c 7.06 KB
Newer Older
1 2 3
/*
 * BMP image format encoder
 * Copyright (c) 2006, 2007 Michel Bardiaux
4
 * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

23
#include "libavutil/imgutils.h"
Paul B Mahol's avatar
Paul B Mahol committed
24
#include "libavutil/avassert.h"
25 26 27
#include "avcodec.h"
#include "bytestream.h"
#include "bmp.h"
28
#include "internal.h"
29

30 31
static const uint32_t monoblack_pal[] = { 0x000000, 0xFFFFFF };
static const uint32_t rgb565_masks[]  = { 0xF800, 0x07E0, 0x001F };
32
static const uint32_t rgb444_masks[]  = { 0x0F00, 0x00F0, 0x000F };
33

34
static av_cold int bmp_encode_init(AVCodecContext *avctx){
35
    switch (avctx->pix_fmt) {
36
    case AV_PIX_FMT_BGRA:
Paul B Mahol's avatar
Paul B Mahol committed
37 38
        avctx->bits_per_coded_sample = 32;
        break;
39
    case AV_PIX_FMT_BGR24:
40 41
        avctx->bits_per_coded_sample = 24;
        break;
42 43 44
    case AV_PIX_FMT_RGB555:
    case AV_PIX_FMT_RGB565:
    case AV_PIX_FMT_RGB444:
45 46
        avctx->bits_per_coded_sample = 16;
        break;
47 48 49 50 51 52
    case AV_PIX_FMT_RGB8:
    case AV_PIX_FMT_BGR8:
    case AV_PIX_FMT_RGB4_BYTE:
    case AV_PIX_FMT_BGR4_BYTE:
    case AV_PIX_FMT_GRAY8:
    case AV_PIX_FMT_PAL8:
53 54
        avctx->bits_per_coded_sample = 8;
        break;
55
    case AV_PIX_FMT_MONOBLACK:
56 57 58 59
        avctx->bits_per_coded_sample = 1;
        break;
    default:
        av_log(avctx, AV_LOG_INFO, "unsupported pixel format\n");
60
        return AVERROR(EINVAL);
61 62
    }

63 64 65 66
    avctx->coded_frame = av_frame_alloc();
    if (!avctx->coded_frame)
        return AVERROR(ENOMEM);

67 68 69
    return 0;
}

70 71 72
static int bmp_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                            const AVFrame *pict, int *got_packet)
{
73
    const AVFrame * const p = pict;
74
    int n_bytes_image, n_bytes_per_row, n_bytes, i, n, hsize, ret;
75
    const uint32_t *pal = NULL;
76
    uint32_t palette256[256];
77 78
    int pad_bytes_per_row, pal_entries = 0, compression = BMP_RGB;
    int bit_count = avctx->bits_per_coded_sample;
79
    uint8_t *ptr, *buf;
80

81 82
    avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
    avctx->coded_frame->key_frame = 1;
83
    switch (avctx->pix_fmt) {
84
    case AV_PIX_FMT_RGB444:
85 86 87 88
        compression = BMP_BITFIELDS;
        pal = rgb444_masks; // abuse pal to hold color masks
        pal_entries = 3;
        break;
89
    case AV_PIX_FMT_RGB565:
90 91 92 93
        compression = BMP_BITFIELDS;
        pal = rgb565_masks; // abuse pal to hold color masks
        pal_entries = 3;
        break;
94 95 96 97 98
    case AV_PIX_FMT_RGB8:
    case AV_PIX_FMT_BGR8:
    case AV_PIX_FMT_RGB4_BYTE:
    case AV_PIX_FMT_BGR4_BYTE:
    case AV_PIX_FMT_GRAY8:
Paul B Mahol's avatar
Paul B Mahol committed
99
        av_assert1(bit_count == 8);
100
        avpriv_set_systematic_pal2(palette256, avctx->pix_fmt);
101 102
        pal = palette256;
        break;
103
    case AV_PIX_FMT_PAL8:
104 105
        pal = (uint32_t *)p->data[1];
        break;
106
    case AV_PIX_FMT_MONOBLACK:
107 108 109 110 111 112 113
        pal = monoblack_pal;
        break;
    }
    if (pal && !pal_entries) pal_entries = 1 << bit_count;
    n_bytes_per_row = ((int64_t)avctx->width * (int64_t)bit_count + 7LL) >> 3LL;
    pad_bytes_per_row = (4 - n_bytes_per_row) & 3;
    n_bytes_image = avctx->height * (n_bytes_per_row + pad_bytes_per_row);
114 115 116 117 118

