libavcodec/bmpenc.c

   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 #include "internal.h"
  28
  29 static const uint32_t monoblack_pal[] = { 0x000000, 0xFFFFFF };
  30 static const uint32_t rgb565_masks[]  = { 0xF800, 0x07E0, 0x001F };
  31 static const uint32_t rgb444_masks[]  = { 0x0F00, 0x00F0, 0x000F };
  32
  33 static av_cold int bmp_encode_init(AVCodecContext *avctx){
  34     BMPContext *s = avctx->priv_data;
  35
  36     avcodec_get_frame_defaults(&s->picture);
  37     avctx->coded_frame = &s->picture;
  38
  39     switch (avctx->pix_fmt) {
  40     case AV_PIX_FMT_BGR24:
  41         avctx->bits_per_coded_sample = 24;
  42         break;
  43     case AV_PIX_FMT_RGB555:
  44     case AV_PIX_FMT_RGB565:
  45     case AV_PIX_FMT_RGB444:
  46         avctx->bits_per_coded_sample = 16;
  47         break;
  48     case AV_PIX_FMT_RGB8:
  49     case AV_PIX_FMT_BGR8:
  50     case AV_PIX_FMT_RGB4_BYTE:
  51     case AV_PIX_FMT_BGR4_BYTE:
  52     case AV_PIX_FMT_GRAY8:
  53     case AV_PIX_FMT_PAL8:
  54         avctx->bits_per_coded_sample = 8;
  55         break;
  56     case AV_PIX_FMT_MONOBLACK:
  57         avctx->bits_per_coded_sample = 1;
  58         break;
  59     default:
  60         av_log(avctx, AV_LOG_INFO, "unsupported pixel format\n");
  61         return -1;
  62     }
  63
  64     return 0;
  65 }
  66
  67 static int bmp_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
  68                             const AVFrame *pict, int *got_packet)
  69 {
  70     BMPContext *s = avctx->priv_data;
  71     AVFrame * const p = &s->picture;
  72     int n_bytes_image, n_bytes_per_row, n_bytes, i, n, hsize, ret;
  73     const uint32_t *pal = NULL;
  74     int pad_bytes_per_row, pal_entries = 0, compression = BMP_RGB;
  75     int bit_count = avctx->bits_per_coded_sample;
  76     uint8_t *ptr, *buf;
  77     *p = *pict;
  78     p->pict_type= AV_PICTURE_TYPE_I;
  79     p->key_frame= 1;
  80     switch (avctx->pix_fmt) {
  81     case AV_PIX_FMT_RGB444:
  82         compression = BMP_BITFIELDS;
  83         pal = rgb444_masks; // abuse pal to hold color masks
  84         pal_entries = 3;
  85         break;
  86     case AV_PIX_FMT_RGB565:
  87         compression = BMP_BITFIELDS;
  88         pal = rgb565_masks; // abuse pal to hold color masks
  89         pal_entries = 3;
  90         break;
  91     case AV_PIX_FMT_RGB8:
  92     case AV_PIX_FMT_BGR8:
  93     case AV_PIX_FMT_RGB4_BYTE:
  94     case AV_PIX_FMT_BGR4_BYTE:
  95     case AV_PIX_FMT_GRAY8:
  96         avpriv_set_systematic_pal2((uint32_t*)p->data[1], avctx->pix_fmt);
  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_alloc_packet(pkt, n_bytes)) < 0) {
 116         av_log(avctx, AV_LOG_ERROR, "Error getting output packet.\n");
 117         return ret;
 118     }
 119     buf = pkt->data;
 120     bytestream_put_byte(&buf, 'B');                   // BITMAPFILEHEADER.bfType
 121     bytestream_put_byte(&buf, 'M');                   // do.
 122     bytestream_put_le32(&buf, n_bytes);               // BITMAPFILEHEADER.bfSize
 123     bytestream_put_le16(&buf, 0);                     // BITMAPFILEHEADER.bfReserved1
 124     bytestream_put_le16(&buf, 0);                     // BITMAPFILEHEADER.bfReserved2
 125     bytestream_put_le32(&buf, hsize);                 // BITMAPFILEHEADER.bfOffBits
 126     bytestream_put_le32(&buf, SIZE_BITMAPINFOHEADER); // BITMAPINFOHEADER.biSize
 127     bytestream_put_le32(&buf, avctx->width);          // BITMAPINFOHEADER.biWidth
 128     bytestream_put_le32(&buf, avctx->height);         // BITMAPINFOHEADER.biHeight
 129     bytestream_put_le16(&buf, 1);                     // BITMAPINFOHEADER.biPlanes
 130     bytestream_put_le16(&buf, bit_count);             // BITMAPINFOHEADER.biBitCount
 131     bytestream_put_le32(&buf, compression);           // BITMAPINFOHEADER.biCompression
 132     bytestream_put_le32(&buf, n_bytes_image);         // BITMAPINFOHEADER.biSizeImage
 133     bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biXPelsPerMeter
 134     bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biYPelsPerMeter
 135     bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biClrUsed
 136     bytestream_put_le32(&buf, 0);                     // BITMAPINFOHEADER.biClrImportant
 137     for (i = 0; i < pal_entries; i++)
 138         bytestream_put_le32(&buf, pal[i] & 0xFFFFFF);
 139     // BMP files are bottom-to-top so we start from the end...
 140     ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
 141     buf = pkt->data + hsize;
 142     for(i = 0; i < avctx->height; i++) {
 143         if (bit_count == 16) {
 144             const uint16_t *src = (const uint16_t *) ptr;
 145             uint16_t *dst = (uint16_t *) buf;
 146             for(n = 0; n < avctx->width; n++)
 147                 AV_WL16(dst + n, src[n]);
 148         } else {
 149             memcpy(buf, ptr, n_bytes_per_row);
 150         }
 151         buf += n_bytes_per_row;
 152         memset(buf, 0, pad_bytes_per_row);
 153         buf += pad_bytes_per_row;
 154         ptr -= p->linesize[0]; // ... and go back
 155     }
 156
 157     pkt->flags |= AV_PKT_FLAG_KEY;
 158     *got_packet = 1;
 159     return 0;
 160 }
 161
 162 AVCodec ff_bmp_encoder = {
 163     .name           = "bmp",
 164     .type           = AVMEDIA_TYPE_VIDEO,
 165     .id             = AV_CODEC_ID_BMP,
 166     .priv_data_size = sizeof(BMPContext),
 167     .init           = bmp_encode_init,
 168     .encode2        = bmp_encode_frame,
 169     .pix_fmts       = (const enum AVPixelFormat[]){
 170         AV_PIX_FMT_BGR24,
 171         AV_PIX_FMT_RGB555, AV_PIX_FMT_RGB444, AV_PIX_FMT_RGB565,
 172         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,
 173         AV_PIX_FMT_MONOBLACK,
 174         AV_PIX_FMT_NONE
 175     },
 176     .long_name      = NULL_IF_CONFIG_SMALL("BMP (Windows and OS/2 bitmap)"),
 177 };