115 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			115 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Alias PIX image encoder
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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 FFmpeg.
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 *
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 * FFmpeg 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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 * FFmpeg 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 FFmpeg; 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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#include "libavutil/intreadwrite.h"
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#include "avcodec.h"
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#include "bytestream.h"
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#include "codec_internal.h"
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#include "encode.h"
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#define ALIAS_HEADER_SIZE 10
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static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
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                        const AVFrame *frame, int *got_packet)
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{
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    int width, height, bits_pixel, length, ret;
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    uint8_t *buf;
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    width  = avctx->width;
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    height = avctx->height;
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    if (width > 65535 || height > 65535 ||
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        width * height >= INT_MAX / 4 - ALIAS_HEADER_SIZE) {
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        av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n", width, height);
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        return AVERROR_INVALIDDATA;
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    }
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    switch (avctx->pix_fmt) {
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    case AV_PIX_FMT_GRAY8:
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        bits_pixel = 8;
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        break;
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    case AV_PIX_FMT_BGR24:
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        bits_pixel = 24;
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        break;
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    default:
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        return AVERROR(EINVAL);
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    }
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    length = ALIAS_HEADER_SIZE + 4 * width * height; // max possible
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    if ((ret = ff_alloc_packet(avctx, pkt, length)) < 0)
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        return ret;
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    buf = pkt->data;
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    /* Encode header. */
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    bytestream_put_be16(&buf, width);
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    bytestream_put_be16(&buf, height);
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    bytestream_put_be32(&buf, 0); /* X, Y offset */
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    bytestream_put_be16(&buf, bits_pixel);
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    for (int j = 0, bytes_pixel = bits_pixel >> 3; j < height; j++) {
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        const uint8_t *in_buf = frame->data[0] + frame->linesize[0] * j;
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        const uint8_t *const line_end = in_buf + bytes_pixel * width;
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        while (in_buf < line_end) {
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            int count = 0;
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            int pixel;
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            if (avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
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                pixel = *in_buf;
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                while (count < 255 && in_buf < line_end && pixel == *in_buf) {
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                    count++;
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                    in_buf++;
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                }
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                bytestream_put_byte(&buf, count);
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                bytestream_put_byte(&buf, pixel);
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            } else { /* AV_PIX_FMT_BGR24 */
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                pixel = AV_RB24(in_buf);
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                while (count < 255 && in_buf < line_end &&
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                       pixel == AV_RB24(in_buf)) {
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                    count++;
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                    in_buf += 3;
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                }
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                bytestream_put_byte(&buf, count);
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                bytestream_put_be24(&buf, pixel);
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            }
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        }
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    }
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    /* Total length */
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    av_shrink_packet(pkt, buf - pkt->data);
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    *got_packet = 1;
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    return 0;
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}
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const FFCodec ff_alias_pix_encoder = {
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    .p.name    = "alias_pix",
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    CODEC_LONG_NAME("Alias/Wavefront PIX image"),
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    .p.type    = AVMEDIA_TYPE_VIDEO,
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    .p.id      = AV_CODEC_ID_ALIAS_PIX,
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    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
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    FF_CODEC_ENCODE_CB(encode_frame),
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    .p.pix_fmts = (const enum AVPixelFormat[]) {
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        AV_PIX_FMT_BGR24, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
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    },
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};
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