/* * BMP image format decoder * Copyright (c) 2005 Mans Rullgard * * 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 */ #include "avcodec.h" #include "bytestream.h" #include "bmp.h" #include "msrledec.h" static av_cold int bmp_decode_init(AVCodecContext *avctx){ BMPContext *s = avctx->priv_data; avcodec_get_frame_defaults((AVFrame*)&s->picture); avctx->coded_frame = (AVFrame*)&s->picture; return 0; } static int bmp_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; BMPContext *s = avctx->priv_data; AVFrame *picture = data; AVFrame *p = &s->picture; unsigned int fsize, hsize; int width, height; unsigned int depth; BiCompression comp; unsigned int ihsize; int i, j, n, linesize; uint32_t rgb[3]; uint8_t *ptr; int dsize; const uint8_t *buf0 = buf; if(buf_size < 14){ av_log(avctx, AV_LOG_ERROR, "buf size too small (%d)\n", buf_size); return -1; } if(bytestream_get_byte(&buf) != 'B' || bytestream_get_byte(&buf) != 'M') { av_log(avctx, AV_LOG_ERROR, "bad magic number\n"); return -1; } fsize = bytestream_get_le32(&buf); if(buf_size < fsize){ av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d), trying to decode anyway\n", buf_size, fsize); fsize = buf_size; } buf += 2; /* reserved1 */ buf += 2; /* reserved2 */ hsize = bytestream_get_le32(&buf); /* header size */ ihsize = bytestream_get_le32(&buf); /* more header size */ if(ihsize + 14 > hsize){ av_log(avctx, AV_LOG_ERROR, "invalid header size %d\n", hsize); return -1; } /* sometimes file size is set to some headers size, set a real size in that case */ if(fsize == 14 || fsize == ihsize + 14) fsize = buf_size - 2; if(fsize <= hsize){ av_log(avctx, AV_LOG_ERROR, "declared file size is less than header size (%d < %d)\n", fsize, hsize); return -1; } switch(ihsize){ case 40: // windib case 56: // windib v3 case 64: // OS/2 v2 case 108: // windib v4 case 124: // windib v5 width = bytestream_get_le32(&buf); height = bytestream_get_le32(&buf); break; case 12: // OS/2 v1 width = bytestream_get_le16(&buf); height = bytestream_get_le16(&buf); break; default: av_log(avctx, AV_LOG_ERROR, "unsupported BMP file, patch welcome\n"); return -1; } if(bytestream_get_le16(&buf) != 1){ /* planes */ av_log(avctx, AV_LOG_ERROR, "invalid BMP header\n"); return -1; } depth = bytestream_get_le16(&buf); if(ihsize == 40 || ihsize == 64 || ihsize == 56) comp = bytestream_get_le32(&buf); else comp = BMP_RGB; if(comp != BMP_RGB && comp != BMP_BITFIELDS && comp != BMP_RLE4 && comp != BMP_RLE8){ av_log(avctx, AV_LOG_ERROR, "BMP coding %d not supported\n", comp); return -1; } if(comp == BMP_BITFIELDS){ buf += 20; rgb[0] = bytestream_get_le32(&buf); rgb[1] = bytestream_get_le32(&buf); rgb[2] = bytestream_get_le32(&buf); } avctx->width = width; avctx->height = height > 0? height: -height; avctx->pix_fmt = PIX_FMT_NONE; switch(depth){ case 32: if(comp == BMP_BITFIELDS){ rgb[0] = (rgb[0] >> 15) & 3; rgb[1] = (rgb[1] >> 15) & 3; rgb[2] = (rgb[2] >> 15) & 3; if(rgb[0] + rgb[1] + rgb[2] != 3 || rgb[0] == rgb[1] || rgb[0] == rgb[2] || rgb[1] == rgb[2]){ break; } } else { rgb[0] = 2; rgb[1] = 1; rgb[2] = 0; } avctx->pix_fmt = PIX_FMT_BGRA; break; case 24: avctx->pix_fmt = PIX_FMT_BGR24; break; case 16: if(comp == BMP_RGB) avctx->pix_fmt = PIX_FMT_RGB555; if(comp == BMP_BITFIELDS) avctx->pix_fmt = rgb[1] == 0x07E0 ? PIX_FMT_RGB565 : PIX_FMT_RGB555; break; case 8: if(hsize - ihsize - 14 > 0) avctx->pix_fmt = PIX_FMT_PAL8; else avctx->pix_fmt = PIX_FMT_GRAY8; break; case 1: case 4: if(hsize - ihsize - 14 > 0){ avctx->pix_fmt = PIX_FMT_PAL8; }else{ av_log(avctx, AV_LOG_ERROR, "Unknown palette for %d-colour BMP\n", 1<<depth); return -1; } break; default: av_log(avctx, AV_LOG_ERROR, "depth %d not supported\n", depth); return -1; } if(avctx->pix_fmt == PIX_FMT_NONE){ av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n"); return -1; } if(p->data[0]) avctx->release_buffer(avctx, p); p->reference = 0; if(avctx->get_buffer(avctx, p) < 0){ av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return -1; } p->pict_type = AV_PICTURE_TYPE_I; p->key_frame = 1; buf = buf0 + hsize; dsize = buf_size - hsize; /* Line size in file multiple of 4 */ n = ((avctx->width * depth + 31) / 8) & ~3; if(n * avctx->height > dsize && comp != BMP_RLE4 && comp != BMP_RLE8){ av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n", dsize, n * avctx->height); return -1; } // RLE may skip decoding some picture areas, so blank picture before decoding if(comp == BMP_RLE4 || comp == BMP_RLE8) memset(p->data[0], 0, avctx->height * p->linesize[0]); if(depth == 4 || depth == 8) memset(p->data[1], 0, 1024); if(height > 0){ ptr = p->data[0] + (avctx->height - 1) * p->linesize[0]; linesize = -p->linesize[0]; } else { ptr = p->data[0]; linesize = p->linesize[0]; } if(avctx->pix_fmt == PIX_FMT_PAL8){ int colors = 1 << depth; if(ihsize >= 36){ int t; buf = buf0 + 46; t = bytestream_get_le32(&buf); if(t < 0 || t > (1 << depth)){ av_log(avctx, AV_LOG_ERROR, "Incorrect number of colors - %X for bitdepth %d\n", t, depth); }else if(t){ colors = t; } } buf = buf0 + 14 + ihsize; //palette location if((hsize-ihsize-14) < (colors << 2)){ // OS/2 bitmap, 3 bytes per palette entry for(i = 0; i < colors; i++) ((uint32_t*)p->data[1])[i] = (0xff<<24) | bytestream_get_le24(&buf); }else{ for(i = 0; i < colors; i++) ((uint32_t*)p->data[1])[i] = 0xFFU << 24 | bytestream_get_le32(&buf); } buf = buf0 + hsize; } if(comp == BMP_RLE4 || comp == BMP_RLE8){ if(height < 0){ p->data[0] += p->linesize[0] * (avctx->height - 1); p->linesize[0] = -p->linesize[0]; } ff_msrle_decode(avctx, (AVPicture*)p, depth, buf, dsize); if(height < 0){ p->data[0] += p->linesize[0] * (avctx->height - 1); p->linesize[0] = -p->linesize[0]; } }else{ switch(depth){ case 1: for (i = 0; i < avctx->height; i++) { int j; for (j = 0; j < n; j++) { ptr[j*8+0] = buf[j] >> 7; ptr[j*8+1] = (buf[j] >> 6) & 1; ptr[j*8+2] = (buf[j] >> 5) & 1; ptr[j*8+3] = (buf[j] >> 4) & 1; ptr[j*8+4] = (buf[j] >> 3) & 1; ptr[j*8+5] = (buf[j] >> 2) & 1; ptr[j*8+6] = (buf[j] >> 1) & 1; ptr[j*8+7] = buf[j] & 1; } buf += n; ptr += linesize; } break; case 8: case 24: for(i = 0; i < avctx->height; i++){ memcpy(ptr, buf, n); buf += n; ptr += linesize; } break; case 4: for(i = 0; i < avctx->height; i++){ int j; for(j = 0; j < n; j++){ ptr[j*2+0] = (buf[j] >> 4) & 0xF; ptr[j*2+1] = buf[j] & 0xF; } buf += n; ptr += linesize; } break; case 16: for(i = 0; i < avctx->height; i++){ const uint16_t *src = (const uint16_t *) buf; uint16_t *dst = (uint16_t *) ptr; for(j = 0; j < avctx->width; j++) *dst++ = av_le2ne16(*src++); buf += n; ptr += linesize; } break; case 32: for(i = 0; i < avctx->height; i++){ const uint8_t *src = buf; uint8_t *dst = ptr; for(j = 0; j < avctx->width; j++){ dst[0] = src[rgb[2]]; dst[1] = src[rgb[1]]; dst[2] = src[rgb[0]]; /* The Microsoft documentation states: * "The high byte in each DWORD is not used." * Both GIMP and ImageMagick store the alpha transparency value * in the high byte for 32bit bmp files. */ dst[3] = src[3]; dst += 4; src += 4; } buf += n; ptr += linesize; } break; default: av_log(avctx, AV_LOG_ERROR, "BMP decoder is broken\n"); return -1; } } *picture = s->picture; *data_size = sizeof(AVPicture); return buf_size; } static av_cold int bmp_decode_end(AVCodecContext *avctx) { BMPContext* c = avctx->priv_data; if (c->picture.data[0]) avctx->release_buffer(avctx, &c->picture); return 0; } AVCodec ff_bmp_decoder = { .name = "bmp", .type = AVMEDIA_TYPE_VIDEO, .id = CODEC_ID_BMP, .priv_data_size = sizeof(BMPContext), .init = bmp_decode_init, .close = bmp_decode_end, .decode = bmp_decode_frame, .capabilities = CODEC_CAP_DR1, .long_name = NULL_IF_CONFIG_SMALL("BMP image"), };