103 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			103 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * Microsoft Paint (MSP) version 2 decoder
 | |
|  * Copyright (c) 2020 Peter Ross (pross@xvid.org)
 | |
|  *
 | |
|  * 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
 | |
|  */
 | |
| 
 | |
| /**
 | |
|  * @file
 | |
|  * Microsoft Paint (MSP) version 2 decoder
 | |
|  */
 | |
| 
 | |
| #include "avcodec.h"
 | |
| #include "bytestream.h"
 | |
| #include "codec_internal.h"
 | |
| #include "decode.h"
 | |
| 
 | |
| static int msp2_decode_frame(AVCodecContext *avctx, AVFrame *p,
 | |
|                              int *got_frame, AVPacket *avpkt)
 | |
| {
 | |
|     const uint8_t *buf = avpkt->data;
 | |
|     int buf_size       = avpkt->size;
 | |
|     int ret;
 | |
|     unsigned int x, y, width = (avctx->width + 7) / 8;
 | |
|     GetByteContext idx, gb;
 | |
| 
 | |
|     if (buf_size <= 2 * avctx->height)
 | |
|         return AVERROR_INVALIDDATA;
 | |
| 
 | |
|     avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
 | |
| 
 | |
|     if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
 | |
|         return ret;
 | |
| 
 | |
|     p->pict_type = AV_PICTURE_TYPE_I;
 | |
|     p->flags |= AV_FRAME_FLAG_KEY;
 | |
| 
 | |
|     bytestream2_init(&idx, buf, 2 * avctx->height);
 | |
|     buf += 2 * avctx->height;
 | |
|     buf_size -= 2 * avctx->height;
 | |
| 
 | |
|     for (y = 0; y < avctx->height; y++) {
 | |
|         unsigned int pkt_size = bytestream2_get_le16(&idx);
 | |
|         if (!pkt_size) {
 | |
|             memset(p->data[0] + y * p->linesize[0], 0xFF, width);
 | |
|             continue;
 | |
|         }
 | |
| 
 | |
|         if (pkt_size > buf_size) {
 | |
|             av_log(avctx, AV_LOG_WARNING, "image probably corrupt\n");
 | |
|             pkt_size = buf_size;
 | |
|         }
 | |
| 
 | |
|         bytestream2_init(&gb, buf, pkt_size);
 | |
|         x = 0;
 | |
|         while (bytestream2_get_bytes_left(&gb) && x < width) {
 | |
|             int size = bytestream2_get_byte(&gb);
 | |
|             if (size) {
 | |
|                 size = FFMIN(size, bytestream2_get_bytes_left(&gb));
 | |
|                 memcpy(p->data[0] + y * p->linesize[0] + x, gb.buffer, FFMIN(size, width - x));
 | |
|                 bytestream2_skip(&gb, size);
 | |
|             } else {
 | |
|                 int value;
 | |
|                 size = bytestream2_get_byte(&gb);
 | |
|                 if (!size)
 | |
|                     avpriv_request_sample(avctx, "escape value");
 | |
|                 value = bytestream2_get_byte(&gb);
 | |
|                 memset(p->data[0] + y * p->linesize[0] + x, value, FFMIN(size, width - x));
 | |
|             }
 | |
|             x += size;
 | |
|         }
 | |
| 
 | |
|         buf += pkt_size;
 | |
|         buf_size -= pkt_size;
 | |
|     }
 | |
| 
 | |
|     *got_frame = 1;
 | |
|     return buf_size;
 | |
| }
 | |
| 
 | |
| const FFCodec ff_msp2_decoder = {
 | |
|     .p.name         = "msp2",
 | |
|     CODEC_LONG_NAME("Microsoft Paint (MSP) version 2"),
 | |
|     .p.type         = AVMEDIA_TYPE_VIDEO,
 | |
|     .p.id           = AV_CODEC_ID_MSP2,
 | |
|     .p.capabilities = AV_CODEC_CAP_DR1,
 | |
|     FF_CODEC_DECODE_CB(msp2_decode_frame),
 | |
| };
 |