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			129 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			129 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Alias PIX image decoder
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|  * Copyright (C) 2014 Vittorio Giovara <vittorio.giovara@gmail.com>
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|  *
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|  * This file is part of Libav.
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|  *
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|  * Libav is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Lesser General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2.1 of the License, or (at your option) any later version.
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|  *
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|  * Libav is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Lesser General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Lesser General Public
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|  * License along with Libav; if not, write to the Free Software
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|  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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|  */
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| 
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| #include "libavutil/intreadwrite.h"
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| 
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| #include "avcodec.h"
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| #include "bytestream.h"
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| #include "internal.h"
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| 
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| #define ALIAS_HEADER_SIZE 10
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| 
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| static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
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|                         AVPacket *avpkt)
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| {
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|     AVFrame *f = data;
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|     GetByteContext gb;
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|     int width, height, ret, bits_pixel, pixel;
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|     uint8_t *out_buf;
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|     uint8_t count;
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|     int x, y;
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| 
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|     bytestream2_init(&gb, avpkt->data, avpkt->size);
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| 
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|     if (bytestream2_get_bytes_left(&gb) < ALIAS_HEADER_SIZE) {
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|         av_log(avctx, AV_LOG_ERROR, "Header too small %d.\n", avpkt->size);
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|         return AVERROR_INVALIDDATA;
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|     }
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| 
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|     width  = bytestream2_get_be16u(&gb);
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|     height = bytestream2_get_be16u(&gb);
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|     bytestream2_skipu(&gb, 4); // obsolete X, Y offset
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|     bits_pixel = bytestream2_get_be16u(&gb);
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| 
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|     if (bits_pixel == 24)
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|         avctx->pix_fmt = AV_PIX_FMT_BGR24;
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|     else if (bits_pixel == 8)
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|         avctx->pix_fmt = AV_PIX_FMT_GRAY8;
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|     else {
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|         av_log(avctx, AV_LOG_ERROR, "Invalid pixel format.\n");
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|         return AVERROR_INVALIDDATA;
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|     }
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| 
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|     ret = ff_set_dimensions(avctx, width, height);
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|     if (ret < 0)
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|         return ret;
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| 
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|     ret = ff_get_buffer(avctx, f, 0);
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|     if (ret < 0)
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|         return ret;
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| 
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|     f->pict_type = AV_PICTURE_TYPE_I;
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|     f->key_frame = 1;
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| 
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|     x = 0;
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|     y = 1;
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|     out_buf = f->data[0];
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|     while (bytestream2_get_bytes_left(&gb) > 0) {
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|         int i;
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| 
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|         /* set buffer at the right position at every new line */
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|         if (x == avctx->width) {
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|             x = 0;
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|             out_buf = f->data[0] + f->linesize[0] * y++;
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|             if (y > avctx->height) {
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|                 av_log(avctx, AV_LOG_ERROR,
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|                        "Ended frame decoding with %d bytes left.\n",
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|                        bytestream2_get_bytes_left(&gb));
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|                 return AVERROR_INVALIDDATA;
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|             }
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|         }
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| 
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|         /* read packet and copy data */
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|         count = bytestream2_get_byteu(&gb);
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|         if (!count || x + count > avctx->width) {
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|             av_log(avctx, AV_LOG_ERROR, "Invalid run length %d.\n", count);
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|             return AVERROR_INVALIDDATA;
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|         }
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| 
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|         if (avctx->pix_fmt == AV_PIX_FMT_BGR24) {
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|             pixel = bytestream2_get_be24(&gb);
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|             for (i = 0; i < count; i++) {
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|                 AV_WB24(out_buf, pixel);
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|                 out_buf += 3;
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|             }
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|         } else { // AV_PIX_FMT_GRAY8
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|             pixel = bytestream2_get_byte(&gb);
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|             for (i = 0; i < count; i++)
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|                 *out_buf++ = pixel;
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|         }
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| 
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|         x += i;
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|     }
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| 
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|     if (x != width || y != height) {
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|         av_log(avctx, AV_LOG_ERROR, "Picture stopped at %d,%d.\n", x, y);
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|         return AVERROR_INVALIDDATA;
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|     }
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| 
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|     *got_frame = 1;
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|     return avpkt->size;
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| }
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| 
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| AVCodec ff_alias_pix_decoder = {
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|     .name         = "alias_pix",
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|     .long_name    = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"),
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|     .type         = AVMEDIA_TYPE_VIDEO,
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|     .id           = AV_CODEC_ID_ALIAS_PIX,
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|     .decode       = decode_frame,
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|     .capabilities = CODEC_CAP_DR1,
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| };
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