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ffmpeg / libavcodec / 8bps.c @ 2029f312

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/*
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 * Quicktime Planar RGB (8BPS) Video Decoder
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 * Copyright (C) 2003 Roberto Togni
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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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 */
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/**
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 * @file 8bps.c
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 * QT 8BPS Video Decoder by Roberto Togni <rtogni at bresciaonline dot it>
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 * For more information about the 8BPS format, visit:
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 *   http://www.pcisys.net/~melanson/codecs/
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 *
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 * Supports: PAL8 (RGB 8bpp, paletted)
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 *         : BGR24 (RGB 24bpp) (can also output it as RGB32)
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 *         : RGB32 (RGB 32bpp, 4th plane is probably alpha and it's ignored)
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 *
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 */
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#include <stdio.h>
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#include <stdlib.h>
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#include "avcodec.h"
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static const enum PixelFormat pixfmt_rgb24[] = {PIX_FMT_BGR24, PIX_FMT_RGB32, -1};
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/*
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 * Decoder context
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 */
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typedef struct EightBpsContext {
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        AVCodecContext *avctx;
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        AVFrame pic;
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        unsigned char planes;
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        unsigned char planemap[4];
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} EightBpsContext;
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/*
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 *
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 * Decode a frame
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 *
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 */
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static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size)
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{
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        EightBpsContext * const c = avctx->priv_data;
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        unsigned char *encoded = (unsigned char *)buf;
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        unsigned char *pixptr, *pixptr_end;
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        unsigned int height = avctx->height; // Real image height
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        unsigned int dlen, p, row;
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        unsigned char *lp, *dp;
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        unsigned char count;
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        unsigned int px_inc;
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        unsigned int planes = c->planes;
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        unsigned char *planemap = c->planemap;
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        if(c->pic.data[0])
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                avctx->release_buffer(avctx, &c->pic);
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        c->pic.reference = 0;
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        c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
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        if(avctx->get_buffer(avctx, &c->pic) < 0){
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                av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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                return -1;
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        }
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        /* Set data pointer after line lengths */
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        dp = encoded + planes * (height << 1);
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        /* Ignore alpha plane, don't know what to do with it */
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        if (planes == 4)
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                planes--;
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        px_inc = planes + (avctx->pix_fmt == PIX_FMT_RGB32);
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        for (p = 0; p < planes; p++) {
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                /* Lines length pointer for this plane */
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                lp = encoded + p * (height << 1);
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                /* Decode a plane */
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                for(row = 0; row < height; row++) {
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                        pixptr = c->pic.data[0] + row * c->pic.linesize[0] + planemap[p];
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                        pixptr_end = pixptr + c->pic.linesize[0];
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                        dlen = be2me_16(*(unsigned short *)(lp+row*2));
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                        /* Decode a row of this plane */
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                        while(dlen > 0) {
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                                if(dp + 1 >= buf+buf_size) return -1;
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                                if ((count = *dp++) <= 127) {
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                                        count++;
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                                        dlen -= count + 1;
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                                        if (pixptr + count * px_inc > pixptr_end)
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                                            break;
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                                        if(dp + count > buf+buf_size) return -1;
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                                        while(count--) {
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                                                *pixptr = *dp++;
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                                                pixptr += px_inc;
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                                        }
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                                } else {
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                                        count = 257 - count;
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                                        if (pixptr + count * px_inc > pixptr_end)
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                                            break;
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                                        while(count--) {
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                                                *pixptr = *dp;
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                                                pixptr += px_inc;
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                                        }
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                                        dp++;
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                                        dlen -= 2;
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                                }
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                        }
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                }
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        }
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        if (avctx->palctrl) {
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                memcpy (c->pic.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
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                if (avctx->palctrl->palette_changed) {
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                        c->pic.palette_has_changed = 1;
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                        avctx->palctrl->palette_changed = 0;
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                } else
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                        c->pic.palette_has_changed = 0;
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        }
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        *data_size = sizeof(AVFrame);
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        *(AVFrame*)data = c->pic;
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        /* always report that the buffer was completely consumed */
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        return buf_size;
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}
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/*
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 *
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 * Init 8BPS decoder
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 *
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 */
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static int decode_init(AVCodecContext *avctx)
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{
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        EightBpsContext * const c = avctx->priv_data;
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        c->avctx = avctx;
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        c->pic.data[0] = NULL;
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    if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
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        return 1;
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    }
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        switch (avctx->bits_per_sample) {
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                case 8:
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                        avctx->pix_fmt = PIX_FMT_PAL8;
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                        c->planes = 1;
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                        c->planemap[0] = 0; // 1st plane is palette indexes
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                        if (avctx->palctrl == NULL) {
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                                av_log(avctx, AV_LOG_ERROR, "Error: PAL8 format but no palette from demuxer.\n");
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                                return -1;
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                        }
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                        break;
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                case 24:
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                        avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);
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                        c->planes = 3;
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                        c->planemap[0] = 2; // 1st plane is red
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                        c->planemap[1] = 1; // 2nd plane is green
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                        c->planemap[2] = 0; // 3rd plane is blue
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                        break;
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                case 32:
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                        avctx->pix_fmt = PIX_FMT_RGB32;
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                        c->planes = 4;
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#ifdef WORDS_BIGENDIAN
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                        c->planemap[0] = 1; // 1st plane is red
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                        c->planemap[1] = 2; // 2nd plane is green
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                        c->planemap[2] = 3; // 3rd plane is blue
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                        c->planemap[3] = 0; // 4th plane is alpha???
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#else
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                        c->planemap[0] = 2; // 1st plane is red
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                        c->planemap[1] = 1; // 2nd plane is green
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                        c->planemap[2] = 0; // 3rd plane is blue
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                        c->planemap[3] = 3; // 4th plane is alpha???
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#endif
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                        break;
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                default:
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                        av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n", avctx->bits_per_sample);
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                        return -1;
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        }
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  return 0;
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}
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/*
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 *
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 * Uninit 8BPS decoder
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 *
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 */
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static int decode_end(AVCodecContext *avctx)
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{
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        EightBpsContext * const c = avctx->priv_data;
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        if (c->pic.data[0])
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                avctx->release_buffer(avctx, &c->pic);
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        return 0;
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}
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AVCodec eightbps_decoder = {
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        "8bps",
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        CODEC_TYPE_VIDEO,
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        CODEC_ID_8BPS,
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        sizeof(EightBpsContext),
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        decode_init,
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        NULL,
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        decode_end,
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        decode_frame,
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        CODEC_CAP_DR1,
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};