    // STRUCTURE.field refer to the MSVC documentation for BITMAPFILEHEADER
    // and related pages.
#define SIZE_BITMAPFILEHEADER 14
#define SIZE_BITMAPINFOHEADER 40
119
    hsize = SIZE_BITMAPFILEHEADER + SIZE_BITMAPINFOHEADER + (pal_entries << 2);
120
    n_bytes = n_bytes_image + hsize;
121
    if ((ret = ff_alloc_packet2(avctx, pkt, n_bytes)) < 0)
122 123
        return ret;
    buf = pkt->data;
124 125 126 127 128 129 130 131 132 133
    bytestream_put_byte(&buf, 'B');                   // BITMAPFILEHEADER.bfType
    bytestream_put_byte(&buf, 'M');                   // do.
    bytestream_put_le32(&buf, n_bytes);               // BITMAPFILEHEADER.bfSize
    bytestream_put_le16(&buf, 0);                     // BITMAPFILEHEADER.bfReserved1
    bytestream_put_le16(&buf, 0);                     // BITMAPFILEHEADER.bfReserved2
    bytestream_put_le32(&buf, hsize);                 // BITMAPFILEHEADER.bfOffBits
    bytestream_put_le32(&buf, SIZE_BITMAPINFOHEADER); // BITMAPINFOHEADER.biSize
    bytestream_put_le32(&buf, avctx->width);          // BITMAPINFOHEADER.biWidth
    bytestream_put_le32(&buf, avctx->height);         // BITMAPINFOHEADER.biHeight
    bytestream_put_le16(&buf, 1);                     // BITMAPINFOHEADER.biPlanes
134 135
    bytestream_put_le16(&buf, bit_count);             // BITMAPINFOHEADER.biBitCount
    bytestream_put_le32(&buf, compression);           // BITMAPINFOHEADER.biCompression
136 137 138 139 140
    bytestream_put_le32(&buf, n_bytes_image);         // BITMAPINFOHEADER.biSizeImage
    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biXPelsPerMeter
    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biYPelsPerMeter
    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biClrUsed
    bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biClrImportant
141 142
    for (i = 0; i < pal_entries; i++)
        bytestream_put_le32(&buf, pal[i] & 0xFFFFFF);
143 144
    // BMP files are bottom-to-top so we start from the end...
    ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
145
    buf = pkt->data + hsize;
146
    for(i = 0; i < avctx->height; i++) {
147 148 149 150 151 152 153 154 155 156 157
        if (bit_count == 16) {
            const uint16_t *src = (const uint16_t *) ptr;
            uint16_t *dst = (uint16_t *) buf;
            for(n = 0; n < avctx->width; n++)
                AV_WL16(dst + n, src[n]);
        } else {
            memcpy(buf, ptr, n_bytes_per_row);
        }
        buf += n_bytes_per_row;
        memset(buf, 0, pad_bytes_per_row);
        buf += pad_bytes_per_row;
158 159
        ptr -= p->linesize[0]; // ... and go back
    }
160 161 162 163

    pkt->flags |= AV_PKT_FLAG_KEY;
    *got_packet = 1;
    return 0;
164 165
}

166 167 168 169 170 171
static av_cold int bmp_encode_close(AVCodecContext *avctx)
{
    av_frame_free(&avctx->coded_frame);
    return 0;
}

172
AVCodec ff_bmp_encoder = {
173
    .name           = "bmp",
174
    .long_name      = NULL_IF_CONFIG_SMALL("BMP (Windows and OS/2 bitmap)"),
175
    .type           = AVMEDIA_TYPE_VIDEO,
176
    .id             = AV_CODEC_ID_BMP,
177
    .init           = bmp_encode_init,
178
    .encode2        = bmp_encode_frame,
179
    .close          = bmp_encode_close,
180
    .pix_fmts       = (const enum AVPixelFormat[]){
181 182
        AV_PIX_FMT_BGRA, AV_PIX_FMT_BGR24,
        AV_PIX_FMT_RGB565, AV_PIX_FMT_RGB555, AV_PIX_FMT_RGB444,
183 184 185
        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,
        AV_PIX_FMT_MONOBLACK,
        AV_PIX_FMT_NONE
186
    },
187
};